https://www.neuroelectrics.com/wiki/api.php?action=feedcontributions&user=Guillem&feedformat=atomNeuroelectric's Wiki - User contributions [en]2024-03-28T23:36:30ZUser contributionsMediaWiki 1.31.1https://www.neuroelectrics.com/wiki/index.php?title=Interacting_with_NIC&diff=1583Interacting with NIC2016-05-02T07:55:45Z<p>Guillem: /* Receiving and sending data streams using LSL */</p>
<hr />
<div>In this page we describe how you can interact with NIC (Neuroelectrics Instrument Controller, the software for control with NE devices) using other software. <br />
<br />
== About Synchronization: general principles ==<br />
[[File:Master slave synchronization.png|200px|thumb|left| The Master system's clock is the only one used in the whole system. The master system either gathers the data from the slave systems to provide a single output or sends its clock so the slave systems can provide their outputs using that clock]]<br />
To coordinate different data sources or events to a single clock is known as synchronization.<br />
<br />
When using Enobio at least there are two different clocks that need to be synchronized: The clock of the Enobio wireless sensor which is in charge of sampling the EEG data recorded by the electrodes, and the clock of the host where NIC runs and receives the EEG data from the Bluetooth connection.<br />
<br />
NIC uses the clock from the Enobio sensor as master. The Enobio clock is received by NIC through the data streaming. The EEG data is sampled at 500 Hz, so every sample is delayed 2 ms from the previous one. In traditional wired system the data will be received by the control software as it is sampled so the two clocks might be directly synchronized. However in wireless system such as the Enobio one, some latency might be introduced in the wireless channel due to RF interference and re-transmission of data.<br />
<br />
NIC implements an algorithm that compensates this latency and finds out the offset between the clock from Enobio and the one from the host where NIC runs. When NIC receives information from third-party applications that need to be synchronized with the EEG data, like markers that signal when external events occur, it compensates the timestamp of the received data so it is aligned with the EEG data streaming.<br />
<br />
In the scenario described above, when NIC collects markers that are sent by other applications, another clock to be synchronized is introduced in the system. This is the clock from the host that sends the markers. NIC provides two ways of gathering such markers. Both of them are described in the following sections. The first one does not provide any synchronization mechanism, this is the reception of markers using a TCP/IP server where the clients connect to and send their markers. This method might be useful when the time synchronization requirements do not need accuracy under the 100 ms.<br />
<br />
The second method uses the [https://code.google.com/p/labstreaminglayer/ Lab Streaming Layer (LSL)], which incorporates built-in network and synchronization capabilities that allow synchronization accuracy on 1 ms so it perfectly fits application like the one that detect [[Event_Related_Potentials_(ERPs) | ERPs signals]].<br />
<br />
<br />
<!--talk about hardware set up to manually determine this deviation and fix it through advanced NIC properties--><br />
<br />
== Sending Markers to NIC from other software or hardware ==<br />
=== Sending Markers using TCP/IP ===<br />
<!-- talk about the marker server: port number, protocol --><br />
TCP (Transmission Control Protocol) is a connection-oriented protocol for transferring data reliably in either direction between a pair of users.<br />
<br />
NIC provides a TCP server that other softwares can connect to in order to send markers. Those received markers are synchronized with the EEG streaming and written in the penultimate column of the .easy files for further analysis.<br />
<br />
You need to create a TCP client inside your external software. The connection of the TCP client to the NIC TCP server is done using the standard TCP/IP connection protocols available in different programming languages. Up to five clients can simultaneously send markers to NIC by making a TCP/IP connection to this port. The TCP clients can be located in the same machine running NIC or they can also be in another machine located in the same network as the machine running NIC.<br />
<br />
If the TCP client is located in an external machine in the same network as the machine running NIC, you just need the to connect to the IP of the machine running NIC, shown in the right bottom corner of NIC, and the '''TCP/IP port 1234'''. If the TCP client is located at the same machine running NIC, the IP to which you have to connect is the local IP 127.0.0.1 and port 1234. Once the client is connected, you'll see a progress bar in the right bottom corner of NIC showing the connection.<br />
<br />
Once a client is connected it needs to send the following string in order to send a marker:<br />
<TRIGGER>XXXX</TRIGGER><br />
Where XXXX can represent any integer number different from zero (from -2147483647 to +2147483647). This marker will be co-registered in the output files generated by NIC to the corresponding EEG sample. For instance, in the output tabulated text file, the column just after the timestamp one is filled with zeros if no markers are received. When a marker is received its corresponding number is set to that column. See the following example:<br />
<br />
...<br />
26748 -27675 35631 42398 532666 64345 12376 40988 0 1382432459788<br />
26865 -26683 35685 42450 532711 64821 12376 41046 0 1382432459790<br />
26810 -26821 35531 41997 532821 64945 13164 41099 0 1382432459792<br />
26749 -26995 35325 42008 532712 64377 13478 41286 0 1382432459794<br />
26796 -27245 35932 42391 532923 64245 13620 41117 300 1382432459796 <-- Reception of the marker #300<br />
26622 -27510 35501 42630 532876 64193 13031 40986 0 1382432459798<br />
26751 -27912 35611 42003 532345 64344 12967 40731 0 1382432459800<br />
...<br />
<br />
[[File:Markers audio signal.png|200px|thumb|right| Plot of markers received by NIC and an audio signal recorded by Enobio]]<br />
Please take as an example [[Media:Matlab Markers Example.zip | ''this'']] Matlab code which connects to NIC to send markers every time a tone is played back through the sound card. If you connected the output of the computer sound card to one of the Enobio electrodes you would be able to see the alignment between the markers and the played tones.<br />
<br />
The following link [http://wiki.neuroelectrics.com/images/7/76/Eprime2NIC_example.zip eprime2NIC_example.zip] also contains an example on how to send TCP markers from E-Prime to NIC.<br />
<br />
=== Sending markers using LSL ===<br />
<!-- talk about LSL client: string and integer markers --><br />
NIC is compliant with the [https://code.google.com/p/labstreaminglayer/ Lab Streaming Layer (LSL)] protocol so makers can be co-registered with the EEG signal by setting up a LSL marker outlet (see this [https://code.google.com/p/labstreaminglayer/source/browse/LSL/liblsl/examples/C/SendStringMarkersC/SendStringMarkersC.c example]). The received LSL markers are synchronized with the EEG streaming data and written in the penultimate column of the .easy files for further analysis.<br />
<br />
The external software sending the LSL markers can be located in the same machine running NIC or it can also be in another machine located in the same network as the machine running NIC.<br />
<br />
The LSL handles both the networking and time-synchronization isues between the sender and receiver hosts obtaining reliability on order of 1 ms (see the time-synchronization validation [https://code.google.com/p/labstreaminglayer/wiki/TimeSynchronizationValidation tests]).<br />
<br />
[[File:NIC LSL settings.png|200px|thumb|left| NIC settings for configuring the reception of markers through LSL]]<br />
NIC needs little configuration in order to receive the markers from a LSL outlet present in the local network. When the LSL marker outlet sends integer-type markers only the name of the outlet needs to be configured in NIC.<br />
<br />
Please go to "''EEG Setup -> Settings -> Markers from Lab Streaming Layer''" and set the name that your LSL marker outlet has. NIC will automatically look for a marker outlet with this name and will connect to it. If the outlet sends '''integer-type markers''' then no further configuration is needed. All the received makers will be co-registered along with the EEG signal to the output files.<br />
<br />
In case the outlet sends '''string-type markers''' then there are some considerations that have to be taken into account. The LSL outlet sending string-type markers has to format them as XML tags. The following example is taken from the string markers that the Presentation software sends when the LSL extension manager is installed (see the [[Event_Related_Potentials_(ERPs)#Presentation | Working with ERPs]] section). You can see that NIC will decode the string looking for the tag that is configured in the "''EEG Setup -> Settings -> Markers from Lab Streaming Layer''" settings, ''ecode'' in this case. The marker number 37 will be registered at the reception of this string:<br />
<pevent><etype>Picture</etype>'''<ecode>37</ecode>'''<unc>209.638092041016</unc>test</pevent><br />
<br />
<!-- talk about TTL hardware triggering --><br />
<br />
=== Sending TTL pulses ===<br />
NIC can also receive a TTL signal and display it through one of its EEG channels using our [http://www.neuroelectrics.com/products/accessories/ext-ttl-trigger-adapter/ TTL adapter].<br />
<br />
This option requires to have a [http://en.wikipedia.org/wiki/Parallel_port#Pinouts parallel port] in the computer running the external software. If you don't have a parallel port, you can also install a PCI Express card emulating a parallel port. Please see the user manual of our [http://www.neuroelectrics.com/download/NE_TTL_Trigger_Receiver_UserManual.pdf TTL adapter] for detailed information on how to set up the connections. <br />
<br />
The following pins of the TTL adapter should be connected to the following pins from the parallel port:<br />
* Pin 1 (Vcc 5V) from the adapter should be connected to any data pin (pins 2-9) of the parallel port. This pin should always be activated at 5V.<br />
* Pin 2 (TTL input) from the adapter should be connected to another data pin (pins 2-9) of the parallel port. This pin should only be activated whenever a TTL pulse is sent.<br />
* Pin 3 (ground) from the adapter should be connected to any ground pin (pins 18-25) of the parallel port.<br />
<br />
NOTE: the TTL signal will be synchronized with the EEG streaming data and you'll see the TTL pulses in the EEG channel you have used to connect it, but the TTL pulses will not be "written" in the penultimate column of the .easy files as markers. The "detection of the edges" of the TTL pulses in the EEG channel for offline analysis is responsability of the user.<br />
<br />
=== Sending Markers using the keyboard ===<br />
<br />
You can also send manual events using the number keys (1-9) of your keyboard. To configure the codes for each marker, you can go to the EEG setup --> Settings tab --> Markers in the NIC software, as described in page 14 of NIC's [http://www.neuroelectrics.com/download/NIC_User_Manual_1_3_12.pdf user manual].<br />
<br />
== Receiving data streams from NIC ==<br />
=== Receiving data streams using TCP/IP ===<br />
The NIC software has a TCP/IP server that streams the EEG data received from Enobio. Up to 5 clients can connect to that server simultaneously in order to receive the EEG data ans perform the desired operations in real time.<br />
<br />
The software clients that want to receive the EEG data in real time from NIC need to connect to the '''TCP/IP port 1234''' of the host where the NIC software is running. Once the client software is connected to the server, it will receive the EEG data streaming according to the following format:<br />
-------------------------------------------------------------------------------------------<br />
| Channel 1 | ... | Channel N | <br />
-------------------------------------------------------------------------------------------<br />
| (MSB) Byte#1 | Byte#2 | Byte#3 | (LSB) Byte#4 | ... | Byte#1 | Byte#2 | Byte#3 | Byte#4 |<br />
-------------------------------------------------------------------------------------------<br />
Each EEG sample is sent as a two-complement 4 byte value. The unit of the EEG sample is nano volts and its range is from -400000000 to +400000000 nV. The most significant byte is sent first. The following code in 'C' shows how to decode the streaming from the received bytes to EEG sample values. The example assumes that the computer architecture is little-endian.<br />
// byte3 = 0xFF, byte2 = 0x8F, byte1 = 0x99, byte0 = 0x61<br />
signed int32_t sample = 0;<br />
sample += byte3;<br />
sample = sample << 8;<br />
sample += byte2;<br />
sample = sample << 8;<br />
sample += byte1;<br />
sample = sample << 8;<br />
sample += byte0;<br />
// sample = -141584031 nV<br />
<br />
The client will receive first the four bytes from channel 1, then the next four bytes from channel 2 and so on till receiving the four bytes from the last channel of Enobio (8 or 20 depending of the type of Enobio/Starstim NIC handles). Then channel 1 bytes are receiving again.<br />
<br />
The following links are a Java and a Matlab example clients that connects to NIC and receive the EEG streaming: [[Media:Java_TCP_Enobio_Client.zip | Java client]], [[Media:Matlab_TCP_Enobio_Client.zip | Matlab client]]<br />
<br />
=== Receiving data streams and markers using TCP/IP ===<br />
It is also possible to receive the markers that NIC collects using the TCP/IP connection. By enabling this feature from the NIC settings the markers are sent along with the EEG streaming through the same TCP/IP connection. In this case the markers are sent as a four-bytes integer after the last EEG channel. The most significant byte is sent first. The data streaming will have the following format then:<br />
<br />
-----------------------------------------------------------------------------------------------------------------------------------<br />
| Channel 1 | ... | Channel N | Marker |<br />
-----------------------------------------------------------------------------------------------------------------------------------<br />
| (MSB) Byte#1 | Byte#2 | Byte#3 | (LSB) Byte#4 | ... | Byte#1 | Byte#2 | Byte#3 | Byte#4 | Byte#1 | Byte#2 | Byte#3 | Byte#4 |<br />
-----------------------------------------------------------------------------------------------------------------------------------<br />
<br />
[[File:Markers_through_TCP_setting.png|200px|thumb|left| NIC settings for configuring the sending of markers through the TCP/IP connection]]<br />
<br />
Those markers correspond to the ones received by NIC from third-party software using [[Interacting_with_NIC#Sending_Markers_using_TCP.2FIP | TCP/IP]] or [[Interacting_with_NIC#Sending_markers_using_LSL | LSL]], the manual markers that can be inserted while recording by pressing the keys from 1 to 9 and the stimulation events in the case of the StarStim device such as start and stop stimulation and when any parameter is changed from MatNIC.<br />
<br />
=== Receiving and sending data streams using LSL ===<br />
<!-- talk about receiving the data stream using the LSL --><br />
<br />
NIC streams the received EEG data from Enobio usign the Lab Streaming Layer. NIC creates a LSL outlet with the following settings:<br />
Name: (choosen in NIC EEG settings)<br />
Type: EEG<br />
Channel count: 8, 20 or 32 depending of the Enobio NIC handles<br />
Nominal sample rate: 500<br />
Channel format: float_32<br />
Unique source ID: The Enobio type plus its mac address<br />
An LSL client software needs to connect to this outlet in order to receive the EEG streaming data. The received values are expressed in nanovolts and its range is from -400000000 to +400000000.<br />
<br />
Using LSL is possible to access to the accelerometer data too. The outlet the LSL clients need to connect to has the following settings:<br />
Name: (choosen in NIC EEG settings)<br />
Type: Accelerometer<br />
Channel count: 3<br />
Nominal sample rate: 100<br />
Channel format: float_32<br />
Unique source ID: The Enobio type plus its mac address plus the "Acc" string<br />
<br />
Using LSL is possible to access markers generated from another NIC. The outlet the LSL clients need to connect to has the following settings:<br />
Name: (choosen in NIC EEG settings)<br />
Type: Markers<br />
Channel count: 1<br />
Nominal sample rate: n/a<br />
Channel format: Int_32<br />
Unique source ID: The Enobio type plus its mac address plus the "Marker" string<br />
<br />
NIC streams some markers when starts or stops stimulation with the following settings:<br />
Name: (choosen in NIC EEG settings)<br />
Type: Markers<br />
Channel count: 1<br />
Nominal sample rate: n/a<br />
Channel format: Int_32<br />
Unique source ID: The device type plus its mac address plus the "Marker" string<br />
<br />
NIC streams signal quality level for each channel:<br />
Name: (choosen in NIC EEG settings)<br />
Type: Quality<br />
Channel count: 8,20 or 32<br />
Nominal sample rate: 1<br />
Channel format: Float_32<br />
Unique source ID: The device type plus its mac address plus the "Marker" string<br />
<br />
The names of the Outlets, are for the version 1.3.12. For previous versions, the name of the outlet is "NIC"<br />
<br />
== Sending commands to NIC ==<br />
<!-- talk about the features of NIC being controlling (Enobio and StarStim) using a command-based protocol--><br />
<!-- talk about MatNIC as a set of routines that wrap this protocol to provide the functionalities of command NIC from Matlab --><br />
<!-- provide examples --><br />
<br />
NIC can be remotely commanded from a third-party software through a set of commands that can be sent using a TCP/IP connection. NIC listens to the '''TCP/IP port 1235''' for incoming connections. The clients that connect to that port can command the following actions:<br />
/--------------------------------------------------\<br />
| Action | Device |<br />
|--------------------------------------------------|<br />
| Start EEG streaming | Enobio & StarStim |<br />
| Stop EEG streaming | Enobio & StarStim |<br />
| Start Stimulation | StarStim |<br />
| Abort Stimulation | StarStim |<br />
| Online tACS Frequency Change | StarStim |<br />
| Online tACS Amplitude change | StarStim |<br />
| Online tDCS Amplitude change | StarStim |<br />
| Load template | StarStim |<br />
| Request status | Enobio & StarStim |<br />
\--------------------------------------------------/<br />
<br />
NIC responds to those commands with a set of status commands to indicate whether the commands are successfully processed, the stimulation is ready to be started and so on. The following table shows all the possible status value that NIC might send.<br />
<br />
/--------------------------------------------------------\<br />
| Status | Device |<br />
|--------------------------------------------------------|<br />
| Remote control allowed | Enobio & StarStim |<br />
| Remote control rejected | Enobio & StarStim |<br />
| Device is idle | Enobio & StarStim |<br />
| EEG streaming is ON | Enobio & StarStim |<br />
| EEG streaming is OFF | Enobio & StarStim | <br />
| Template not loaded | StarStim |<br />
| Template loaded | StarStim |<br />
| Stimulation is ready to be started | StarStim |<br />
| Stimulation is ON | StarStim |<br />
| Stimulation is OFF | StarStim |<br />
\--------------------------------------------------------/<br />
<br />
MatNIC is a Matlab toolkit that wraps all these commands and status code in a set of Matlab functions that allow remotely controlling NIC. See the [[MatNIC_Matlab_Toolkit|'''MatNIC section''']] for more info.</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=MediaWiki:Sidebar&diff=1289MediaWiki:Sidebar2015-06-16T14:12:55Z<p>Guillem: </p>
<hr />
<div>* BASIC USE<br />
** goodies-url|Manuals & downloads<br />
<!-- ** tutorials-url|Tutorials --><br />
** nic-url|About NIC<br />
** tips-url|Tips & Tricks<br />
** faq-url | FAQs<br />
** troubleshooting-url|TroubleShooting<br />
** safety-url|Safety<br />
** white-url|White Papers<br />
** starstimpapers-url|Starstim Papers<br />
** enobiopapers-url|Enobio Papers<br />
<br />
* EEG APPLICATIONS<br />
** erp-url|Working with ERPs<br />
** bci-url|BCI Apps<br />
** neurosurfer-url|NeuroSurfer<br />
** BrainBodyMeasures|Brain & Body Measures<br />
<br />
* STIMULATION (tCS)<br />
** abouttcs-url | What is tCS?<br />
** blinding-url | Sham & Blinding<br />
** multifocal-url | Multifocal tCS (MtCS)<br />
** montages-url| tCS & MtCS Montages<br />
** electricfields-url|StimWeaver<br />
<br />
* DATA ANALYSIS<br />
** nicoffline-url|NIC Offline<br />
** dataprocessing-url|Matlab<br />
** filesformat-url|NE Files and formats<br />
<br />
* ADVANCED<br />
** matnic-url|MatNIC toolkit<br />
** interactingwithnic-url|Interaction with NIC<br />
** api-url|Working with the API</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Interacting_with_NIC&diff=1229Interacting with NIC2015-05-14T15:39:49Z<p>Guillem: /* Receiving data streams using LSL */</p>
<hr />
<div>In this page we describe how you can interact with NIC (Neuroelectrics Instrument Controller, the software for control with NE devices) using other software. <br />
<br />
== About Synchronization: general principles ==<br />
[[File:Master slave synchronization.png|200px|thumb|left| The Master system's clock is the only one used in the whole system. The master system either gathers the data from the slave systems to provide a single output or sends its clock so the slave systems can provide their outputs using that clock]]<br />
To coordinate different data sources or events to a single clock is known as synchronization.<br />
<br />
When using Enobio at least there are two different clocks that need to be synchronized: The clock of the Enobio wireless sensor which is in charge of sampling the EEG data recorded by the electrodes, and the clock of the host where NIC runs and receives the EEG data from the Bluetooth connection.<br />
<br />
NIC uses the clock from the Enobio sensor as master. The Enobio clock is received by NIC through the data streaming. The EEG data is sampled at 500 Hz, so every sample is delayed 2 ms from the previous one. In traditional wired system the data will be received by the control software as it is sampled so the two clocks might be directly synchronized. However in wireless system such as the Enobio one, some latency might be introduced in the wireless channel due to RF interference and re-transmission of data.<br />
<br />
NIC implements an algorithm that compensates this latency and finds out the offset between the clock from Enobio and the one from the host where NIC runs. When NIC receives information from third-party applications that need to be synchronized with the EEG data, like markers that signal when external events occur, it compensates the timestamp of the received data so it is aligned with the EEG data streaming.<br />
<br />
In the scenario described above, when NIC collects markers that are sent by other applications, another clock to be synchronized is introduced in the system. This is the clock from the host that sends the markers. NIC provides two ways of gathering such markers. Both of them are described in the following sections. The first one does not provide any synchronization mechanism, this is the reception of markers using a TCP/IP server where the clients connect to and send their markers. This method might be useful when the time synchronization requirements do not need accuracy under the 100 ms.<br />
<br />
The second method uses the [https://code.google.com/p/labstreaminglayer/ Lab Streaming Layer (LSL)], which incorporates built-in network and synchronization capabilities that allow synchronization accuracy on 1 ms so it perfectly fits application like the one that detect [[Event_Related_Potentials_(ERPs) | ERPs signals]].<br />
<br />
<br />
<!--talk about hardware set up to manually determine this deviation and fix it through advanced NIC properties--><br />
<br />
== Sending Markers to NIC from other software or hardware ==<br />
=== Sending Markers using TCP/IP ===<br />
<!-- talk about the marker server: port number, protocol --><br />
NIC provides a server that other software can connect to in order to send markers. Those received markers are synchronized with the EEG streaming for further analysis.<br />
<br />
This NIC server is running in the '''TCP/IP port 1234'''. Up to five clients can simultaneously send markers to NIC by making a TCP/IP connection to this port.<br />
<br />
Once a client is connected it needs to send the following string in order to send a marker:<br />
<TRIGGER>XXXX</TRIGGER><br />
Where XXXX can represent any integer number different from zero (from -2147483647 to +2147483647). This marker will be co-registered in the output files generated by NIC to the corresponding EEG sample. For instance, in the output tabulated text file, the column just after the timestamp one is filled with zeros if no markers are received. When a marker is received its corresponding number is set to that column. See the following example:<br />
<br />
...<br />
26748 -27675 35631 42398 532666 64345 12376 40988 0 1382432459788<br />
26865 -26683 35685 42450 532711 64821 12376 41046 0 1382432459790<br />
26810 -26821 35531 41997 532821 64945 13164 41099 0 1382432459792<br />
26749 -26995 35325 42008 532712 64377 13478 41286 0 1382432459794<br />
26796 -27245 35932 42391 532923 64245 13620 41117 300 1382432459796 <-- Reception of the marker #300<br />
26622 -27510 35501 42630 532876 64193 13031 40986 0 1382432459798<br />
26751 -27912 35611 42003 532345 64344 12967 40731 0 1382432459800<br />
...<br />
<br />
[[File:Markers audio signal.png|200px|thumb|left| Plot of markers received by NIC and an audio signal recorded by Enobio]]<br />
Please take as an example [[Media:Matlab Markers Example.zip | ''this'']] Matlab code which connects to NIC to send markers every time a tone is played back through the sound card. If you connected the output of the computer sound card to one of the Enobio electrodes you would be able to see the alignment between the markers and the played tones.<br />
<br />
=== Sending markers using LSL ===<br />
<!-- talk about LSL client: string and integer markers --><br />
NIC is compliant with the [https://code.google.com/p/labstreaminglayer/ Lab Streaming Layer (LSL)] protocol so makers can be co-registered with the EEG signal by setting up a LSL marker outlet (see this [https://code.google.com/p/labstreaminglayer/source/browse/LSL/liblsl/examples/C/SendStringMarkersC/SendStringMarkersC.c example]).<br />
<br />
The LSL handles both the networking and time-synchronization isues between the sender and receiver hosts obtaining reliability on order of 1 ms (see the time-synchronization validation [https://code.google.com/p/labstreaminglayer/wiki/TimeSynchronizationValidation tests]).<br />
<br />
[[File:NIC LSL settings.png|200px|thumb|left| NIC settings for configuring the reception of markers through LSL]]<br />
NIC needs little configuration in order to receive the markers from a LSL outlet present in the local network. When the LSL marker outlet sends integer-type markers only the name of the outlet needs to be configured in NIC.<br />
<br />
Please go to "''EEG Setup -> Settings -> Markers from Lab Streaming Layer''" and set the name that your LSL marker outlet has. NIC will automatically look for a marker outlet with this name and will connect to it. If the outlet sends integer-type integers then no further configuration is needed. All the received makers will be co-registered along with the EEG signal to the output files.<br />
<br />
In case the outlet sends string-type markers then there are some considerations that have to be taken into account. The LSL outlet sending string-type markers has to format them as XML tags. The following example is taken from the string markers that the Presentation software sends when the LSL extension manager is installed (see the [[Event_Related_Potentials_(ERPs)#Presentation | Working with ERPs]] section). You can see that NIC will decode the string looking for the tag that is configured in the "''EEG Setup -> Settings -> Markers from Lab Streaming Layer''" settings, ''ecode'' in this case. The marker number 37 will be registered at the reception of this string:<br />
<pevent><etype>Picture</etype>'''<ecode>37</ecode>'''<unc>209.638092041016</unc>test</pevent><br />
<br />
<!-- talk about TTL hardware triggering --><br />
=== Sending TTL pulses ===<br />
NIC can also receive a TTL signal and display it through one of its EEG channels using our [http://www.neuroelectrics.com/products/accessories/ext-ttl-trigger-adapter/ TTL adapter].<br />
<br />
This option requires to have a [http://en.wikipedia.org/wiki/Parallel_port#Pinouts parallel port] in the computer running the stimulus software. If you don't have a parallel port, you can also install a PCI Express card emulating a parallel port. Please see the user manual of our [http://www.neuroelectrics.com/download/NE_TTL_Trigger_Receiver_UserManual.pdf TTL adapter] for detailed information on how to set up the connections. <br />
<br />
The following pins of the TTL adapter should be connected to the following pins from the parallel port:<br />
* Pin 1 (Vcc 5V) from the adapter should be connected to any data pin (pins 2-9) of the parallel port. This pin should always be activated at 5V.<br />
* Pin 2 (TTL input) from the adapter should be connected to another data pin (pins 2-9) of the parallel port. This pin should only be activated whenever a TTL pulse is sent.<br />
* Pin 3 (ground) from the adapter should be connected to any ground pin (pins 18-25) of the parallel port.<br />
<br />
=== Sending Markers using the keyboard ===<br />
<br />
You can also send manual events using the number keys (1-9) of your keyboard. To configure the codes for each marker, you can go to the EEG setup --> Settings tab --> Markers in the NIC software, as described in page 14 of NIC's [http://www.neuroelectrics.com/download/NIC_User_Manual_1_3_12.pdf user manual].<br />
<br />
== Receiving data streams from NIC ==<br />
=== Receiving data streams using TCP/IP ===<br />
The NIC software has a TCP/IP server that streams the EEG data received from Enobio. Up to 5 clients can connect to that server simultaneously in order to receive the EEG data ans perform the desired operations in real time.<br />
<br />
The software clients that want to receive the EEG data in real time from NIC need to connect to the '''TCP/IP port 1234''' of the host where the NIC software is running. Once the client software is connected to the server, it will receive the EEG data streaming according to the following format:<br />
-------------------------------------------------------------------------------------------<br />
| Channel 1 | ... | Channel N | <br />
-------------------------------------------------------------------------------------------<br />
| (MSB) Byte#1 | Byte#2 | Byte#3 | (LSB) Byte#4 | ... | Byte#1 | Byte#2 | Byte#3 | Byte#4 |<br />
-------------------------------------------------------------------------------------------<br />
Each EEG sample is sent as a two-complement 4 byte value. The unit of the EEG sample is nano volts and its range is from -400000000 to +400000000 nV. The most significant byte is sent first. The following code in 'C' shows how to decode the streaming from the received bytes to EEG sample values. The example assumes that the computer architecture is little-endian.<br />
// byte3 = 0xFF, byte2 = 0x8F, byte1 = 0x99, byte0 = 0x61<br />
signed int32_t sample = 0;<br />
sample += byte3;<br />
sample = sample << 8;<br />
sample += byte2;<br />
sample = sample << 8;<br />
sample += byte1;<br />
sample = sample << 8;<br />
sample += byte0;<br />
// sample = -141584031 nV<br />
<br />
The client will receive first the four bytes from channel 1, then the next four bytes from channel 2 and so on till receiving the four bytes from the last channel of Enobio (8 or 20 depending of the type of Enobio/Starstim NIC handles). Then channel 1 bytes are receiving again.<br />
<br />
The following links are a Java and a Matlab example clients that connects to NIC and receive the EEG streaming: [[Media:Java_TCP_Enobio_Client.zip | Java client]], [[Media:Matlab_TCP_Enobio_Client.zip | Matlab client]]<br />
<br />
=== Receiving data streams and markers using TCP/IP ===<br />
It is also possible to receive the markers that NIC collects using the TCP/IP connection. By enabling this feature from the NIC settings the markers are sent along with the EEG streaming through the same TCP/IP connection. In this case the markers are sent as a four-bytes integer after the last EEG channel. The most significant byte is sent first. The data streaming will have the following format then:<br />
<br />
-----------------------------------------------------------------------------------------------------------------------------------<br />
| Channel 1 | ... | Channel N | Marker |<br />
-----------------------------------------------------------------------------------------------------------------------------------<br />
| (MSB) Byte#1 | Byte#2 | Byte#3 | (LSB) Byte#4 | ... | Byte#1 | Byte#2 | Byte#3 | Byte#4 | Byte#1 | Byte#2 | Byte#3 | Byte#4 |<br />
-----------------------------------------------------------------------------------------------------------------------------------<br />
<br />
[[File:Markers_through_TCP_setting.png|200px|thumb|left| NIC settings for configuring the sending of markers through the TCP/IP connection]]<br />
<br />
Those markers correspond to the ones received by NIC from third-party software using [[Interacting_with_NIC#Sending_Markers_using_TCP.2FIP | TCP/IP]] or [[Interacting_with_NIC#Sending_markers_using_LSL | LSL]], the manual markers that can be inserted while recording by pressing the keys from 1 to 9 and the stimulation events in the case of the StarStim device such as start and stop stimulation and when any parameter is changed from MatNIC.<br />
<br />
=== Receiving and sending data streams using LSL ===<br />
<!-- talk about receiving the data stream using the LSL --><br />
<br />
NIC streams the received EEG data from Enobio usign the Lab Streaming Layer. NIC creates a LSL outlet with the following settings:<br />
Name: NIC<br />
Type: EEG<br />
Channel count: 8 or 20 depending of the Enobio NIC handles<br />
Nominal sample rate: 500<br />
Channel format: float_32<br />
Unique source ID: The Enobio type plus its mac address<br />
An LSL client software needs to connect to this outlet in order to receive the EEG streaming data. The received values are expressed in nanovolts and its range is from -400000000 to +400000000.<br />
<br />
Using LSL is possible to access to the accelerometer data too. The outlet the LSL clients need to connect to has the following settings:<br />
Name: NIC<br />
Type: Accelerometer<br />
Channel count: 3<br />
Nominal sample rate: 100<br />
Channel format: float_32<br />
Unique source ID: The Enobio type plus its mac address plus the "Acc" string<br />
<br />
Using LSL is possible to access markers generated from another NIC. The outlet the LSL clients need to connect to has the following settings:<br />
Name: NIC<br />
Type: Markers<br />
Channel count: 1<br />
Nominal sample rate: n/a<br />
Channel format: Int_32<br />
Unique source ID: The Enobio type plus its mac address plus the "Marker" string<br />
<br />
NIC streams some markers when starts or stops stimulation with the following settings:<br />
Name: (choosen in NIC EEG settings)<br />
Type: Markers<br />
Channel count: 1<br />
Nominal sample rate: n/a<br />
Channel format: Int_32<br />
Unique source ID: The device type plus its mac address plus the "Marker" string<br />
<br />
The names of the Outlets, are for the version 1.3.12. For previous versions, the name of the outlet is "Enobio"<br />
<br />
== Sending commands to NIC ==<br />
<!-- talk about the features of NIC being controlling (Enobio and StarStim) using a command-based protocol--><br />
<!-- talk about MatNIC as a set of routines that wrap this protocol to provide the functionalities of command NIC from Matlab --><br />
<!-- provide examples --><br />
<br />
NIC can be remotely commanded from a third-party software through a set of commands that can be sent using a TCP/IP connection. NIC listens to the '''TCP/IP port 1235''' for incoming connections. The clients that connect to that port can command the following actions:<br />
/--------------------------------------------------\<br />
| Action | Device |<br />
|--------------------------------------------------|<br />
| Start EEG streaming | Enobio & StarStim |<br />
| Stop EEG streaming | Enobio & StarStim |<br />
| Start Stimulation | StarStim |<br />
| Abort Stimulation | StarStim |<br />
| Online tACS Frequency Change | StarStim |<br />
| Online tACS Amplitude change | StarStim |<br />
| Online tDCS Amplitude change | StarStim |<br />
| Load template | StarStim |<br />
| Request status | Enobio & StarStim |<br />
\--------------------------------------------------/<br />
<br />
NIC responds to those commands with a set of status commands to indicate whether the commands are successfully processed, the stimulation is ready to be started and so on. The following table shows all the possible status value that NIC might send.<br />
<br />
/--------------------------------------------------------\<br />
| Status | Device |<br />
|--------------------------------------------------------|<br />
| Remote control allowed | Enobio & StarStim |<br />
| Remote control rejected | Enobio & StarStim |<br />
| Device is idle | Enobio & StarStim |<br />
| EEG streaming is ON | Enobio & StarStim |<br />
| EEG streaming is OFF | Enobio & StarStim | <br />
| Template not loaded | StarStim |<br />
| Template loaded | StarStim |<br />
| Stimulation is ready to be started | StarStim |<br />
| Stimulation is ON | StarStim |<br />
| Stimulation is OFF | StarStim |<br />
\--------------------------------------------------------/<br />
<br />
MatNIC is a Matlab toolkit that wraps all these commands and status code in a set of Matlab functions that allow remotely controlling NIC. See the [[MatNIC_Matlab_Toolkit|'''MatNIC section''']] for more info.</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Simulating_tCS_Electric_Fields_in_the_Brain&diff=1225Simulating tCS Electric Fields in the Brain2015-04-27T11:46:16Z<p>Guillem: /* Introduction: the electric fields in the brain under tCS */</p>
<hr />
<div>= Introduction: the electric fields in the brain under tCS =<br />
<br />
We discuss here first the methodology for computing electric fields in the brain as implemented in our software. We then provide and overview as well as tips on use of our StimWeaver software and service.<br />
<br />
For more information about the basic mechanisms and technologies in tCS, please see [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3944133/ Ruffini et al. 2013] <ref> Ruffini, G., Wendling, F., Merlet, I., Molaee-Ardekani, B., Mekkonen, A., Salvador, R., Soria-Frisch, A., Grau, C., Dunne, S., Miranda, P., 2013. Transcranial current brain stimulation (tCS):models and technologies. IEEE Transactions on Neural Systems and Rehabilitation Engineering 21, 333–345.</ref> as well as <br />
[http://www.starlab.es/sites/starlab.es/files/HIVE-D1.1%20State-of-the-art-V1.3withcovers-small.pdf this hive-eu.org project deliverable] <ref> P. C. Miranda (FFCUL), F. Wendling, I. Merlet, B. Molaee- Ardekani (INSERM), G. Ruffini (Ed.), S. Dunne, A. Soria- Frisch and D. Whitmer (Starlab), D1.1– Review of state-of-the-art in currents distri- bution and effects, HIVE FP7-FET Open project, 2009 </ref>.<br />
