How to measure the contact quality between the electrodes and the head skin

Hiroki · October 2018

I use the Cython and the Ultracortex heaset for the experiment.

The experiment takes about 30 minutes.

I thought, if I checked the contact quality between the electrodes and the skin before the experiment, the quality may vary during the experiment, and it might be worse at the end of the experiment.

So I want to measure the contact quality at real-time.

Can we measure it?

I read the cyton SDK reference, but couldn't understand...

http://docs.openbci.com/OpenBCI Software/04-OpenBCI_Cyton_SDK#openbci-cyton-sdk-command-set-leadoff-impedance-commands

Hiroki · October 2018

This is another but similar question related to this thread's question.

When I do the experiment, I arrange the position of electrodes and conditions between the electrodes and the skin so that the EEG amplitudes at the resting-state measured by the OpenBCI_GUI be around 10 uVrms.

Is this enough?

wjcroft · October 2018

Hiroki, hi.

You could measure in real-time using the GUI feature (ohm-buttons) that shows the impedance. Then if you need real-time data in another app, stream the data out from the GUI using LSL. You can also do a search here on the forum, there are many threads concerning impedance and acceptable ranges.

Impedance is the metric usually employed to check electrode satisfactory contact.

http://docs.openbci.com/OpenBCI Software/01-OpenBCI_GUI#the-openbci-gui-cool-gui-features

https://www.google.com/search?as_q=impedance+range&as_sitesearch=openbci.com

http://openbci.com/forum/index.php?p=/discussion/165/measuring-electrode-impedance

Regards,

William

How to measure the contact quality between the electrodes and the head skin

Comments