The electrodes lose their connection in the middle of the session.

bathiya

Device information
we purchased open bci cyton board with 8 channels and open bci headband kit.
When we record EEG signals from a person, the electrodes placed on the forehead often become "railed,". Despite adjusting the electrodes to ensure they make proper contact with the skin, the issue persists and they do not stop railed. Often the same problem happens in other electrodes too.
How to overcome this issue.

wjcroft

Hi Bathiya,

Have you tried first 'cleaning' the forehead and other areas of skin oils, sweat, etc., before applying the headband? Both the flat electrodes and the comb electrodes must contact clean skin for best results.

Have you tried 'tightening' the band to see if that improves? Are you checking the electrode impedances, lower is better.

William

bathiya

Dear William,

Thank you for your prompt response. We have followed all the steps you mentioned, but the issue persists.

wjcroft

Have you been able to get ANY valid EEG from your setup, since purchase? Are you following the tutorial to view Alpha?

https://docs.openbci.com/GettingStarted/Biosensing-Setups/EEGSetup/#4-alpha-brain-waves-eeg

Where is your reference electrode? A bad reference connection will result in poor EEG on all channels.

https://docs.openbci.com/AddOns/Headwear/HeadBand/