<br />
A forthcoming paper will discuss the optimization of tCS montages from well defined cortical target maps<br />
<ref> Giulio Ruffini, Michael D. Fox, Oscar Ripolles, Pedro Cavaleiro Miranda, Alvaro Pascual-Leone, <br />
Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields, accepted for publication in Neuroimage 2014 </ref><br />
<br />
<br />
The mechanisms underlying the after-effects of tDCS are still the subject of investigation, but in all cases these local changes are brought about by the '''accumulated action of the applied electric field over time''', directly or indirectly. For this reason we focus here on electric field optimization. <br />
<br />
<br />
[[File:principles.png|200px|thumb|left| Interaction of Electric field and neuron through membrane space constant and main fiber axis]]<br />
Moreover, given that that there are strong directional effects in the interaction of electric fields and neurons, i.e., '''neurons are influenced mostly by the component of the electric field parallel to their trajectory'''<br />
<ref>Ranck, J., 1975. Which elements are excited in electrical stimulation of the mammalian central nervous system: a review. Brain Res 98, 417–440.</ref> <br />
<ref>Rattay, F., 1986. Analysis of models for external stimulation of axons. IEEE Transactions on Biomedical Engineering 33, 974–977.</ref><br />
<ref> Rushton, W.A.H., 1927. The effect upon the threshold for nervous excitation of the length of nerve exposed, and the angle between current and nerve. J Physiol 63, 357–77.</ref><br />
<ref> Roth, B.J., 1994. Mechanisms for electrical stimulation of excitable tissue. Crit Rev Biomed Eng 22, 253–305.</ref><br />
<ref>Bikson, M., Inoue, M., Akiyama, H., Deans, J.K., Fox, J.E., Miyakawa, H., Jefferys, J.G., 2004. Effects of uniform extracellular dc electric fields on excitability in rat hippocampal slices in vitro. J Physiol 557, 175–90. </ref><br />
<ref> Fröhlich, F., McCormick, D.A., 2010. Endogenous electric fields may guide neocortical network activity. Neuron 67, 129–143.</ref>, <br />
and that the effects of tDCS depend on its polarity, knowledge about the orientation of the electric field is crucial in predicting the effects of stimulation. The components of the field perpendicular and parallel to the cortical surface are of special importance, since pyramidal cells are mostly aligned perpendicular to the surface, while many cortical interneurons and axonal projections of pyramidal cells tend to align tangentially<br />
<ref> Day, B., Dressler, D., Maertens de Noordhout, A., Marsden, C., Nakashima, K., Rothwell, J., Thompson, P., 1989. Electric and magnetic stimulation of human motor cortex: surface emg and single motor unit responses. J. Physiol 122, 449–473.</ref><br />
<ref> Fox, P.T., Narayana, S., Tandon, N., Sandoval, H., Fox, S.P., Kochunov, P., Lancaster, J.L., 2004. Column-based model of electric field excitation of cerebral cortex. Hum Brain Mapp 22, 1–14.</ref><br />
<ref> Kammer, T., Vorwerg, M., Herrnberger, B., 2007. Anisotropy in the visual cortex investigated by neuronavigated transcranial magnetic stimulation. Neuroimage 36, 313–321.</ref>. Thus, an important element in modeling is to provide the electric field distribution and orientation relative to the grey matter (GM) and white matter (WM) surfaces (the latter might be important to study the possibility of polarizing corticospinal axons, their collaterals and other projection neurons). In order to do this, we work here with a realistic head model derived from structural MRI images [http://www.ncbi.nlm.nih.gov/pubmed/23274187 | Miranda et al. 2013] <ref name="Miranda2013a"> Miranda, P.C., Mekonnen, A., Salvador, R., Ruffini, G., 2013. The electric field in the cortex during transcranial current stimulation. Neuroimage 70, 45–58. </ref> to calculate the tCS electric field components rapidly from arbitrary EEG 10-20 montages. Importantly, this modeling approach allows for fast calculation of electric field components normal and parallel to the GM and WM surfaces.<br />
<br />
= StimViewer = <br />
StimViewer is the software component embedded in [http://www.neuroelectrics.com/enobio/software | '''NIC'''] which is activated when in use with [http://www.neuroelectrics.com/products/starstim/ | '''StarStim''']. StimViewer is a fast simulation engine to produce electric fields in the brain associated with a particular tCS montage and display them on two surfaces: the outer cortex or inner cortex.<br />
<br />
[[File:fem-simus.png|200px|thumb|left| Simulation FEM framework ]]<br />
The electric field calculations were performed using the realistic head model described in [http://www.ncbi.nlm.nih.gov/pubmed/23274187 | Miranda et al. 2013aa] <ref name="Miranda2013a" /> . Briefly, tissue boundaries were derived from MR images (scalp, skull, cerebrospinal fluid (CSF) – including ventricles, Grey Matter and White Matter) and the Finite Element Method was used to calculate the electric potential in the head, subject to the appropriate boundary conditions. Tissues were assumed to be uniform and isotropic and values for their electric conductivity were taken from the literature. <br />
<br />
In order to compute electric fields rapidly, we have made use of the principle of superposition. This states that with appropriate boundary conditions, the solution to a general N-electrode problem can be expressed as a linear combination of ''N-1'' bipolar ones. A fixed reference electrode is first chosen, and then all the bipolar solutions using this electrode are computed. A general solution with an arbitrary number of ''N'' electrodes can then easily be computed. <br />
[[File:StimViewer1.png|200px|thumb|left| Simulation of E fields: time slicing (Potential) ]] <br />
<br />
<br />
Using StimViewer you can display the '''electric Potential V''' and the '''normal''' (i.e., perpendicular) component of the electric field to the cortical surface (E_n, which can be positive or negative). In the convention used here, a positive value for the component of the electric field normal to the cortical surface means the electric field component normal is pointing ''into'' the cortex. According to the literature, such a field would be excitatory. On the other hand, an electric field pointing out of the cortex (negative normal component) would be inhibitory.<br />
<br />
[File:StimViewer3.png|200px|thumb|left| Simulation of E fields: magnitude of tangential component ]] <br />
<br />
You can also display the '''magnitude of the tangential component''' (||E_t||), or the '''total magnitude''' (||E||). <br />
<br />
<br />
[[File:StimViewer2.png|200px|thumb|left| Simulation of E fields: time slicing ]] <br />
<br />
[[File:StimViewer4.png|200px|thumb|left| Simulation of E fields: Multichannel, E field magnitude on cortex ]] <br />
<br />
For time varying protocols (such as tACS), you can also use a '''temporal slider''' to display the fields at different time points. Alternatively you can display the time average of the magnitude of the field, which we call the '''influence map'''.<br />
<br />
= StimWeaver =<br />
StimWeaver is an optimization service created by Neuroelectrics and based on StimViewer technology. It has been designed to create stimulation montages (electrode positions as well as currents) specifically adapted to user-defined targets. <br />
<br />
<!-- There are two ways to optimize a montage with StimWeaver, which we now describe. --><br />
<!-- '''User Optimization''': Using StimWeaver you first define stimulation targets in the cortex (grey matter-CSF or white matter-grey matter interface).--><br />
<!-- Once this is done you can create and multichannel tCS montages and evaluate them using quality matching measures. --><br />
<!-- '''StimWeaver Service''': You can also use StimWeaver to define the optimization problem (i.e., targets) and send it to Neuroelectrics. --><br />
<br />
Our staff will produce a mathematically optimized montage based on your specifications (target map, maximal currents, number of electrodes, etc.). Our optimization software (StimWeaver) carries out a thorough search in the space of electrode locations and currents to produce the best solution for the specified target.<br />
<br />
Please see our recent paper on the subject of '''optimization of montages starting from well-defined cortical target maps''' <ref><br />
[http://www.sciencedirect.com/science/article/pii/S1053811913012068 Giulio Ruffini, Michael D. Fox, Oscar Ripolles, Pedro Cavaleiro Miranda, Alvaro Pascual-Leone, Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields, available online, Dec 15, Neuroimage (2013)]<br />
</ref>.<br />
<br />
'''Contact us at info@neuroelectrics.com for more information.'''<br />
<br />
= References =<br />
<br />
<references/><br />
<br />
= References =<br />
<references /></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Simulating_tCS_Electric_Fields_in_the_Brain&diff=1224Simulating tCS Electric Fields in the Brain2015-04-27T11:41:48Z<p>Guillem: /* Introduction: the electric fields in the brain under tCS */</p>
<hr />
<div>= Introduction: the electric fields in the brain under tCS =<br />
<br />
We discuss here first the methodology for computing electric fields in the brain as implemented in our software. We then provide and overview as well as tips on use of our StimWeaver software and service.<br />
<br />
For more information about the basic mechanisms and technologies in tCS, please see [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3944133/ Ruffini et al. 2013] <ref> Ruffini, G., Wendling, F., Merlet, I., Molaee-Ardekani, B., Mekkonen, A., Salvador, R., Soria-Frisch, A., Grau, C., Dunne, S., Miranda, P., 2013. Transcranial current brain stimulation (tCS):models and technologies. IEEE Transactions on Neural Systems and Rehabilitation Engineering 21, 333–345.</ref> as well as <br />
[http://starlab.es/sites/starlab.es/files/HIVE-D1.1%20State-of-the-art-V1.3withcovers-small.pdf this hive-eu.org project deliverable] <ref> P. C. Miranda (FFCUL), F. Wendling, I. Merlet, B. Molaee- Ardekani (INSERM), G. Ruffini (Ed.), S. Dunne, A. Soria- Frisch and D. Whitmer (Starlab), D1.1– Review of state-of-the-art in currents distri- bution and effects, HIVE FP7-FET Open project, 2009 </ref>.<br />
<br />
A forthcoming paper will discuss the optimization of tCS montages from well defined cortical target maps<br />
<ref> Giulio Ruffini, Michael D. Fox, Oscar Ripolles, Pedro Cavaleiro Miranda, Alvaro Pascual-Leone, <br />
Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields, accepted for publication in Neuroimage 2014 </ref><br />
<br />
<br />
The mechanisms underlying the after-effects of tDCS are still the subject of investigation, but in all cases these local changes are brought about by the '''accumulated action of the applied electric field over time''', directly or indirectly. For this reason we focus here on electric field optimization. <br />
<br />
<br />
[[File:principles.png|200px|thumb|left| Interaction of Electric field and neuron through membrane space constant and main fiber axis]]<br />
Moreover, given that that there are strong directional effects in the interaction of electric fields and neurons, i.e., '''neurons are influenced mostly by the component of the electric field parallel to their trajectory'''<br />
<ref>Ranck, J., 1975. Which elements are excited in electrical stimulation of the mammalian central nervous system: a review. Brain Res 98, 417–440.</ref> <br />
<ref>Rattay, F., 1986. Analysis of models for external stimulation of axons. IEEE Transactions on Biomedical Engineering 33, 974–977.</ref><br />
<ref> Rushton, W.A.H., 1927. The effect upon the threshold for nervous excitation of the length of nerve exposed, and the angle between current and nerve. J Physiol 63, 357–77.</ref><br />
<ref> Roth, B.J., 1994. Mechanisms for electrical stimulation of excitable tissue. Crit Rev Biomed Eng 22, 253–305.</ref><br />
<ref>Bikson, M., Inoue, M., Akiyama, H., Deans, J.K., Fox, J.E., Miyakawa, H., Jefferys, J.G., 2004. Effects of uniform extracellular dc electric fields on excitability in rat hippocampal slices in vitro. J Physiol 557, 175–90. </ref><br />
<ref> Fröhlich, F., McCormick, D.A., 2010. Endogenous electric fields may guide neocortical network activity. Neuron 67, 129–143.</ref>, <br />
and that the effects of tDCS depend on its polarity, knowledge about the orientation of the electric field is crucial in predicting the effects of stimulation. The components of the field perpendicular and parallel to the cortical surface are of special importance, since pyramidal cells are mostly aligned perpendicular to the surface, while many cortical interneurons and axonal projections of pyramidal cells tend to align tangentially<br />
<ref> Day, B., Dressler, D., Maertens de Noordhout, A., Marsden, C., Nakashima, K., Rothwell, J., Thompson, P., 1989. Electric and magnetic stimulation of human motor cortex: surface emg and single motor unit responses. J. Physiol 122, 449–473.</ref><br />
<ref> Fox, P.T., Narayana, S., Tandon, N., Sandoval, H., Fox, S.P., Kochunov, P., Lancaster, J.L., 2004. Column-based model of electric field excitation of cerebral cortex. Hum Brain Mapp 22, 1–14.</ref><br />
<ref> Kammer, T., Vorwerg, M., Herrnberger, B., 2007. Anisotropy in the visual cortex investigated by neuronavigated transcranial magnetic stimulation. Neuroimage 36, 313–321.</ref>. Thus, an important element in modeling is to provide the electric field distribution and orientation relative to the grey matter (GM) and white matter (WM) surfaces (the latter might be important to study the possibility of polarizing corticospinal axons, their collaterals and other projection neurons). In order to do this, we work here with a realistic head model derived from structural MRI images [http://www.ncbi.nlm.nih.gov/pubmed/23274187 | Miranda et al. 2013] <ref name="Miranda2013a"> Miranda, P.C., Mekonnen, A., Salvador, R., Ruffini, G., 2013. The electric field in the cortex during transcranial current stimulation. Neuroimage 70, 45–58. </ref> to calculate the tCS electric field components rapidly from arbitrary EEG 10-20 montages. Importantly, this modeling approach allows for fast calculation of electric field components normal and parallel to the GM and WM surfaces.<br />
<br />
= StimViewer = <br />
StimViewer is the software component embedded in [http://www.neuroelectrics.com/enobio/software | '''NIC'''] which is activated when in use with [http://www.neuroelectrics.com/products/starstim/ | '''StarStim''']. StimViewer is a fast simulation engine to produce electric fields in the brain associated with a particular tCS montage and display them on two surfaces: the outer cortex or inner cortex.<br />
<br />
[[File:fem-simus.png|200px|thumb|left| Simulation FEM framework ]]<br />
The electric field calculations were performed using the realistic head model described in [http://www.ncbi.nlm.nih.gov/pubmed/23274187 | Miranda et al. 2013aa] <ref name="Miranda2013a" /> . Briefly, tissue boundaries were derived from MR images (scalp, skull, cerebrospinal fluid (CSF) – including ventricles, Grey Matter and White Matter) and the Finite Element Method was used to calculate the electric potential in the head, subject to the appropriate boundary conditions. Tissues were assumed to be uniform and isotropic and values for their electric conductivity were taken from the literature. <br />
<br />
In order to compute electric fields rapidly, we have made use of the principle of superposition. This states that with appropriate boundary conditions, the solution to a general N-electrode problem can be expressed as a linear combination of ''N-1'' bipolar ones. A fixed reference electrode is first chosen, and then all the bipolar solutions using this electrode are computed. A general solution with an arbitrary number of ''N'' electrodes can then easily be computed. <br />
[[File:StimViewer1.png|200px|thumb|left| Simulation of E fields: time slicing (Potential) ]] <br />
<br />
<br />
Using StimViewer you can display the '''electric Potential V''' and the '''normal''' (i.e., perpendicular) component of the electric field to the cortical surface (E_n, which can be positive or negative). In the convention used here, a positive value for the component of the electric field normal to the cortical surface means the electric field component normal is pointing ''into'' the cortex. According to the literature, such a field would be excitatory. On the other hand, an electric field pointing out of the cortex (negative normal component) would be inhibitory.<br />
<br />
[File:StimViewer3.png|200px|thumb|left| Simulation of E fields: magnitude of tangential component ]] <br />
<br />
You can also display the '''magnitude of the tangential component''' (||E_t||), or the '''total magnitude''' (||E||). <br />
<br />
<br />
[[File:StimViewer2.png|200px|thumb|left| Simulation of E fields: time slicing ]] <br />
<br />
[[File:StimViewer4.png|200px|thumb|left| Simulation of E fields: Multichannel, E field magnitude on cortex ]] <br />
<br />
For time varying protocols (such as tACS), you can also use a '''temporal slider''' to display the fields at different time points. Alternatively you can display the time average of the magnitude of the field, which we call the '''influence map'''.<br />
<br />
= StimWeaver =<br />
StimWeaver is an optimization service created by Neuroelectrics and based on StimViewer technology. It has been designed to create stimulation montages (electrode positions as well as currents) specifically adapted to user-defined targets. <br />
<br />
<!-- There are two ways to optimize a montage with StimWeaver, which we now describe. --><br />
<!-- '''User Optimization''': Using StimWeaver you first define stimulation targets in the cortex (grey matter-CSF or white matter-grey matter interface).--><br />
<!-- Once this is done you can create and multichannel tCS montages and evaluate them using quality matching measures. --><br />
<!-- '''StimWeaver Service''': You can also use StimWeaver to define the optimization problem (i.e., targets) and send it to Neuroelectrics. --><br />
<br />
Our staff will produce a mathematically optimized montage based on your specifications (target map, maximal currents, number of electrodes, etc.). Our optimization software (StimWeaver) carries out a thorough search in the space of electrode locations and currents to produce the best solution for the specified target.<br />
<br />
Please see our recent paper on the subject of '''optimization of montages starting from well-defined cortical target maps''' <ref><br />
[http://www.sciencedirect.com/science/article/pii/S1053811913012068 Giulio Ruffini, Michael D. Fox, Oscar Ripolles, Pedro Cavaleiro Miranda, Alvaro Pascual-Leone, Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields, available online, Dec 15, Neuroimage (2013)]<br />
</ref>.<br />
<br />
'''Contact us at info@neuroelectrics.com for more information.'''<br />
<br />
= References =<br />
<br />
<references/><br />
<br />
= References =<br />
<references /></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Simulating_tCS_Electric_Fields_in_the_Brain&diff=1223Simulating tCS Electric Fields in the Brain2015-04-27T11:40:35Z<p>Guillem: /* Introduction: the electric fields in the brain under tCS */</p>
<hr />
<div>= Introduction: the electric fields in the brain under tCS =<br />
<br />
We discuss here first the methodology for computing electric fields in the brain as implemented in our software. We then provide and overview as well as tips on use of our StimWeaver software and service.<br />
<br />
For more information about the basic mechanisms and technologies in tCS, please see [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3944133/ Ruffini et al. 2013] <ref> Ruffini, G., Wendling, F., Merlet, I., Molaee-Ardekani, B., Mekkonen, A., Salvador, R., Soria-Frisch, A., Grau, C., Dunne, S., Miranda, P., 2013. Transcranial current brain stimulation (tCS):models and technologies. IEEE Transactions on Neural Systems and Rehabilitation Engineering 21, 333–345.</ref> as well as <br />
[http://starlab.es/sites/starlab.es/files/HIVE-D1.1%20State-of-the-art-V1.3withcovers-small.pdf | this hive-eu.org project deliverable] <ref> P. C. Miranda (FFCUL), F. Wendling, I. Merlet, B. Molaee- Ardekani (INSERM), G. Ruffini (Ed.), S. Dunne, A. Soria- Frisch and D. Whitmer (Starlab), D1.1– Review of state-of-the-art in currents distri- bution and effects, HIVE FP7-FET Open project, 2009 </ref>.<br />
<br />
A forthcoming paper will discuss the optimization of tCS montages from well defined cortical target maps<br />
<ref> Giulio Ruffini, Michael D. Fox, Oscar Ripolles, Pedro Cavaleiro Miranda, Alvaro Pascual-Leone, <br />
Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields, accepted for publication in Neuroimage 2014 </ref><br />
<br />
<br />
The mechanisms underlying the after-effects of tDCS are still the subject of investigation, but in all cases these local changes are brought about by the '''accumulated action of the applied electric field over time''', directly or indirectly. For this reason we focus here on electric field optimization. <br />
<br />
<br />
[[File:principles.png|200px|thumb|left| Interaction of Electric field and neuron through membrane space constant and main fiber axis]]<br />
Moreover, given that that there are strong directional effects in the interaction of electric fields and neurons, i.e., '''neurons are influenced mostly by the component of the electric field parallel to their trajectory'''<br />
<ref>Ranck, J., 1975. Which elements are excited in electrical stimulation of the mammalian central nervous system: a review. Brain Res 98, 417–440.</ref> <br />
<ref>Rattay, F., 1986. Analysis of models for external stimulation of axons. IEEE Transactions on Biomedical Engineering 33, 974–977.</ref><br />
<ref> Rushton, W.A.H., 1927. The effect upon the threshold for nervous excitation of the length of nerve exposed, and the angle between current and nerve. J Physiol 63, 357–77.</ref><br />
<ref> Roth, B.J., 1994. Mechanisms for electrical stimulation of excitable tissue. Crit Rev Biomed Eng 22, 253–305.</ref><br />
<ref>Bikson, M., Inoue, M., Akiyama, H., Deans, J.K., Fox, J.E., Miyakawa, H., Jefferys, J.G., 2004. Effects of uniform extracellular dc electric fields on excitability in rat hippocampal slices in vitro. J Physiol 557, 175–90. </ref><br />
<ref> Fröhlich, F., McCormick, D.A., 2010. Endogenous electric fields may guide neocortical network activity. Neuron 67, 129–143.</ref>, <br />
and that the effects of tDCS depend on its polarity, knowledge about the orientation of the electric field is crucial in predicting the effects of stimulation. The components of the field perpendicular and parallel to the cortical surface are of special importance, since pyramidal cells are mostly aligned perpendicular to the surface, while many cortical interneurons and axonal projections of pyramidal cells tend to align tangentially<br />
<ref> Day, B., Dressler, D., Maertens de Noordhout, A., Marsden, C., Nakashima, K., Rothwell, J., Thompson, P., 1989. Electric and magnetic stimulation of human motor cortex: surface emg and single motor unit responses. J. Physiol 122, 449–473.</ref><br />
<ref> Fox, P.T., Narayana, S., Tandon, N., Sandoval, H., Fox, S.P., Kochunov, P., Lancaster, J.L., 2004. Column-based model of electric field excitation of cerebral cortex. Hum Brain Mapp 22, 1–14.</ref><br />
<ref> Kammer, T., Vorwerg, M., Herrnberger, B., 2007. Anisotropy in the visual cortex investigated by neuronavigated transcranial magnetic stimulation. Neuroimage 36, 313–321.</ref>. Thus, an important element in modeling is to provide the electric field distribution and orientation relative to the grey matter (GM) and white matter (WM) surfaces (the latter might be important to study the possibility of polarizing corticospinal axons, their collaterals and other projection neurons). In order to do this, we work here with a realistic head model derived from structural MRI images [http://www.ncbi.nlm.nih.gov/pubmed/23274187 | Miranda et al. 2013] <ref name="Miranda2013a"> Miranda, P.C., Mekonnen, A., Salvador, R., Ruffini, G., 2013. The electric field in the cortex during transcranial current stimulation. Neuroimage 70, 45–58. </ref> to calculate the tCS electric field components rapidly from arbitrary EEG 10-20 montages. Importantly, this modeling approach allows for fast calculation of electric field components normal and parallel to the GM and WM surfaces.<br />
<br />
= StimViewer = <br />
StimViewer is the software component embedded in [http://www.neuroelectrics.com/enobio/software | '''NIC'''] which is activated when in use with [http://www.neuroelectrics.com/products/starstim/ | '''StarStim''']. StimViewer is a fast simulation engine to produce electric fields in the brain associated with a particular tCS montage and display them on two surfaces: the outer cortex or inner cortex.<br />
<br />
[[File:fem-simus.png|200px|thumb|left| Simulation FEM framework ]]<br />
The electric field calculations were performed using the realistic head model described in [http://www.ncbi.nlm.nih.gov/pubmed/23274187 | Miranda et al. 2013aa] <ref name="Miranda2013a" /> . Briefly, tissue boundaries were derived from MR images (scalp, skull, cerebrospinal fluid (CSF) – including ventricles, Grey Matter and White Matter) and the Finite Element Method was used to calculate the electric potential in the head, subject to the appropriate boundary conditions. Tissues were assumed to be uniform and isotropic and values for their electric conductivity were taken from the literature. <br />
<br />
In order to compute electric fields rapidly, we have made use of the principle of superposition. This states that with appropriate boundary conditions, the solution to a general N-electrode problem can be expressed as a linear combination of ''N-1'' bipolar ones. A fixed reference electrode is first chosen, and then all the bipolar solutions using this electrode are computed. A general solution with an arbitrary number of ''N'' electrodes can then easily be computed. <br />
[[File:StimViewer1.png|200px|thumb|left| Simulation of E fields: time slicing (Potential) ]] <br />
<br />
<br />
Using StimViewer you can display the '''electric Potential V''' and the '''normal''' (i.e., perpendicular) component of the electric field to the cortical surface (E_n, which can be positive or negative). In the convention used here, a positive value for the component of the electric field normal to the cortical surface means the electric field component normal is pointing ''into'' the cortex. According to the literature, such a field would be excitatory. On the other hand, an electric field pointing out of the cortex (negative normal component) would be inhibitory.<br />
<br />
[File:StimViewer3.png|200px|thumb|left| Simulation of E fields: magnitude of tangential component ]] <br />
<br />
You can also display the '''magnitude of the tangential component''' (||E_t||), or the '''total magnitude''' (||E||). <br />
<br />
<br />
[[File:StimViewer2.png|200px|thumb|left| Simulation of E fields: time slicing ]] <br />
<br />
[[File:StimViewer4.png|200px|thumb|left| Simulation of E fields: Multichannel, E field magnitude on cortex ]] <br />
<br />
For time varying protocols (such as tACS), you can also use a '''temporal slider''' to display the fields at different time points. Alternatively you can display the time average of the magnitude of the field, which we call the '''influence map'''.<br />
<br />
= StimWeaver =<br />
StimWeaver is an optimization service created by Neuroelectrics and based on StimViewer technology. It has been designed to create stimulation montages (electrode positions as well as currents) specifically adapted to user-defined targets. <br />
<br />
<!-- There are two ways to optimize a montage with StimWeaver, which we now describe. --><br />
<!-- '''User Optimization''': Using StimWeaver you first define stimulation targets in the cortex (grey matter-CSF or white matter-grey matter interface).--><br />
<!-- Once this is done you can create and multichannel tCS montages and evaluate them using quality matching measures. --><br />
<!-- '''StimWeaver Service''': You can also use StimWeaver to define the optimization problem (i.e., targets) and send it to Neuroelectrics. --><br />
<br />
Our staff will produce a mathematically optimized montage based on your specifications (target map, maximal currents, number of electrodes, etc.). Our optimization software (StimWeaver) carries out a thorough search in the space of electrode locations and currents to produce the best solution for the specified target.<br />
<br />
Please see our recent paper on the subject of '''optimization of montages starting from well-defined cortical target maps''' <ref><br />
[http://www.sciencedirect.com/science/article/pii/S1053811913012068 Giulio Ruffini, Michael D. Fox, Oscar Ripolles, Pedro Cavaleiro Miranda, Alvaro Pascual-Leone, Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields, available online, Dec 15, Neuroimage (2013)]<br />
</ref>.<br />
<br />
'''Contact us at info@neuroelectrics.com for more information.'''<br />
<br />
= References =<br />
<br />
<references/><br />
<br />
= References =<br />
<references /></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Simulating_tCS_Electric_Fields_in_the_Brain&diff=1222Simulating tCS Electric Fields in the Brain2015-04-27T11:39:05Z<p>Guillem: /* Introduction: the electric fields in the brain under tCS */</p>
<hr />
<div>= Introduction: the electric fields in the brain under tCS =<br />
<br />
We discuss here first the methodology for computing electric fields in the brain as implemented in our software. We then provide and overview as well as tips on use of our StimWeaver software and service.<br />
<br />
For more information about the basic mechanisms and technologies in tCS, please see [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3944133/ | Ruffini et al. 2013] <ref> Ruffini, G., Wendling, F., Merlet, I., Molaee-Ardekani, B., Mekkonen, A., Salvador, R., Soria-Frisch, A., Grau, C., Dunne, S., Miranda, P., 2013. Transcranial current brain stimulation (tCS):models and technologies. IEEE Transactions on Neural Systems and Rehabilitation Engineering 21, 333–345.</ref> as well as <br />
[http://starlab.es/sites/starlab.es/files/HIVE-D1.1%20State-of-the-art-V1.3withcovers-small.pdf | this hive-eu.org project deliverable] <ref> P. C. Miranda (FFCUL), F. Wendling, I. Merlet, B. Molaee- Ardekani (INSERM), G. Ruffini (Ed.), S. Dunne, A. Soria- Frisch and D. Whitmer (Starlab), D1.1– Review of state-of-the-art in currents distri- bution and effects, HIVE FP7-FET Open project, 2009 </ref>.<br />
<br />
A forthcoming paper will discuss the optimization of tCS montages from well defined cortical target maps<br />
<ref> Giulio Ruffini, Michael D. Fox, Oscar Ripolles, Pedro Cavaleiro Miranda, Alvaro Pascual-Leone, <br />
Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields, accepted for publication in Neuroimage 2014 </ref><br />
<br />
<br />
The mechanisms underlying the after-effects of tDCS are still the subject of investigation, but in all cases these local changes are brought about by the '''accumulated action of the applied electric field over time''', directly or indirectly. For this reason we focus here on electric field optimization. <br />
<br />
<br />
[[File:principles.png|200px|thumb|left| Interaction of Electric field and neuron through membrane space constant and main fiber axis]]<br />
Moreover, given that that there are strong directional effects in the interaction of electric fields and neurons, i.e., '''neurons are influenced mostly by the component of the electric field parallel to their trajectory'''<br />
<ref>Ranck, J., 1975. Which elements are excited in electrical stimulation of the mammalian central nervous system: a review. Brain Res 98, 417–440.</ref> <br />
<ref>Rattay, F., 1986. Analysis of models for external stimulation of axons. IEEE Transactions on Biomedical Engineering 33, 974–977.</ref><br />
<ref> Rushton, W.A.H., 1927. The effect upon the threshold for nervous excitation of the length of nerve exposed, and the angle between current and nerve. J Physiol 63, 357–77.</ref><br />
<ref> Roth, B.J., 1994. Mechanisms for electrical stimulation of excitable tissue. Crit Rev Biomed Eng 22, 253–305.</ref><br />
<ref>Bikson, M., Inoue, M., Akiyama, H., Deans, J.K., Fox, J.E., Miyakawa, H., Jefferys, J.G., 2004. Effects of uniform extracellular dc electric fields on excitability in rat hippocampal slices in vitro. J Physiol 557, 175–90. </ref><br />
<ref> Fröhlich, F., McCormick, D.A., 2010. Endogenous electric fields may guide neocortical network activity. Neuron 67, 129–143.</ref>, <br />
and that the effects of tDCS depend on its polarity, knowledge about the orientation of the electric field is crucial in predicting the effects of stimulation. The components of the field perpendicular and parallel to the cortical surface are of special importance, since pyramidal cells are mostly aligned perpendicular to the surface, while many cortical interneurons and axonal projections of pyramidal cells tend to align tangentially<br />
<ref> Day, B., Dressler, D., Maertens de Noordhout, A., Marsden, C., Nakashima, K., Rothwell, J., Thompson, P., 1989. Electric and magnetic stimulation of human motor cortex: surface emg and single motor unit responses. J. Physiol 122, 449–473.</ref><br />
<ref> Fox, P.T., Narayana, S., Tandon, N., Sandoval, H., Fox, S.P., Kochunov, P., Lancaster, J.L., 2004. Column-based model of electric field excitation of cerebral cortex. Hum Brain Mapp 22, 1–14.</ref><br />
<ref> Kammer, T., Vorwerg, M., Herrnberger, B., 2007. Anisotropy in the visual cortex investigated by neuronavigated transcranial magnetic stimulation. Neuroimage 36, 313–321.</ref>. Thus, an important element in modeling is to provide the electric field distribution and orientation relative to the grey matter (GM) and white matter (WM) surfaces (the latter might be important to study the possibility of polarizing corticospinal axons, their collaterals and other projection neurons). In order to do this, we work here with a realistic head model derived from structural MRI images [http://www.ncbi.nlm.nih.gov/pubmed/23274187 | Miranda et al. 2013] <ref name="Miranda2013a"> Miranda, P.C., Mekonnen, A., Salvador, R., Ruffini, G., 2013. The electric field in the cortex during transcranial current stimulation. Neuroimage 70, 45–58. </ref> to calculate the tCS electric field components rapidly from arbitrary EEG 10-20 montages. Importantly, this modeling approach allows for fast calculation of electric field components normal and parallel to the GM and WM surfaces.<br />
<br />
= StimViewer = <br />
StimViewer is the software component embedded in [http://www.neuroelectrics.com/enobio/software | '''NIC'''] which is activated when in use with [http://www.neuroelectrics.com/products/starstim/ | '''StarStim''']. StimViewer is a fast simulation engine to produce electric fields in the brain associated with a particular tCS montage and display them on two surfaces: the outer cortex or inner cortex.<br />
<br />
[[File:fem-simus.png|200px|thumb|left| Simulation FEM framework ]]<br />
The electric field calculations were performed using the realistic head model described in [http://www.ncbi.nlm.nih.gov/pubmed/23274187 | Miranda et al. 2013aa] <ref name="Miranda2013a" /> . Briefly, tissue boundaries were derived from MR images (scalp, skull, cerebrospinal fluid (CSF) – including ventricles, Grey Matter and White Matter) and the Finite Element Method was used to calculate the electric potential in the head, subject to the appropriate boundary conditions. Tissues were assumed to be uniform and isotropic and values for their electric conductivity were taken from the literature. <br />
<br />
In order to compute electric fields rapidly, we have made use of the principle of superposition. This states that with appropriate boundary conditions, the solution to a general N-electrode problem can be expressed as a linear combination of ''N-1'' bipolar ones. A fixed reference electrode is first chosen, and then all the bipolar solutions using this electrode are computed. A general solution with an arbitrary number of ''N'' electrodes can then easily be computed. <br />
[[File:StimViewer1.png|200px|thumb|left| Simulation of E fields: time slicing (Potential) ]] <br />
<br />
<br />
Using StimViewer you can display the '''electric Potential V''' and the '''normal''' (i.e., perpendicular) component of the electric field to the cortical surface (E_n, which can be positive or negative). In the convention used here, a positive value for the component of the electric field normal to the cortical surface means the electric field component normal is pointing ''into'' the cortex. According to the literature, such a field would be excitatory. On the other hand, an electric field pointing out of the cortex (negative normal component) would be inhibitory.<br />
<br />
[File:StimViewer3.png|200px|thumb|left| Simulation of E fields: magnitude of tangential component ]] <br />
<br />
You can also display the '''magnitude of the tangential component''' (||E_t||), or the '''total magnitude''' (||E||). <br />
<br />
<br />
[[File:StimViewer2.png|200px|thumb|left| Simulation of E fields: time slicing ]] <br />
<br />
[[File:StimViewer4.png|200px|thumb|left| Simulation of E fields: Multichannel, E field magnitude on cortex ]] <br />
<br />
For time varying protocols (such as tACS), you can also use a '''temporal slider''' to display the fields at different time points. Alternatively you can display the time average of the magnitude of the field, which we call the '''influence map'''.<br />
<br />
= StimWeaver =<br />
StimWeaver is an optimization service created by Neuroelectrics and based on StimViewer technology. It has been designed to create stimulation montages (electrode positions as well as currents) specifically adapted to user-defined targets. <br />
<br />
<!-- There are two ways to optimize a montage with StimWeaver, which we now describe. --><br />
<!-- '''User Optimization''': Using StimWeaver you first define stimulation targets in the cortex (grey matter-CSF or white matter-grey matter interface).--><br />
<!-- Once this is done you can create and multichannel tCS montages and evaluate them using quality matching measures. --><br />
<!-- '''StimWeaver Service''': You can also use StimWeaver to define the optimization problem (i.e., targets) and send it to Neuroelectrics. --><br />
<br />
Our staff will produce a mathematically optimized montage based on your specifications (target map, maximal currents, number of electrodes, etc.). Our optimization software (StimWeaver) carries out a thorough search in the space of electrode locations and currents to produce the best solution for the specified target.<br />
<br />
Please see our recent paper on the subject of '''optimization of montages starting from well-defined cortical target maps''' <ref><br />
[http://www.sciencedirect.com/science/article/pii/S1053811913012068 Giulio Ruffini, Michael D. Fox, Oscar Ripolles, Pedro Cavaleiro Miranda, Alvaro Pascual-Leone, Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields, available online, Dec 15, Neuroimage (2013)]<br />
</ref>.<br />
<br />
'''Contact us at info@neuroelectrics.com for more information.'''<br />
<br />
= References =<br />
<br />
<references/><br />
<br />
= References =<br />
<references /></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Simulating_tCS_Electric_Fields_in_the_Brain&diff=1221Simulating tCS Electric Fields in the Brain2015-04-27T11:38:11Z<p>Guillem: /* Introduction: the electric fields in the brain under tCS */</p>
