> From: Soon Lee
>
> Hi everyone
>
> is there any circuit that i can use to measure, detect, heart pulse?
>
> thanks

The only one I've had practical experience of was one that used a small
light bulb to measure blood volume through a fingertip. Because of the
heat it got uncomfortable, a LED would have been better.The waveform
from the photocell was quite distinct and easy to amplify to a logic level.
The one I should have made was a small clip with an LED tx/rx pair that
went on the earlobe. I think this would give better results than a finger as
earlobes don't have bone in them.