How do you make a cheap myoelectric sensor or a cheap ecg/ekg sensor?

I'm pretty new to soldering, and circuit building. And I'm working on making an exoskeleton, but don't know how to build the sensors for it. So if you have any information, it would be appreciated.

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kovo8 years ago
There was a very nice article in MAKE volume 11, pg 158 on DIY ECGs. I think it would make a good starting point for your experimentation. I've attached a link that might work (it takes you to a preview) or you might find the magazine at your library.

http://www.make-digital.com/make/vol11/?pg=161
Lewanuva31 (author)  kovo8 years ago
Thanks alot, the article is great.
I would like to jump aboard your project as I have some ideas and theroies myself of increasing human capacitance by a small percentage and amplifying static discharge to create a bio-perpetuating energy source for such an exoskeleton.
contact me at my page if you are interested in further discussion.
JZweige7 years ago
I made an ECG device, with connection to a laptop. The build is detailed in the instructable:

https://www.instructables.com/id/ECG-on-your-laptop/
dauty7 years ago
You guys are gods, thanks so much for the info!
legionlabs8 years ago
The Open EEG project has a lot of great information! http://openeeg.sourceforge.net/doc/

However, it would be possible to build something simpler and cheaper, as an instrumentation op amp should not be absolutely required. It sounds like what you need is a myoelectric sensor only, and that can be accomplished with simpler stuff. I would try taking an ordinary JFET op-amp (I recommend OPA2132) and putting it in a high-gain, non-inverting configuration, in series with a 60Hz input filter (the human body acts like an antenna and picks up a fair amount of 60Hz interference, which you don't want). The sensor should be well shielded with copper or aluminium foil, and the foil connected to the circuit ground (coaxial cable is your friend here). Hook this setup to a reasonable oscilloscope, with the scope's external ground connected and a 10x voltage divider on the probe. See if it can detect muscle movement electrically. If so, time to get out a microcontroller with an ADC!

Do NOT run this circuit of mains power. Not only will it introduce too much interference, but you don't want a nasty shock. Power everything using one or more 9v batteries, and a virtual ground circuit for the +/- rails of the opamp.