<hr />
<div>= Introduction: the electric fields in the brain under tCS =<br />
<br />
We discuss here first the methodology for computing electric fields in the brain as implemented in our software. We then provide and overview as well as tips on use of our StimWeaver software and service.<br />
<br />
For more information about the basic mechanisms and technologies in tCS, please see [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3944133/| Ruffini et al. 2013] <ref> Ruffini, G., Wendling, F., Merlet, I., Molaee-Ardekani, B., Mekkonen, A., Salvador, R., Soria-Frisch, A., Grau, C., Dunne, S., Miranda, P., 2013. Transcranial current brain stimulation (tCS):models and technologies. IEEE Transactions on Neural Systems and Rehabilitation Engineering 21, 333–345.</ref> as well as <br />
[http://starlab.es/sites/starlab.es/files/HIVE-D1.1%20State-of-the-art-V1.3withcovers-small.pdf | this hive-eu.org project deliverable] <ref> P. C. Miranda (FFCUL), F. Wendling, I. Merlet, B. Molaee- Ardekani (INSERM), G. Ruffini (Ed.), S. Dunne, A. Soria- Frisch and D. Whitmer (Starlab), D1.1– Review of state-of-the-art in currents distri- bution and effects, HIVE FP7-FET Open project, 2009 </ref>.<br />
<br />
A forthcoming paper will discuss the optimization of tCS montages from well defined cortical target maps<br />
<ref> Giulio Ruffini, Michael D. Fox, Oscar Ripolles, Pedro Cavaleiro Miranda, Alvaro Pascual-Leone, <br />
Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields, accepted for publication in Neuroimage 2014 </ref><br />
<br />
<br />
The mechanisms underlying the after-effects of tDCS are still the subject of investigation, but in all cases these local changes are brought about by the '''accumulated action of the applied electric field over time''', directly or indirectly. For this reason we focus here on electric field optimization. <br />
<br />
<br />
[[File:principles.png|200px|thumb|left| Interaction of Electric field and neuron through membrane space constant and main fiber axis]]<br />
Moreover, given that that there are strong directional effects in the interaction of electric fields and neurons, i.e., '''neurons are influenced mostly by the component of the electric field parallel to their trajectory'''<br />
<ref>Ranck, J., 1975. Which elements are excited in electrical stimulation of the mammalian central nervous system: a review. Brain Res 98, 417–440.</ref> <br />
<ref>Rattay, F., 1986. Analysis of models for external stimulation of axons. IEEE Transactions on Biomedical Engineering 33, 974–977.</ref><br />
<ref> Rushton, W.A.H., 1927. The effect upon the threshold for nervous excitation of the length of nerve exposed, and the angle between current and nerve. J Physiol 63, 357–77.</ref><br />
<ref> Roth, B.J., 1994. Mechanisms for electrical stimulation of excitable tissue. Crit Rev Biomed Eng 22, 253–305.</ref><br />
<ref>Bikson, M., Inoue, M., Akiyama, H., Deans, J.K., Fox, J.E., Miyakawa, H., Jefferys, J.G., 2004. Effects of uniform extracellular dc electric fields on excitability in rat hippocampal slices in vitro. J Physiol 557, 175–90. </ref><br />
<ref> Fröhlich, F., McCormick, D.A., 2010. Endogenous electric fields may guide neocortical network activity. Neuron 67, 129–143.</ref>, <br />
and that the effects of tDCS depend on its polarity, knowledge about the orientation of the electric field is crucial in predicting the effects of stimulation. The components of the field perpendicular and parallel to the cortical surface are of special importance, since pyramidal cells are mostly aligned perpendicular to the surface, while many cortical interneurons and axonal projections of pyramidal cells tend to align tangentially<br />
<ref> Day, B., Dressler, D., Maertens de Noordhout, A., Marsden, C., Nakashima, K., Rothwell, J., Thompson, P., 1989. Electric and magnetic stimulation of human motor cortex: surface emg and single motor unit responses. J. Physiol 122, 449–473.</ref><br />
<ref> Fox, P.T., Narayana, S., Tandon, N., Sandoval, H., Fox, S.P., Kochunov, P., Lancaster, J.L., 2004. Column-based model of electric field excitation of cerebral cortex. Hum Brain Mapp 22, 1–14.</ref><br />
<ref> Kammer, T., Vorwerg, M., Herrnberger, B., 2007. Anisotropy in the visual cortex investigated by neuronavigated transcranial magnetic stimulation. Neuroimage 36, 313–321.</ref>. Thus, an important element in modeling is to provide the electric field distribution and orientation relative to the grey matter (GM) and white matter (WM) surfaces (the latter might be important to study the possibility of polarizing corticospinal axons, their collaterals and other projection neurons). In order to do this, we work here with a realistic head model derived from structural MRI images [http://www.ncbi.nlm.nih.gov/pubmed/23274187 | Miranda et al. 2013] <ref name="Miranda2013a"> Miranda, P.C., Mekonnen, A., Salvador, R., Ruffini, G., 2013. The electric field in the cortex during transcranial current stimulation. Neuroimage 70, 45–58. </ref> to calculate the tCS electric field components rapidly from arbitrary EEG 10-20 montages. Importantly, this modeling approach allows for fast calculation of electric field components normal and parallel to the GM and WM surfaces.<br />
<br />
= StimViewer = <br />
StimViewer is the software component embedded in [http://www.neuroelectrics.com/enobio/software | '''NIC'''] which is activated when in use with [http://www.neuroelectrics.com/products/starstim/ | '''StarStim''']. StimViewer is a fast simulation engine to produce electric fields in the brain associated with a particular tCS montage and display them on two surfaces: the outer cortex or inner cortex.<br />
<br />
[[File:fem-simus.png|200px|thumb|left| Simulation FEM framework ]]<br />
The electric field calculations were performed using the realistic head model described in [http://www.ncbi.nlm.nih.gov/pubmed/23274187 | Miranda et al. 2013aa] <ref name="Miranda2013a" /> . Briefly, tissue boundaries were derived from MR images (scalp, skull, cerebrospinal fluid (CSF) – including ventricles, Grey Matter and White Matter) and the Finite Element Method was used to calculate the electric potential in the head, subject to the appropriate boundary conditions. Tissues were assumed to be uniform and isotropic and values for their electric conductivity were taken from the literature. <br />
<br />
In order to compute electric fields rapidly, we have made use of the principle of superposition. This states that with appropriate boundary conditions, the solution to a general N-electrode problem can be expressed as a linear combination of ''N-1'' bipolar ones. A fixed reference electrode is first chosen, and then all the bipolar solutions using this electrode are computed. A general solution with an arbitrary number of ''N'' electrodes can then easily be computed. <br />
[[File:StimViewer1.png|200px|thumb|left| Simulation of E fields: time slicing (Potential) ]] <br />
<br />
<br />
Using StimViewer you can display the '''electric Potential V''' and the '''normal''' (i.e., perpendicular) component of the electric field to the cortical surface (E_n, which can be positive or negative). In the convention used here, a positive value for the component of the electric field normal to the cortical surface means the electric field component normal is pointing ''into'' the cortex. According to the literature, such a field would be excitatory. On the other hand, an electric field pointing out of the cortex (negative normal component) would be inhibitory.<br />
<br />
[File:StimViewer3.png|200px|thumb|left| Simulation of E fields: magnitude of tangential component ]] <br />
<br />
You can also display the '''magnitude of the tangential component''' (||E_t||), or the '''total magnitude''' (||E||). <br />
<br />
<br />
[[File:StimViewer2.png|200px|thumb|left| Simulation of E fields: time slicing ]] <br />
<br />
[[File:StimViewer4.png|200px|thumb|left| Simulation of E fields: Multichannel, E field magnitude on cortex ]] <br />
<br />
For time varying protocols (such as tACS), you can also use a '''temporal slider''' to display the fields at different time points. Alternatively you can display the time average of the magnitude of the field, which we call the '''influence map'''.<br />
<br />
= StimWeaver =<br />
StimWeaver is an optimization service created by Neuroelectrics and based on StimViewer technology. It has been designed to create stimulation montages (electrode positions as well as currents) specifically adapted to user-defined targets. <br />
<br />
<!-- There are two ways to optimize a montage with StimWeaver, which we now describe. --><br />
<!-- '''User Optimization''': Using StimWeaver you first define stimulation targets in the cortex (grey matter-CSF or white matter-grey matter interface).--><br />
<!-- Once this is done you can create and multichannel tCS montages and evaluate them using quality matching measures. --><br />
<!-- '''StimWeaver Service''': You can also use StimWeaver to define the optimization problem (i.e., targets) and send it to Neuroelectrics. --><br />
<br />
Our staff will produce a mathematically optimized montage based on your specifications (target map, maximal currents, number of electrodes, etc.). Our optimization software (StimWeaver) carries out a thorough search in the space of electrode locations and currents to produce the best solution for the specified target.<br />
<br />
Please see our recent paper on the subject of '''optimization of montages starting from well-defined cortical target maps''' <ref><br />
[http://www.sciencedirect.com/science/article/pii/S1053811913012068 Giulio Ruffini, Michael D. Fox, Oscar Ripolles, Pedro Cavaleiro Miranda, Alvaro Pascual-Leone, Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields, available online, Dec 15, Neuroimage (2013)]<br />
</ref>.<br />
<br />
'''Contact us at info@neuroelectrics.com for more information.'''<br />
<br />
= References =<br />
<br />
<references/><br />
<br />
= References =<br />
<references /></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Safety&diff=1218Safety2015-04-22T07:16:00Z<p>Guillem: /* References */</p>
<hr />
<div>== Enobio ==<br />
There are no special safety considerations for Enobio. However, for safety reasons, neither [http://neuroelectrics.com/enobio | '''Enobio'''] nor [http://neuroelectrics.com/starstim | '''StarStim'''] will operate while charging. In order to charge your NECBOX device, plug it via the USB port to a computer or power supply, and make sure the power switch of the NECBOX is in OFF position. If it is in the ON position, the device will not charge.<br />
<br />
== StarStim ==<br />
Please note: tCS therapy should be supervised by a trained medical doctor. Modalities other than tDCS (tACS, tRNS) are for research purposes only.<br />
<br />
Starstim is a CE medically certified product. However, it is not FDA approved for clinical use (tDCS, tACS or tRNS aren't approved as of yet) - it is classified as an investigational device under US federal law.<br />
<br />
Built-in safety measures: <br />
Maximal current at an electrode and voltage accross two points is limied (2 mA and 30 V respectively)<br />
Maximal injected current by all electrodes at any given time limited to 4 mA<br />
Continuous impedance check and limited application time (1h) <br />
<br />
There are no studies in the literature describing the effects of direct current treatments on pregnant women, or children below 18 years, or patients with pacemakers, intracranial electrodes, implanted defibrillators, or any other prosthesis. Before applying [http://neuroelectrics.com/starstim | '''StarStim'''], make sure that pacemakers, intracranial electrodes, defibrillators, or any other prosthesis are not implanted in the patient. Otherwise, the application of DC currents could be unsafe.<br />
<br />
For safety, [http://neuroelectrics.com/starstim '''Starstim'''] is limited in the following ways. It will not operate if the contact impedance is above 20 kOhm. It can only provide potential differences across electrode of 30 V to deliver a maximum, at any electrode of (+ or -) 2 mA of current. <br />
<br />
Our software allows for configurable, long, ramp up and ramp down times to maximize user comfort.<br />
<br />
Based on abundant literature, the guideline for clinical use is to keep average current densities in electrodes below 2 mA/35 cm2= 0.06 mA/cm2. Such stimulation current densities are far from the threshold for tissue damage (14.3 mA/cm2) recently indicated for tDCS in an animal model. Typical applications times are of 20 min or less.<br />
<br />
Current densities above 0.06 mA/cm2 (but always well below 14.3 mA/cm^2) are for advanced clinical or research purposes only.<br />
<br />
Stimulation session durations beyond 40 minutes are for research purposes only.<br />
<br />
In addition, electrode positions above cranial foramina and fissures should be avoided because these could increase beyond safety limits the effective current density. <br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] can only be used with specifically designed Neuroelectrics electrodes.<br />
<br />
With sponge electrodes, the use of sodium chloride solution, the regular replacement of the sponge, and the careful inspection of the condition of the skin under the electrode before and after tDCS is recommended.<br />
Observed Adverse Effects include: skin itching, tingling, headache, burning sensation and discomfort. In rare cases, skin lesions have been observed. If skin lesions are observed, the treatment must be suspended and the equipment revised.<br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] components must never be opened or damaged. Before using check that [http://neuroelectrics.com/starstim | '''StarStim'''] components, including electrodes, are undamaged and clean.<br />
<br />
=== Safety Guide ===<br />
The following chart is provided to guide operators, providing safety zones for different electrode current densities. Note this is an updated chart from the 2012 version. The only change is the removal of the "Uncharted Territory" zone. During the last year several groups have been working with our Pi electrodes using up to 2 mA of currents, and no ill effects have been reported. <br />
<br />
[[File:safety2013.png |300px|thumb|left|2012 Safety Chart (update from 2012)]]<br />
<br />
It illustrates the MAX average current density that can be used for mainstream clinical applications, advanced clinical applications, research as a function of electrode size. <br />
<br />
'''Please note: the proposed limits are not based on available negative evidence (i.e., findings of Adverse Effects with higher current densities). Rather, it is a conservative statement based on the limited experience with current densities above 2 mA/35 cm2).'''<br />
<br />
With regards to the use of small electrodes in tCS, it is worthwhile noting that the ratio of current/electrode area (I/A ratio) is not a good indicator of cortical electric field magnitude. More specifically, in Miranda et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758822/ Pedro Cavaleiro Miranda, Paula Faria and Mark Hallett, What does the ratio of injected current to electrode area tell us about current density in the brain during tDCS?, Clin Neurophysiol. Jun 2009; 120(6): 1183–1187.]<br />
</ref>, is is shown that for smaller electrodes, more current than predicted by the I/A ratio was required to achieve a predetermined current density in the brain. <br />
<br />
<br />
In the last few years several studies have employed small electrodes with no ill side effects (e.g., Faria et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pubmed/23123281 Faria P1, Fregni F, Sebastião F, Dias AI, Leal A., Feasibility of focal transcranial DC polarization with simultaneous EEG recording: preliminary assessment in healthy subjects and human epilepsy, Epilepsy Behav. 2012 Nov;25(3):417-25]<br />
</ref>).<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
=== Dosage ===<br />
For the stimulation using starstim, NIC gives an informative value about the dosage of a session. The dosage is the amount of charge that the user receives during the session.<br />
This calculation is done following the equation:<br />
<br />
[[File:Dosage.png |200px|thumb|left|Dosage equation]]<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
== References ==<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Safety&diff=1217Safety2015-04-22T07:15:50Z<p>Guillem: /* References */</p>
<hr />
<div>== Enobio ==<br />
There are no special safety considerations for Enobio. However, for safety reasons, neither [http://neuroelectrics.com/enobio | '''Enobio'''] nor [http://neuroelectrics.com/starstim | '''StarStim'''] will operate while charging. In order to charge your NECBOX device, plug it via the USB port to a computer or power supply, and make sure the power switch of the NECBOX is in OFF position. If it is in the ON position, the device will not charge.<br />
<br />
== StarStim ==<br />
Please note: tCS therapy should be supervised by a trained medical doctor. Modalities other than tDCS (tACS, tRNS) are for research purposes only.<br />
<br />
Starstim is a CE medically certified product. However, it is not FDA approved for clinical use (tDCS, tACS or tRNS aren't approved as of yet) - it is classified as an investigational device under US federal law.<br />
<br />
Built-in safety measures: <br />
Maximal current at an electrode and voltage accross two points is limied (2 mA and 30 V respectively)<br />
Maximal injected current by all electrodes at any given time limited to 4 mA<br />
Continuous impedance check and limited application time (1h) <br />
<br />
There are no studies in the literature describing the effects of direct current treatments on pregnant women, or children below 18 years, or patients with pacemakers, intracranial electrodes, implanted defibrillators, or any other prosthesis. Before applying [http://neuroelectrics.com/starstim | '''StarStim'''], make sure that pacemakers, intracranial electrodes, defibrillators, or any other prosthesis are not implanted in the patient. Otherwise, the application of DC currents could be unsafe.<br />
<br />
For safety, [http://neuroelectrics.com/starstim '''Starstim'''] is limited in the following ways. It will not operate if the contact impedance is above 20 kOhm. It can only provide potential differences across electrode of 30 V to deliver a maximum, at any electrode of (+ or -) 2 mA of current. <br />
<br />
Our software allows for configurable, long, ramp up and ramp down times to maximize user comfort.<br />
<br />
Based on abundant literature, the guideline for clinical use is to keep average current densities in electrodes below 2 mA/35 cm2= 0.06 mA/cm2. Such stimulation current densities are far from the threshold for tissue damage (14.3 mA/cm2) recently indicated for tDCS in an animal model. Typical applications times are of 20 min or less.<br />
<br />
Current densities above 0.06 mA/cm2 (but always well below 14.3 mA/cm^2) are for advanced clinical or research purposes only.<br />
<br />
Stimulation session durations beyond 40 minutes are for research purposes only.<br />
<br />
In addition, electrode positions above cranial foramina and fissures should be avoided because these could increase beyond safety limits the effective current density. <br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] can only be used with specifically designed Neuroelectrics electrodes.<br />
<br />
With sponge electrodes, the use of sodium chloride solution, the regular replacement of the sponge, and the careful inspection of the condition of the skin under the electrode before and after tDCS is recommended.<br />
Observed Adverse Effects include: skin itching, tingling, headache, burning sensation and discomfort. In rare cases, skin lesions have been observed. If skin lesions are observed, the treatment must be suspended and the equipment revised.<br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] components must never be opened or damaged. Before using check that [http://neuroelectrics.com/starstim | '''StarStim'''] components, including electrodes, are undamaged and clean.<br />
<br />
=== Safety Guide ===<br />
The following chart is provided to guide operators, providing safety zones for different electrode current densities. Note this is an updated chart from the 2012 version. The only change is the removal of the "Uncharted Territory" zone. During the last year several groups have been working with our Pi electrodes using up to 2 mA of currents, and no ill effects have been reported. <br />
<br />
[[File:safety2013.png |300px|thumb|left|2012 Safety Chart (update from 2012)]]<br />
<br />
It illustrates the MAX average current density that can be used for mainstream clinical applications, advanced clinical applications, research as a function of electrode size. <br />
<br />
'''Please note: the proposed limits are not based on available negative evidence (i.e., findings of Adverse Effects with higher current densities). Rather, it is a conservative statement based on the limited experience with current densities above 2 mA/35 cm2).'''<br />
<br />
With regards to the use of small electrodes in tCS, it is worthwhile noting that the ratio of current/electrode area (I/A ratio) is not a good indicator of cortical electric field magnitude. More specifically, in Miranda et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758822/ Pedro Cavaleiro Miranda, Paula Faria and Mark Hallett, What does the ratio of injected current to electrode area tell us about current density in the brain during tDCS?, Clin Neurophysiol. Jun 2009; 120(6): 1183–1187.]<br />
</ref>, is is shown that for smaller electrodes, more current than predicted by the I/A ratio was required to achieve a predetermined current density in the brain. <br />
<br />
<br />
In the last few years several studies have employed small electrodes with no ill side effects (e.g., Faria et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pubmed/23123281 Faria P1, Fregni F, Sebastião F, Dias AI, Leal A., Feasibility of focal transcranial DC polarization with simultaneous EEG recording: preliminary assessment in healthy subjects and human epilepsy, Epilepsy Behav. 2012 Nov;25(3):417-25]<br />
</ref>).<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
=== Dosage ===<br />
For the stimulation using starstim, NIC gives an informative value about the dosage of a session. The dosage is the amount of charge that the user receives during the session.<br />
This calculation is done following the equation:<br />
<br />
[[File:Dosage.png |200px|thumb|left|Dosage equation]]<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
== References ==<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Safety&diff=1216Safety2015-04-22T07:15:41Z<p>Guillem: /* StarStim */</p>
<hr />
<div>== Enobio ==<br />
There are no special safety considerations for Enobio. However, for safety reasons, neither [http://neuroelectrics.com/enobio | '''Enobio'''] nor [http://neuroelectrics.com/starstim | '''StarStim'''] will operate while charging. In order to charge your NECBOX device, plug it via the USB port to a computer or power supply, and make sure the power switch of the NECBOX is in OFF position. If it is in the ON position, the device will not charge.<br />
<br />
== StarStim ==<br />
Please note: tCS therapy should be supervised by a trained medical doctor. Modalities other than tDCS (tACS, tRNS) are for research purposes only.<br />
<br />
Starstim is a CE medically certified product. However, it is not FDA approved for clinical use (tDCS, tACS or tRNS aren't approved as of yet) - it is classified as an investigational device under US federal law.<br />
<br />
Built-in safety measures: <br />
Maximal current at an electrode and voltage accross two points is limied (2 mA and 30 V respectively)<br />
Maximal injected current by all electrodes at any given time limited to 4 mA<br />
Continuous impedance check and limited application time (1h) <br />
<br />
There are no studies in the literature describing the effects of direct current treatments on pregnant women, or children below 18 years, or patients with pacemakers, intracranial electrodes, implanted defibrillators, or any other prosthesis. Before applying [http://neuroelectrics.com/starstim | '''StarStim'''], make sure that pacemakers, intracranial electrodes, defibrillators, or any other prosthesis are not implanted in the patient. Otherwise, the application of DC currents could be unsafe.<br />
<br />
For safety, [http://neuroelectrics.com/starstim '''Starstim'''] is limited in the following ways. It will not operate if the contact impedance is above 20 kOhm. It can only provide potential differences across electrode of 30 V to deliver a maximum, at any electrode of (+ or -) 2 mA of current. <br />
<br />
Our software allows for configurable, long, ramp up and ramp down times to maximize user comfort.<br />
<br />
Based on abundant literature, the guideline for clinical use is to keep average current densities in electrodes below 2 mA/35 cm2= 0.06 mA/cm2. Such stimulation current densities are far from the threshold for tissue damage (14.3 mA/cm2) recently indicated for tDCS in an animal model. Typical applications times are of 20 min or less.<br />
<br />
Current densities above 0.06 mA/cm2 (but always well below 14.3 mA/cm^2) are for advanced clinical or research purposes only.<br />
<br />
Stimulation session durations beyond 40 minutes are for research purposes only.<br />
<br />
In addition, electrode positions above cranial foramina and fissures should be avoided because these could increase beyond safety limits the effective current density. <br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] can only be used with specifically designed Neuroelectrics electrodes.<br />
<br />
With sponge electrodes, the use of sodium chloride solution, the regular replacement of the sponge, and the careful inspection of the condition of the skin under the electrode before and after tDCS is recommended.<br />
Observed Adverse Effects include: skin itching, tingling, headache, burning sensation and discomfort. In rare cases, skin lesions have been observed. If skin lesions are observed, the treatment must be suspended and the equipment revised.<br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] components must never be opened or damaged. Before using check that [http://neuroelectrics.com/starstim | '''StarStim'''] components, including electrodes, are undamaged and clean.<br />
<br />
=== Safety Guide ===<br />
The following chart is provided to guide operators, providing safety zones for different electrode current densities. Note this is an updated chart from the 2012 version. The only change is the removal of the "Uncharted Territory" zone. During the last year several groups have been working with our Pi electrodes using up to 2 mA of currents, and no ill effects have been reported. <br />
<br />
[[File:safety2013.png |300px|thumb|left|2012 Safety Chart (update from 2012)]]<br />
<br />
It illustrates the MAX average current density that can be used for mainstream clinical applications, advanced clinical applications, research as a function of electrode size. <br />
<br />
'''Please note: the proposed limits are not based on available negative evidence (i.e., findings of Adverse Effects with higher current densities). Rather, it is a conservative statement based on the limited experience with current densities above 2 mA/35 cm2).'''<br />
<br />
With regards to the use of small electrodes in tCS, it is worthwhile noting that the ratio of current/electrode area (I/A ratio) is not a good indicator of cortical electric field magnitude. More specifically, in Miranda et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758822/ Pedro Cavaleiro Miranda, Paula Faria and Mark Hallett, What does the ratio of injected current to electrode area tell us about current density in the brain during tDCS?, Clin Neurophysiol. Jun 2009; 120(6): 1183–1187.]<br />
</ref>, is is shown that for smaller electrodes, more current than predicted by the I/A ratio was required to achieve a predetermined current density in the brain. <br />
<br />
<br />
In the last few years several studies have employed small electrodes with no ill side effects (e.g., Faria et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pubmed/23123281 Faria P1, Fregni F, Sebastião F, Dias AI, Leal A., Feasibility of focal transcranial DC polarization with simultaneous EEG recording: preliminary assessment in healthy subjects and human epilepsy, Epilepsy Behav. 2012 Nov;25(3):417-25]<br />
</ref>).<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
=== Dosage ===<br />
For the stimulation using starstim, NIC gives an informative value about the dosage of a session. The dosage is the amount of charge that the user receives during the session.<br />
This calculation is done following the equation:<br />
<br />
[[File:Dosage.png |200px|thumb|left|Dosage equation]]<br />
<br />
== References ==<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Safety&diff=1215Safety2015-04-22T07:15:18Z<p>Guillem: /* StarStim */</p>
<hr />
<div>== Enobio ==<br />
There are no special safety considerations for Enobio. However, for safety reasons, neither [http://neuroelectrics.com/enobio | '''Enobio'''] nor [http://neuroelectrics.com/starstim | '''StarStim'''] will operate while charging. In order to charge your NECBOX device, plug it via the USB port to a computer or power supply, and make sure the power switch of the NECBOX is in OFF position. If it is in the ON position, the device will not charge.<br />
<br />
== StarStim ==<br />
Please note: tCS therapy should be supervised by a trained medical doctor. Modalities other than tDCS (tACS, tRNS) are for research purposes only.<br />
<br />
Starstim is a CE medically certified product. However, it is not FDA approved for clinical use (tDCS, tACS or tRNS aren't approved as of yet) - it is classified as an investigational device under US federal law.<br />
<br />
Built-in safety measures: <br />
Maximal current at an electrode and voltage accross two points is limied (2 mA and 30 V respectively)<br />
Maximal injected current by all electrodes at any given time limited to 4 mA<br />
Continuous impedance check and limited application time (1h) <br />
<br />
There are no studies in the literature describing the effects of direct current treatments on pregnant women, or children below 18 years, or patients with pacemakers, intracranial electrodes, implanted defibrillators, or any other prosthesis. Before applying [http://neuroelectrics.com/starstim | '''StarStim'''], make sure that pacemakers, intracranial electrodes, defibrillators, or any other prosthesis are not implanted in the patient. Otherwise, the application of DC currents could be unsafe.<br />
<br />
For safety, [http://neuroelectrics.com/starstim '''Starstim'''] is limited in the following ways. It will not operate if the contact impedance is above 20 kOhm. It can only provide potential differences across electrode of 30 V to deliver a maximum, at any electrode of (+ or -) 2 mA of current. <br />
<br />
Our software allows for configurable, long, ramp up and ramp down times to maximize user comfort.<br />
<br />
Based on abundant literature, the guideline for clinical use is to keep average current densities in electrodes below 2 mA/35 cm2= 0.06 mA/cm2. Such stimulation current densities are far from the threshold for tissue damage (14.3 mA/cm2) recently indicated for tDCS in an animal model. Typical applications times are of 20 min or less.<br />
<br />
Current densities above 0.06 mA/cm2 (but always well below 14.3 mA/cm^2) are for advanced clinical or research purposes only.<br />
<br />
Stimulation session durations beyond 40 minutes are for research purposes only.<br />
<br />
In addition, electrode positions above cranial foramina and fissures should be avoided because these could increase beyond safety limits the effective current density. <br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] can only be used with specifically designed Neuroelectrics electrodes.<br />
<br />
With sponge electrodes, the use of sodium chloride solution, the regular replacement of the sponge, and the careful inspection of the condition of the skin under the electrode before and after tDCS is recommended.<br />
Observed Adverse Effects include: skin itching, tingling, headache, burning sensation and discomfort. In rare cases, skin lesions have been observed. If skin lesions are observed, the treatment must be suspended and the equipment revised.<br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] components must never be opened or damaged. Before using check that [http://neuroelectrics.com/starstim | '''StarStim'''] components, including electrodes, are undamaged and clean.<br />
<br />
=== Safety Guide ===<br />
The following chart is provided to guide operators, providing safety zones for different electrode current densities. Note this is an updated chart from the 2012 version. The only change is the removal of the "Uncharted Territory" zone. During the last year several groups have been working with our Pi electrodes using up to 2 mA of currents, and no ill effects have been reported. <br />
<br />
[[File:safety2013.png |300px|thumb|left|2012 Safety Chart (update from 2012)]]<br />
<br />
It illustrates the MAX average current density that can be used for mainstream clinical applications, advanced clinical applications, research as a function of electrode size. <br />
<br />
'''Please note: the proposed limits are not based on available negative evidence (i.e., findings of Adverse Effects with higher current densities). Rather, it is a conservative statement based on the limited experience with current densities above 2 mA/35 cm2).'''<br />
<br />
With regards to the use of small electrodes in tCS, it is worthwhile noting that the ratio of current/electrode area (I/A ratio) is not a good indicator of cortical electric field magnitude. More specifically, in Miranda et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758822/ Pedro Cavaleiro Miranda, Paula Faria and Mark Hallett, What does the ratio of injected current to electrode area tell us about current density in the brain during tDCS?, Clin Neurophysiol. Jun 2009; 120(6): 1183–1187.]<br />
</ref>, is is shown that for smaller electrodes, more current than predicted by the I/A ratio was required to achieve a predetermined current density in the brain. <br />
<br />
<br />
In the last few years several studies have employed small electrodes with no ill side effects (e.g., Faria et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pubmed/23123281 Faria P1, Fregni F, Sebastião F, Dias AI, Leal A., Feasibility of focal transcranial DC polarization with simultaneous EEG recording: preliminary assessment in healthy subjects and human epilepsy, Epilepsy Behav. 2012 Nov;25(3):417-25]<br />
</ref>).<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
=== Dosage ===<br />
For the stimulation using starstim, NIC gives an informative value about the dosage of a session. The dosage is the amount of charge that the user receives during the session.<br />
This calculation is done following the equation:<br />
<br />
[[File:Dosage.png |200px|thumb|left|Dosage equation]]<br />
<br />
== References ==<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Safety&diff=1214Safety2015-04-22T07:15:09Z<p>Guillem: /* StarStim */</p>
<hr />
<div>== Enobio ==<br />
There are no special safety considerations for Enobio. However, for safety reasons, neither [http://neuroelectrics.com/enobio | '''Enobio'''] nor [http://neuroelectrics.com/starstim | '''StarStim'''] will operate while charging. In order to charge your NECBOX device, plug it via the USB port to a computer or power supply, and make sure the power switch of the NECBOX is in OFF position. If it is in the ON position, the device will not charge.<br />
<br />
== StarStim ==<br />
Please note: tCS therapy should be supervised by a trained medical doctor. Modalities other than tDCS (tACS, tRNS) are for research purposes only.<br />
<br />
Starstim is a CE medically certified product. However, it is not FDA approved for clinical use (tDCS, tACS or tRNS aren't approved as of yet) - it is classified as an investigational device under US federal law.<br />
<br />
Built-in safety measures: <br />
Maximal current at an electrode and voltage accross two points is limied (2 mA and 30 V respectively)<br />
Maximal injected current by all electrodes at any given time limited to 4 mA<br />
Continuous impedance check and limited application time (1h) <br />
<br />
There are no studies in the literature describing the effects of direct current treatments on pregnant women, or children below 18 years, or patients with pacemakers, intracranial electrodes, implanted defibrillators, or any other prosthesis. Before applying [http://neuroelectrics.com/starstim | '''StarStim'''], make sure that pacemakers, intracranial electrodes, defibrillators, or any other prosthesis are not implanted in the patient. Otherwise, the application of DC currents could be unsafe.<br />
<br />
For safety, [http://neuroelectrics.com/starstim '''Starstim'''] is limited in the following ways. It will not operate if the contact impedance is above 20 kOhm. It can only provide potential differences across electrode of 30 V to deliver a maximum, at any electrode of (+ or -) 2 mA of current. <br />
<br />
Our software allows for configurable, long, ramp up and ramp down times to maximize user comfort.<br />
<br />
Based on abundant literature, the guideline for clinical use is to keep average current densities in electrodes below 2 mA/35 cm2= 0.06 mA/cm2. Such stimulation current densities are far from the threshold for tissue damage (14.3 mA/cm2) recently indicated for tDCS in an animal model. Typical applications times are of 20 min or less.<br />
<br />
Current densities above 0.06 mA/cm2 (but always well below 14.3 mA/cm^2) are for advanced clinical or research purposes only.<br />
<br />
Stimulation session durations beyond 40 minutes are for research purposes only.<br />
<br />
In addition, electrode positions above cranial foramina and fissures should be avoided because these could increase beyond safety limits the effective current density. <br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] can only be used with specifically designed Neuroelectrics electrodes.<br />
<br />
With sponge electrodes, the use of sodium chloride solution, the regular replacement of the sponge, and the careful inspection of the condition of the skin under the electrode before and after tDCS is recommended.<br />
Observed Adverse Effects include: skin itching, tingling, headache, burning sensation and discomfort. In rare cases, skin lesions have been observed. If skin lesions are observed, the treatment must be suspended and the equipment revised.<br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] components must never be opened or damaged. Before using check that [http://neuroelectrics.com/starstim | '''StarStim'''] components, including electrodes, are undamaged and clean.<br />
<br />
=== Safety Guide ===<br />
The following chart is provided to guide operators, providing safety zones for different electrode current densities. Note this is an updated chart from the 2012 version. The only change is the removal of the "Uncharted Territory" zone. During the last year several groups have been working with our Pi electrodes using up to 2 mA of currents, and no ill effects have been reported. <br />
<br />
[[File:safety2013.png |300px|thumb|left|2012 Safety Chart (update from 2012)]]<br />
<br />
