Measure pulse with 2 hands like a gym treadmill?

Projects General Guidance
1

I want to measure a person's pulse in an interactive exhibit.

There are many "fingertip" sensors, such as this

fingertip pulse.png
fingertip pulse sensor

but I want to use a metal surface like that seen on gym treadmills.

treadmill pulse.png
treadmill pulse sensors

Would it be possible to remove a gym treadmill sensor and hook it up to an Arduino?

Is the technique used in metal gym treadmill sensors different than the finger tip sensors?

This is a link to a replacement part for a treadmill. It only has a single tab on the back, would I need to get two of these?

Could I hook it up to this "Single Lead Heart Rate Monitor" AD8232
from Sparkfun?

AD8232.png
AD8232 Monitor

fingertip pulse.png

treadmill pulse.png

AD8232.png

2

The price on that "replacement part" is absurd. Not sure what the material is but I suspect stainless steel tubing would work OK.

The Sparkfun breakout looks good when I check the design. "Single lead" refers to the multiple different arm and leg connections available on an ECG machine. It always requires two electrodes - actually three including the ground or "right leg" connection. Note that any such equipment you make must not connect in any way to mains power, only run from a 3.7 V LiPo or three or four "AA" batteries.

3

Paul__B:
It always requires two electrodes - actually three including the ground or "right leg" connection.

Thank you for your reply. I got the sensor and the 3 electrodes. In testing it doesn't seem to work if I hold just the L and R electrodes against my skin. I got it to work occasionally with all three electrodes.

The third "right leg" connection, you said this is ground? Should I connect that to the GND pin on the Arduino?

How do I get it to work like the treadmill at the gym? Is the treadmill using a different sensing technique? There are only two sensors on the treadmill since I only have to hold on with 2 hands right?