Biopotential Signal Library

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jamlam

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Just wondering if the Biopotential Signal Library using the ADS129x chip is still in development. I'm a gastroenterologist and can envision many potential clinical uses for a powerful, low cost system like this.
 
I did a thesis on this so I could point you in the right direction if you'd like? It was mainly based on ECGs though.

What sort of data are you looking to monitor/aquire?
 
Surface EMG, or more precisely EGG, smooth muscle signals of the stomach and intestines. These tend to be very low frequency and amplitude, so a challenge to detect among the noise of skeletal muscles.
 
I didn't know that Paul put something up on hackaday using the Ti ADS1294. He hasn't mentioned it on the forum that I know of. Would be cool.

Are you wanting to measure low amplitude muscle activity from muscles that lie underneath other large muscles, and do this from the skin? Doesn't seem likely.
 
I didn't know that Paul put something up on hackaday using the Ti ADS1294. He hasn't mentioned it on the forum that I know of. Would be cool.

Are you wanting to measure low amplitude muscle activity from muscles that lie underneath other large muscles, and do this from the skin? Doesn't seem likely.

@linuxgeek I think you will find that the leg bone is connected to the knee bone.
 
EGG (electrogastrography) has been used clinically for over 20 years. It just takes a calm patient and a lot of signal conditioning...
 
Interesting. Sounds like it's fraught with difficulties. I claim ignorance here, but I still am a bit skeptical. I guess if the frequency characteristics are much different from the other muscles. My initial reaction is that impedance changes would confound changes in bio-electrical activity, and that you almost need a DC amplifier for those low frequencies (~0.05Hz). The amount of artifact from various places like ECG, pulse, breathing, swallowing, skeletal muscles, and movement must create a very small signal-to-noise ratio. I'd like to read more about this. thanks for bringing it up.
 
Sadly, this project (so far) has never really got off the ground. It's one of so many projects I will eventually do.....
 
Hi Paul.
Thats a shame that you have stopped. With the greater interest in EMG and DIY prosthetics it could become very useful.
Dave
 
Eventually I'll work on this again. But I'm just 1 guy. I have to prioritize. Right now, I'm working on the new K66-based Teensy. After that's released, and I've made more progress on supporting its new peripherals, huge improvements to the PJRC website and bringing real debug support to the Arduino IDE are going to be my top priorities for a while.
 
I understand entirely Paul :)

Likewise I tend to be very busy on my own projects :) so I know what you mean.

Take care and the k66 sounds very interesting.

Dave
 
Paul - whats the best way to send you a private message. There is a project that uses the Teensy that I think you'd be interested in.
Dave
 
Have a look at using wavelet transforms for reducing noise. I've had good results with this in the past

Right leg drive systems can help to increase the CMRR
 
If there's something confidential you need to send, my regular email is best. But really, if something is a secret I usually prefer not to know. Life is simpler that way. :) Please be aware I fall far behind on email and many messages go unanswered. I'm absolutely not available to get involved in any more projects.
 
FYI, OpenBCI uses the ADS1299: http://openbci.com/

While it is nominally aimed at EEG, I've also used it for ECG (see here) and EOG (see here) and others have used for EMG. I've not tried EGG, but it sounds interesting.

Note that OpenBCI is wireless (some of my pictures show an older Arduino/USB version). The wireless version is much better for subject safety.

The wireless OpenBCI streams data to a PC which you can access as a packet of data from a serial port. Or you can useheir GUI to get the data, though the GUI is aimed at EEG. You could also alter their GUI as it is open source (programmed in Processing, which is Java).

Chip
 
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