Difference between revisions of "Files & Formats"
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26 Comumns: there is accelerometer, AddSensor. | 26 Comumns: there is accelerometer, AddSensor. | ||
− | Enobio 32 will have >=34 | + | Enobio 32 will have >=34 and >=36 if acc data is present |
34 Columns: no AddSensor, no accelerometer | 34 Columns: no AddSensor, no accelerometer | ||
35 Comumns: no accelerometer, but there is AddSensor | 35 Comumns: no accelerometer, but there is AddSensor |
Revision as of 17:41, 18 December 2013
Neuroelectrics devices generate a series of files and formats. Proprietary ones are in bold:
- The .easy data format (ASCII, plain text) - The .info file (ASCII, plain text) - The .edf (EDF+) and ".nedf" data formats (binary) - The .stim file (ASCII, plain text) - The .sdeeg SD card data format (binary)
In general, time keeping is given with time stamps per sample in ms since Jan 1st 1970 (Unix time).
Stimulation generated files
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).
the .info file associated with a stimulation session
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:
StartDate (first EEG timestamp): 1361377909087 Device class: StarStim Device Mac: 00:07:80:58:9C:1A NIC version: v1.1.9 Firmware version: 699 Line filter status: OFF Additional channel status:OFF Number of records of Stimulation: 46 (1 second/record) Total number of channels: 8 Number of EEG channels: 6 Number of stimulation channels: 1 Stimulation sampling rate: 500 Samples/second Stimulation units: uA Ramp up duration (s): 15 Ramp down duration (s): 15 Shamp ramp duration (s): OFF Stimulation duration (s): 1200 Type of stimulation: tACS+ Stimulation parameters: Channel 1: Position: C3 Type: EEG Recording Channel 2: Position: C4 Type: Stimulation Anodal Amplitude (uA): 100 Offset (uA): 0 Frequency (Hz): 10 Channel 3: Position: Ch3 Type: EEG Recording Channel 4: Position: Ch4 Type: Return Percentage return: 100% Channel 5: Position: Ch5 Type: EEG Recording Channel 6: Position: Ch6 Type: EEG Recording Channel 7: Position: Ch7 Type: EEG Recording Channel 8: Position: Ch8 Type: EEG Recording Trigger information: Code Description 1 Subject moved 2 Eyes opened 3 Eyes closed 4 sleeping 5 EEG signals are noisy 6 7 8 9
the .stim file
This ASCII file contains a record of the currents at each electrode.
There is a row per time sample with one column per channel (units in uA).
The last column contains the time stamps per sample in ms since Jan 1st 1970 (Unix time).
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). 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).
246 -246 -1 -1 -1 -1 -1 -1 1381762713753 246 -246 -1 -1 -1 -1 -1 -1 1381762713754 246 -246 -1 -1 -1 -1 -1 -1 1381762713755 246 -246 -1 -1 -1 -1 -1 -1 1381762713756 246 -246 -1 -1 -1 -1 -1 -1 1381762713757 247 -247 -1 -1 -1 -1 -1 -1 1381762713758 247 -247 -1 -1 -1 -1 -1 -1 1381762713759 247 -247 -1 -1 -1 -1 -1 -1 1381762713760 247 -247 -1 -1 -1 -1 -1 -1 1381762713761 247 -247 -1 -1 -1 -1 -1 -1 1381762713762 247 -247 -1 -1 -1 -1 -1 -1 1381762713763 248 -248 -1 -1 -1 -1 -1 -1 1381762713764 248 -248 -1 -1 -1 -1 -1 -1 1381762713765
EEG data files and formats
the .info file associated with an EEG only session
Here is an example of what this plain text file contains. The name of the file would be something like '20131011141257_demo.info:
StartDate (first EEG timestamp): 1381493577260 Device class: Enobio20 Device MAC: 00:07:80:63:F0:CD NIC version: v1.2.9 Firmware version: 699 Line filter status: 60 Hz Additional channel status: OFF Total number of channels: 20 Number of EEG channels: 20 Number of records of EEG: 15381 Number of packets lost: 0(0.00%) EEG sampling rate: 500 Samples/second EEG units: nV EEG montage: Channel 1: P7 Channel 2: P4 Channel 3: Cz Channel 4: Pz Channel 5: P3 Channel 6: P8 Channel 7: O1 Channel 8: O2 Channel 9: T8 Channel 10: F8 Channel 11: C4 Channel 12: F4 Channel 13: Fp2 Channel 14: Fz Channel 15: C3 Channel 16: F3 Channel 17: Fp1 Channel 18: T7 Channel 19: F7 Channel 20: EXT Number of records of Accelerometer: 30 (1 second/record) Number of channels of Accelerometer: 3 Accelerometer sampling rate: 100 Samples/second Accelerometer units: mm/s^2 Trigger information: Code Description 1 EventA 2 EventB 3 Movement 4 Eyeblink 5 6 7 8 9
The .easy data format (ASCII)
ABOUT THE NE ASCII DATA FORMAT (July 2012): NE ASCII files contain one line per time sample. Each line contains first the EEG data (8 or 20 channels, depending on the device, with units in nV), followed by three acceleration channels (aX,aY,aZ in mm/s^2- millimeters per second squared), an *optional* external input channel, a trigger flag (int32) and, finally, a timestamp in Unix time (ms from Jan 1 1970): Ch1(nV) ... Ch8or20(nV) aX(mg) aY(mg) aZ(mg) AddSensor Flags(uint32) TimeStamp (ms) Therefore Enobio8/StarStim will have a minimum of 8+2 (10) columns, or 8+3=11 if no accelerometer or >= 8+4 (with accelerometer). In summary: Enobio8/20 10 Columns: no AddSensor, no accelerometer data: 11 Comumns: no accelerometer, but there is AddSensor 13 Columns: there is accelerometer, but no Addsensor 14 Comumns: there is accelerometer, AddSensor. Enobio 20 will have >= 22 and >=24 columns if acc. data present: 22 Columns: no AddSensor, no accelerometer 23 Comumns: no accelerometer, but there is AddSensor 25 Columns: there is accelerometer, no AddSensor 26 Comumns: there is accelerometer, AddSensor. Enobio 32 will have >=34 and >=36 if acc data is present 34 Columns: no AddSensor, no accelerometer 35 Comumns: no accelerometer, but there is AddSensor 37 Columns: there is accelerometer, no AddSensor 38 Comumns: there is accelerometer, AddSensor.
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:
-1 -1 8999110 29602960 27793792 19921829 -3670597 18110801 -2745 9561 -912 0 1353011252736 -1 -1 8902360 29539254 27764085 19818737 -3924179 18143799 -2745 9561 -912 0 1353011252738 -1 -1 8827496 29457477 27727511 19748117 -4140377 18101551 -2745 9561 -912 0 1353011252740 -1 -1 8779812 29376462 27720311 19705727 -4315472 18054868 -2745 9561 -912 0 1353011252742
The .edf (binary, EDF+) data format
This is the standard | 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).
The .nedf (binary) data format
This is Neuroelectrics proprietary data format. It is lossless (full 24 bit) binary. It can be opened by NIC Offline and exported/saved into any of the other NE formats.
The .sdeeg SD card data
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.