It illustrates the MAX average current density that can be used for mainstream clinical applications, advanced clinical applications, research as a function of electrode size. <br />
<br />
'''Please note: the proposed limits are not based on available negative evidence (i.e., findings of Adverse Effects with higher current densities). Rather, it is a conservative statement based on the limited experience with current densities above 2 mA/35 cm2).'''<br />
<br />
With regards to the use of small electrodes in tCS, it is worthwhile noting that the ratio of current/electrode area (I/A ratio) is not a good indicator of cortical electric field magnitude. More specifically, in Miranda et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758822/ Pedro Cavaleiro Miranda, Paula Faria and Mark Hallett, What does the ratio of injected current to electrode area tell us about current density in the brain during tDCS?, Clin Neurophysiol. Jun 2009; 120(6): 1183–1187.]<br />
</ref>, is is shown that for smaller electrodes, more current than predicted by the I/A ratio was required to achieve a predetermined current density in the brain. <br />
<br />
<br />
In the last few years several studies have employed small electrodes with no ill side effects (e.g., Faria et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pubmed/23123281 Faria P1, Fregni F, Sebastião F, Dias AI, Leal A., Feasibility of focal transcranial DC polarization with simultaneous EEG recording: preliminary assessment in healthy subjects and human epilepsy, Epilepsy Behav. 2012 Nov;25(3):417-25]<br />
</ref>).<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
=== Dosage ===<br />
For the stimulation using starstim, NIC gives an informative value about the dosage of a session. The dosage is the amount of charge that the user receives during the session.<br />
This calculation is done following the equation:<br />
<br />
[[File:Dosage.png |200px|thumb|left|Dosage equation]]<br />
<br />
== References ==<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Safety&diff=1213Safety2015-04-22T07:14:59Z<p>Guillem: /* StarStim */</p>
<hr />
<div>== Enobio ==<br />
There are no special safety considerations for Enobio. However, for safety reasons, neither [http://neuroelectrics.com/enobio | '''Enobio'''] nor [http://neuroelectrics.com/starstim | '''StarStim'''] will operate while charging. In order to charge your NECBOX device, plug it via the USB port to a computer or power supply, and make sure the power switch of the NECBOX is in OFF position. If it is in the ON position, the device will not charge.<br />
<br />
== StarStim ==<br />
Please note: tCS therapy should be supervised by a trained medical doctor. Modalities other than tDCS (tACS, tRNS) are for research purposes only.<br />
<br />
Starstim is a CE medically certified product. However, it is not FDA approved for clinical use (tDCS, tACS or tRNS aren't approved as of yet) - it is classified as an investigational device under US federal law.<br />
<br />
Built-in safety measures: <br />
Maximal current at an electrode and voltage accross two points is limied (2 mA and 30 V respectively)<br />
Maximal injected current by all electrodes at any given time limited to 4 mA<br />
Continuous impedance check and limited application time (1h) <br />
<br />
There are no studies in the literature describing the effects of direct current treatments on pregnant women, or children below 18 years, or patients with pacemakers, intracranial electrodes, implanted defibrillators, or any other prosthesis. Before applying [http://neuroelectrics.com/starstim | '''StarStim'''], make sure that pacemakers, intracranial electrodes, defibrillators, or any other prosthesis are not implanted in the patient. Otherwise, the application of DC currents could be unsafe.<br />
<br />
For safety, [http://neuroelectrics.com/starstim '''Starstim'''] is limited in the following ways. It will not operate if the contact impedance is above 20 kOhm. It can only provide potential differences across electrode of 30 V to deliver a maximum, at any electrode of (+ or -) 2 mA of current. <br />
<br />
Our software allows for configurable, long, ramp up and ramp down times to maximize user comfort.<br />
<br />
Based on abundant literature, the guideline for clinical use is to keep average current densities in electrodes below 2 mA/35 cm2= 0.06 mA/cm2. Such stimulation current densities are far from the threshold for tissue damage (14.3 mA/cm2) recently indicated for tDCS in an animal model. Typical applications times are of 20 min or less.<br />
<br />
Current densities above 0.06 mA/cm2 (but always well below 14.3 mA/cm^2) are for advanced clinical or research purposes only.<br />
<br />
Stimulation session durations beyond 40 minutes are for research purposes only.<br />
<br />
In addition, electrode positions above cranial foramina and fissures should be avoided because these could increase beyond safety limits the effective current density. <br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] can only be used with specifically designed Neuroelectrics electrodes.<br />
<br />
With sponge electrodes, the use of sodium chloride solution, the regular replacement of the sponge, and the careful inspection of the condition of the skin under the electrode before and after tDCS is recommended.<br />
Observed Adverse Effects include: skin itching, tingling, headache, burning sensation and discomfort. In rare cases, skin lesions have been observed. If skin lesions are observed, the treatment must be suspended and the equipment revised.<br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] components must never be opened or damaged. Before using check that [http://neuroelectrics.com/starstim | '''StarStim'''] components, including electrodes, are undamaged and clean.<br />
<br />
=== Safety Guide ===<br />
The following chart is provided to guide operators, providing safety zones for different electrode current densities. Note this is an updated chart from the 2012 version. The only change is the removal of the "Uncharted Territory" zone. During the last year several groups have been working with our Pi electrodes using up to 2 mA of currents, and no ill effects have been reported. <br />
<br />
[[File:safety2013.png |300px|thumb|left|2012 Safety Chart (update from 2012)]]<br />
<br />
It illustrates the MAX average current density that can be used for mainstream clinical applications, advanced clinical applications, research as a function of electrode size. <br />
<br />
'''Please note: the proposed limits are not based on available negative evidence (i.e., findings of Adverse Effects with higher current densities). Rather, it is a conservative statement based on the limited experience with current densities above 2 mA/35 cm2).'''<br />
<br />
With regards to the use of small electrodes in tCS, it is worthwhile noting that the ratio of current/electrode area (I/A ratio) is not a good indicator of cortical electric field magnitude. More specifically, in Miranda et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758822/ Pedro Cavaleiro Miranda, Paula Faria and Mark Hallett, What does the ratio of injected current to electrode area tell us about current density in the brain during tDCS?, Clin Neurophysiol. Jun 2009; 120(6): 1183–1187.]<br />
</ref>, is is shown that for smaller electrodes, more current than predicted by the I/A ratio was required to achieve a predetermined current density in the brain. <br />
<br />
<br />
In the last few years several studies have employed small electrodes with no ill side effects (e.g., Faria et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pubmed/23123281 Faria P1, Fregni F, Sebastião F, Dias AI, Leal A., Feasibility of focal transcranial DC polarization with simultaneous EEG recording: preliminary assessment in healthy subjects and human epilepsy, Epilepsy Behav. 2012 Nov;25(3):417-25]<br />
</ref>).<br />
<br />
<br />
<br />
<br />
<br />
<br />
=== Dosage ===<br />
For the stimulation using starstim, NIC gives an informative value about the dosage of a session. The dosage is the amount of charge that the user receives during the session.<br />
This calculation is done following the equation:<br />
<br />
[[File:Dosage.png |200px|thumb|left|Dosage equation]]<br />
<br />
== References ==<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Safety&diff=1212Safety2015-04-22T07:14:37Z<p>Guillem: /* Safety Guide */</p>
<hr />
<div>== Enobio ==<br />
There are no special safety considerations for Enobio. However, for safety reasons, neither [http://neuroelectrics.com/enobio | '''Enobio'''] nor [http://neuroelectrics.com/starstim | '''StarStim'''] will operate while charging. In order to charge your NECBOX device, plug it via the USB port to a computer or power supply, and make sure the power switch of the NECBOX is in OFF position. If it is in the ON position, the device will not charge.<br />
<br />
== StarStim ==<br />
Please note: tCS therapy should be supervised by a trained medical doctor. Modalities other than tDCS (tACS, tRNS) are for research purposes only.<br />
<br />
Starstim is a CE medically certified product. However, it is not FDA approved for clinical use (tDCS, tACS or tRNS aren't approved as of yet) - it is classified as an investigational device under US federal law.<br />
<br />
Built-in safety measures: <br />
Maximal current at an electrode and voltage accross two points is limied (2 mA and 30 V respectively)<br />
Maximal injected current by all electrodes at any given time limited to 4 mA<br />
Continuous impedance check and limited application time (1h) <br />
<br />
There are no studies in the literature describing the effects of direct current treatments on pregnant women, or children below 18 years, or patients with pacemakers, intracranial electrodes, implanted defibrillators, or any other prosthesis. Before applying [http://neuroelectrics.com/starstim | '''StarStim'''], make sure that pacemakers, intracranial electrodes, defibrillators, or any other prosthesis are not implanted in the patient. Otherwise, the application of DC currents could be unsafe.<br />
<br />
For safety, [http://neuroelectrics.com/starstim '''Starstim'''] is limited in the following ways. It will not operate if the contact impedance is above 20 kOhm. It can only provide potential differences across electrode of 30 V to deliver a maximum, at any electrode of (+ or -) 2 mA of current. <br />
<br />
Our software allows for configurable, long, ramp up and ramp down times to maximize user comfort.<br />
<br />
Based on abundant literature, the guideline for clinical use is to keep average current densities in electrodes below 2 mA/35 cm2= 0.06 mA/cm2. Such stimulation current densities are far from the threshold for tissue damage (14.3 mA/cm2) recently indicated for tDCS in an animal model. Typical applications times are of 20 min or less.<br />
<br />
Current densities above 0.06 mA/cm2 (but always well below 14.3 mA/cm^2) are for advanced clinical or research purposes only.<br />
<br />
Stimulation session durations beyond 40 minutes are for research purposes only.<br />
<br />
In addition, electrode positions above cranial foramina and fissures should be avoided because these could increase beyond safety limits the effective current density. <br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] can only be used with specifically designed Neuroelectrics electrodes.<br />
<br />
With sponge electrodes, the use of sodium chloride solution, the regular replacement of the sponge, and the careful inspection of the condition of the skin under the electrode before and after tDCS is recommended.<br />
Observed Adverse Effects include: skin itching, tingling, headache, burning sensation and discomfort. In rare cases, skin lesions have been observed. If skin lesions are observed, the treatment must be suspended and the equipment revised.<br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] components must never be opened or damaged. Before using check that [http://neuroelectrics.com/starstim | '''StarStim'''] components, including electrodes, are undamaged and clean.<br />
<br />
=== Safety Guide ===<br />
The following chart is provided to guide operators, providing safety zones for different electrode current densities. Note this is an updated chart from the 2012 version. The only change is the removal of the "Uncharted Territory" zone. During the last year several groups have been working with our Pi electrodes using up to 2 mA of currents, and no ill effects have been reported. <br />
<br />
[[File:safety2013.png |300px|thumb|left|2012 Safety Chart (update from 2012)]]<br />
<br />
It illustrates the MAX average current density that can be used for mainstream clinical applications, advanced clinical applications, research as a function of electrode size. <br />
<br />
'''Please note: the proposed limits are not based on available negative evidence (i.e., findings of Adverse Effects with higher current densities). Rather, it is a conservative statement based on the limited experience with current densities above 2 mA/35 cm2).'''<br />
<br />
With regards to the use of small electrodes in tCS, it is worthwhile noting that the ratio of current/electrode area (I/A ratio) is not a good indicator of cortical electric field magnitude. More specifically, in Miranda et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758822/ Pedro Cavaleiro Miranda, Paula Faria and Mark Hallett, What does the ratio of injected current to electrode area tell us about current density in the brain during tDCS?, Clin Neurophysiol. Jun 2009; 120(6): 1183–1187.]<br />
</ref>, is is shown that for smaller electrodes, more current than predicted by the I/A ratio was required to achieve a predetermined current density in the brain. <br />
<br />
<br />
In the last few years several studies have employed small electrodes with no ill side effects (e.g., Faria et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pubmed/23123281 Faria P1, Fregni F, Sebastião F, Dias AI, Leal A., Feasibility of focal transcranial DC polarization with simultaneous EEG recording: preliminary assessment in healthy subjects and human epilepsy, Epilepsy Behav. 2012 Nov;25(3):417-25]<br />
</ref>).<br />
<br />
=== Dosage ===<br />
For the stimulation using starstim, NIC gives an informative value about the dosage of a session. The dosage is the amount of charge that the user receives during the session.<br />
This calculation is done following the equation:<br />
<br />
[[File:Dosage.png |200px|thumb|left|Dosage equation]]<br />
<br />
== References ==<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Safety&diff=1211Safety2015-04-22T07:14:14Z<p>Guillem: /* StarStim */</p>
<hr />
<div>== Enobio ==<br />
There are no special safety considerations for Enobio. However, for safety reasons, neither [http://neuroelectrics.com/enobio | '''Enobio'''] nor [http://neuroelectrics.com/starstim | '''StarStim'''] will operate while charging. In order to charge your NECBOX device, plug it via the USB port to a computer or power supply, and make sure the power switch of the NECBOX is in OFF position. If it is in the ON position, the device will not charge.<br />
<br />
== StarStim ==<br />
Please note: tCS therapy should be supervised by a trained medical doctor. Modalities other than tDCS (tACS, tRNS) are for research purposes only.<br />
<br />
Starstim is a CE medically certified product. However, it is not FDA approved for clinical use (tDCS, tACS or tRNS aren't approved as of yet) - it is classified as an investigational device under US federal law.<br />
<br />
Built-in safety measures: <br />
Maximal current at an electrode and voltage accross two points is limied (2 mA and 30 V respectively)<br />
Maximal injected current by all electrodes at any given time limited to 4 mA<br />
Continuous impedance check and limited application time (1h) <br />
<br />
There are no studies in the literature describing the effects of direct current treatments on pregnant women, or children below 18 years, or patients with pacemakers, intracranial electrodes, implanted defibrillators, or any other prosthesis. Before applying [http://neuroelectrics.com/starstim | '''StarStim'''], make sure that pacemakers, intracranial electrodes, defibrillators, or any other prosthesis are not implanted in the patient. Otherwise, the application of DC currents could be unsafe.<br />
<br />
For safety, [http://neuroelectrics.com/starstim '''Starstim'''] is limited in the following ways. It will not operate if the contact impedance is above 20 kOhm. It can only provide potential differences across electrode of 30 V to deliver a maximum, at any electrode of (+ or -) 2 mA of current. <br />
<br />
Our software allows for configurable, long, ramp up and ramp down times to maximize user comfort.<br />
<br />
Based on abundant literature, the guideline for clinical use is to keep average current densities in electrodes below 2 mA/35 cm2= 0.06 mA/cm2. Such stimulation current densities are far from the threshold for tissue damage (14.3 mA/cm2) recently indicated for tDCS in an animal model. Typical applications times are of 20 min or less.<br />
<br />
Current densities above 0.06 mA/cm2 (but always well below 14.3 mA/cm^2) are for advanced clinical or research purposes only.<br />
<br />
Stimulation session durations beyond 40 minutes are for research purposes only.<br />
<br />
In addition, electrode positions above cranial foramina and fissures should be avoided because these could increase beyond safety limits the effective current density. <br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] can only be used with specifically designed Neuroelectrics electrodes.<br />
<br />
With sponge electrodes, the use of sodium chloride solution, the regular replacement of the sponge, and the careful inspection of the condition of the skin under the electrode before and after tDCS is recommended.<br />
Observed Adverse Effects include: skin itching, tingling, headache, burning sensation and discomfort. In rare cases, skin lesions have been observed. If skin lesions are observed, the treatment must be suspended and the equipment revised.<br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] components must never be opened or damaged. Before using check that [http://neuroelectrics.com/starstim | '''StarStim'''] components, including electrodes, are undamaged and clean.<br />
<br />
=== Safety Guide ===<br />
The following chart is provided to guide operators, providing safety zones for different electrode current densities. Note this is an updated chart from the 2012 version. The only change is the removal of the "Uncharted Territory" zone. During the last year several groups have been working with our Pi electrodes using up to 2 mA of currents, and no ill effects have been reported. <br />
<br />
[[File:safety2013.png |400px|thumb|left|2012 Safety Chart (update from 2012)]]<br />
<br />
[[File:tdcs safety1.png|100px|thumb|left|Safety Chart 2012]]<br />
<br />
It illustrates the MAX average current density that can be used for mainstream clinical applications, advanced clinical applications, research as a function of electrode size. <br />
<br />
'''Please note: the proposed limits are not based on available negative evidence (i.e., findings of Adverse Effects with higher current densities). Rather, it is a conservative statement based on the limited experience with current densities above 2 mA/35 cm2).'''<br />
<br />
With regards to the use of small electrodes in tCS, it is worthwhile noting that the ratio of current/electrode area (I/A ratio) is not a good indicator of cortical electric field magnitude. More specifically, in Miranda et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758822/ Pedro Cavaleiro Miranda, Paula Faria and Mark Hallett, What does the ratio of injected current to electrode area tell us about current density in the brain during tDCS?, Clin Neurophysiol. Jun 2009; 120(6): 1183–1187.]<br />
</ref>, is is shown that for smaller electrodes, more current than predicted by the I/A ratio was required to achieve a predetermined current density in the brain. <br />
<br />
<br />
In the last few years several studies have employed small electrodes with no ill side effects (e.g., Faria et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pubmed/23123281 Faria P1, Fregni F, Sebastião F, Dias AI, Leal A., Feasibility of focal transcranial DC polarization with simultaneous EEG recording: preliminary assessment in healthy subjects and human epilepsy, Epilepsy Behav. 2012 Nov;25(3):417-25]<br />
</ref>).<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
=== Dosage ===<br />
For the stimulation using starstim, NIC gives an informative value about the dosage of a session. The dosage is the amount of charge that the user receives during the session.<br />
This calculation is done following the equation:<br />
<br />
[[File:Dosage.png |200px|thumb|left|Dosage equation]]<br />
<br />
== References ==<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Safety&diff=1210Safety2015-04-22T07:13:48Z<p>Guillem: /* StarStim */</p>
<hr />
<div>== Enobio ==<br />
There are no special safety considerations for Enobio. However, for safety reasons, neither [http://neuroelectrics.com/enobio | '''Enobio'''] nor [http://neuroelectrics.com/starstim | '''StarStim'''] will operate while charging. In order to charge your NECBOX device, plug it via the USB port to a computer or power supply, and make sure the power switch of the NECBOX is in OFF position. If it is in the ON position, the device will not charge.<br />
<br />
== StarStim ==<br />
Please note: tCS therapy should be supervised by a trained medical doctor. Modalities other than tDCS (tACS, tRNS) are for research purposes only.<br />
<br />
Starstim is a CE medically certified product. However, it is not FDA approved for clinical use (tDCS, tACS or tRNS aren't approved as of yet) - it is classified as an investigational device under US federal law.<br />
<br />
Built-in safety measures: <br />
Maximal current at an electrode and voltage accross two points is limied (2 mA and 30 V respectively)<br />
Maximal injected current by all electrodes at any given time limited to 4 mA<br />
Continuous impedance check and limited application time (1h) <br />
<br />
There are no studies in the literature describing the effects of direct current treatments on pregnant women, or children below 18 years, or patients with pacemakers, intracranial electrodes, implanted defibrillators, or any other prosthesis. Before applying [http://neuroelectrics.com/starstim | '''StarStim'''], make sure that pacemakers, intracranial electrodes, defibrillators, or any other prosthesis are not implanted in the patient. Otherwise, the application of DC currents could be unsafe.<br />
<br />
For safety, [http://neuroelectrics.com/starstim '''Starstim'''] is limited in the following ways. It will not operate if the contact impedance is above 20 kOhm. It can only provide potential differences across electrode of 30 V to deliver a maximum, at any electrode of (+ or -) 2 mA of current. <br />
<br />
Our software allows for configurable, long, ramp up and ramp down times to maximize user comfort.<br />
<br />
Based on abundant literature, the guideline for clinical use is to keep average current densities in electrodes below 2 mA/35 cm2= 0.06 mA/cm2. Such stimulation current densities are far from the threshold for tissue damage (14.3 mA/cm2) recently indicated for tDCS in an animal model. Typical applications times are of 20 min or less.<br />
<br />
Current densities above 0.06 mA/cm2 (but always well below 14.3 mA/cm^2) are for advanced clinical or research purposes only.<br />
<br />
Stimulation session durations beyond 40 minutes are for research purposes only.<br />
<br />
In addition, electrode positions above cranial foramina and fissures should be avoided because these could increase beyond safety limits the effective current density. <br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] can only be used with specifically designed Neuroelectrics electrodes.<br />
<br />
With sponge electrodes, the use of sodium chloride solution, the regular replacement of the sponge, and the careful inspection of the condition of the skin under the electrode before and after tDCS is recommended.<br />
Observed Adverse Effects include: skin itching, tingling, headache, burning sensation and discomfort. In rare cases, skin lesions have been observed. If skin lesions are observed, the treatment must be suspended and the equipment revised.<br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] components must never be opened or damaged. Before using check that [http://neuroelectrics.com/starstim | '''StarStim'''] components, including electrodes, are undamaged and clean.<br />
<br />
=== Safety Guide ===<br />
The following chart is provided to guide operators, providing safety zones for different electrode current densities. Note this is an updated chart from the 2012 version. The only change is the removal of the "Uncharted Territory" zone. During the last year several groups have been working with our Pi electrodes using up to 2 mA of currents, and no ill effects have been reported. <br />
<br />
[[File:safety2013.png |400px|thumb|left|2012 Safety Chart (update from 2012)]]<br />
<br />
[[File:tdcs safety1.png|100px|thumb|left|Safety Chart 2012]]<br />
<br />
It illustrates the MAX average current density that can be used for mainstream clinical applications, advanced clinical applications, research as a function of electrode size. <br />
<br />
'''Please note: the proposed limits are not based on available negative evidence (i.e., findings of Adverse Effects with higher current densities). Rather, it is a conservative statement based on the limited experience with current densities above 2 mA/35 cm2).'''<br />
<br />
With regards to the use of small electrodes in tCS, it is worthwhile noting that the ratio of current/electrode area (I/A ratio) is not a good indicator of cortical electric field magnitude. More specifically, in Miranda et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758822/ Pedro Cavaleiro Miranda, Paula Faria and Mark Hallett, What does the ratio of injected current to electrode area tell us about current density in the brain during tDCS?, Clin Neurophysiol. Jun 2009; 120(6): 1183–1187.]<br />
</ref>, is is shown that for smaller electrodes, more current than predicted by the I/A ratio was required to achieve a predetermined current density in the brain. <br />
<br />
<br />
In the last few years several studies have employed small electrodes with no ill side effects (e.g., Faria et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pubmed/23123281 Faria P1, Fregni F, Sebastião F, Dias AI, Leal A., Feasibility of focal transcranial DC polarization with simultaneous EEG recording: preliminary assessment in healthy subjects and human epilepsy, Epilepsy Behav. 2012 Nov;25(3):417-25]<br />
</ref>).<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
=== Dosage ===<br />
For the stimulation using starstim, NIC gives an informative value about the dosage of a session. The dosage is the amount of charge that the user receives during the session.<br />
This calculation is done following the equation:<br />
<br />
[[File:Dosage.png |200px|thumb|left|Dosage equation]]<br />
<br />
== References ==<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Safety&diff=1209Safety2015-04-22T07:13:25Z<p>Guillem: /* StarStim */</p>
<hr />
<div>== Enobio ==<br />
There are no special safety considerations for Enobio. However, for safety reasons, neither [http://neuroelectrics.com/enobio | '''Enobio'''] nor [http://neuroelectrics.com/starstim | '''StarStim'''] will operate while charging. In order to charge your NECBOX device, plug it via the USB port to a computer or power supply, and make sure the power switch of the NECBOX is in OFF position. If it is in the ON position, the device will not charge.<br />
<br />
== StarStim ==<br />
Please note: tCS therapy should be supervised by a trained medical doctor. Modalities other than tDCS (tACS, tRNS) are for research purposes only.<br />
<br />
Starstim is a CE medically certified product. However, it is not FDA approved for clinical use (tDCS, tACS or tRNS aren't approved as of yet) - it is classified as an investigational device under US federal law.<br />
<br />
Built-in safety measures: <br />
Maximal current at an electrode and voltage accross two points is limied (2 mA and 30 V respectively)<br />
Maximal injected current by all electrodes at any given time limited to 4 mA<br />
Continuous impedance check and limited application time (1h) <br />
<br />
There are no studies in the literature describing the effects of direct current treatments on pregnant women, or children below 18 years, or patients with pacemakers, intracranial electrodes, implanted defibrillators, or any other prosthesis. Before applying [http://neuroelectrics.com/starstim | '''StarStim'''], make sure that pacemakers, intracranial electrodes, defibrillators, or any other prosthesis are not implanted in the patient. Otherwise, the application of DC currents could be unsafe.<br />
<br />
For safety, [http://neuroelectrics.com/starstim '''Starstim'''] is limited in the following ways. It will not operate if the contact impedance is above 20 kOhm. It can only provide potential differences across electrode of 30 V to deliver a maximum, at any electrode of (+ or -) 2 mA of current. <br />
<br />
Our software allows for configurable, long, ramp up and ramp down times to maximize user comfort.<br />
<br />
Based on abundant literature, the guideline for clinical use is to keep average current densities in electrodes below 2 mA/35 cm2= 0.06 mA/cm2. Such stimulation current densities are far from the threshold for tissue damage (14.3 mA/cm2) recently indicated for tDCS in an animal model. Typical applications times are of 20 min or less.<br />
<br />
Current densities above 0.06 mA/cm2 (but always well below 14.3 mA/cm^2) are for advanced clinical or research purposes only.<br />
<br />
Stimulation session durations beyond 40 minutes are for research purposes only.<br />
<br />
In addition, electrode positions above cranial foramina and fissures should be avoided because these could increase beyond safety limits the effective current density. <br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] can only be used with specifically designed Neuroelectrics electrodes.<br />
<br />
With sponge electrodes, the use of sodium chloride solution, the regular replacement of the sponge, and the careful inspection of the condition of the skin under the electrode before and after tDCS is recommended.<br />
Observed Adverse Effects include: skin itching, tingling, headache, burning sensation and discomfort. In rare cases, skin lesions have been observed. If skin lesions are observed, the treatment must be suspended and the equipment revised.<br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] components must never be opened or damaged. Before using check that [http://neuroelectrics.com/starstim | '''StarStim'''] components, including electrodes, are undamaged and clean.<br />
<br />
=== Safety Guide ===<br />
The following chart is provided to guide operators, providing safety zones for different electrode current densities. Note this is an updated chart from the 2012 version. The only change is the removal of the "Uncharted Territory" zone. During the last year several groups have been working with our Pi electrodes using up to 2 mA of currents, and no ill effects have been reported. <br />
<br />
[[File:safety2013.png |400px|thumb|left|2012 Safety Chart (update from 2012)]]<br />
<br />
[[File:tdcs safety1.png|100px|thumb|left|Safety Chart 2012]]<br />
<br />
It illustrates the MAX average current density that can be used for mainstream clinical applications, advanced clinical applications, research as a function of electrode size. <br />
<br />
'''Please note: the proposed limits are not based on available negative evidence (i.e., findings of Adverse Effects with higher current densities). Rather, it is a conservative statement based on the limited experience with current densities above 2 mA/35 cm2).'''<br />
<br />
With regards to the use of small electrodes in tCS, it is worthwhile noting that the ratio of current/electrode area (I/A ratio) is not a good indicator of cortical electric field magnitude. More specifically, in Miranda et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758822/ Pedro Cavaleiro Miranda, Paula Faria and Mark Hallett, What does the ratio of injected current to electrode area tell us about current density in the brain during tDCS?, Clin Neurophysiol. Jun 2009; 120(6): 1183–1187.]<br />
</ref>, is is shown that for smaller electrodes, more current than predicted by the I/A ratio was required to achieve a predetermined current density in the brain. <br />
<br />
<br />
In the last few years several studies have employed small electrodes with no ill side effects (e.g., Faria et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pubmed/23123281 Faria P1, Fregni F, Sebastião F, Dias AI, Leal A., Feasibility of focal transcranial DC polarization with simultaneous EEG recording: preliminary assessment in healthy subjects and human epilepsy, Epilepsy Behav. 2012 Nov;25(3):417-25]<br />
</ref>).<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
=== Dosage ===<br />
For the stimulation using starstim, NIC gives an informative value about the dosage of a session. The dosage is the amount of charge that the user receives during the session.<br />
This calculation is done following the equation:<br />
<br />
[[File:Dosage.png |200px|thumb|left|Dosage equation]]<br />
<br />
== References ==<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Safety&diff=1208Safety2015-04-22T07:07:45Z<p>Guillem: /* StarStim */</p>
<hr />
<div>== Enobio ==<br />
There are no special safety considerations for Enobio. However, for safety reasons, neither [http://neuroelectrics.com/enobio | '''Enobio'''] nor [http://neuroelectrics.com/starstim | '''StarStim'''] will operate while charging. In order to charge your NECBOX device, plug it via the USB port to a computer or power supply, and make sure the power switch of the NECBOX is in OFF position. If it is in the ON position, the device will not charge.<br />
<br />
== StarStim ==<br />
Please note: tCS therapy should be supervised by a trained medical doctor. Modalities other than tDCS (tACS, tRNS) are for research purposes only.<br />
<br />
Starstim is a CE medically certified product. However, it is not FDA approved for clinical use (tDCS, tACS or tRNS aren't approved as of yet) - it is classified as an investigational device under US federal law.<br />
<br />
Built-in safety measures: <br />
Maximal current at an electrode and voltage accross two points is limied (2 mA and 30 V respectively)<br />
Maximal injected current by all electrodes at any given time limited to 4 mA<br />
Continuous impedance check and limited application time (1h) <br />
<br />
There are no studies in the literature describing the effects of direct current treatments on pregnant women, or children below 18 years, or patients with pacemakers, intracranial electrodes, implanted defibrillators, or any other prosthesis. Before applying [http://neuroelectrics.com/starstim | '''StarStim'''], make sure that pacemakers, intracranial electrodes, defibrillators, or any other prosthesis are not implanted in the patient. Otherwise, the application of DC currents could be unsafe.<br />
<br />
For safety, [http://neuroelectrics.com/starstim '''Starstim'''] is limited in the following ways. It will not operate if the contact impedance is above 20 kOhm. It can only provide potential differences across electrode of 30 V to deliver a maximum, at any electrode of (+ or -) 2 mA of current. <br />
<br />
Our software allows for configurable, long, ramp up and ramp down times to maximize user comfort.<br />
<br />
Based on abundant literature, the guideline for clinical use is to keep average current densities in electrodes below 2 mA/35 cm2= 0.06 mA/cm2. Such stimulation current densities are far from the threshold for tissue damage (14.3 mA/cm2) recently indicated for tDCS in an animal model. Typical applications times are of 20 min or less.<br />
<br />
Current densities above 0.06 mA/cm2 (but always well below 14.3 mA/cm^2) are for advanced clinical or research purposes only.<br />
<br />
Stimulation session durations beyond 40 minutes are for research purposes only.<br />
<br />
In addition, electrode positions above cranial foramina and fissures should be avoided because these could increase beyond safety limits the effective current density. <br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] can only be used with specifically designed Neuroelectrics electrodes.<br />
<br />
With sponge electrodes, the use of sodium chloride solution, the regular replacement of the sponge, and the careful inspection of the condition of the skin under the electrode before and after tDCS is recommended.<br />
Observed Adverse Effects include: skin itching, tingling, headache, burning sensation and discomfort. In rare cases, skin lesions have been observed. If skin lesions are observed, the treatment must be suspended and the equipment revised.<br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] components must never be opened or damaged. Before using check that [http://neuroelectrics.com/starstim | '''StarStim'''] components, including electrodes, are undamaged and clean.<br />
<br />
=== Safety Guide ===<br />
The following chart is provided to guide operators, providing safety zones for different electrode current densities. Note this is an updated chart from the 2012 version. The only change is the removal of the "Uncharted Territory" zone. During the last year several groups have been working with our Pi electrodes using up to 2 mA of currents, and no ill effects have been reported. <br />
<br />
[[File:safety2013.png |400px|thumb|left|2012 Safety Chart (update from 2012)]]<br />
<br />
[[File:tdcs safety1.png|100px|thumb|left|Safety Chart 2012]]<br />
<br />
It illustrates the MAX average current density that can be used for mainstream clinical applications, advanced clinical applications, research as a function of electrode size. <br />
<br />
'''Please note: the proposed limits are not based on available negative evidence (i.e., findings of Adverse Effects with higher current densities). Rather, it is a conservative statement based on the limited experience with current densities above 2 mA/35 cm2).'''<br />
<br />
With regards to the use of small electrodes in tCS, it is worthwhile noting that the ratio of current/electrode area (I/A ratio) is not a good indicator of cortical electric field magnitude. More specifically, in Miranda et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758822/ Pedro Cavaleiro Miranda, Paula Faria and Mark Hallett, What does the ratio of injected current to electrode area tell us about current density in the brain during tDCS?, Clin Neurophysiol. Jun 2009; 120(6): 1183–1187.]<br />
</ref>, is is shown that for smaller electrodes, more current than predicted by the I/A ratio was required to achieve a predetermined current density in the brain. <br />
<br />
<br />
In the last few years several studies have employed small electrodes with no ill side effects (e.g., Faria et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pubmed/23123281 Faria P1, Fregni F, Sebastião F, Dias AI, Leal A., Feasibility of focal transcranial DC polarization with simultaneous EEG recording: preliminary assessment in healthy subjects and human epilepsy, Epilepsy Behav. 2012 Nov;25(3):417-25]<br />
</ref>).<br />
<br />
=== Dosage ===<br />
For the stimulation using starstim, NIC gives an informative value about the dosage of a session. The dosage is the amount of charge that the user receives during the session.<br />
