Hi my friends
Dear Udhay i hope there isn't any problem from your side that i have asked my question here in your thread .
In continue of dselec's question : what are the benefits of those transistors in that arrangement ?
By the way , a friend of mine told me , the right leg in our body can be considered as ground of our body . and we will have 12 leads of measurement . i designed a circuit ( subtracter amplifier with opamp and ( of course it was an active LPF too ! ) but i don't know why when i connected the electrodes into my right leg and my heart and the other leads , the waveform that i saw in my oscilloscope was awful ! it was alike with everything unless waveform of ECG ! where can be the problem ?
Best Regards
Goldsmith