Heartbeat Sensor

[logickills]

What is the easiest/cheapest way I could detect a heartbeat from outside a shirt? I am trying to make a small device that will detect a heart beat and then pulse an led.

Thanks!

 

[alex88]

Not easy if you need detect outside shirt.

 

[eptheta]

I'm probably very wrong, but check a piezo sensor... They usually have low stress requirements..
But i've never used one so don't take my word for it.