This calculation is done following the equation:<br />
<br />
[[File:Dosage.png |200px|thumb|left|Dosage equation]]<br />
<br />
== References ==<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=File:Dosage.png&diff=1207File:Dosage.png2015-04-22T07:07:13Z<p>Guillem: Dosage calculation equation</p>
<hr />
<div>Dosage calculation equation</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Safety&diff=1206Safety2015-04-22T07:05:43Z<p>Guillem: /* StarStim */</p>
<hr />
<div>== Enobio ==<br />
There are no special safety considerations for Enobio. However, for safety reasons, neither [http://neuroelectrics.com/enobio | '''Enobio'''] nor [http://neuroelectrics.com/starstim | '''StarStim'''] will operate while charging. In order to charge your NECBOX device, plug it via the USB port to a computer or power supply, and make sure the power switch of the NECBOX is in OFF position. If it is in the ON position, the device will not charge.<br />
<br />
== StarStim ==<br />
Please note: tCS therapy should be supervised by a trained medical doctor. Modalities other than tDCS (tACS, tRNS) are for research purposes only.<br />
<br />
Starstim is a CE medically certified product. However, it is not FDA approved for clinical use (tDCS, tACS or tRNS aren't approved as of yet) - it is classified as an investigational device under US federal law.<br />
<br />
Built-in safety measures: <br />
Maximal current at an electrode and voltage accross two points is limied (2 mA and 30 V respectively)<br />
Maximal injected current by all electrodes at any given time limited to 4 mA<br />
Continuous impedance check and limited application time (1h) <br />
<br />
There are no studies in the literature describing the effects of direct current treatments on pregnant women, or children below 18 years, or patients with pacemakers, intracranial electrodes, implanted defibrillators, or any other prosthesis. Before applying [http://neuroelectrics.com/starstim | '''StarStim'''], make sure that pacemakers, intracranial electrodes, defibrillators, or any other prosthesis are not implanted in the patient. Otherwise, the application of DC currents could be unsafe.<br />
<br />
For safety, [http://neuroelectrics.com/starstim '''Starstim'''] is limited in the following ways. It will not operate if the contact impedance is above 20 kOhm. It can only provide potential differences across electrode of 30 V to deliver a maximum, at any electrode of (+ or -) 2 mA of current. <br />
<br />
Our software allows for configurable, long, ramp up and ramp down times to maximize user comfort.<br />
<br />
Based on abundant literature, the guideline for clinical use is to keep average current densities in electrodes below 2 mA/35 cm2= 0.06 mA/cm2. Such stimulation current densities are far from the threshold for tissue damage (14.3 mA/cm2) recently indicated for tDCS in an animal model. Typical applications times are of 20 min or less.<br />
<br />
Current densities above 0.06 mA/cm2 (but always well below 14.3 mA/cm^2) are for advanced clinical or research purposes only.<br />
<br />
Stimulation session durations beyond 40 minutes are for research purposes only.<br />
<br />
In addition, electrode positions above cranial foramina and fissures should be avoided because these could increase beyond safety limits the effective current density. <br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] can only be used with specifically designed Neuroelectrics electrodes.<br />
<br />
With sponge electrodes, the use of sodium chloride solution, the regular replacement of the sponge, and the careful inspection of the condition of the skin under the electrode before and after tDCS is recommended.<br />
Observed Adverse Effects include: skin itching, tingling, headache, burning sensation and discomfort. In rare cases, skin lesions have been observed. If skin lesions are observed, the treatment must be suspended and the equipment revised.<br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] components must never be opened or damaged. Before using check that [http://neuroelectrics.com/starstim | '''StarStim'''] components, including electrodes, are undamaged and clean.<br />
<br />
=== Safety Guide ===<br />
The following chart is provided to guide operators, providing safety zones for different electrode current densities. Note this is an updated chart from the 2012 version. The only change is the removal of the "Uncharted Territory" zone. During the last year several groups have been working with our Pi electrodes using up to 2 mA of currents, and no ill effects have been reported. <br />
<br />
[[File:safety2013.png |400px|thumb|left|2012 Safety Chart (update from 2012)]]<br />
<br />
[[File:tdcs safety1.png|100px|thumb|left|Safety Chart 2012]]<br />
<br />
It illustrates the MAX average current density that can be used for mainstream clinical applications, advanced clinical applications, research as a function of electrode size. <br />
<br />
'''Please note: the proposed limits are not based on available negative evidence (i.e., findings of Adverse Effects with higher current densities). Rather, it is a conservative statement based on the limited experience with current densities above 2 mA/35 cm2).'''<br />
<br />
With regards to the use of small electrodes in tCS, it is worthwhile noting that the ratio of current/electrode area (I/A ratio) is not a good indicator of cortical electric field magnitude. More specifically, in Miranda et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758822/ Pedro Cavaleiro Miranda, Paula Faria and Mark Hallett, What does the ratio of injected current to electrode area tell us about current density in the brain during tDCS?, Clin Neurophysiol. Jun 2009; 120(6): 1183–1187.]<br />
</ref>, is is shown that for smaller electrodes, more current than predicted by the I/A ratio was required to achieve a predetermined current density in the brain. <br />
<br />
<br />
In the last few years several studies have employed small electrodes with no ill side effects (e.g., Faria et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pubmed/23123281 Faria P1, Fregni F, Sebastião F, Dias AI, Leal A., Feasibility of focal transcranial DC polarization with simultaneous EEG recording: preliminary assessment in healthy subjects and human epilepsy, Epilepsy Behav. 2012 Nov;25(3):417-25]<br />
</ref>).<br />
<br />
=== Dosage ===<br />
For the stimulation using starstim, NIC gives an informative value about the dosage of a session. The dosage is the amount of charge that the user receives during the session.<br />
This calculation is done following the equation:<br />
<br />
[[File:safety2013.png |200px|thumb|left|Dosage equation]]<br />
<br />
== References ==<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Safety&diff=1205Safety2015-04-22T07:04:48Z<p>Guillem: /* StarStim */</p>
<hr />
<div>== Enobio ==<br />
There are no special safety considerations for Enobio. However, for safety reasons, neither [http://neuroelectrics.com/enobio | '''Enobio'''] nor [http://neuroelectrics.com/starstim | '''StarStim'''] will operate while charging. In order to charge your NECBOX device, plug it via the USB port to a computer or power supply, and make sure the power switch of the NECBOX is in OFF position. If it is in the ON position, the device will not charge.<br />
<br />
== StarStim ==<br />
Please note: tCS therapy should be supervised by a trained medical doctor. Modalities other than tDCS (tACS, tRNS) are for research purposes only.<br />
<br />
Starstim is a CE medically certified product. However, it is not FDA approved for clinical use (tDCS, tACS or tRNS aren't approved as of yet) - it is classified as an investigational device under US federal law.<br />
<br />
Built-in safety measures: <br />
Maximal current at an electrode and voltage accross two points is limied (2 mA and 30 V respectively)<br />
Maximal injected current by all electrodes at any given time limited to 4 mA<br />
Continuous impedance check and limited application time (1h) <br />
<br />
There are no studies in the literature describing the effects of direct current treatments on pregnant women, or children below 18 years, or patients with pacemakers, intracranial electrodes, implanted defibrillators, or any other prosthesis. Before applying [http://neuroelectrics.com/starstim | '''StarStim'''], make sure that pacemakers, intracranial electrodes, defibrillators, or any other prosthesis are not implanted in the patient. Otherwise, the application of DC currents could be unsafe.<br />
<br />
For safety, [http://neuroelectrics.com/starstim '''Starstim'''] is limited in the following ways. It will not operate if the contact impedance is above 20 kOhm. It can only provide potential differences across electrode of 30 V to deliver a maximum, at any electrode of (+ or -) 2 mA of current. <br />
<br />
Our software allows for configurable, long, ramp up and ramp down times to maximize user comfort.<br />
<br />
Based on abundant literature, the guideline for clinical use is to keep average current densities in electrodes below 2 mA/35 cm2= 0.06 mA/cm2. Such stimulation current densities are far from the threshold for tissue damage (14.3 mA/cm2) recently indicated for tDCS in an animal model. Typical applications times are of 20 min or less.<br />
<br />
Current densities above 0.06 mA/cm2 (but always well below 14.3 mA/cm^2) are for advanced clinical or research purposes only.<br />
<br />
Stimulation session durations beyond 40 minutes are for research purposes only.<br />
<br />
In addition, electrode positions above cranial foramina and fissures should be avoided because these could increase beyond safety limits the effective current density. <br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] can only be used with specifically designed Neuroelectrics electrodes.<br />
<br />
With sponge electrodes, the use of sodium chloride solution, the regular replacement of the sponge, and the careful inspection of the condition of the skin under the electrode before and after tDCS is recommended.<br />
Observed Adverse Effects include: skin itching, tingling, headache, burning sensation and discomfort. In rare cases, skin lesions have been observed. If skin lesions are observed, the treatment must be suspended and the equipment revised.<br />
<br />
[http://neuroelectrics.com/starstim | '''StarStim'''] components must never be opened or damaged. Before using check that [http://neuroelectrics.com/starstim | '''StarStim'''] components, including electrodes, are undamaged and clean.<br />
<br />
=== Safety Guide ===<br />
The following chart is provided to guide operators, providing safety zones for different electrode current densities. Note this is an updated chart from the 2012 version. The only change is the removal of the "Uncharted Territory" zone. During the last year several groups have been working with our Pi electrodes using up to 2 mA of currents, and no ill effects have been reported. <br />
<br />
[[File:safety2013.png |400px|thumb|left|2012 Safety Chart (update from 2012)]]<br />
<br />
[[File:tdcs safety1.png|100px|thumb|left|Safety Chart 2012]]<br />
<br />
It illustrates the MAX average current density that can be used for mainstream clinical applications, advanced clinical applications, research as a function of electrode size. <br />
<br />
'''Please note: the proposed limits are not based on available negative evidence (i.e., findings of Adverse Effects with higher current densities). Rather, it is a conservative statement based on the limited experience with current densities above 2 mA/35 cm2).'''<br />
<br />
With regards to the use of small electrodes in tCS, it is worthwhile noting that the ratio of current/electrode area (I/A ratio) is not a good indicator of cortical electric field magnitude. More specifically, in Miranda et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758822/ Pedro Cavaleiro Miranda, Paula Faria and Mark Hallett, What does the ratio of injected current to electrode area tell us about current density in the brain during tDCS?, Clin Neurophysiol. Jun 2009; 120(6): 1183–1187.]<br />
</ref>, is is shown that for smaller electrodes, more current than predicted by the I/A ratio was required to achieve a predetermined current density in the brain. <br />
<br />
<br />
In the last few years several studies have employed small electrodes with no ill side effects (e.g., Faria et al<ref><br />
[http://www.ncbi.nlm.nih.gov/pubmed/23123281 Faria P1, Fregni F, Sebastião F, Dias AI, Leal A., Feasibility of focal transcranial DC polarization with simultaneous EEG recording: preliminary assessment in healthy subjects and human epilepsy, Epilepsy Behav. 2012 Nov;25(3):417-25]<br />
</ref>).<br />
<br />
=== Dosage ===<br />
For the stimulation using starstim, NIC gives an informative value about the dosage of a session. The dosage is the amount of charge that the user receives during the session.<br />
This calculation is done following the equation:<br />
<br />
[[File:tdcs safety1.png|100px|thumb|left|Dosage equation]]<br />
<br />
== References ==<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Files_%26_Formats&diff=1192Files & Formats2015-03-05T22:28:16Z<p>Guillem: /* The .edf (binary, EDF+) data format */</p>
<hr />
<div>Neuroelectrics devices generate a series of files and formats. Proprietary ones are in bold: <br />
- The '''.''easy''''' data format (ASCII, plain text) <br />
- The '''.''info''''' file (ASCII, plain text)<br />
- The .'''edf''' (EDF+) and '''".nedf"''' data formats (binary)<br />
- The '''.''stim''''' file (ASCII, plain text)<br />
- The '''.''sdeeg''''' SD card data format (binary)<br />
<br />
In general, time keeping is given with time stamps per sample in ms since Jan 1st 1970 ([http://en.wikipedia.org/wiki/Unix_time| Unix time]).<br />
<br />
= Stimulation generated files =<br />
Neuroelectrics stimulation StarStim class devices generate stimulation specific files as well as EEG data. Here we describe the former (for EEG see the EEG data section).<br />
<br />
<br />
<br />
== the .'''info''' file associated with a stimulation session ==<br />
Here is an example of the ASCII data file associated to a stimulation session. The name of the file would be something like '''20130220112635_Patient01.info'': <br />
<br />
StartDate (first EEG timestamp): 1361377909087 <br />
Device class: StarStim<br />
Device Mac: 00:07:80:58:9C:1A<br />
NIC version: v1.1.9<br />
Firmware version: 699<br />
Line filter status: OFF<br />
Additional channel status:OFF<br />
Number of records of Stimulation: 46 (1 second/record)<br />
Total number of channels: 8<br />
Number of EEG channels: 6<br />
Number of stimulation channels: 1<br />
Stimulation sampling rate: 500 Samples/second<br />
Stimulation units: uA<br />
Ramp up duration (s): 15<br />
Ramp down duration (s): 15<br />
Shamp ramp duration (s): OFF<br />
Stimulation duration (s): 1200<br />
Type of stimulation: tACS+<br />
Stimulation parameters:<br />
Channel 1: <br />
Position: C3<br />
Type: EEG Recording<br />
Channel 2: <br />
Position: C4<br />
Type: Stimulation Anodal<br />
Amplitude (uA): 100<br />
Offset (uA): 0<br />
Frequency (Hz): 10<br />
Channel 3: <br />
Position: Ch3<br />
Type: EEG Recording<br />
Channel 4: <br />
Position: Ch4<br />
Type: Return<br />
Percentage return: 100%<br />
Channel 5: <br />
Position: Ch5<br />
Type: EEG Recording<br />
Channel 6: <br />
Position: Ch6<br />
Type: EEG Recording<br />
Channel 7: <br />
Position: Ch7<br />
Type: EEG Recording<br />
Channel 8: <br />
Position: Ch8<br />
Type: EEG Recording<br />
Trigger information:<br />
Code Description<br />
1 Subject moved<br />
2 Eyes opened<br />
3 Eyes closed<br />
4 sleeping<br />
5 EEG signals are noisy<br />
6 <br />
7 <br />
8 <br />
9<br />
<br />
== the .'''stim''' file ==<br />
This ASCII file contains a record of the currents at each electrode. <br />
<br />
There is a row per time sample with one column per channel (units in uA).<br />
<br />
The last column contains the time stamps per sample in ms since Jan 1st 1970 ([http://en.wikipedia.org/wiki/Unix_time| Unix time]).<br />
<br />
Here is the typical content of a .stim file. There are 8 columns (one per channel). Channels with a constant value of -1 identify channels not used for stimulation (they would be used for EEG). <br />
The first two columns provide injected current in uA, with a + sign indicating injection of current into the scalp. The last column is the Unix timestamp (ms).<br />
<br />
246 -246 -1 -1 -1 -1 -1 -1 1381762713753<br />
246 -246 -1 -1 -1 -1 -1 -1 1381762713754<br />
246 -246 -1 -1 -1 -1 -1 -1 1381762713755<br />
246 -246 -1 -1 -1 -1 -1 -1 1381762713756<br />
246 -246 -1 -1 -1 -1 -1 -1 1381762713757<br />
247 -247 -1 -1 -1 -1 -1 -1 1381762713758<br />
247 -247 -1 -1 -1 -1 -1 -1 1381762713759<br />
247 -247 -1 -1 -1 -1 -1 -1 1381762713760<br />
247 -247 -1 -1 -1 -1 -1 -1 1381762713761<br />
247 -247 -1 -1 -1 -1 -1 -1 1381762713762<br />
247 -247 -1 -1 -1 -1 -1 -1 1381762713763<br />
248 -248 -1 -1 -1 -1 -1 -1 1381762713764<br />
248 -248 -1 -1 -1 -1 -1 -1 1381762713765<br />
<br />
= EEG data files and formats = <br />
<br />
== the .'''info''' file associated with an EEG only session ==<br />
<br />
Here is an example of what this plain text file contains. The name of the file would be something like '''20131011141257_demo.info'': <br />
<br />
StartDate (first EEG timestamp): 1381493577260<br />
Device class: Enobio20<br />
Device MAC: 00:07:80:63:F0:CD<br />
NIC version: v1.2.9<br />
Firmware version: 699<br />
Line filter status: 60 Hz<br />
Additional channel status: OFF<br />
Total number of channels: 20<br />
Number of EEG channels: 20<br />
Number of records of EEG: 15381<br />
Number of packets lost: 0(0.00%)<br />
EEG sampling rate: 500 Samples/second<br />
EEG units: nV<br />
EEG montage:<br />
Channel 1: P7<br />
Channel 2: P4<br />
Channel 3: Cz<br />
Channel 4: Pz<br />
Channel 5: P3<br />
Channel 6: P8<br />
Channel 7: O1<br />
Channel 8: O2<br />
Channel 9: T8<br />
Channel 10: F8<br />
Channel 11: C4<br />
Channel 12: F4<br />
Channel 13: Fp2<br />
Channel 14: Fz<br />
Channel 15: C3<br />
Channel 16: F3<br />
Channel 17: Fp1<br />
Channel 18: T7<br />
Channel 19: F7<br />
Channel 20: EXT<br />
Number of records of Accelerometer: 30 (1 second/record)<br />
Number of channels of Accelerometer: 3<br />
Accelerometer sampling rate: 100 Samples/second<br />
Accelerometer units: mm/s^2<br />
Trigger information:<br />
Code Description<br />
1 EventA<br />
2 EventB<br />
3 Movement<br />
4 Eyeblink<br />
5 <br />
6 <br />
7 <br />
8 <br />
9<br />
<br />
== The .'''easy''' data format (ASCII) ==<br />
ABOUT THE NE ASCII DATA FORMAT (July 2012): <br />
NE ASCII files contain one line per time sample. Each line contains<br />
first the EEG data (8 or 20 channels, depending on the device, with<br />
units in nV), followed by three acceleration channels (aX,aY,aZ <br />
in mm/s^2- millimeters per second squared), an *optional* external <br />
input channel, a trigger flag (int32) and, finally, <br />
a timestamp in Unix time (ms from Jan 1 1970):<br />
<br />
Ch1(nV) ... Ch8or20(nV) aX(mg) aY(mg) aZ(mg) AddSensor Flags(uint32) TimeStamp (ms)<br />
<br />
Therefore Enobio8/StarStim will have a minimum of 8+2 (10) columns, or 8+3=11 if no <br />
accelerometer or >= 8+4 (with accelerometer). In summary:<br />
<br />
Enobio8/20<br />
10 Columns: no AddSensor, no accelerometer data:<br />
11 Comumns: no accelerometer, but there is AddSensor<br />
13 Columns: there is accelerometer, but no Addsensor<br />
14 Comumns: there is accelerometer, AddSensor.<br />
<br />
Enobio 20 will have >= 22 and >=24 columns if acc. data present:<br />
22 Columns: no AddSensor, no accelerometer<br />
23 Comumns: no accelerometer, but there is AddSensor<br />
25 Columns: there is accelerometer, no AddSensor <br />
26 Comumns: there is accelerometer, AddSensor.<br />
<br />
Enobio 32 will have >=34 and >=36 if acc data is present<br />
34 Columns: no AddSensor, no accelerometer<br />
35 Comumns: no accelerometer, but there is AddSensor<br />
37 Columns: there is accelerometer, no AddSensor <br />
38 Comumns: there is accelerometer, AddSensor.<br />
<br />
<br />
Here is an example from a StarStim device (8 Channels) where the first 4 channels are used for stimulation (with "-1"s), and with accelerometer data (3 channels), markers and timestamp:<br />
<br />
-1 -1 8999110 29602960 27793792 19921829 -3670597 18110801 -2745 9561 -912 0 1353011252736<br />
-1 -1 8902360 29539254 27764085 19818737 -3924179 18143799 -2745 9561 -912 0 1353011252738<br />
-1 -1 8827496 29457477 27727511 19748117 -4140377 18101551 -2745 9561 -912 0 1353011252740<br />
-1 -1 8779812 29376462 27720311 19705727 -4315472 18054868 -2745 9561 -912 0 1353011252742<br />
<br />
== The .'''edf''' (binary, EDF+) data format ==<br />
This is the standard [http://www.edfplus.info/specs/edf.html | EDF data format]. Files in this format can be opened from EDF data readers as well as with NIC Offline (and exported/saved into any of the other NE formats).<br />
The EDF+ format has only 16 bits of quantization. To avoid any distortion of the signal the EDF+ files are pre-processed including: <br />
<br />
- High pass filtering of the signal at 0.1 Hz<br />
<br />
- Clipping of the signal at [-32.767mV, 32.767mV]<br />
<br />
== The .'''nedf''' (binary) data format ==<br />
This is Neuroelectrics proprietary data format (NEDF). It is lossless (full 24 bit) binary. It can be opened by NIC Offline and exported/saved into any of the other NE formats. Additionally, at section [[Data_Processing_with_Matlab#Working_with_NEDF_files]] you can also find Matlab code to open NEDF files.<br />
<br />
= The '''.sdeeg''' SD card data =<br />
This is another proprietary, binary data format. It can be opened with NIC Offline software and exported/saved into any of the other NE formats.</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Files_%26_Formats&diff=1191Files & Formats2015-03-05T22:27:58Z<p>Guillem: /* The .edf (binary, EDF+) data format */</p>
<hr />
<div>Neuroelectrics devices generate a series of files and formats. Proprietary ones are in bold: <br />
- The '''.''easy''''' data format (ASCII, plain text) <br />
- The '''.''info''''' file (ASCII, plain text)<br />
- The .'''edf''' (EDF+) and '''".nedf"''' data formats (binary)<br />
- The '''.''stim''''' file (ASCII, plain text)<br />
- The '''.''sdeeg''''' SD card data format (binary)<br />
<br />
In general, time keeping is given with time stamps per sample in ms since Jan 1st 1970 ([http://en.wikipedia.org/wiki/Unix_time| Unix time]).<br />
<br />
= Stimulation generated files =<br />
Neuroelectrics stimulation StarStim class devices generate stimulation specific files as well as EEG data. Here we describe the former (for EEG see the EEG data section).<br />
<br />
<br />
<br />
== the .'''info''' file associated with a stimulation session ==<br />
Here is an example of the ASCII data file associated to a stimulation session. The name of the file would be something like '''20130220112635_Patient01.info'': <br />
<br />
StartDate (first EEG timestamp): 1361377909087 <br />
Device class: StarStim<br />
Device Mac: 00:07:80:58:9C:1A<br />
NIC version: v1.1.9<br />
Firmware version: 699<br />
Line filter status: OFF<br />
Additional channel status:OFF<br />
Number of records of Stimulation: 46 (1 second/record)<br />
Total number of channels: 8<br />
Number of EEG channels: 6<br />
Number of stimulation channels: 1<br />
Stimulation sampling rate: 500 Samples/second<br />
Stimulation units: uA<br />
Ramp up duration (s): 15<br />
Ramp down duration (s): 15<br />
Shamp ramp duration (s): OFF<br />
Stimulation duration (s): 1200<br />
Type of stimulation: tACS+<br />
Stimulation parameters:<br />
Channel 1: <br />
Position: C3<br />
Type: EEG Recording<br />
Channel 2: <br />
Position: C4<br />
Type: Stimulation Anodal<br />
Amplitude (uA): 100<br />
Offset (uA): 0<br />
Frequency (Hz): 10<br />
Channel 3: <br />
Position: Ch3<br />
Type: EEG Recording<br />
Channel 4: <br />
Position: Ch4<br />
Type: Return<br />
Percentage return: 100%<br />
Channel 5: <br />
Position: Ch5<br />
Type: EEG Recording<br />
Channel 6: <br />
Position: Ch6<br />
Type: EEG Recording<br />
Channel 7: <br />
Position: Ch7<br />
Type: EEG Recording<br />
Channel 8: <br />
Position: Ch8<br />
Type: EEG Recording<br />
Trigger information:<br />
Code Description<br />
1 Subject moved<br />
2 Eyes opened<br />
3 Eyes closed<br />
4 sleeping<br />
5 EEG signals are noisy<br />
6 <br />
7 <br />
8 <br />
9<br />
<br />
== the .'''stim''' file ==<br />
This ASCII file contains a record of the currents at each electrode. <br />
<br />
There is a row per time sample with one column per channel (units in uA).<br />
<br />
The last column contains the time stamps per sample in ms since Jan 1st 1970 ([http://en.wikipedia.org/wiki/Unix_time| Unix time]).<br />
<br />
Here is the typical content of a .stim file. There are 8 columns (one per channel). Channels with a constant value of -1 identify channels not used for stimulation (they would be used for EEG). <br />
The first two columns provide injected current in uA, with a + sign indicating injection of current into the scalp. The last column is the Unix timestamp (ms).<br />
<br />
246 -246 -1 -1 -1 -1 -1 -1 1381762713753<br />
246 -246 -1 -1 -1 -1 -1 -1 1381762713754<br />
246 -246 -1 -1 -1 -1 -1 -1 1381762713755<br />
246 -246 -1 -1 -1 -1 -1 -1 1381762713756<br />
246 -246 -1 -1 -1 -1 -1 -1 1381762713757<br />
247 -247 -1 -1 -1 -1 -1 -1 1381762713758<br />
247 -247 -1 -1 -1 -1 -1 -1 1381762713759<br />
247 -247 -1 -1 -1 -1 -1 -1 1381762713760<br />
247 -247 -1 -1 -1 -1 -1 -1 1381762713761<br />
247 -247 -1 -1 -1 -1 -1 -1 1381762713762<br />
247 -247 -1 -1 -1 -1 -1 -1 1381762713763<br />
248 -248 -1 -1 -1 -1 -1 -1 1381762713764<br />
248 -248 -1 -1 -1 -1 -1 -1 1381762713765<br />
<br />
= EEG data files and formats = <br />
<br />
== the .'''info''' file associated with an EEG only session ==<br />
<br />
Here is an example of what this plain text file contains. The name of the file would be something like '''20131011141257_demo.info'': <br />
<br />
StartDate (first EEG timestamp): 1381493577260<br />
Device class: Enobio20<br />
Device MAC: 00:07:80:63:F0:CD<br />
NIC version: v1.2.9<br />
Firmware version: 699<br />
Line filter status: 60 Hz<br />
Additional channel status: OFF<br />
Total number of channels: 20<br />
Number of EEG channels: 20<br />
Number of records of EEG: 15381<br />
Number of packets lost: 0(0.00%)<br />
EEG sampling rate: 500 Samples/second<br />
EEG units: nV<br />
EEG montage:<br />
Channel 1: P7<br />
Channel 2: P4<br />
Channel 3: Cz<br />
Channel 4: Pz<br />
Channel 5: P3<br />
Channel 6: P8<br />
Channel 7: O1<br />
Channel 8: O2<br />
Channel 9: T8<br />
Channel 10: F8<br />
Channel 11: C4<br />
Channel 12: F4<br />
Channel 13: Fp2<br />
Channel 14: Fz<br />
Channel 15: C3<br />
Channel 16: F3<br />
Channel 17: Fp1<br />
Channel 18: T7<br />
Channel 19: F7<br />
Channel 20: EXT<br />
Number of records of Accelerometer: 30 (1 second/record)<br />
Number of channels of Accelerometer: 3<br />
Accelerometer sampling rate: 100 Samples/second<br />
Accelerometer units: mm/s^2<br />
Trigger information:<br />
Code Description<br />
1 EventA<br />
2 EventB<br />
3 Movement<br />
4 Eyeblink<br />
5 <br />
6 <br />
7 <br />
8 <br />
9<br />
<br />
== The .'''easy''' data format (ASCII) ==<br />
ABOUT THE NE ASCII DATA FORMAT (July 2012): <br />
NE ASCII files contain one line per time sample. Each line contains<br />
first the EEG data (8 or 20 channels, depending on the device, with<br />
units in nV), followed by three acceleration channels (aX,aY,aZ <br />
in mm/s^2- millimeters per second squared), an *optional* external <br />
input channel, a trigger flag (int32) and, finally, <br />
a timestamp in Unix time (ms from Jan 1 1970):<br />
<br />
Ch1(nV) ... Ch8or20(nV) aX(mg) aY(mg) aZ(mg) AddSensor Flags(uint32) TimeStamp (ms)<br />
<br />
Therefore Enobio8/StarStim will have a minimum of 8+2 (10) columns, or 8+3=11 if no <br />
accelerometer or >= 8+4 (with accelerometer). In summary:<br />
<br />
Enobio8/20<br />
10 Columns: no AddSensor, no accelerometer data:<br />
11 Comumns: no accelerometer, but there is AddSensor<br />
13 Columns: there is accelerometer, but no Addsensor<br />
14 Comumns: there is accelerometer, AddSensor.<br />
<br />
Enobio 20 will have >= 22 and >=24 columns if acc. data present:<br />
22 Columns: no AddSensor, no accelerometer<br />
23 Comumns: no accelerometer, but there is AddSensor<br />
25 Columns: there is accelerometer, no AddSensor <br />
26 Comumns: there is accelerometer, AddSensor.<br />
<br />
Enobio 32 will have >=34 and >=36 if acc data is present<br />
34 Columns: no AddSensor, no accelerometer<br />
35 Comumns: no accelerometer, but there is AddSensor<br />
37 Columns: there is accelerometer, no AddSensor <br />
38 Comumns: there is accelerometer, AddSensor.<br />
<br />
<br />
Here is an example from a StarStim device (8 Channels) where the first 4 channels are used for stimulation (with "-1"s), and with accelerometer data (3 channels), markers and timestamp:<br />
<br />
-1 -1 8999110 29602960 27793792 19921829 -3670597 18110801 -2745 9561 -912 0 1353011252736<br />
-1 -1 8902360 29539254 27764085 19818737 -3924179 18143799 -2745 9561 -912 0 1353011252738<br />
-1 -1 8827496 29457477 27727511 19748117 -4140377 18101551 -2745 9561 -912 0 1353011252740<br />
-1 -1 8779812 29376462 27720311 19705727 -4315472 18054868 -2745 9561 -912 0 1353011252742<br />
<br />
== The .'''edf''' (binary, EDF+) data format ==<br />
This is the standard [http://www.edfplus.info/specs/edf.html | EDF data format]. Files in this format can be opened from EDF data readers as well as with NIC Offline (and exported/saved into any of the other NE formats).<br />
The EDF+ format has only 16 bits of quantization. To avoid any distortion of the signal the EDF+ files are pre-processed including: <br />
- High pass filtering of the signal at 0.1 Hz<br />
- Clipping of the signal at [-32.767mV, 32.767mV]<br />
<br />
== The .'''nedf''' (binary) data format ==<br />
This is Neuroelectrics proprietary data format (NEDF). It is lossless (full 24 bit) binary. It can be opened by NIC Offline and exported/saved into any of the other NE formats. Additionally, at section [[Data_Processing_with_Matlab#Working_with_NEDF_files]] you can also find Matlab code to open NEDF files.<br />
<br />
= The '''.sdeeg''' SD card data =<br />
This is another proprietary, binary data format. It can be opened with NIC Offline software and exported/saved into any of the other NE formats.</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=File:Test.png&diff=1106File:Test.png2014-12-02T09:22:57Z<p>Guillem: </p>
<hr />
<div></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Event_Related_Potentials_(ERPs)&diff=1057Event Related Potentials (ERPs)2014-09-03T14:27:42Z<p>Guillem: /* Presentation */</p>
<hr />
<div>= About Event Related Potentials (ERPs) =<br />
An '''event-related potential''' ('''ERP''') is the measured brain response that is the direct result of a specific sense|sensory, cognition|cognitive, or motor system|motor event.<ref name="Luck">Luck, Steven J. (2005). An Introduction to the Event-Related Potential Technique. The MIT Press. ISBN 0-262-12277-4.</ref>.<br />
<br />
Those brain response can be measured with electroencephalography (EEG) using devices such as [http://www.neuroelectrics.com/enobio Enobio]. EEG reflects thousands of simultaneously ongoing brain processes. This means that the brain response to a single stimulus or event of interest is not usually visible in the EEG recording of a single trial. To see the brain's response to a stimulus, the experimenter must conduct many trials (usually in the order of 100 or more) and average the results together, causing random brain activity to be averaged out and the relevant waveform to remain, called the ERP.<ref name "Coles">Coles, Michael G.H.; Michael D. Rugg (1996). "Event-related brain potentials: an introduction". Electrophysiology of Mind. Oxford Scholarship Online Monographs. pp. 1–27</ref><br />
<br />
These stimuli can be visual, auditory, tactile and even olfactory and gustatory. In order to record those event-related potential the recording set-up needs to '''synchronise''' very accurately both the stimuli presentation and the EEG recording device. Commonly the software in charge of presenting the stimuli send a marker to the EEG recording system each time a stimuli is presented. If the triggers are properly recorded along with the EEG signal, an automatic pre-processing step can automatically cut the signal in epochs for further averaging.<br />
<br />
Further information regarding ERPs and its different types can be found in the following two links:[http://blog.neuroelectrics.com/blog/bid/237205/Event-Related-Potential-Our-Brain-Response-To-External-Stimuli 1] [http://blog.neuroelectrics.com/blog/bid/318938/14-Event-Related-Potentials-Components-and-Modalities 2], as well as in our White Papers<br />
<ref name="NEWP201401">Neuroelectrics NEWP201401, Event Synchronization of EEG data using the LSL, [http://wiki.neuroelectrics.com/index.php/Neuroelectrics_White_Papers]</ref><br />
<ref name="NEWP201403">Neuroelectrics NEWP201403, Extraction of ERPs with NE devices, [http://wiki.neuroelectrics.com/index.php/Neuroelectrics_White_Papers]</ref>.<br />
<br />
= Presentation Software =<br />
There are several software that can set-up an experiment which presents some stimulus (audio, images, video, etc.) to a subject in order to elicit ERPs in the EEG signal. It is very important that the recorded EEG data is synchronised with those stimulus in order to detect the ERPs when analyzing the data. The [http://www.neuroelectrics.com/enobio/software NIC] software provides the basic infrastructure to receive those markers from this kind of software every time a stimuli is presented. Please refer to the [[Interacting_with_NIC]] section for the details on how NIC handles the reception of the markers.<br />
<br />
In the following section we detail how some of the most relevant presentation software can be configured to send markers to NIC.<br />
== Presentation ==<br />
The [http://www.neurobs.com/ Presentation] software allows to connect to a remote application by using sockets in the [http://www.neurobs.com/pres_docs/html/03_presentation/01_getting_started/04_scenarios/02_pcl_programs.htm PCL program section] of an experiment scenario. This socket can be used to send markers to NIC every time a stimuli is presented. The following [[Media:DemoPresentationTriggerNIC.sce.txt | ''example'']] shows how to proceed in order to send markers to NIC.<br />
<br />
scenario = "Sending triggers to NIC";<br />
<br />
begin;<br />
<br />
text { caption = "Hello world!"; font_size = 24; } hello;<br />
<br />
picture {<br />
text hello;<br />
x = 0; y = 100;<br />
} hello_pic;<br />
<br />
trial {<br />
picture hello_pic;<br />
time = 0;<br />
} hello_trial;<br />
<br />
begin_pcl;<br />
<br />
bool isConnected = false;<br />
# socket creation<br />
socket s = new socket();<br />
<br />
hello.set_caption( "Connecting to trigger server..." );<br />
hello.redraw();<br />
hello_trial.set_duration( 1000 );<br />
hello_trial.present();<br />
<br />
# Connect to the NIC server. The example assumes that NIC runs<br />
# on the same computer as Presentation. Change "localhost" by the IP or<br />
# computer's name where NIC is running. The NIC server runs on port 1234.<br />
# The time-out at 5 secs (5000 ms) can be changed according to your needs.<br />
# 8 bits for the codification and no ecryption.<br />
isConnected = s.open( "localhost", 1234, 5000, socket::ANSI , socket::UNENCRYPTED );<br />
if isConnected == true<br />
then<br />
hello_trial.set_duration( 3000 );<br />
loop<br />
int i = 1<br />
until<br />
i > 50<br />
begin<br />
hello.set_caption( "Sending trigger # " + string( i ) );<br />
hello.redraw();<br />
# The NIC server process a trigger whenever it receives <br />
# a string with the following format:<br />
# <TRIGGER>xxx</TRIGGER><br />
# where xxx is any number different from zero.<br />
s.send("<TRIGGER>" + string( i ) + "</TRIGGER>");<br />
hello_trial.present();<br />
<br />
i = i + 1<br />
end<br />
else<br />
hello.set_caption( "Time out connecting to the server" );<br />
hello.redraw();<br />
hello_trial.present();<br />
end<br />
[[File:Presentation tcpip settings.png|200px|thumb|left| TCP/IP configuration settings in the Presentation software]]<br />
[[File:Presentation extension manager.png|200px|thumb|left| Presentation extension manager]]<br />
[[File:Lsl data port properties.png|200px|thumb|left| LSL data port properties]]<br />
The line<br />
''isConnected = s.open( "localhost", 1234, 5000, socket::ANSI , socket::UNENCRYPTED );''<br />
can be simplified to the following in case the parameters are set in "Settings->Advanced->TCP/IP Defaults".<br />
''isConnected = s.open();<br />
<br />
An alternative way of synchronising the presented stimulus by the Presentation software and NIC is by means of the [https://code.google.com/p/labstreaminglayer/ Lab Streaming Layer (LSL)] protocol. To get use of this functionality you need to install the [http://www.neurobs.com/menu_presentation/menu_download/tools LSL Presentation Extension] in you Presentation software through the Presentation extension manager.<br />
<br />
Once the extension is registered, it can be selected as a data port in Presentation's port settings. Information about the stream outlet name, ID, and connection status can be found in the data port properties window reachable through the "Properties" button that appears when the data port is selected within Presentation's port settings. The Connection Settings property allows users to choose whether the LSL stream outlet should be automatically opened whenever when Presentation starts, or whether it must be manually opened after Presentation is launched.<br />
All events that are logged in the Presentation logfile will also be sent out as LSL markers.<br />
<br />
<br />
Please refer to the [[Interacting_with_NIC]] section for the details on how to configure NIC to handle the reception of the markers from the LSL.<br />
<br />
== ePrime ==<br />
[http://www.pstnet.com/eprime.cfm E-Prime] is a suite of applications for designing and running experiments. This software can send markers to NIC in a similar way as the Presentation software. By using its programming features a socket can be created to connect to the host and port where NIC runs and then send marker whenever the stimuli are presented.<br />
<br />
The following link [http://www.neuroelectrics.com/sites/neuroelectrics.com/files/enobio/eprime2NIC_example.zip eprime2NIC_example.zip] contains an example on how to send markers from E-Prime to NIC.<br />
<br />
== Matlab ==<br />
Matlab can also be used to generate ERP experiments. It can send markers to NIC using the LSL library.<br />
To do it, it's necessary to install the LSL library in Matlab and send the triggers following the LSL standard for markers.<br />
<br />
The following [http://www.neuroelectrics.com/sites/neuroelectrics.com/files/enobio/Enobio_Matlab_Markers.m Matlab Script] contains an example on how to send markers from Matlab to NIC.<br />
<br />
The latest version of the Matlab LSL library can be download from [ftp://sccn.ucsd.edu/pub/software/LSL/SDK/ here].<br />
<br />
= References =<br />
<references /></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=About_tCS&diff=1053About tCS2014-07-29T08:18:29Z<p>Guillem: /* What is tRNS? */</p>
<hr />
