colorimetric oximeter(heart beat and/or oxygen saturation)

Projects General Guidance
1

Hi,
I'm trying to build a heart beat captor.

from WikiPedia:

Based on :http://tinkerish.com/blog/?p=181

So with :
TSL230

With a red LED of 660nm and another IR-LED of 940nm.

First it looks possible.
Quite nice to begin :wink:

Have anyone already tried or seen a sort of schematic or board to begin?
Do I need to use Op Amp to amplify ?

thanks for your answer(s?)