Thread: Sofia-EOG - open source software and hardware for REM detection

Well the electronics aren't that simple, but not hard to setup either: a breadboard, an AD620, a resistor, two wires to the computer, 3 electrodes, and 2x( 3x1.5 volt batteries) (+4,5v and -4,5v) . I'm currently rebuilding , because I couldn't get any sensible output with the old setup (I must have dislocated something, or in the worst case shorted the amplifier in some way). EOG, ECG and EEG are very similar. It's just that the biopotentials that we're measuring are with similar values. ECG can use 3 or more electrodes. EOG usually uses 3 . EEG I think uses around 6 normally , but there are scientific setups that use hundreds. I'm a med student and in neurology we saw that the EEG machine detects eye movements as artefacts (more proof that all three are relatively the same machine).
About the mask - the idea is that there will always be noise and movement and so on , but in your sleep (especially REM) your body is pretty still. My mask isn't really a mask - its a tennis headband. Here's a picture:

And it's ok to wear while sleeping. With the electrodes there's the problem that when wearing the mask for the whole night I'm left with 3 slightly visible marks on the forehead. But I guess that's mostly fixable if using different electrodes.
So, my idea is that if the electrodes have skin contact (it doesn't even have to be optimal), when you aren't moving there should be little noise and the eye movements should be detectable.
The picture wasn't really rich on information, just a pic from the archive as I mentioned. But the setup then was identical with the EEG tutorial (so just the AD620). With this setup for a long time I managed to get clear ECG and EOG data (with the software filter applied). Now I have to figure out what broke in the last year.