<div>Brain function can be modified by applying a weak electrical current using contact electrodes placed over the scalp (transcranial). This kind of brain stimulation receives the name of transcranial Current Stimulation (tCS). <br />
To learn more, please read our review on tCS models and technologies<ref>Giulio Ruffini, Fabrice Wendling, Isabelle Merlet, Behnam Molaee-Ardekani, Abeye Mekonnen, Ricardo Salvador, Aureli Soria-Frisch, Carles Grau, Stephen Dunne, and Pedro C. Miranda, '''Transcranial Current Brain Stimulation (tCS):<br />
Models and Technologies''', IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING, VOL. 21, NO. 3, MAY 2013 </ref><br />
<ref> [[media:HIVE-D1.1_State-of-the-art-V1.3withcovers-small.pdf| '''Brain Stimulation: models, experiments and open questions, HIVE deliverable D1.1, hive-eu.org, June 2009''' ]]</ref>. You can also find more information on tCS at http://hive-eu.org.<br />
<br />
<br />
To date, the most studied tCS type is transcranial Direct Current Stimulation (tDCS).<br />
The basic version of this idea is simple: a current is injected using a battery to the brain through one electrode placed over the scalp above the targeted brain cortical area, and recruited by return electrodes positioned over the scalp, or, alternatively, at an extracephalic position.<br />
Using scalp electrodes, tCS generates weak electrical currents and electric fields (measured in Volts per meter) in the brain. These electric fields modulate neuronal activity.<br />
The main differentiating features of tCS techniques are a) the delivery of weak currents through the scalp (with electrode current intensity to area ratios of about 0.3-5 A/m2) b) at low frequencies (typically < 1 kHz) resulting in weak electric fields in the brain (with amplitudes of about 0.2-2 V/m).<br />
<br />
<br />
= What is tDCS? =<br />
<br />
tDCS (transcranial Direct Current Stimulation) is a kind of tCS where the stimulation currents are held constant (as in DC current), and the most popular and used of tCS techniques.<br />
In general terms, anodal stimulation (current is injected into the brain) over a cortical region has excitatory effects, and cathodal (current is collected from the brain) has inhibitory effects. <br />
tDCS stimulation produce short term effects (increase/decrease) on neuronal excitability, and long lasting plastic after-effects involving synaptic modification (see, e.g., Marquez et al., 2012 and references therin). These underlie the clinical utility of tDCS .<br />
<br />
= What is tACS? =<br />
<br />
Like tDCS, tACS is a form of tCS where the transcranial stimulation currents are time dependent with a sinusoidal shape (as in AC current). Amplitude, frequency and relative phases across stimulation electrodes can be controlled. tACS stimulation may provide a powerful way to couple to the oscillatory behavior of the brain, which is at present an active research field in basic and clinical Neuroscience.<br />
<br />
= What is tRNS? =<br />
<br />
tRNS (transcranial Random Noise Stimulation) is a type of tCS where the stimulation current is varied randomly. Unlike tDCS, tRNS has been recently introduced and there is little experience with its use. However, it appears as if its main effects are excitatory.<br />
<br />
Types of tRNS:<br />
<br />
- Full-band tRNS: the tRNS is generated for the entire band of the device, from 0 to 500Hz.<br />
<br />
- Bandpassed tRNS: the full-band tRNS is filtered using a bandpass filter (low pass and high pass inlcuded). Then the tRNS is only applied in a certain band (i.e. 100-400 Hz). This can be configured in NIC from version 1.3.12 on.<br />
<br />
tRNS setting in NIC:<br />
<br />
[[File:tRNSfilt.jpg|500px]]<br />
<br />
<br />
Bandpass filtered tRNS frequency plot:<br />
<br />
[[File:BandpassNoise.jpg|400px]]<br />
<br />
<br />
- Coloured tRNS: the tRNS is generated following a linear slope at the frequency domaing. This slope can be positive or negative. This function is only available from MatNIC.<br />
<br />
Coloured tRNS frequency plot:<br />
<br />
[[File:ColourNoise.jpg|400px]]<br />
<br />
= What is Sham stimulation? =<br />
<br />
Sham stimulation is a generic term to indicate an inactive form of stimulation (e.g., a very brief or weak one) that is used in research to control for the placebo effect. The subject believes he/she is being stimulated normally, but there should not be any real effects.<br />
<br />
In StarStim Sham is implemented by ramping down (slowly) the current immediately after the ramp up period, and by ramping up (slowly) the current right before the final ramp down portion of the session. This way, the subject feels the ramp up and ramp down events (which are the most noticeable in tCS), but does not receive a significant dose of tCS.<br />
<br />
= What should a modern tCS device offer? StarStim design guidelines: =<br />
<br />
<br />
These are the requirements in which we based our tCS design:<br />
<br />
- Current control at each electrode <br />
<br />
This ensures that the Electric field in the brain is held constant/controlled <br />
(e.g., a simple battery system will not ensure this, since the actual electric fields induced in the brain will depend on contact impedance at the electrodes)<br />
<br />
- Multiple channels for better control of the spatial distribution of the electric fields<br />
- Use of standard sponge electrodes or more modern Ag/AgCl EEG like electrodes<br />
- Ease of use despite complexity of the technology<br />
- Multiple waveforms: tDCS, tACS and tRNS<br />
- Measurement of EEG before, during and after stimulation<br />
- Safety features including maximal currents and impedance control<br />
<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=About_tCS&diff=1052About tCS2014-07-29T08:17:54Z<p>Guillem: /* What is tRNS? */</p>
<hr />
<div>Brain function can be modified by applying a weak electrical current using contact electrodes placed over the scalp (transcranial). This kind of brain stimulation receives the name of transcranial Current Stimulation (tCS). <br />
To learn more, please read our review on tCS models and technologies<ref>Giulio Ruffini, Fabrice Wendling, Isabelle Merlet, Behnam Molaee-Ardekani, Abeye Mekonnen, Ricardo Salvador, Aureli Soria-Frisch, Carles Grau, Stephen Dunne, and Pedro C. Miranda, '''Transcranial Current Brain Stimulation (tCS):<br />
Models and Technologies''', IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING, VOL. 21, NO. 3, MAY 2013 </ref><br />
<ref> [[media:HIVE-D1.1_State-of-the-art-V1.3withcovers-small.pdf| '''Brain Stimulation: models, experiments and open questions, HIVE deliverable D1.1, hive-eu.org, June 2009''' ]]</ref>. You can also find more information on tCS at http://hive-eu.org.<br />
<br />
<br />
To date, the most studied tCS type is transcranial Direct Current Stimulation (tDCS).<br />
The basic version of this idea is simple: a current is injected using a battery to the brain through one electrode placed over the scalp above the targeted brain cortical area, and recruited by return electrodes positioned over the scalp, or, alternatively, at an extracephalic position.<br />
Using scalp electrodes, tCS generates weak electrical currents and electric fields (measured in Volts per meter) in the brain. These electric fields modulate neuronal activity.<br />
The main differentiating features of tCS techniques are a) the delivery of weak currents through the scalp (with electrode current intensity to area ratios of about 0.3-5 A/m2) b) at low frequencies (typically < 1 kHz) resulting in weak electric fields in the brain (with amplitudes of about 0.2-2 V/m).<br />
<br />
<br />
= What is tDCS? =<br />
<br />
tDCS (transcranial Direct Current Stimulation) is a kind of tCS where the stimulation currents are held constant (as in DC current), and the most popular and used of tCS techniques.<br />
In general terms, anodal stimulation (current is injected into the brain) over a cortical region has excitatory effects, and cathodal (current is collected from the brain) has inhibitory effects. <br />
tDCS stimulation produce short term effects (increase/decrease) on neuronal excitability, and long lasting plastic after-effects involving synaptic modification (see, e.g., Marquez et al., 2012 and references therin). These underlie the clinical utility of tDCS .<br />
<br />
= What is tACS? =<br />
<br />
Like tDCS, tACS is a form of tCS where the transcranial stimulation currents are time dependent with a sinusoidal shape (as in AC current). Amplitude, frequency and relative phases across stimulation electrodes can be controlled. tACS stimulation may provide a powerful way to couple to the oscillatory behavior of the brain, which is at present an active research field in basic and clinical Neuroscience.<br />
<br />
= What is tRNS? =<br />
<br />
tRNS (transcranial Random Noise Stimulation) is a type of tCS where the stimulation current is varied randomly. Unlike tDCS, tRNS has been recently introduced and there is little experience with its use. However, it appears as if its main effects are excitatory.<br />
<br />
Types of tRNS:<br />
<br />
- Full-band tRNS: the tRNS is generated for the entire band of the device, from 0 to 500Hz.<br />
<br />
- Bandpassed tRNS: the full-band tRNS is filtered using a bandpass filter (low pass and high pass inlcuded). Then the tRNS is only applied in a certain band (i.e. 100-400 Hz). This can be configured in NIC from version 1.3.12 on.<br />
<br />
tRNS setting in NIC:<br />
<br />
[[File:tRNSfilt.jpg|500px]]<br />
<br />
<br />
Bandpass filtered tRNS frequency plot:<br />
<br />
[[File:BandpassNoise.jpg|400px]]<br />
<br />
<br />
- Coloured tRNS: the tRNS is generated following a linear slope at the frequency domaing. This slope can be positive or negative. This function is only available from MatNIC.<br />
<br />
[[File:ColourNoise.jpg|400px]]<br />
<br />
= What is Sham stimulation? =<br />
<br />
Sham stimulation is a generic term to indicate an inactive form of stimulation (e.g., a very brief or weak one) that is used in research to control for the placebo effect. The subject believes he/she is being stimulated normally, but there should not be any real effects.<br />
<br />
In StarStim Sham is implemented by ramping down (slowly) the current immediately after the ramp up period, and by ramping up (slowly) the current right before the final ramp down portion of the session. This way, the subject feels the ramp up and ramp down events (which are the most noticeable in tCS), but does not receive a significant dose of tCS.<br />
<br />
= What should a modern tCS device offer? StarStim design guidelines: =<br />
<br />
<br />
These are the requirements in which we based our tCS design:<br />
<br />
- Current control at each electrode <br />
<br />
This ensures that the Electric field in the brain is held constant/controlled <br />
(e.g., a simple battery system will not ensure this, since the actual electric fields induced in the brain will depend on contact impedance at the electrodes)<br />
<br />
- Multiple channels for better control of the spatial distribution of the electric fields<br />
- Use of standard sponge electrodes or more modern Ag/AgCl EEG like electrodes<br />
- Ease of use despite complexity of the technology<br />
- Multiple waveforms: tDCS, tACS and tRNS<br />
- Measurement of EEG before, during and after stimulation<br />
- Safety features including maximal currents and impedance control<br />
<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=About_tCS&diff=1051About tCS2014-07-29T08:17:28Z<p>Guillem: /* What is tRNS? */</p>
<hr />
<div>Brain function can be modified by applying a weak electrical current using contact electrodes placed over the scalp (transcranial). This kind of brain stimulation receives the name of transcranial Current Stimulation (tCS). <br />
To learn more, please read our review on tCS models and technologies<ref>Giulio Ruffini, Fabrice Wendling, Isabelle Merlet, Behnam Molaee-Ardekani, Abeye Mekonnen, Ricardo Salvador, Aureli Soria-Frisch, Carles Grau, Stephen Dunne, and Pedro C. Miranda, '''Transcranial Current Brain Stimulation (tCS):<br />
Models and Technologies''', IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING, VOL. 21, NO. 3, MAY 2013 </ref><br />
<ref> [[media:HIVE-D1.1_State-of-the-art-V1.3withcovers-small.pdf| '''Brain Stimulation: models, experiments and open questions, HIVE deliverable D1.1, hive-eu.org, June 2009''' ]]</ref>. You can also find more information on tCS at http://hive-eu.org.<br />
<br />
<br />
To date, the most studied tCS type is transcranial Direct Current Stimulation (tDCS).<br />
The basic version of this idea is simple: a current is injected using a battery to the brain through one electrode placed over the scalp above the targeted brain cortical area, and recruited by return electrodes positioned over the scalp, or, alternatively, at an extracephalic position.<br />
Using scalp electrodes, tCS generates weak electrical currents and electric fields (measured in Volts per meter) in the brain. These electric fields modulate neuronal activity.<br />
The main differentiating features of tCS techniques are a) the delivery of weak currents through the scalp (with electrode current intensity to area ratios of about 0.3-5 A/m2) b) at low frequencies (typically < 1 kHz) resulting in weak electric fields in the brain (with amplitudes of about 0.2-2 V/m).<br />
<br />
<br />
= What is tDCS? =<br />
<br />
tDCS (transcranial Direct Current Stimulation) is a kind of tCS where the stimulation currents are held constant (as in DC current), and the most popular and used of tCS techniques.<br />
In general terms, anodal stimulation (current is injected into the brain) over a cortical region has excitatory effects, and cathodal (current is collected from the brain) has inhibitory effects. <br />
tDCS stimulation produce short term effects (increase/decrease) on neuronal excitability, and long lasting plastic after-effects involving synaptic modification (see, e.g., Marquez et al., 2012 and references therin). These underlie the clinical utility of tDCS .<br />
<br />
= What is tACS? =<br />
<br />
Like tDCS, tACS is a form of tCS where the transcranial stimulation currents are time dependent with a sinusoidal shape (as in AC current). Amplitude, frequency and relative phases across stimulation electrodes can be controlled. tACS stimulation may provide a powerful way to couple to the oscillatory behavior of the brain, which is at present an active research field in basic and clinical Neuroscience.<br />
<br />
= What is tRNS? =<br />
<br />
tRNS (transcranial Random Noise Stimulation) is a type of tCS where the stimulation current is varied randomly. Unlike tDCS, tRNS has been recently introduced and there is little experience with its use. However, it appears as if its main effects are excitatory.<br />
<br />
Types of tRNS:<br />
<br />
- Full-band tRNS: the tRNS is generated for the entire band of the device, from 0 to 500Hz.<br />
<br />
- Bandpassed tRNS: the full-band tRNS is filtered using a bandpass filter (low pass and high pass inlcuded). Then the tRNS is only applied in a certain band (i.e. 100-400 Hz). This can be configured in NIC from version 1.3.12 on.<br />
<br />
tRNS setting in NIC:<br />
<br />
[[File:tRNSfilt.jpg|600px]]<br />
<br />
Bandpass filtered tRNS frequency plot:<br />
<br />
[[File:BandpassNoise.jpg|600px]]<br />
<br />
- Coloured tRNS: the tRNS is generated following a linear slope at the frequency domaing. This slope can be positive or negative. This function is only available from MatNIC.<br />
<br />
[[File:ColourNoise.jpg|600px]]<br />
<br />
= What is Sham stimulation? =<br />
<br />
Sham stimulation is a generic term to indicate an inactive form of stimulation (e.g., a very brief or weak one) that is used in research to control for the placebo effect. The subject believes he/she is being stimulated normally, but there should not be any real effects.<br />
<br />
In StarStim Sham is implemented by ramping down (slowly) the current immediately after the ramp up period, and by ramping up (slowly) the current right before the final ramp down portion of the session. This way, the subject feels the ramp up and ramp down events (which are the most noticeable in tCS), but does not receive a significant dose of tCS.<br />
<br />
= What should a modern tCS device offer? StarStim design guidelines: =<br />
<br />
<br />
These are the requirements in which we based our tCS design:<br />
<br />
- Current control at each electrode <br />
<br />
This ensures that the Electric field in the brain is held constant/controlled <br />
(e.g., a simple battery system will not ensure this, since the actual electric fields induced in the brain will depend on contact impedance at the electrodes)<br />
<br />
- Multiple channels for better control of the spatial distribution of the electric fields<br />
- Use of standard sponge electrodes or more modern Ag/AgCl EEG like electrodes<br />
- Ease of use despite complexity of the technology<br />
- Multiple waveforms: tDCS, tACS and tRNS<br />
- Measurement of EEG before, during and after stimulation<br />
- Safety features including maximal currents and impedance control<br />
<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=File:BandpassNoise.jpg&diff=1050File:BandpassNoise.jpg2014-07-29T08:09:06Z<p>Guillem: </p>
<hr />
<div></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=File:ColourNoise.jpg&diff=1049File:ColourNoise.jpg2014-07-29T08:08:42Z<p>Guillem: </p>
<hr />
<div></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=File:TRNSfilt.jpg&diff=1048File:TRNSfilt.jpg2014-07-29T08:07:54Z<p>Guillem: </p>
<hr />
<div></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=About_tCS&diff=1047About tCS2014-07-29T07:57:15Z<p>Guillem: /* What is tRNS? */</p>
<hr />
<div>Brain function can be modified by applying a weak electrical current using contact electrodes placed over the scalp (transcranial). This kind of brain stimulation receives the name of transcranial Current Stimulation (tCS). <br />
To learn more, please read our review on tCS models and technologies<ref>Giulio Ruffini, Fabrice Wendling, Isabelle Merlet, Behnam Molaee-Ardekani, Abeye Mekonnen, Ricardo Salvador, Aureli Soria-Frisch, Carles Grau, Stephen Dunne, and Pedro C. Miranda, '''Transcranial Current Brain Stimulation (tCS):<br />
Models and Technologies''', IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING, VOL. 21, NO. 3, MAY 2013 </ref><br />
<ref> [[media:HIVE-D1.1_State-of-the-art-V1.3withcovers-small.pdf| '''Brain Stimulation: models, experiments and open questions, HIVE deliverable D1.1, hive-eu.org, June 2009''' ]]</ref>. You can also find more information on tCS at http://hive-eu.org.<br />
<br />
<br />
To date, the most studied tCS type is transcranial Direct Current Stimulation (tDCS).<br />
The basic version of this idea is simple: a current is injected using a battery to the brain through one electrode placed over the scalp above the targeted brain cortical area, and recruited by return electrodes positioned over the scalp, or, alternatively, at an extracephalic position.<br />
Using scalp electrodes, tCS generates weak electrical currents and electric fields (measured in Volts per meter) in the brain. These electric fields modulate neuronal activity.<br />
The main differentiating features of tCS techniques are a) the delivery of weak currents through the scalp (with electrode current intensity to area ratios of about 0.3-5 A/m2) b) at low frequencies (typically < 1 kHz) resulting in weak electric fields in the brain (with amplitudes of about 0.2-2 V/m).<br />
<br />
<br />
= What is tDCS? =<br />
<br />
tDCS (transcranial Direct Current Stimulation) is a kind of tCS where the stimulation currents are held constant (as in DC current), and the most popular and used of tCS techniques.<br />
In general terms, anodal stimulation (current is injected into the brain) over a cortical region has excitatory effects, and cathodal (current is collected from the brain) has inhibitory effects. <br />
tDCS stimulation produce short term effects (increase/decrease) on neuronal excitability, and long lasting plastic after-effects involving synaptic modification (see, e.g., Marquez et al., 2012 and references therin). These underlie the clinical utility of tDCS .<br />
<br />
= What is tACS? =<br />
<br />
Like tDCS, tACS is a form of tCS where the transcranial stimulation currents are time dependent with a sinusoidal shape (as in AC current). Amplitude, frequency and relative phases across stimulation electrodes can be controlled. tACS stimulation may provide a powerful way to couple to the oscillatory behavior of the brain, which is at present an active research field in basic and clinical Neuroscience.<br />
<br />
= What is tRNS? =<br />
<br />
tRNS (transcranial Random Noise Stimulation) is a type of tCS where the stimulation current is varied randomly. Unlike tDCS, tRNS has been recently introduced and there is little experience with its use. However, it appears as if its main effects are excitatory.<br />
<br />
Types of tRNS:<br />
<br />
- Full-band tRNS: the tRNS is generated for the entire band of the device, from 0 to 500Hz.<br />
<br />
- Bandpassed tRNS: the full-band tRNS is filtered using a bandpass filter (low pass and high pass inlcuded). Then the tRNS is only applied in a certain band (i.e. 100-400 Hz). This can be configured in NIC from version 1.3.12 on.<br />
<br />
- Coloured tRNS: the tRNS is generated following a linear slope at the frequency domaing. This slope can be positive or negative. This function is only available from MatNIC.<br />
<br />
= What is Sham stimulation? =<br />
<br />
Sham stimulation is a generic term to indicate an inactive form of stimulation (e.g., a very brief or weak one) that is used in research to control for the placebo effect. The subject believes he/she is being stimulated normally, but there should not be any real effects.<br />
<br />
In StarStim Sham is implemented by ramping down (slowly) the current immediately after the ramp up period, and by ramping up (slowly) the current right before the final ramp down portion of the session. This way, the subject feels the ramp up and ramp down events (which are the most noticeable in tCS), but does not receive a significant dose of tCS.<br />
<br />
= What should a modern tCS device offer? StarStim design guidelines: =<br />
<br />
<br />
These are the requirements in which we based our tCS design:<br />
<br />
- Current control at each electrode <br />
<br />
This ensures that the Electric field in the brain is held constant/controlled <br />
(e.g., a simple battery system will not ensure this, since the actual electric fields induced in the brain will depend on contact impedance at the electrodes)<br />
<br />
- Multiple channels for better control of the spatial distribution of the electric fields<br />
- Use of standard sponge electrodes or more modern Ag/AgCl EEG like electrodes<br />
- Ease of use despite complexity of the technology<br />
- Multiple waveforms: tDCS, tACS and tRNS<br />
- Measurement of EEG before, during and after stimulation<br />
- Safety features including maximal currents and impedance control<br />
<br />
<references/></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Troubleshooting_/_Problem_Solving&diff=1046Troubleshooting / Problem Solving2014-07-29T07:37:18Z<p>Guillem: /* Some known problems and solutions: */</p>
<hr />
<div>== Troubleshooting connectivity issues with Bluetooth ==<br />
<br />
=== Basic Information ===<br />
<br />
The Enobio/StarStim NECBOX connects to the computer using the windows bluetooth stack.<br />
It is important to check if the computer has the Windows stack installed and working. This is not obvious when:<br />
<br />
The computer is a toshiba Laptop (it might use the Toshiba Stack)<br />
The computer has Windows XP (The stack depends on the dongle used)<br />
<br />
If the computer has integrated bluetooth hardware, the system shall be used with their integrated bluetooth. Do not use the provided dongle in a computer that has integrated bluetooth (such as a Mac).<br />
<br />
=== Some known problems and solutions: ===<br />
<br />
In '''Windows''', after a certain time, the device doesn't connect anymore : remove the bluetooth device from the BT device manager and remove the associated COM ports from the device manager.<br />
Let NIC install them again.<br />
<br />
When connecting to a new device, some computers show a message "a Bluetooth device is trying to connect". The user should click on this message and validate the connection. This message might be hidden, so the user should check on the bluetooth icon from Windows.<br />
<br />
With a '''Windows 8''' installation you find it is impossible to connect: contact NE for a new Bluetooth library.<br />
<br />
In '''Mac''' OS you may need to allow the system to run NIC. If needed (the system will ask you or tell you that app is not allowed), go to System Preferences as an administrator / Security & Privacy, and check the box Allowing apps downloaded from anywhere.<br />
<br />
With some newer '''Mac laptops''', bluetooth connectivity is affected by Wifi (seem like Apple is now using a single antenna for both bluetooth and wifi), so Wifi must be turned off while you use NIC. You can still use regular ethernet via cable, however (you may need to get a Thunderbolt to Ethernet adaptor). <br />
<br />
With '''Maverick''' (the latest OS X release as of Nov 2013) and NIC v1.2.10 or before, you will need to disable the App Nap feature for NIC. In order to do this, open a Terminal and type <br />
<br />
defaults write com.yourcompany.NIC NSAppSleepDisabled -bool YES<br />
<br />
Later versions of NIC will fix this transparently.<br />
<br />
== EEG recording issues ==<br />
<br />
If you find noisy signals even after waiting for a few minutes for the electrochemistry to stabilize, check first the DRL/CMS electrode placement. If all electrode signals are noisy you may have a bad DRL/CMS setup. Remove these electrodes, clean the area (mastoid) with a napkin and water/alcohol, and reattach with fresch StickTrodes. Remember to place the both on a mastoid (left or right, but together), with CMS on top (in a quieter "bone" area) and the DRL right underneath (not touching).<br />
<br />
You should also ensure you have a reasonable battery charge (>20%).<br />
<br />
If a single channel is at fault, add more gel (unless you are using a DryTrode) and try to establish a good mechanical contact between the electrode and the scalp, removing some hair if you can. If this still does not work, try replacing the electrode using a new (or othewise well-behaved one). <br />
<br />
If the problem persists, you may have cabling issue. Try to swap cables across two electrodes (one behaving well, the other bad) to see if the problem follows the cable or the electrode. <br />
<br />
If you have a NE Testboard, you can check that the NECBOX is functioning properly by connecting it to the testboard and observing signal quality in all electrodes. If a channel is misbehaving, contact our Technical Support.<br />
<br />
== Stimulation issues ==<br />
<br />
=== Problem: the impedance check returns too high impedances. ===<br />
<br />
Note: normally the measured impedances of the impedance check might be higher before stimulation, but when the experiment starts after some time they might fall down. This is normal (stimulation can itself lower impedance).<br />
<br />
If impedances are too high you can:<br />
- Add more saline solution to the electrodes and check again<br />
- Move your hair to avoid as much hair as possible under the electrode<br />
- Add some saline solution directly at the hair at the electrode zone<br />
- Check that the DRL/CMS electrodes are correctly placed<br />
<br />
Impedances depend on skin type, and can vary quite a bit across individuals.<br />
<br />
You should also ensure you have a reasonable battery charge (>20%).<br />
<br />
== Using the NE Testboard ==<br />
<br />
A good tool for debugging is our testboard ([http://www.neuroelectrics.com/support contact us] if you want one). This board connects to your NECBOX and allows to test different system functionalities as well as discard problem areas. <br />
<br />
The testboard (we call it an "artificial head", but this is stretching things a bit) is a collection of resistors connected so that the impedance seen by any electrode wire is about 5 KOhm (the resistors have a precision of about 5%). Resistors produce (Nyquist) noise as well as pick up noise from the environment (try waiving a magnet near the board, for example). A NE device connected to a testboard will respond as a properly placed system in a subject, with a very similar electrical environment. <br />
<br />
[[File:testboard.JPG |250px|thumb|left| Neuroelectrics testboard]]<br />
[[File:testboardmosaic.png |250px|thumb|left| Connection to NECBOX using flat cable (to test NECBOX)]]<br />
<br />
<br />
=== Using the testboard for EEG testing ===<br />
<br />
<br />
Suppose you have a very noisy channel, and you have tested replacing electrodes (electrodes can be damaged by dirt, light and contact with metals) with the same result (signals still noisy). Is the problem electrode or electrode contact (apparently not, you have checked that replacing the electrode for another one), the cable harness (cables damaged) or is the device faulty? <br />
<br />
You can use your the testboard to record EEG and test your NECBOX. Using the flat cable connector to connect your device (that is, not using the standard cables) to the testboard you should see small EEG signals, with an STD of about 1-2 uV in the 1-40 Hz band. If this checks, your device is working properly. If you see larger signals, there may be an issue with your device ([http://www.neuroelectrics.com/support contact us]). <br />
<br />
If the flat cable test does not detect a problem with the NECBOX, you may have an issue with your cables or electrodes (but those you already tested). In order to check for this, we provide in the testboard an alternative connection using our standard cable harness with clips. This connectors, labeled P1 to P4, should be used to connect a couple of electrode channel leads to P1 and P2, and then the CMS and DRL cables to P3 and P4. This allows for checking integrity of the faulty channels. <br />
[[File:testboardclips.png |250px|thumb|left|Connection to NECBOX using clip connectors with cable harness (to test NECBOX+harness)]]<br />
<br />
In summary, a possible approach to troubleshooting bad EEG signals in a channel is: <br />
<br />
1 - Test first the contact and then electrode by swapping electrodes. <br />
<br />
If this does not solve the problem, <br />
2 - Test the cable using the clip connectors in the testboard. <br />
Replacing the cables should solve the problem. If not, <br />
3 - Test the NECBOX using the flat cable. <br />
<br />
If this fails, [http://www.neuroelectrics.com/support contact us].<br />
<br />
=== Using the testboard for stimulation testing ===<br />
Simply connect your testboard to your Starstim device using the flat cable, program your protocol and launch it to ensure everything is working as you expect. If you want to check the currents injected, you can use resistors R1 to R8 - they are all in series with each channel cable (using Ohm's law, V=IxR). Just measure the potential drop across a resistor with a voltmeter, and divided the result by 5 kOhm to get the current through that cable in mA. Since the precision of resistor resistance is 5%, you can use a digimeter to measure the resistance as well for more precision.<br />
<br />
If you have problems with some electrode impedance, use the clip connector setup described above to test it.</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=About_Sham_and_Double-blind_experiments&diff=1045About Sham and Double-blind experiments2014-07-25T08:44:59Z<p>Guillem: /* Sham */</p>
<hr />
<div>With Starstim you can easily implement "sham" stimulation session and also double-blind experiments. <br />
<br />
== Sham ==<br />
In tCS, [[ About_tCS#What_is_Sham_stimulation.3F | Sham]] refers to creating an experience for the subject akin to real stimulation, without actually applying significant currents. The subject believes he/she is being stimulated normally, but there should not be any real effects. The goal is to control for placebo effects in treatment. Whether you are doing a doble or single-blind experiment, stimulation sham mode is needed to control for placebo effects. With Starstim, Sham mode is implemented by ramping up and down the current at the beginning/end of stimulation respectively, as it is during these times when the subject can feel the strongest sensations during stimulation.<br />
The setting of the Sham ramp time depends on the protocol and sensations of the patients, therefore it can be adjusted.<br />
<br />
Below there are the pictures to show a normal Stimulation profile and a Sham stimulation profile.<br />
<br />
Normal Stimulation Profile:<br />
<br />
[[File:ShamNO.jpg|600px]]<br />
<br />
Sham Stimulation Profile:<br />
<br />
[[File:Sham.jpg|600px]]<br />
<br />
== Single and Double Blinding ==<br />
In '''single-blind''' trials, the operator knows which stimulation type is being applied, but the subject doesn't. <br />
<br />
In '''double-blind''' experiments, the goal is to have both operator and subject blind to which type of stimulation is being applied (e.g., active vs. sham, or anodal vs. cathodal, etc). See our detailed '''[http://www.neuroelectrics.com/sites/neuroelectrics.com/files/enobio/Double_Blind_mode_user_manual.pdf StarStim Double-Blind Mode Manual]''' for more information on how to configure your experiments and NIC for double-blind trials.</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=About_Sham_and_Double-blind_experiments&diff=1044About Sham and Double-blind experiments2014-07-25T08:42:31Z<p>Guillem: /* Sham */</p>
<hr />
<div>With Starstim you can easily implement "sham" stimulation session and also double-blind experiments. <br />
<br />
== Sham ==<br />
In tCS, [[ About_tCS#What_is_Sham_stimulation.3F | Sham]] refers to creating an experience for the subject akin to real stimulation, without actually applying significant currents. The subject believes he/she is being stimulated normally, but there should not be any real effects. The goal is to control for placebo effects in treatment. Whether you are doing a doble or single-blind experiment, stimulation sham mode is needed to control for placebo effects. With Starstim, Sham mode is implemented by ramping up and down the current at the beginning/end of stimulation respectively, as it is during these times when the subject can feel the strongest sensations during stimulation.<br />
<br />
Normal Stimulation Profile:<br />
<br />
[[File:ShamNO.jpg|600px]]<br />
<br />
Sham Stimulation Profile:<br />
<br />
[[File:Sham.jpg|600px]]<br />
<br />
== Single and Double Blinding ==<br />
In '''single-blind''' trials, the operator knows which stimulation type is being applied, but the subject doesn't. <br />
<br />
In '''double-blind''' experiments, the goal is to have both operator and subject blind to which type of stimulation is being applied (e.g., active vs. sham, or anodal vs. cathodal, etc). See our detailed '''[http://www.neuroelectrics.com/sites/neuroelectrics.com/files/enobio/Double_Blind_mode_user_manual.pdf StarStim Double-Blind Mode Manual]''' for more information on how to configure your experiments and NIC for double-blind trials.</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=About_Sham_and_Double-blind_experiments&diff=1043About Sham and Double-blind experiments2014-07-25T08:39:38Z<p>Guillem: /* Sham */</p>
<hr />
<div>With Starstim you can easily implement "sham" stimulation session and also double-blind experiments. <br />
<br />
== Sham ==<br />
In tCS, [[ About_tCS#What_is_Sham_stimulation.3F | Sham]] refers to creating an experience for the subject akin to real stimulation, without actually applying significant currents. The subject believes he/she is being stimulated normally, but there should not be any real effects. The goal is to control for placebo effects in treatment. Whether you are doing a doble or single-blind experiment, stimulation sham mode is needed to control for placebo effects. With Starstim, Sham mode is implemented by ramping up and down the current at the beginning/end of stimulation respectively, as it is during these times when the subject can feel the strongest sensations during stimulation.<br />
<br />
Normal Stimulation Profile:<br />
<br />
[[File:ShamNO.jpg]]<br />
<br />
Sham Stimulation Profile:<br />
<br />
[[File:Sham.jpg]]<br />
<br />
== Single and Double Blinding ==<br />
In '''single-blind''' trials, the operator knows which stimulation type is being applied, but the subject doesn't. <br />
<br />
In '''double-blind''' experiments, the goal is to have both operator and subject blind to which type of stimulation is being applied (e.g., active vs. sham, or anodal vs. cathodal, etc). See our detailed '''[http://www.neuroelectrics.com/sites/neuroelectrics.com/files/enobio/Double_Blind_mode_user_manual.pdf StarStim Double-Blind Mode Manual]''' for more information on how to configure your experiments and NIC for double-blind trials.</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=File:ShamNO.jpg&diff=1042File:ShamNO.jpg2014-07-25T08:34:00Z<p>Guillem: </p>
<hr />
<div></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=File:Sham.jpg&diff=1041File:Sham.jpg2014-07-25T08:33:27Z<p>Guillem: </p>
<hr />
<div></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Interacting_with_NIC&diff=1040Interacting with NIC2014-07-25T08:26:27Z<p>Guillem: /* Receiving data streams using LSL */</p>
<hr />
<div>In this page we describe how you can interact with NIC (Neuroelectrics Instrument Controller, the software for control with NE devices) using other software. <br />
<br />
== About Synchronization: general principles ==<br />
[[File:Master slave synchronization.png|200px|thumb|left| The Master system's clock is the only one used in the whole system. The master system either gathers the data from the slave systems to provide a single output or sends its clock so the slave systems can provide their outputs using that clock]]<br />
To coordinate different data sources or events to a single clock is known as synchronization.<br />
<br />
When using Enobio at least there are two different clocks that need to be synchronized: The clock of the Enobio wireless sensor which is in charge of sampling the EEG data recorded by the electrodes, and the clock of the host where NIC runs and receives the EEG data from the Bluetooth connection.<br />
<br />
NIC uses the clock from the Enobio sensor as master. The Enobio clock is received by NIC through the data streaming. The EEG data is sampled at 500 Hz, so every sample is delayed 2 ms from the previous one. In traditional wired system the data will be received by the control software as it is sampled so the two clocks might be directly synchronized. However in wireless system such as the Enobio one, some latency might be introduced in the wireless channel due to RF interference and re-transmission of data.<br />
<br />
NIC implements an algorithm that compensates this latency and finds out the offset between the clock from Enobio and the one from the host where NIC runs. When NIC receives information from third-party applications that need to be synchronized with the EEG data, like markers that signal when external events occur, it compensates the timestamp of the received data so it is aligned with the EEG data streaming.<br />
<br />
