Lie Detector Project

Hi.

Does any wan knows how to create a lie detector that can be linked to a computer to dispaly the results.

The idea is to take readings like heart beat, blood pressure and skin resistance to detect a lie.

It is juz like a polygraph system.

I'm having problem i getting a suitable circuit and the rite software to display these three input and show whether a person is lying. In wat way can I linked the circuit to the computer ???

Wat would U recommemded??????
In need of Schematics and software programs.

Pls giv me some suggestions on websites that I can looked up or some guidelines on ways to appraoch this problem.

do the indepedent block like breath sensor, rate sensor , oxygen sensor etc.take the o/p digitize it with an ADC , and make it a seriel/parallel stream (use a micro) , link it to a pc. write a s/w to read the serial port/parallel port and use the graphics libs to plot it on screen.

Use the sensors from a madical digi presure/bloodmeter (don't know the exact english term ). It costs like 50$ (a new one) but it contains the sensor and reads hart rate, blood presures etc.. I think it's much easier to take the signal from the uC used and interface it with the PC. About the skin resistance....use a ADC chip and interface it (trought a uC) with the PC.
Quite OK project and can be done but might get a bit expensive (250$ at least).