I wish I did, it was at a university biofeedback lab in about 2000. I'd guess anybody who works with biofeedback devices could recommend something better by now anyway.

Heh, ok, yes I expected you to say something like this. I had biofeedback therapy as a child (also jaw/bruxism related), and those devices looked archaic, even for that time :)

Speaking of which...What about a retro-computing project in QBasic?

https://archive.org/details/ElectronicsNow199612/page/n36/mo...

:)

I'm tempted to build something like this, probably more in this field: https://en.wikipedia.org/wiki/Electromyography

But ... I can't find the time.