In the scenario described above, when NIC collects markers that are sent by other applications, another clock to be synchronized is introduced in the system. This is the clock from the host that sends the markers. NIC provides two ways of gathering such markers. Both of them are described in the following sections. The first one does not provide any synchronization mechanism, this is the reception of markers using a TCP/IP server where the clients connect to and send their markers. This method might be useful when the time synchronization requirements do not need accuracy under the 100 ms.<br />
<br />
The second method uses the [https://code.google.com/p/labstreaminglayer/ Lab Streaming Layer (LSL)], which incorporates built-in network and synchronization capabilities that allow synchronization accuracy on 1 ms so it perfectly fits application like the one that detect [[Event_Related_Potentials_(ERPs) | ERPs signals]].<br />
<br />
<br />
<!--talk about hardware set up to manually determine this deviation and fix it through advanced NIC properties--><br />
<br />
== Sending Markers to NIC from other software or hardware ==<br />
=== Sending Markers using TCP/IP ===<br />
<!-- talk about the marker server: port number, protocol --><br />
NIC provides a server that other software can connect to in order to send markers. Those received markers are synchronized with the EEG streaming for further analysis.<br />
<br />
This NIC server is running in the '''TCP/IP port 1234'''. Up to five clients can simultaneously send markers to NIC by making a TCP/IP connection to this port.<br />
<br />
Once a client is connected it needs to send the following string in order to send a marker:<br />
<TRIGGER>XXXX</TRIGGER><br />
Where XXXX can represent any integer number different from zero (from -2147483647 to +2147483647). This marker will be co-registered in the output files generated by NIC to the corresponding EEG sample. For instance, in the output tabulated text file, the column just after the timestamp one is filled with zeros if no markers are received. When a marker is received its corresponding number is set to that column. See the following example:<br />
<br />
...<br />
26748 -27675 35631 42398 532666 64345 12376 40988 0 1382432459788<br />
26865 -26683 35685 42450 532711 64821 12376 41046 0 1382432459790<br />
26810 -26821 35531 41997 532821 64945 13164 41099 0 1382432459792<br />
26749 -26995 35325 42008 532712 64377 13478 41286 0 1382432459794<br />
26796 -27245 35932 42391 532923 64245 13620 41117 300 1382432459796 <-- Reception of the marker #300<br />
26622 -27510 35501 42630 532876 64193 13031 40986 0 1382432459798<br />
26751 -27912 35611 42003 532345 64344 12967 40731 0 1382432459800<br />
...<br />
<br />
[[File:Markers audio signal.png|200px|thumb|left| Plot of markers received by NIC and an audio signal recorded by Enobio]]<br />
Please take as an example [[Media:Matlab Markers Example.zip | ''this'']] Matlab code which connects to NIC to send markers every time a tone is played back through the sound card. If you connected the output of the computer sound card to one of the Enobio electrodes you would be able to see the alignment between the markers and the played tones.<br />
<br />
=== Sending markers using LSL ===<br />
<!-- talk about LSL client: string and integer markers --><br />
NIC is compliant with the [https://code.google.com/p/labstreaminglayer/ Lab Streaming Layer (LSL)] protocol so makers can be co-registered with the EEG signal by setting up a LSL marker outlet (see this [https://code.google.com/p/labstreaminglayer/source/browse/LSL/liblsl/examples/C/SendStringMarkersC/SendStringMarkersC.c example]).<br />
<br />
The LSL handles both the networking and time-synchronization isues between the sender and receiver hosts obtaining reliability on order of 1 ms (see the time-synchronization validation [https://code.google.com/p/labstreaminglayer/wiki/TimeSynchronizationValidation tests]).<br />
<br />
[[File:NIC LSL settings.png|200px|thumb|left| NIC settings for configuring the reception of markers through LSL]]<br />
NIC needs little configuration in order to receive the markers from a LSL outlet present in the local network. When the LSL marker outlet sends integer-type markers only the name of the outlet needs to be configured in NIC.<br />
<br />
Please go to "''EEG Setup -> Settings -> Markers from Lab Streaming Layer''" and set the name that your LSL marker outlet has. NIC will automatically look for a marker outlet with this name and will connect to it. If the outlet sends integer-type integers then no further configuration is needed. All the received makers will be co-registered along with the EEG signal to the output files.<br />
<br />
In case the outlet sends string-type markers then there are some considerations that have to be taken into account. The LSL outlet sending string-type markers has to format them as XML tags. The following example is taken from the string markers that the Presentation software sends when the LSL extension manager is installed (see the [[Event_Related_Potentials_(ERPs)#Presentation | Working with ERPs]] section). You can see that NIC will decode the string looking for the tag that is configured in the "''EEG Setup -> Settings -> Markers from Lab Streaming Layer''" settings, ''ecode'' in this case. The marker number 37 will be registered at the reception of this string:<br />
<pevent><etype>Picture</etype>'''<ecode>37</ecode>'''<unc>209.638092041016</unc>test</pevent><br />
<br />
<!-- talk about TTL hardware triggering --><br />
<br />
== Receiving data streams from NIC ==<br />
=== Receiving data streams using TCP/IP ===<br />
The NIC software has a TCP/IP server that streams the EEG data received from Enobio. Up to 5 clients can connect to that server simultaneously in order to receive the EEG data ans perform the desired operations in real time.<br />
<br />
The software clients that want to receive the EEG data in real time from NIC need to connect to the '''TCP/IP port 1234''' of the host where the NIC software is running. Once the client software is connected to the server, it will receive the EEG data streaming according to the following format:<br />
-------------------------------------------------------------------------------------------<br />
| Channel 1 | ... | Channel N | <br />
-------------------------------------------------------------------------------------------<br />
| (MSB) Byte#1 | Byte#2 | Byte#3 | (LSB) Byte#4 | ... | Byte#1 | Byte#2 | Byte#3 | Byte#4 |<br />
-------------------------------------------------------------------------------------------<br />
Each EEG sample is sent as a two-complement 4 byte value. The unit of the EEG sample is nano volts and its range is from -400000000 to +400000000 nV. The most significant byte is sent first. The following code in 'C' shows how to decode the streaming from the received bytes to EEG sample values. The example assumes that the computer architecture is little-endian.<br />
// byte3 = 0xFF, byte2 = 0x8F, byte1 = 0x99, byte0 = 0x61<br />
signed int32_t sample = 0;<br />
sample += byte3;<br />
sample = sample << 8;<br />
sample += byte2;<br />
sample = sample << 8;<br />
sample += byte1;<br />
sample = sample << 8;<br />
sample += byte0;<br />
// sample = -141584031 nV<br />
<br />
The client will receive first the four bytes from channel 1, then the next four bytes from channel 2 and so on till receiving the four bytes from the last channel of Enobio (8 or 20 depending of the type of Enobio/Starstim NIC handles). Then channel 1 bytes are receiving again.<br />
<br />
The following links are a Java and a Matlab example clients that connects to NIC and receive the EEG streaming: [[Media:Java_TCP_Enobio_Client.zip | Java client]], [[Media:Matlab_TCP_Enobio_Client.zip | Matlab client]]<br />
<br />
=== Receiving data streams using LSL ===<br />
<!-- talk about receiving the data stream using the LSL --><br />
<br />
NIC streams the received EEG data from Enobio usign the Lab Streaming Layer. NIC creates a LSL outlet with the following settings:<br />
Name: NIC<br />
Type: EEG<br />
Channel count: 8 or 20 depending of the Enobio NIC handles<br />
Nominal sample rate: 500<br />
Channel format: float_32<br />
Unique source ID: The Enobio type plus its mac address<br />
An LSL client software needs to connect to this outlet in order to receive the EEG streaming data. The received values are expressed in nanovolts and its range is from -400000000 to +400000000.<br />
<br />
Using LSL is possible to access to the accelerometer data too. The outlet the LSL clients need to connect to has the following settings:<br />
Name: NIC<br />
Type: Accelerometer<br />
Channel count: 3<br />
Nominal sample rate: 100<br />
Channel format: float_32<br />
Unique source ID: The Enobio type plus its mac address plus the "Acc" string<br />
<br />
Using LSL is possible to access markers generated from another NIC. The outlet the LSL clients need to connect to has the following settings:<br />
Name: NIC<br />
Type: Markers<br />
Channel count: 1<br />
Nominal sample rate: n/a<br />
Channel format: Int_32<br />
Unique source ID: The Enobio type plus its mac address plus the "Marker" string<br />
<br />
The names of the Outlets, are for the version 1.3.12. For previous versions, the name of the outlet is "Enobio"<br />
<br />
== Sending commands to NIC ==<br />
<!-- talk about the features of NIC being controlling (Enobio and StarStim) using a command-based protocol--><br />
<!-- talk about MatNIC as a set of routines that wrap this protocol to provide the functionalities of command NIC from Matlab --><br />
<!-- provide examples --><br />
<br />
NIC can be remotely commanded from a third-party software through a set of commands that can be sent using a TCP/IP connection. NIC listens to the '''TCP/IP port 1235''' for incoming connections. The clients that connect to that port can command the following actions:<br />
/--------------------------------------------------\<br />
| Action | Device |<br />
|--------------------------------------------------|<br />
| Start EEG streaming | Enobio & StarStim |<br />
| Stop EEG streaming | Enobio & StarStim |<br />
| Start Stimulation | StarStim |<br />
| Abort Stimulation | StarStim |<br />
| Online tACS Frequency Change | StarStim |<br />
| Online tACS Amplitude change | StarStim |<br />
| Online tDCS Amplitude change | StarStim |<br />
| Load template | StarStim |<br />
| Request status | Enobio & StarStim |<br />
\--------------------------------------------------/<br />
<br />
NIC responds to those commands with a set of status commands to indicate whether the commands are successfully processed, the stimulation is ready to be started and so on. The following table shows all the possible status value that NIC might send.<br />
<br />
/--------------------------------------------------------\<br />
| Status | Device |<br />
|--------------------------------------------------------|<br />
| Remote control allowed | Enobio & StarStim |<br />
| Remote control rejected | Enobio & StarStim |<br />
| Device is idle | Enobio & StarStim |<br />
| EEG streaming is ON | Enobio & StarStim |<br />
| EEG streaming is OFF | Enobio & StarStim | <br />
| Template not loaded | StarStim |<br />
| Template loaded | StarStim |<br />
| Stimulation is ready to be started | StarStim |<br />
| Stimulation is ON | StarStim |<br />
| Stimulation is OFF | StarStim |<br />
\--------------------------------------------------------/<br />
<br />
MatNIC is a Matlab toolkit that wraps all these commands and status code in a set of Matlab functions that allow remotely controlling NIC. See the [[MatNIC_Matlab_Toolkit|'''MatNIC section''']] for more info.</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Interacting_with_NIC&diff=1039Interacting with NIC2014-07-25T08:07:47Z<p>Guillem: /* Receiving data streams using LSL */</p>
<hr />
<div>In this page we describe how you can interact with NIC (Neuroelectrics Instrument Controller, the software for control with NE devices) using other software. <br />
<br />
== About Synchronization: general principles ==<br />
[[File:Master slave synchronization.png|200px|thumb|left| The Master system's clock is the only one used in the whole system. The master system either gathers the data from the slave systems to provide a single output or sends its clock so the slave systems can provide their outputs using that clock]]<br />
To coordinate different data sources or events to a single clock is known as synchronization.<br />
<br />
When using Enobio at least there are two different clocks that need to be synchronized: The clock of the Enobio wireless sensor which is in charge of sampling the EEG data recorded by the electrodes, and the clock of the host where NIC runs and receives the EEG data from the Bluetooth connection.<br />
<br />
NIC uses the clock from the Enobio sensor as master. The Enobio clock is received by NIC through the data streaming. The EEG data is sampled at 500 Hz, so every sample is delayed 2 ms from the previous one. In traditional wired system the data will be received by the control software as it is sampled so the two clocks might be directly synchronized. However in wireless system such as the Enobio one, some latency might be introduced in the wireless channel due to RF interference and re-transmission of data.<br />
<br />
NIC implements an algorithm that compensates this latency and finds out the offset between the clock from Enobio and the one from the host where NIC runs. When NIC receives information from third-party applications that need to be synchronized with the EEG data, like markers that signal when external events occur, it compensates the timestamp of the received data so it is aligned with the EEG data streaming.<br />
<br />
In the scenario described above, when NIC collects markers that are sent by other applications, another clock to be synchronized is introduced in the system. This is the clock from the host that sends the markers. NIC provides two ways of gathering such markers. Both of them are described in the following sections. The first one does not provide any synchronization mechanism, this is the reception of markers using a TCP/IP server where the clients connect to and send their markers. This method might be useful when the time synchronization requirements do not need accuracy under the 100 ms.<br />
<br />
The second method uses the [https://code.google.com/p/labstreaminglayer/ Lab Streaming Layer (LSL)], which incorporates built-in network and synchronization capabilities that allow synchronization accuracy on 1 ms so it perfectly fits application like the one that detect [[Event_Related_Potentials_(ERPs) | ERPs signals]].<br />
<br />
<br />
<!--talk about hardware set up to manually determine this deviation and fix it through advanced NIC properties--><br />
<br />
== Sending Markers to NIC from other software or hardware ==<br />
=== Sending Markers using TCP/IP ===<br />
<!-- talk about the marker server: port number, protocol --><br />
NIC provides a server that other software can connect to in order to send markers. Those received markers are synchronized with the EEG streaming for further analysis.<br />
<br />
This NIC server is running in the '''TCP/IP port 1234'''. Up to five clients can simultaneously send markers to NIC by making a TCP/IP connection to this port.<br />
<br />
Once a client is connected it needs to send the following string in order to send a marker:<br />
<TRIGGER>XXXX</TRIGGER><br />
Where XXXX can represent any integer number different from zero (from -2147483647 to +2147483647). This marker will be co-registered in the output files generated by NIC to the corresponding EEG sample. For instance, in the output tabulated text file, the column just after the timestamp one is filled with zeros if no markers are received. When a marker is received its corresponding number is set to that column. See the following example:<br />
<br />
...<br />
26748 -27675 35631 42398 532666 64345 12376 40988 0 1382432459788<br />
26865 -26683 35685 42450 532711 64821 12376 41046 0 1382432459790<br />
26810 -26821 35531 41997 532821 64945 13164 41099 0 1382432459792<br />
26749 -26995 35325 42008 532712 64377 13478 41286 0 1382432459794<br />
26796 -27245 35932 42391 532923 64245 13620 41117 300 1382432459796 <-- Reception of the marker #300<br />
26622 -27510 35501 42630 532876 64193 13031 40986 0 1382432459798<br />
26751 -27912 35611 42003 532345 64344 12967 40731 0 1382432459800<br />
...<br />
<br />
[[File:Markers audio signal.png|200px|thumb|left| Plot of markers received by NIC and an audio signal recorded by Enobio]]<br />
Please take as an example [[Media:Matlab Markers Example.zip | ''this'']] Matlab code which connects to NIC to send markers every time a tone is played back through the sound card. If you connected the output of the computer sound card to one of the Enobio electrodes you would be able to see the alignment between the markers and the played tones.<br />
<br />
=== Sending markers using LSL ===<br />
<!-- talk about LSL client: string and integer markers --><br />
NIC is compliant with the [https://code.google.com/p/labstreaminglayer/ Lab Streaming Layer (LSL)] protocol so makers can be co-registered with the EEG signal by setting up a LSL marker outlet (see this [https://code.google.com/p/labstreaminglayer/source/browse/LSL/liblsl/examples/C/SendStringMarkersC/SendStringMarkersC.c example]).<br />
<br />
The LSL handles both the networking and time-synchronization isues between the sender and receiver hosts obtaining reliability on order of 1 ms (see the time-synchronization validation [https://code.google.com/p/labstreaminglayer/wiki/TimeSynchronizationValidation tests]).<br />
<br />
[[File:NIC LSL settings.png|200px|thumb|left| NIC settings for configuring the reception of markers through LSL]]<br />
NIC needs little configuration in order to receive the markers from a LSL outlet present in the local network. When the LSL marker outlet sends integer-type markers only the name of the outlet needs to be configured in NIC.<br />
<br />
Please go to "''EEG Setup -> Settings -> Markers from Lab Streaming Layer''" and set the name that your LSL marker outlet has. NIC will automatically look for a marker outlet with this name and will connect to it. If the outlet sends integer-type integers then no further configuration is needed. All the received makers will be co-registered along with the EEG signal to the output files.<br />
<br />
In case the outlet sends string-type markers then there are some considerations that have to be taken into account. The LSL outlet sending string-type markers has to format them as XML tags. The following example is taken from the string markers that the Presentation software sends when the LSL extension manager is installed (see the [[Event_Related_Potentials_(ERPs)#Presentation | Working with ERPs]] section). You can see that NIC will decode the string looking for the tag that is configured in the "''EEG Setup -> Settings -> Markers from Lab Streaming Layer''" settings, ''ecode'' in this case. The marker number 37 will be registered at the reception of this string:<br />
<pevent><etype>Picture</etype>'''<ecode>37</ecode>'''<unc>209.638092041016</unc>test</pevent><br />
<br />
<!-- talk about TTL hardware triggering --><br />
<br />
== Receiving data streams from NIC ==<br />
=== Receiving data streams using TCP/IP ===<br />
The NIC software has a TCP/IP server that streams the EEG data received from Enobio. Up to 5 clients can connect to that server simultaneously in order to receive the EEG data ans perform the desired operations in real time.<br />
<br />
The software clients that want to receive the EEG data in real time from NIC need to connect to the '''TCP/IP port 1234''' of the host where the NIC software is running. Once the client software is connected to the server, it will receive the EEG data streaming according to the following format:<br />
-------------------------------------------------------------------------------------------<br />
| Channel 1 | ... | Channel N | <br />
-------------------------------------------------------------------------------------------<br />
| (MSB) Byte#1 | Byte#2 | Byte#3 | (LSB) Byte#4 | ... | Byte#1 | Byte#2 | Byte#3 | Byte#4 |<br />
-------------------------------------------------------------------------------------------<br />
Each EEG sample is sent as a two-complement 4 byte value. The unit of the EEG sample is nano volts and its range is from -400000000 to +400000000 nV. The most significant byte is sent first. The following code in 'C' shows how to decode the streaming from the received bytes to EEG sample values. The example assumes that the computer architecture is little-endian.<br />
// byte3 = 0xFF, byte2 = 0x8F, byte1 = 0x99, byte0 = 0x61<br />
signed int32_t sample = 0;<br />
sample += byte3;<br />
sample = sample << 8;<br />
sample += byte2;<br />
sample = sample << 8;<br />
sample += byte1;<br />
sample = sample << 8;<br />
sample += byte0;<br />
// sample = -141584031 nV<br />
<br />
The client will receive first the four bytes from channel 1, then the next four bytes from channel 2 and so on till receiving the four bytes from the last channel of Enobio (8 or 20 depending of the type of Enobio/Starstim NIC handles). Then channel 1 bytes are receiving again.<br />
<br />
The following links are a Java and a Matlab example clients that connects to NIC and receive the EEG streaming: [[Media:Java_TCP_Enobio_Client.zip | Java client]], [[Media:Matlab_TCP_Enobio_Client.zip | Matlab client]]<br />
<br />
=== Receiving data streams using LSL ===<br />
<!-- talk about receiving the data stream using the LSL --><br />
<br />
NIC streams the received EEG data from Enobio usign the Lab Streaming Layer. NIC creates a LSL outlet with the following settings:<br />
Name: NIC<br />
Type: EEG<br />
Channel count: 8 or 20 depending of the Enobio NIC handles<br />
Nominal sample rate: 500<br />
Channel format: float_32<br />
Unique source ID: The Enobio type plus its mac address<br />
An LSL client software needs to connect to this outlet in order to receive the EEG streaming data. The received values are expressed in nanovolts and its range is from -400000000 to +400000000.<br />
<br />
Using LSL is possible to access to the accelerometer data too. The outlet the LSL clients need to connect to has the following settings:<br />
Name: NIC<br />
Type: Accelerometer<br />
Channel count: 3<br />
Nominal sample rate: 100<br />
Channel format: float_32<br />
Unique source ID: The Enobio type plus its mac address plus the "Acc" string<br />
<br />
Using LSL is possible to access markers generated from another NIC. The outlet the LSL clients need to connect to has the following settings:<br />
Name: NIC<br />
Type: Markers<br />
Channel count: 1<br />
Nominal sample rate: n/a<br />
Channel format: Int_32<br />
Unique source ID: The Enobio type plus its mac address plus the "Marker" string<br />
<br />
== Sending commands to NIC ==<br />
<!-- talk about the features of NIC being controlling (Enobio and StarStim) using a command-based protocol--><br />
<!-- talk about MatNIC as a set of routines that wrap this protocol to provide the functionalities of command NIC from Matlab --><br />
<!-- provide examples --><br />
<br />
NIC can be remotely commanded from a third-party software through a set of commands that can be sent using a TCP/IP connection. NIC listens to the '''TCP/IP port 1235''' for incoming connections. The clients that connect to that port can command the following actions:<br />
/--------------------------------------------------\<br />
| Action | Device |<br />
|--------------------------------------------------|<br />
| Start EEG streaming | Enobio & StarStim |<br />
| Stop EEG streaming | Enobio & StarStim |<br />
| Start Stimulation | StarStim |<br />
| Abort Stimulation | StarStim |<br />
| Online tACS Frequency Change | StarStim |<br />
| Online tACS Amplitude change | StarStim |<br />
| Online tDCS Amplitude change | StarStim |<br />
| Load template | StarStim |<br />
| Request status | Enobio & StarStim |<br />
\--------------------------------------------------/<br />
<br />
NIC responds to those commands with a set of status commands to indicate whether the commands are successfully processed, the stimulation is ready to be started and so on. The following table shows all the possible status value that NIC might send.<br />
<br />
/--------------------------------------------------------\<br />
| Status | Device |<br />
|--------------------------------------------------------|<br />
| Remote control allowed | Enobio & StarStim |<br />
| Remote control rejected | Enobio & StarStim |<br />
| Device is idle | Enobio & StarStim |<br />
| EEG streaming is ON | Enobio & StarStim |<br />
| EEG streaming is OFF | Enobio & StarStim | <br />
| Template not loaded | StarStim |<br />
| Template loaded | StarStim |<br />
| Stimulation is ready to be started | StarStim |<br />
| Stimulation is ON | StarStim |<br />
| Stimulation is OFF | StarStim |<br />
\--------------------------------------------------------/<br />
<br />
MatNIC is a Matlab toolkit that wraps all these commands and status code in a set of Matlab functions that allow remotely controlling NIC. See the [[MatNIC_Matlab_Toolkit|'''MatNIC section''']] for more info.</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Event_Related_Potentials_(ERPs)&diff=1038Event Related Potentials (ERPs)2014-07-24T09:46:28Z<p>Guillem: /* ePrime */</p>
<hr />
<div>= About Event Related Potentials (ERPs) =<br />
An '''event-related potential''' ('''ERP''') is the measured brain response that is the direct result of a specific sense|sensory, cognition|cognitive, or motor system|motor event.<ref name="Luck">Luck, Steven J. (2005). An Introduction to the Event-Related Potential Technique. The MIT Press. ISBN 0-262-12277-4.</ref>.<br />
<br />
Those brain response can be measured with electroencephalography (EEG) using devices such as [http://www.neuroelectrics.com/enobio Enobio]. EEG reflects thousands of simultaneously ongoing brain processes. This means that the brain response to a single stimulus or event of interest is not usually visible in the EEG recording of a single trial. To see the brain's response to a stimulus, the experimenter must conduct many trials (usually in the order of 100 or more) and average the results together, causing random brain activity to be averaged out and the relevant waveform to remain, called the ERP.<ref name "Coles">Coles, Michael G.H.; Michael D. Rugg (1996). "Event-related brain potentials: an introduction". Electrophysiology of Mind. Oxford Scholarship Online Monographs. pp. 1–27</ref><br />
<br />
These stimuli can be visual, auditory, tactile and even olfactory and gustatory. In order to record those event-related potential the recording set-up needs to '''synchronise''' very accurately both the stimuli presentation and the EEG recording device. Commonly the software in charge of presenting the stimuli send a marker to the EEG recording system each time a stimuli is presented. If the triggers are properly recorded along with the EEG signal, an automatic pre-processing step can automatically cut the signal in epochs for further averaging.<br />
<br />
Further information regarding ERPs and its different types can be found in the following two links:[http://blog.neuroelectrics.com/blog/bid/237205/Event-Related-Potential-Our-Brain-Response-To-External-Stimuli 1] [http://blog.neuroelectrics.com/blog/bid/318938/14-Event-Related-Potentials-Components-and-Modalities 2], as well as in our White Papers<br />
<ref name="NEWP201401">Neuroelectrics NEWP201401, Event Synchronization of EEG data using the LSL, [http://wiki.neuroelectrics.com/index.php/Neuroelectrics_White_Papers]</ref><br />
<ref name="NEWP201403">Neuroelectrics NEWP201403, Extraction of ERPs with NE devices, [http://wiki.neuroelectrics.com/index.php/Neuroelectrics_White_Papers]</ref>.<br />
<br />
= Presentation Software =<br />
There are several software that can set-up an experiment which presents some stimulus (audio, images, video, etc.) to a subject in order to elicit ERPs in the EEG signal. It is very important that the recorded EEG data is synchronised with those stimulus in order to detect the ERPs when analyzing the data. The [http://www.neuroelectrics.com/enobio/software NIC] software provides the basic infrastructure to receive those markers from this kind of software every time a stimuli is presented. Please refer to the [[Interacting_with_NIC]] section for the details on how NIC handles the reception of the markers.<br />
<br />
In the following section we detail how some of the most relevant presentation software can be configured to send markers to NIC.<br />
== Presentation ==<br />
The [http://www.neurobs.com/ Presentation] software allows to connect to a remote application by using sockets in the [http://www.neurobs.com/pres_docs/html/03_presentation/01_getting_started/04_scenarios/02_pcl_programs.htm PCL program section] of an experiment scenario. This socket can be used to send markers to NIC every time a stimuli is presented. The following [[Media:DemoPresentationTriggerNIC.sce.txt | ''example'']] shows how to proceed in order to send markers to NIC.<br />
<br />
scenario = "Sending triggers to NIC";<br />
<br />
begin;<br />
<br />
text { caption = "Hello world!"; font_size = 24; } hello;<br />
<br />
picture {<br />
text hello;<br />
x = 0; y = 100;<br />
} hello_pic;<br />
<br />
trial {<br />
picture hello_pic;<br />
time = 0;<br />
} hello_trial;<br />
<br />
begin_pcl;<br />
<br />
bool isConnected = false;<br />
# socket creation<br />
socket s = new socket();<br />
<br />
hello.set_caption( "Connecting to trigger server..." );<br />
hello.redraw();<br />
hello_trial.set_duration( 1000 );<br />
hello_trial.present();<br />
<br />
# Connect to the NIC server. The example assumes that NIC runs<br />
# on the same computer as Presentation. Change "localhost" by the IP or<br />
# computer's name where NIC is running. The NIC server runs on port 1234.<br />
# The time-out at 5 secs (5000 ms) can be changed according to your needs.<br />
# 8 bits for the codification and no ecryption.<br />
isConnected = s.open( "localhost", 1234, 5000, socket::ANSI , socket::UNENCRYPTED );<br />
if isConnected == true<br />
then<br />
hello_trial.set_duration( 3000 );<br />
loop<br />
int i = 1<br />
until<br />
i > 50<br />
begin<br />
hello.set_caption( "Sending trigger # " + string( i ) );<br />
hello.redraw();<br />
# The NIC server process a trigger whenever it receives <br />
# a string with the following format:<br />
# <TRIGGER>xxx</TRIGGER><br />
# where xxx is any number different from zero.<br />
s.send("<TRIGGER>" + string( i ) + "</TRIGGER>");<br />
hello_trial.present();<br />
<br />
i = i + 1<br />
end<br />
else<br />
hello.set_caption( "Time out connecting to the server" );<br />
hello.redraw();<br />
hello_trial.present();<br />
end<br />
[[File:Presentation tcpip settings.png|200px|thumb|left| TCP/IP configuration settings in the Presentation software]]<br />
[[File:Presentation extension manager.png|200px|thumb|left| Presentation extension manager]]<br />
[[File:Lsl data port properties.png|200px|thumb|left| LSL data port properties]]<br />
The line<br />
''isConnected = s.open( "localhost", 1234, 5000, socket::ANSI , socket::UNENCRYPTED );''<br />
can be simplified to the following in case the parameters are set in "Settings->Advanced->TCP/IP Defaults".<br />
''isConnected = s.open();<br />
<br />
An alternative way of synchronising the presented stimulus by the Presentation software and NIC is by means of the [https://code.google.com/p/labstreaminglayer/ Lab Streaming Layer (LSL)] protocol. To get use of this functionality you need to install the [http://sourceforge.net/projects/lslpresentation/ LSL Presentation Extension] in you Presentation software through the Presentation extension manager.<br />
<br />
Once the extension is registered, it can be selected as a data port in Presentation's port settings. Information about the stream outlet name, ID, and connection status can be found in the data port properties window reachable through the "Properties" button that appears when the data port is selected within Presentation's port settings. The Connection Settings property allows users to choose whether the LSL stream outlet should be automatically opened whenever when Presentation starts, or whether it must be manually opened after Presentation is launched.<br />
All events that are logged in the Presentation logfile will also be sent out as LSL markers.<br />
<br />
<br />
Please refer to the [[Interacting_with_NIC]] section for the details on how to configure NIC to handle the reception of the markers from the LSL.<br />
<br />
== ePrime ==<br />
[http://www.pstnet.com/eprime.cfm E-Prime] is a suite of applications for designing and running experiments. This software can send markers to NIC in a similar way as the Presentation software. By using its programming features a socket can be created to connect to the host and port where NIC runs and then send marker whenever the stimuli are presented.<br />
<br />
The following link [http://www.neuroelectrics.com/sites/neuroelectrics.com/files/enobio/eprime2NIC_example.zip eprime2NIC_example.zip] contains an example on how to send markers from E-Prime to NIC.<br />
<br />
== Matlab ==<br />
Matlab can also be used to generate ERP experiments. It can send markers to NIC using the LSL library.<br />
To do it, it's necessary to install the LSL library in Matlab and send the triggers following the LSL standard for markers.<br />
<br />
The following [http://www.neuroelectrics.com/sites/neuroelectrics.com/files/enobio/Enobio_Matlab_Markers.m Matlab Script] contains an example on how to send markers from Matlab to NIC.<br />
<br />
The latest version of the Matlab LSL library can be download from [ftp://sccn.ucsd.edu/pub/software/LSL/SDK/ here].<br />
<br />
= References =<br />
<references /></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Event_Related_Potentials_(ERPs)&diff=1037Event Related Potentials (ERPs)2014-07-24T09:46:17Z<p>Guillem: /* ePrime */</p>
<hr />
<div>= About Event Related Potentials (ERPs) =<br />
An '''event-related potential''' ('''ERP''') is the measured brain response that is the direct result of a specific sense|sensory, cognition|cognitive, or motor system|motor event.<ref name="Luck">Luck, Steven J. (2005). An Introduction to the Event-Related Potential Technique. The MIT Press. ISBN 0-262-12277-4.</ref>.<br />
<br />
Those brain response can be measured with electroencephalography (EEG) using devices such as [http://www.neuroelectrics.com/enobio Enobio]. EEG reflects thousands of simultaneously ongoing brain processes. This means that the brain response to a single stimulus or event of interest is not usually visible in the EEG recording of a single trial. To see the brain's response to a stimulus, the experimenter must conduct many trials (usually in the order of 100 or more) and average the results together, causing random brain activity to be averaged out and the relevant waveform to remain, called the ERP.<ref name "Coles">Coles, Michael G.H.; Michael D. Rugg (1996). "Event-related brain potentials: an introduction". Electrophysiology of Mind. Oxford Scholarship Online Monographs. pp. 1–27</ref><br />
<br />
These stimuli can be visual, auditory, tactile and even olfactory and gustatory. In order to record those event-related potential the recording set-up needs to '''synchronise''' very accurately both the stimuli presentation and the EEG recording device. Commonly the software in charge of presenting the stimuli send a marker to the EEG recording system each time a stimuli is presented. If the triggers are properly recorded along with the EEG signal, an automatic pre-processing step can automatically cut the signal in epochs for further averaging.<br />
<br />
Further information regarding ERPs and its different types can be found in the following two links:[http://blog.neuroelectrics.com/blog/bid/237205/Event-Related-Potential-Our-Brain-Response-To-External-Stimuli 1] [http://blog.neuroelectrics.com/blog/bid/318938/14-Event-Related-Potentials-Components-and-Modalities 2], as well as in our White Papers<br />
<ref name="NEWP201401">Neuroelectrics NEWP201401, Event Synchronization of EEG data using the LSL, [http://wiki.neuroelectrics.com/index.php/Neuroelectrics_White_Papers]</ref><br />
<ref name="NEWP201403">Neuroelectrics NEWP201403, Extraction of ERPs with NE devices, [http://wiki.neuroelectrics.com/index.php/Neuroelectrics_White_Papers]</ref>.<br />
<br />
= Presentation Software =<br />
There are several software that can set-up an experiment which presents some stimulus (audio, images, video, etc.) to a subject in order to elicit ERPs in the EEG signal. It is very important that the recorded EEG data is synchronised with those stimulus in order to detect the ERPs when analyzing the data. The [http://www.neuroelectrics.com/enobio/software NIC] software provides the basic infrastructure to receive those markers from this kind of software every time a stimuli is presented. Please refer to the [[Interacting_with_NIC]] section for the details on how NIC handles the reception of the markers.<br />
<br />
In the following section we detail how some of the most relevant presentation software can be configured to send markers to NIC.<br />
== Presentation ==<br />
The [http://www.neurobs.com/ Presentation] software allows to connect to a remote application by using sockets in the [http://www.neurobs.com/pres_docs/html/03_presentation/01_getting_started/04_scenarios/02_pcl_programs.htm PCL program section] of an experiment scenario. This socket can be used to send markers to NIC every time a stimuli is presented. The following [[Media:DemoPresentationTriggerNIC.sce.txt | ''example'']] shows how to proceed in order to send markers to NIC.<br />
<br />
scenario = "Sending triggers to NIC";<br />
<br />
begin;<br />
<br />
text { caption = "Hello world!"; font_size = 24; } hello;<br />
<br />
picture {<br />
text hello;<br />
x = 0; y = 100;<br />
} hello_pic;<br />
<br />
trial {<br />
picture hello_pic;<br />
time = 0;<br />
} hello_trial;<br />
<br />
begin_pcl;<br />
<br />
bool isConnected = false;<br />
# socket creation<br />
socket s = new socket();<br />
<br />
hello.set_caption( "Connecting to trigger server..." );<br />
hello.redraw();<br />
hello_trial.set_duration( 1000 );<br />
hello_trial.present();<br />
<br />
# Connect to the NIC server. The example assumes that NIC runs<br />
# on the same computer as Presentation. Change "localhost" by the IP or<br />
# computer's name where NIC is running. The NIC server runs on port 1234.<br />
# The time-out at 5 secs (5000 ms) can be changed according to your needs.<br />
# 8 bits for the codification and no ecryption.<br />
isConnected = s.open( "localhost", 1234, 5000, socket::ANSI , socket::UNENCRYPTED );<br />
if isConnected == true<br />
then<br />
hello_trial.set_duration( 3000 );<br />
loop<br />
int i = 1<br />
until<br />
i > 50<br />
begin<br />
hello.set_caption( "Sending trigger # " + string( i ) );<br />
hello.redraw();<br />
# The NIC server process a trigger whenever it receives <br />
# a string with the following format:<br />
# <TRIGGER>xxx</TRIGGER><br />
# where xxx is any number different from zero.<br />
s.send("<TRIGGER>" + string( i ) + "</TRIGGER>");<br />
hello_trial.present();<br />
<br />
i = i + 1<br />
end<br />
else<br />
hello.set_caption( "Time out connecting to the server" );<br />
hello.redraw();<br />
hello_trial.present();<br />
end<br />
[[File:Presentation tcpip settings.png|200px|thumb|left| TCP/IP configuration settings in the Presentation software]]<br />
[[File:Presentation extension manager.png|200px|thumb|left| Presentation extension manager]]<br />
[[File:Lsl data port properties.png|200px|thumb|left| LSL data port properties]]<br />
The line<br />
''isConnected = s.open( "localhost", 1234, 5000, socket::ANSI , socket::UNENCRYPTED );''<br />
