Hi, I am doing an ecg circuit to detect bpm and showing ecg waveform in the serial plotter. I
am using AD623AN and LM358. Attach is the circuit that I have found. I try out the circuit but there are a lot of noises. Is there any way to get a clear signal. Furthermore, I would also like to get the ecg waveform is there any way to do it. Can anyone provide any source code that is workable. Thank you in advance.
[http://www.sharpround.com/wp-content/uploads/2014/11/ecg_handout.pdf]
Please post the picture here. The link doesn't work for some reason.
You do the coding, not forum. Post the best effort.
An ECG is designed to pick up electrical activity of the heart but will pick up the electrical activity of all the muscles and so is noisy by nature. You can filter to get better signal both electronically and in the software. Most ECG machines I work with start with quite a shaky trace and then 'clean it up' so that would suggest significant code. I can't help you with what that code is. You could definitely attach a trace and then add capacitors to see if it improves it. In general you are trying to filter very short wavelengths (relatively speaking)
You can't get away from a large amount of 50/60 Hz noise, so either hardware or software filtering must be applied. As for schematics - what you posted is reasonable but only if the whole system is small, works from a battery and sends out data via radio - then added noise will stay within reasonable limits. Any wire to USB or something like that would make noise amplitude much higher than ECG amplitude, to the point that even a good filter will have a hard time compensating that.
You can check schematics of open source wireless ECG device here: GitHub - ultimaterobotics/uECG: uECG device firmware - other parts of the project linked in description (that's the main repository link with code, PCB design itself and other relevant things are linked on that page) - and I've described my approach to dealing with noise (with pics before/after) here: Project timeline | Details | Hackaday.io - although since that moment it was significantly improved both in firmware and hardware, but the main idea stays the same
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.