electronic circuit for bio medicine practical engineering

Do you mean an electrocardiograph?

Something like this perhaps: http://forum.allaboutcircuits.com/showthread.php?t=30455

Check this thread: http://forum.allaboutcircuits.com/showthread.php?t=29790&highlight=heart+pulse

It supposedly works and give a pulse rate.

John

Hello, Joni. How about a one-transistor stethescope amplifier?

Measuring skin conductance, is always a hit. It is a simple, and safe project perfect for the beginner. It is always fun to test if your friends are telling lies.

I am laughing my head off because a wheatstone bridge for measuring skin conductance was actually my first thought, and the only reason why I suggested the stethescope amplifier instead is just because the amplifier seemed to be more directly medical in its application. I think that a skin conductance meter would be a very useful tool for psychological therapy, though. Another idea, I think, would be to pick up brain waves. A simple brain-wave meter should actually be very easy to build.