can be simplified to the following in case the parameters are set in "Settings->Advanced->TCP/IP Defaults".<br />
''isConnected = s.open();<br />
<br />
An alternative way of synchronising the presented stimulus by the Presentation software and NIC is by means of the [https://code.google.com/p/labstreaminglayer/ Lab Streaming Layer (LSL)] protocol. To get use of this functionality you need to install the [http://sourceforge.net/projects/lslpresentation/ LSL Presentation Extension] in you Presentation software through the Presentation extension manager.<br />
<br />
Once the extension is registered, it can be selected as a data port in Presentation's port settings. Information about the stream outlet name, ID, and connection status can be found in the data port properties window reachable through the "Properties" button that appears when the data port is selected within Presentation's port settings. The Connection Settings property allows users to choose whether the LSL stream outlet should be automatically opened whenever when Presentation starts, or whether it must be manually opened after Presentation is launched.<br />
All events that are logged in the Presentation logfile will also be sent out as LSL markers.<br />
<br />
<br />
Please refer to the [[Interacting_with_NIC]] section for the details on how to configure NIC to handle the reception of the markers from the LSL.<br />
<br />
== ePrime ==<br />
[http://www.pstnet.com/eprime.cfm E-Prime] is a suite of applications for designing and running experiments. This software can send markers to NIC in a similar way as the Presentation software. By using its programming features a socket can be created to connect to the host and port where NIC runs and then send marker whenever the stimuli are presented.<br />
<br />
The following link [http://www.neuroelectrics.com/sites/neuroelectrics.com/files/enobio/eprime2NIC_example.zip | eprime2NIC_example.zip] contains an example on how to send markers from E-Prime to NIC.<br />
<br />
== Matlab ==<br />
Matlab can also be used to generate ERP experiments. It can send markers to NIC using the LSL library.<br />
To do it, it's necessary to install the LSL library in Matlab and send the triggers following the LSL standard for markers.<br />
<br />
The following [http://www.neuroelectrics.com/sites/neuroelectrics.com/files/enobio/Enobio_Matlab_Markers.m Matlab Script] contains an example on how to send markers from Matlab to NIC.<br />
<br />
The latest version of the Matlab LSL library can be download from [ftp://sccn.ucsd.edu/pub/software/LSL/SDK/ here].<br />
<br />
= References =<br />
<references /></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Event_Related_Potentials_(ERPs)&diff=1036Event Related Potentials (ERPs)2014-07-24T09:45:33Z<p>Guillem: /* ePrime */</p>
<hr />
<div>= About Event Related Potentials (ERPs) =<br />
An '''event-related potential''' ('''ERP''') is the measured brain response that is the direct result of a specific sense|sensory, cognition|cognitive, or motor system|motor event.<ref name="Luck">Luck, Steven J. (2005). An Introduction to the Event-Related Potential Technique. The MIT Press. ISBN 0-262-12277-4.</ref>.<br />
<br />
Those brain response can be measured with electroencephalography (EEG) using devices such as [http://www.neuroelectrics.com/enobio Enobio]. EEG reflects thousands of simultaneously ongoing brain processes. This means that the brain response to a single stimulus or event of interest is not usually visible in the EEG recording of a single trial. To see the brain's response to a stimulus, the experimenter must conduct many trials (usually in the order of 100 or more) and average the results together, causing random brain activity to be averaged out and the relevant waveform to remain, called the ERP.<ref name "Coles">Coles, Michael G.H.; Michael D. Rugg (1996). "Event-related brain potentials: an introduction". Electrophysiology of Mind. Oxford Scholarship Online Monographs. pp. 1–27</ref><br />
<br />
These stimuli can be visual, auditory, tactile and even olfactory and gustatory. In order to record those event-related potential the recording set-up needs to '''synchronise''' very accurately both the stimuli presentation and the EEG recording device. Commonly the software in charge of presenting the stimuli send a marker to the EEG recording system each time a stimuli is presented. If the triggers are properly recorded along with the EEG signal, an automatic pre-processing step can automatically cut the signal in epochs for further averaging.<br />
<br />
Further information regarding ERPs and its different types can be found in the following two links:[http://blog.neuroelectrics.com/blog/bid/237205/Event-Related-Potential-Our-Brain-Response-To-External-Stimuli 1] [http://blog.neuroelectrics.com/blog/bid/318938/14-Event-Related-Potentials-Components-and-Modalities 2], as well as in our White Papers<br />
<ref name="NEWP201401">Neuroelectrics NEWP201401, Event Synchronization of EEG data using the LSL, [http://wiki.neuroelectrics.com/index.php/Neuroelectrics_White_Papers]</ref><br />
<ref name="NEWP201403">Neuroelectrics NEWP201403, Extraction of ERPs with NE devices, [http://wiki.neuroelectrics.com/index.php/Neuroelectrics_White_Papers]</ref>.<br />
<br />
= Presentation Software =<br />
There are several software that can set-up an experiment which presents some stimulus (audio, images, video, etc.) to a subject in order to elicit ERPs in the EEG signal. It is very important that the recorded EEG data is synchronised with those stimulus in order to detect the ERPs when analyzing the data. The [http://www.neuroelectrics.com/enobio/software NIC] software provides the basic infrastructure to receive those markers from this kind of software every time a stimuli is presented. Please refer to the [[Interacting_with_NIC]] section for the details on how NIC handles the reception of the markers.<br />
<br />
In the following section we detail how some of the most relevant presentation software can be configured to send markers to NIC.<br />
== Presentation ==<br />
The [http://www.neurobs.com/ Presentation] software allows to connect to a remote application by using sockets in the [http://www.neurobs.com/pres_docs/html/03_presentation/01_getting_started/04_scenarios/02_pcl_programs.htm PCL program section] of an experiment scenario. This socket can be used to send markers to NIC every time a stimuli is presented. The following [[Media:DemoPresentationTriggerNIC.sce.txt | ''example'']] shows how to proceed in order to send markers to NIC.<br />
<br />
scenario = "Sending triggers to NIC";<br />
<br />
begin;<br />
<br />
text { caption = "Hello world!"; font_size = 24; } hello;<br />
<br />
picture {<br />
text hello;<br />
x = 0; y = 100;<br />
} hello_pic;<br />
<br />
trial {<br />
picture hello_pic;<br />
time = 0;<br />
} hello_trial;<br />
<br />
begin_pcl;<br />
<br />
bool isConnected = false;<br />
# socket creation<br />
socket s = new socket();<br />
<br />
hello.set_caption( "Connecting to trigger server..." );<br />
hello.redraw();<br />
hello_trial.set_duration( 1000 );<br />
hello_trial.present();<br />
<br />
# Connect to the NIC server. The example assumes that NIC runs<br />
# on the same computer as Presentation. Change "localhost" by the IP or<br />
# computer's name where NIC is running. The NIC server runs on port 1234.<br />
# The time-out at 5 secs (5000 ms) can be changed according to your needs.<br />
# 8 bits for the codification and no ecryption.<br />
isConnected = s.open( "localhost", 1234, 5000, socket::ANSI , socket::UNENCRYPTED );<br />
if isConnected == true<br />
then<br />
hello_trial.set_duration( 3000 );<br />
loop<br />
int i = 1<br />
until<br />
i > 50<br />
begin<br />
hello.set_caption( "Sending trigger # " + string( i ) );<br />
hello.redraw();<br />
# The NIC server process a trigger whenever it receives <br />
# a string with the following format:<br />
# <TRIGGER>xxx</TRIGGER><br />
# where xxx is any number different from zero.<br />
s.send("<TRIGGER>" + string( i ) + "</TRIGGER>");<br />
hello_trial.present();<br />
<br />
i = i + 1<br />
end<br />
else<br />
hello.set_caption( "Time out connecting to the server" );<br />
hello.redraw();<br />
hello_trial.present();<br />
end<br />
[[File:Presentation tcpip settings.png|200px|thumb|left| TCP/IP configuration settings in the Presentation software]]<br />
[[File:Presentation extension manager.png|200px|thumb|left| Presentation extension manager]]<br />
[[File:Lsl data port properties.png|200px|thumb|left| LSL data port properties]]<br />
The line<br />
''isConnected = s.open( "localhost", 1234, 5000, socket::ANSI , socket::UNENCRYPTED );''<br />
can be simplified to the following in case the parameters are set in "Settings->Advanced->TCP/IP Defaults".<br />
''isConnected = s.open();<br />
<br />
An alternative way of synchronising the presented stimulus by the Presentation software and NIC is by means of the [https://code.google.com/p/labstreaminglayer/ Lab Streaming Layer (LSL)] protocol. To get use of this functionality you need to install the [http://sourceforge.net/projects/lslpresentation/ LSL Presentation Extension] in you Presentation software through the Presentation extension manager.<br />
<br />
Once the extension is registered, it can be selected as a data port in Presentation's port settings. Information about the stream outlet name, ID, and connection status can be found in the data port properties window reachable through the "Properties" button that appears when the data port is selected within Presentation's port settings. The Connection Settings property allows users to choose whether the LSL stream outlet should be automatically opened whenever when Presentation starts, or whether it must be manually opened after Presentation is launched.<br />
All events that are logged in the Presentation logfile will also be sent out as LSL markers.<br />
<br />
<br />
Please refer to the [[Interacting_with_NIC]] section for the details on how to configure NIC to handle the reception of the markers from the LSL.<br />
<br />
== ePrime ==<br />
[http://www.pstnet.com/eprime.cfm E-Prime] is a suite of applications for designing and running experiments. This software can send markers to NIC in a similar way as the Presentation software. By using its programming features a socket can be created to connect to the host and port where NIC runs and then send marker whenever the stimuli are presented.<br />
<br />
The following link [http://www.neuroelectrics.com/sites/neuroelectrics.com/files/enobio/eprime2NIC_example.zip] contains an example on how to send markers from E-Prime to NIC.<br />
<br />
== Matlab ==<br />
Matlab can also be used to generate ERP experiments. It can send markers to NIC using the LSL library.<br />
To do it, it's necessary to install the LSL library in Matlab and send the triggers following the LSL standard for markers.<br />
<br />
The following [http://www.neuroelectrics.com/sites/neuroelectrics.com/files/enobio/Enobio_Matlab_Markers.m Matlab Script] contains an example on how to send markers from Matlab to NIC.<br />
<br />
The latest version of the Matlab LSL library can be download from [ftp://sccn.ucsd.edu/pub/software/LSL/SDK/ here].<br />
<br />
= References =<br />
<references /></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Event_Related_Potentials_(ERPs)&diff=1031Event Related Potentials (ERPs)2014-07-04T09:30:33Z<p>Guillem: </p>
<hr />
<div>= About Event Related Potentials (ERPs) =<br />
An '''event-related potential''' ('''ERP''') is the measured brain response that is the direct result of a specific sense|sensory, cognition|cognitive, or motor system|motor event.<ref name="Luck">Luck, Steven J. (2005). An Introduction to the Event-Related Potential Technique. The MIT Press. ISBN 0-262-12277-4.</ref>.<br />
<br />
Those brain response can be measured with electroencephalography (EEG) using devices such as [http://www.neuroelectrics.com/enobio Enobio]. EEG reflects thousands of simultaneously ongoing brain processes. This means that the brain response to a single stimulus or event of interest is not usually visible in the EEG recording of a single trial. To see the brain's response to a stimulus, the experimenter must conduct many trials (usually in the order of 100 or more) and average the results together, causing random brain activity to be averaged out and the relevant waveform to remain, called the ERP.<ref name "Coles">Coles, Michael G.H.; Michael D. Rugg (1996). "Event-related brain potentials: an introduction". Electrophysiology of Mind. Oxford Scholarship Online Monographs. pp. 1–27</ref><br />
<br />
These stimuli can be visual, auditory, tactile and even olfactory and gustatory. In order to record those event-related potential the recording set-up needs to '''synchronise''' very accurately both the stimuli presentation and the EEG recording device. Commonly the software in charge of presenting the stimuli send a marker to the EEG recording system each time a stimuli is presented. If the triggers are properly recorded along with the EEG signal, an automatic pre-processing step can automatically cut the signal in epochs for further averaging.<br />
<br />
Further information regarding ERPs and its different types can be found in the following two links:[http://blog.neuroelectrics.com/blog/bid/237205/Event-Related-Potential-Our-Brain-Response-To-External-Stimuli 1] [http://blog.neuroelectrics.com/blog/bid/318938/14-Event-Related-Potentials-Components-and-Modalities 2], as well as in our White Papers<br />
<ref name="NEWP201401">Neuroelectrics NEWP201401, Event Synchronization of EEG data using the LSL, [http://wiki.neuroelectrics.com/index.php/Neuroelectrics_White_Papers]</ref><br />
<ref name="NEWP201403">Neuroelectrics NEWP201403, Extraction of ERPs with NE devices, [http://wiki.neuroelectrics.com/index.php/Neuroelectrics_White_Papers]</ref>.<br />
<br />
= Presentation Software =<br />
There are several software that can set-up an experiment which presents some stimulus (audio, images, video, etc.) to a subject in order to elicit ERPs in the EEG signal. It is very important that the recorded EEG data is synchronised with those stimulus in order to detect the ERPs when analyzing the data. The [http://www.neuroelectrics.com/enobio/software NIC] software provides the basic infrastructure to receive those markers from this kind of software every time a stimuli is presented. Please refer to the [[Interacting_with_NIC]] section for the details on how NIC handles the reception of the markers.<br />
<br />
In the following section we detail how some of the most relevant presentation software can be configured to send markers to NIC.<br />
== Presentation ==<br />
The [http://www.neurobs.com/ Presentation] software allows to connect to a remote application by using sockets in the [http://www.neurobs.com/pres_docs/html/03_presentation/01_getting_started/04_scenarios/02_pcl_programs.htm PCL program section] of an experiment scenario. This socket can be used to send markers to NIC every time a stimuli is presented. The following [[Media:DemoPresentationTriggerNIC.sce.txt | ''example'']] shows how to proceed in order to send markers to NIC.<br />
<br />
scenario = "Sending triggers to NIC";<br />
<br />
begin;<br />
<br />
text { caption = "Hello world!"; font_size = 24; } hello;<br />
<br />
picture {<br />
text hello;<br />
x = 0; y = 100;<br />
} hello_pic;<br />
<br />
trial {<br />
picture hello_pic;<br />
time = 0;<br />
} hello_trial;<br />
<br />
begin_pcl;<br />
<br />
bool isConnected = false;<br />
# socket creation<br />
socket s = new socket();<br />
<br />
hello.set_caption( "Connecting to trigger server..." );<br />
hello.redraw();<br />
hello_trial.set_duration( 1000 );<br />
hello_trial.present();<br />
<br />
# Connect to the NIC server. The example assumes that NIC runs<br />
# on the same computer as Presentation. Change "localhost" by the IP or<br />
# computer's name where NIC is running. The NIC server runs on port 1234.<br />
# The time-out at 5 secs (5000 ms) can be changed according to your needs.<br />
# 8 bits for the codification and no ecryption.<br />
isConnected = s.open( "localhost", 1234, 5000, socket::ANSI , socket::UNENCRYPTED );<br />
if isConnected == true<br />
then<br />
hello_trial.set_duration( 3000 );<br />
loop<br />
int i = 1<br />
until<br />
i > 50<br />
begin<br />
hello.set_caption( "Sending trigger # " + string( i ) );<br />
hello.redraw();<br />
# The NIC server process a trigger whenever it receives <br />
# a string with the following format:<br />
# <TRIGGER>xxx</TRIGGER><br />
# where xxx is any number different from zero.<br />
s.send("<TRIGGER>" + string( i ) + "</TRIGGER>");<br />
hello_trial.present();<br />
<br />
i = i + 1<br />
end<br />
else<br />
hello.set_caption( "Time out connecting to the server" );<br />
hello.redraw();<br />
hello_trial.present();<br />
end<br />
[[File:Presentation tcpip settings.png|200px|thumb|left| TCP/IP configuration settings in the Presentation software]]<br />
[[File:Presentation extension manager.png|200px|thumb|left| Presentation extension manager]]<br />
[[File:Lsl data port properties.png|200px|thumb|left| LSL data port properties]]<br />
The line<br />
''isConnected = s.open( "localhost", 1234, 5000, socket::ANSI , socket::UNENCRYPTED );''<br />
can be simplified to the following in case the parameters are set in "Settings->Advanced->TCP/IP Defaults".<br />
''isConnected = s.open();<br />
<br />
An alternative way of synchronising the presented stimulus by the Presentation software and NIC is by means of the [https://code.google.com/p/labstreaminglayer/ Lab Streaming Layer (LSL)] protocol. To get use of this functionality you need to install the [http://sourceforge.net/projects/lslpresentation/ LSL Presentation Extension] in you Presentation software through the Presentation extension manager.<br />
<br />
Once the extension is registered, it can be selected as a data port in Presentation's port settings. Information about the stream outlet name, ID, and connection status can be found in the data port properties window reachable through the "Properties" button that appears when the data port is selected within Presentation's port settings. The Connection Settings property allows users to choose whether the LSL stream outlet should be automatically opened whenever when Presentation starts, or whether it must be manually opened after Presentation is launched.<br />
All events that are logged in the Presentation logfile will also be sent out as LSL markers.<br />
<br />
<br />
Please refer to the [[Interacting_with_NIC]] section for the details on how to configure NIC to handle the reception of the markers from the LSL.<br />
<br />
== ePrime ==<br />
[http://www.pstnet.com/eprime.cfm E-Prime] is a suite of applications for designing and running experiments. This software can send markers to NIC in a similar way as the Presentation software. By using its programming features a socket can be created to connect to the host and port where NIC runs and then send marker whenever the stimuli are presented.<br />
<br />
The following [[media:e-prime.zip | '''zip file''' ]] contains an example on how to send markers from E-Prime to NIC.<br />
<br />
== Matlab ==<br />
Matlab can also be used to generate ERP experiments. It can send markers to NIC using the LSL library.<br />
To do it, it's necessary to install the LSL library in Matlab and send the triggers following the LSL standard for markers.<br />
<br />
The following [http://www.neuroelectrics.com/sites/neuroelectrics.com/files/enobio/Enobio_Matlab_Markers.m Matlab Script] contains an example on how to send markers from Matlab to NIC.<br />
<br />
The latest version of the Matlab LSL library can be download from [ftp://sccn.ucsd.edu/pub/software/LSL/SDK/ here].<br />
<br />
= References =<br />
<references /></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Event_Related_Potentials_(ERPs)&diff=1030Event Related Potentials (ERPs)2014-07-04T09:28:40Z<p>Guillem: </p>
<hr />
<div>= About Event Related Potentials (ERPs) =<br />
An '''event-related potential''' ('''ERP''') is the measured brain response that is the direct result of a specific sense|sensory, cognition|cognitive, or motor system|motor event.<ref name="Luck">Luck, Steven J. (2005). An Introduction to the Event-Related Potential Technique. The MIT Press. ISBN 0-262-12277-4.</ref>.<br />
<br />
Those brain response can be measured with electroencephalography (EEG) using devices such as [http://www.neuroelectrics.com/enobio Enobio]. EEG reflects thousands of simultaneously ongoing brain processes. This means that the brain response to a single stimulus or event of interest is not usually visible in the EEG recording of a single trial. To see the brain's response to a stimulus, the experimenter must conduct many trials (usually in the order of 100 or more) and average the results together, causing random brain activity to be averaged out and the relevant waveform to remain, called the ERP.<ref name "Coles">Coles, Michael G.H.; Michael D. Rugg (1996). "Event-related brain potentials: an introduction". Electrophysiology of Mind. Oxford Scholarship Online Monographs. pp. 1–27</ref><br />
<br />
These stimuli can be visual, auditory, tactile and even olfactory and gustatory. In order to record those event-related potential the recording set-up needs to '''synchronise''' very accurately both the stimuli presentation and the EEG recording device. Commonly the software in charge of presenting the stimuli send a marker to the EEG recording system each time a stimuli is presented. If the triggers are properly recorded along with the EEG signal, an automatic pre-processing step can automatically cut the signal in epochs for further averaging.<br />
<br />
Further information regarding ERPs and its different types can be found in the following two links:[http://blog.neuroelectrics.com/blog/bid/237205/Event-Related-Potential-Our-Brain-Response-To-External-Stimuli 1] [http://blog.neuroelectrics.com/blog/bid/318938/14-Event-Related-Potentials-Components-and-Modalities 2], as well as in our White Papers<br />
<ref name="NEWP201401">Neuroelectrics NEWP201401, Event Synchronization of EEG data using the LSL, [http://wiki.neuroelectrics.com/index.php/Neuroelectrics_White_Papers]</ref><br />
<ref name="NEWP201403">Neuroelectrics NEWP201403, Extraction of ERPs with NE devices, [http://wiki.neuroelectrics.com/index.php/Neuroelectrics_White_Papers]</ref>.<br />
<br />
= Presentation Software =<br />
There are several software that can set-up an experiment which presents some stimulus (audio, images, video, etc.) to a subject in order to elicit ERPs in the EEG signal. It is very important that the recorded EEG data is synchronised with those stimulus in order to detect the ERPs when analyzing the data. The [http://www.neuroelectrics.com/enobio/software NIC] software provides the basic infrastructure to receive those markers from this kind of software every time a stimuli is presented. Please refer to the [[Interacting_with_NIC]] section for the details on how NIC handles the reception of the markers.<br />
<br />
In the following section we detail how some of the most relevant presentation software can be configured to send markers to NIC.<br />
== Presentation ==<br />
The [http://www.neurobs.com/ Presentation] software allows to connect to a remote application by using sockets in the [http://www.neurobs.com/pres_docs/html/03_presentation/01_getting_started/04_scenarios/02_pcl_programs.htm PCL program section] of an experiment scenario. This socket can be used to send markers to NIC every time a stimuli is presented. The following [[Media:DemoPresentationTriggerNIC.sce.txt | ''example'']] shows how to proceed in order to send markers to NIC.<br />
<br />
scenario = "Sending triggers to NIC";<br />
<br />
begin;<br />
<br />
text { caption = "Hello world!"; font_size = 24; } hello;<br />
<br />
picture {<br />
text hello;<br />
x = 0; y = 100;<br />
} hello_pic;<br />
<br />
trial {<br />
picture hello_pic;<br />
time = 0;<br />
} hello_trial;<br />
<br />
begin_pcl;<br />
<br />
bool isConnected = false;<br />
# socket creation<br />
socket s = new socket();<br />
<br />
hello.set_caption( "Connecting to trigger server..." );<br />
hello.redraw();<br />
hello_trial.set_duration( 1000 );<br />
hello_trial.present();<br />
<br />
# Connect to the NIC server. The example assumes that NIC runs<br />
# on the same computer as Presentation. Change "localhost" by the IP or<br />
# computer's name where NIC is running. The NIC server runs on port 1234.<br />
# The time-out at 5 secs (5000 ms) can be changed according to your needs.<br />
# 8 bits for the codification and no ecryption.<br />
isConnected = s.open( "localhost", 1234, 5000, socket::ANSI , socket::UNENCRYPTED );<br />
if isConnected == true<br />
then<br />
hello_trial.set_duration( 3000 );<br />
loop<br />
int i = 1<br />
until<br />
i > 50<br />
begin<br />
hello.set_caption( "Sending trigger # " + string( i ) );<br />
hello.redraw();<br />
# The NIC server process a trigger whenever it receives <br />
# a string with the following format:<br />
# <TRIGGER>xxx</TRIGGER><br />
# where xxx is any number different from zero.<br />
s.send("<TRIGGER>" + string( i ) + "</TRIGGER>");<br />
hello_trial.present();<br />
<br />
i = i + 1<br />
end<br />
else<br />
hello.set_caption( "Time out connecting to the server" );<br />
hello.redraw();<br />
hello_trial.present();<br />
end<br />
[[File:Presentation tcpip settings.png|200px|thumb|left| TCP/IP configuration settings in the Presentation software]]<br />
[[File:Presentation extension manager.png|200px|thumb|left| Presentation extension manager]]<br />
[[File:Lsl data port properties.png|200px|thumb|left| LSL data port properties]]<br />
The line<br />
''isConnected = s.open( "localhost", 1234, 5000, socket::ANSI , socket::UNENCRYPTED );''<br />
can be simplified to the following in case the parameters are set in "Settings->Advanced->TCP/IP Defaults".<br />
''isConnected = s.open();<br />
<br />
An alternative way of synchronising the presented stimulus by the Presentation software and NIC is by means of the [https://code.google.com/p/labstreaminglayer/ Lab Streaming Layer (LSL)] protocol. To get use of this functionality you need to install the [http://sourceforge.net/projects/lslpresentation/ LSL Presentation Extension] in you Presentation software through the Presentation extension manager.<br />
<br />
Once the extension is registered, it can be selected as a data port in Presentation's port settings. Information about the stream outlet name, ID, and connection status can be found in the data port properties window reachable through the "Properties" button that appears when the data port is selected within Presentation's port settings. The Connection Settings property allows users to choose whether the LSL stream outlet should be automatically opened whenever when Presentation starts, or whether it must be manually opened after Presentation is launched.<br />
All events that are logged in the Presentation logfile will also be sent out as LSL markers.<br />
<br />
<br />
Please refer to the [[Interacting_with_NIC]] section for the details on how to configure NIC to handle the reception of the markers from the LSL.<br />
<br />
== ePrime ==<br />
[http://www.pstnet.com/eprime.cfm E-Prime] is a suite of applications for designing and running experiments. This software can send markers to NIC in a similar way as the Presentation software. By using its programming features a socket can be created to connect to the host and port where NIC runs and then send marker whenever the stimuli are presented.<br />
<br />
The following [[media:e-prime.zip | '''zip file''' ]] contains an example on how to send markers from E-Prime to NIC.<br />
<br />
== Matlab ==<br />
Matlab can also be used to generate ERP experiments. It can send markers to NIC using the LSL library.<br />
To do it, it's necessary to install the LSL library in Matlab and send the triggers following the LSL standard.<br />
<br />
The following [http://www.neuroelectrics.com/sites/neuroelectrics.com/files/enobio/Enobio_Matlab_Markers.m Matlab Script] contains an example on how to send markers from Matlab to NIC.<br />
<br />
The latest version of the Matlab LSL library can be download from [ftp://sccn.ucsd.edu/pub/software/LSL/SDK/ here].<br />
<br />
= References =<br />
<references /></div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Troubleshooting_/_Problem_Solving&diff=585Troubleshooting / Problem Solving2013-10-24T06:01:26Z<p>Guillem: /* Stimulation issues */</p>
<hr />
<div>== Troubleshooting connectivity issues with Bluetooth ==<br />
<br />
Basic Information<br />
<br />
The NECBOX connects to the computer using the windows bluetooth stack.<br />
It's important to check if the computer has the Windows stack installed and working. This is not obvious when:<br />
- The computer is a toshiba Laptop (it might use the Toshiba Stack)<br />
- The computer has Windows XP (The stack depends on the dongle used)<br />
<br />
If the computer has bluetooth integrated, the system shall be used with their integrated bluetooth. Do not use the provided dongle in a computer that has bluetooth integrated.<br />
<br />
<br />
Some known problems:<br />
<br />
After a certain time, the device doesn't connect anymore.<br />
Remove the bluetooth device from the BT device manager and remove the associated COM ports from the device manager.<br />
Let NIC install them again.<br />
<br />
In Windows 8 it's impossible to connect. Contact NE for a new Bluetooth library.<br />
<br />
== EEG recording issues ==<br />
<br />
<br />
== Stimulation issues ==<br />
<br />
The impedance check returns too high impedances.<br />
<br />
Normally the measured impedances of the impedance check might be higher, but when the experiment starts after some time they might fall down.<br />
<br />
If there's no good impedances you can:<br />
- Add more saline solution to the electrodes and check again<br />
- Move your hair to avoid as much hair as possible under the electrode<br />
- Add some saline solution directly at the hair at the electrode zone<br />
<br />
Some people have high impedances of his head and might return always values higher than normal.</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Troubleshooting_/_Problem_Solving&diff=584Troubleshooting / Problem Solving2013-10-24T05:55:24Z<p>Guillem: /* Troubleshooting connectivity issues with Bluetooth */</p>
<hr />
<div>== Troubleshooting connectivity issues with Bluetooth ==<br />
<br />
Basic Information<br />
<br />
The NECBOX connects to the computer using the windows bluetooth stack.<br />
It's important to check if the computer has the Windows stack installed and working. This is not obvious when:<br />
- The computer is a toshiba Laptop (it might use the Toshiba Stack)<br />
- The computer has Windows XP (The stack depends on the dongle used)<br />
<br />
If the computer has bluetooth integrated, the system shall be used with their integrated bluetooth. Do not use the provided dongle in a computer that has bluetooth integrated.<br />
<br />
<br />
Some known problems:<br />
<br />
After a certain time, the device doesn't connect anymore.<br />
Remove the bluetooth device from the BT device manager and remove the associated COM ports from the device manager.<br />
Let NIC install them again.<br />
<br />
In Windows 8 it's impossible to connect. Contact NE for a new Bluetooth library.<br />
<br />
== EEG recording issues ==<br />
<br />
<br />
== Stimulation issues ==</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Troubleshooting_/_Problem_Solving&diff=583Troubleshooting / Problem Solving2013-10-23T16:17:47Z<p>Guillem: /* Troubleshooting connectivity issues with Bluetooth */</p>
<hr />
<div>== Troubleshooting connectivity issues with Bluetooth ==<br />
<br />
Basic Information<br />
<br />
The NECBOX connects to the computer using the windows bluetooth stack.<br />
It's important to check if the computer has the Windows stack installed and working. This is not obvious when:<br />
- The computer is a toshiba Laptop (it might use the Toshiba Stack)<br />
- The computer has Windows XP (The stack depends on the dongle used)<br />
<br />
If the computer has bluetooth integrated, the system shall be used with their integrated bluetooth. Do not use the provided dongle in a computer that has bluetooth integrated.<br />
<br />
<br />
Known problems:<br />
<br />
After a certain time, the device doesn't connect anymore.<br />
Remove the bluetooth device from the BT device manager and remove the associated COM ports from the device manager.<br />
Let NIC install them again.<br />
<br />
In Windows 8 it's impossible to connect. Contact NE for a new Bluetooth library.<br />
<br />
== EEG recording issues ==<br />
<br />
<br />
== Stimulation issues ==</div>Guillemhttps://www.neuroelectrics.com/wiki/index.php?title=Tips_%26_Tricks&diff=547Tips & Tricks2013-10-18T06:34:14Z<p>Guillem: /* Electrode duration */</p>
<hr />
<div>=Tips for EEG recording using Enobio or StarStim =<br />
In this page we provide some tips and tricks to work with our systems. Here are some useful resources you should also check: <br />
<br />
- [http://www.jove.com/video/50426/simultaneous-eeg-monitoring-during-transcranial-direct-current | '''StarStim tCS EEG recording (Jove)'''] <br />
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- [http://www.youtube.com/watch?v=JdcG1Qdq4h8 | '''A short introduction to NIC v1.2''']<br />
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- [http://www.youtube.com/watch?v=I5uU20ut8Fk | '''Stimulation configuration with NIC v1.2''']<br />
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== Plan your session well before starting ==<br />
You should have a clear plan covering all the details in your recording session. Prepare to be patient. Setting up always takes a bit longer than expected, and when carrying out experiments ... the third time's the charm!<br />
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Where do you want to place the electrodes? For how long do you want to record? Do you have a good naming scheme for your EEG files? What data formats do you want to save? Do you need accelerometry data? Do you want a line filter applied to the data (if so 50 or 60 Hz?)?<br />
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Do you have an '''electrode referencing''' scheme? You should include in your montage a solution for data referencing. Data will be recorded referenced to the device electrical ground (the CMS electrode), but for data analysis you should always reference the data to an electrode or to the electrode average.<br />
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== Place carefully the CMS and DRL electrodes ==<br />
These two electrodes should go over the left or right mastoid (best to always stick to one side).<br />
First clean up the mastoid area where you are going to attach the DRL/CMS electrodes (using Sticktrode adhesive electrodes). <br />
You can use a paper napkin with some water or alcohol. Removing grease and dry skin will help you get good signal.<br />
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Stick the DRL/CMS electrodes close to each other, with the DRL on the bottom.<br />
These two Sticktrode electrodes should be '''close to each other but not touch.''' The CMS electrode should be on top and squarely on top of the mastoid bone. This will avoid contamination from blood vessels (ECG like signals).<br />
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== Avoid loose wires ==<br />
Try to have a tidy setup with few loose wires. Loose wires are more prone to creating noise from movement. <br />
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== About EEG signal quality measures in NIC ==<br />
As of NIC v1.2, EEG signal quality measures for each electrode are provided in real time. <br />
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If all the channels are in yellow or red zone, you may have an issue with the CMS/DRL electrodes (they create the ground for measurements, so if they are misplaced all the signals will be affected).<br />
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If an electrode is misbehavig, check that it has a good contact and, if possible, add more gel (you can reach the site from another hole in the cap.<br />
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= Tips for great Stimulation sessions using StarStim =<br />
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== Using Sponge electrodes ==<br />
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Sponge electrodes are easy to use. You can place them on the cap and wet them (about 2-4 cubic cm of saline solution will do) prior placing the cap on the subject's head.<br />
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If you have impedance issues, rewet them from a side hole using a syringe. Be careful not to wet the cap.<br />
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== Using Ag/AgCl Pi electrodes ==<br />
Pi electrodes are also easy to use. You can place them on the cap and gel them (fill the electrode hole space and then some more) prior placing the cap on the subject's head. <br />
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If you have impedance issues, regel them from the electrode hole or a side hole using a syringe. <br />
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== The impedance test ==<br />
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You should carry out an impedance test before launching the stimulation. If impedance is too high for some electrode, rewet, regel and check cabling connections. <br />
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Impedance is check while stimulation is ongoing. If the impedance is too high, the stimulation session will self-abort.<br />
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= Everything about electrodes for EEG and stimulation =<br />
[[File:electrodes1.png|200px|thumb|left|]]<br />
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Please see the [http://www.neuroelectrics.com/sites/neuroelectrics.com/files/enobio/Electrodes_User_Manual.pdf | '''Electrode User Manual'''] for a description of our electrodes.<br />
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== Caring for EEG electrodes ==<br />
[[File:electrodes2.png|200px|thumb|left|]]<br />
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It's very important to remove all the gel from the electrodes carefully fater a recording using gel.<br />
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No sunlight exposure or contact with metals might also damage the electrodes.<br />
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== Caring for stimulation electrodes == <br />
[[File:electrodes3.png|200px|thumb|left|]]<br />
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It's important to rinse the electrodes with water in order to remove the salt that might remain after drying.<br />
It is also recommended to dry the metal part to avoid salt on the connectors.<br />
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In case there salt accumulating at the metallic part, it can be washed with some vinegar to remove it.<br />
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== Electrode duration ==<br />
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There's no a fixed statement of number of uses or hours of recording for the EEG electrodes. It depends on how are they cleaned or stored.<br />
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The electrode degradation can be seen when the electrodes have too much noise when recording.<br />
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= Other =</div>Guillem