FWIW analogue ECGs are fairly straightforward, googling should get you
lots of very similar circuits.

NT


Well yes and no, instrumentation amplifiers are not to complicated
discrete or not, but problem is noise, even with low pass filtering
and notch I'm not receiving any useful data.
Before I pass it trough DSP on uC I would like to get most of analog.
I did scourge the web and there isn't much more to find, expect this
magazine.
Maybe it would help and give me an edge over other concepts.

I took some bioengineering books, there are many options to eliminate
noise but I'm simply not comfortable with them, for example forcing a
weak current trough body and others potentially dangerous
interventions.