Guide to using the EOG, EMG and ECG sensors on the Versatile 32 and Versatile 64 EEG systems
What it measures:
The ExG sensors are used to measure electrical activity between a pair of sensors (differential). They are typically used for one of these measurements:
EMG: Electromyogram, a way of measuring the electrical activity produced by skeletal muscles during contraction.
ECG: Electrocardiogram (also called "EKG"), a measure of the electrical activity of the heart vs time.
EOG: Electrooculogram, a measure of potential between the front and back of the eyeball as a way of determining relative orientation of the eye.
Sports, rehabilitation, kinesiology, psychology, biomechanics, neuromarketing, human factors, etc.
How to use:
Connect the sensors to the participant using standard adhesive disposable electrodes like the Aqua-Tac (pictured here).
Electrode locations depend on the application (EMG, EOG, ECG). ExG electrodes are bipolar, requiring one electrode positioned on either side of the area to be measured. Consult standard practices for the electrode positions for ECG, EMG, EOG, etc.
The Versatile 32 EEG system has 2 bipolar ExG leads.
The Versatile 64 EEG system has 4 bipolar ExG leads
In both cases, ground is provided by the ground channel 0 in the EEG cap.
How to clean:
The electrode itself is disposable. Clean the leads with mild soap and water. Avoid getting the connectors wet. Allow the sensors and all wiring to dry completely before use. The adhesive electrodes themselves are disposable.
Autoclave is not recommended.
Right-click on wave view in Bitbrain Device Viewer to view data-visualization filter settings.
Under "Notch-Filter" we recommend setting this to the preset matching your country's AC frequency (presets exist for USA/Japan at 60 Hz, and Europe at 50 Hz).
Under "Other Filter" click "enabled"
Set filter type to "Bandpass"
For ECG and EOG detection:
Set Low (Hz) to 0.5 Hz
Set High (Hz) to 30 Hz
For EMG detection:
Set Low (Hz) to 1 Hz
Set High (Hz) to 100 Hz
Type is "Butterworth"
Order set to 4
Output: ExG data output is reported in µV
Data Range: ±420 mV
Data Noise: <4 µVRMS (0.5-30Hz)
Output Type: Bipolar analog