measurement of heart with ...?

Can I measure the heart or pulse with some form of something, for example puck.js and capacitive touch?
Trying for some gimmics
I will google latter for basic information, but if anyone has "the answer" (not 42) then feel free to show interest or input :)

Edit:
Changes Gordon, this is great :) http://forum.espruino.com/comments/13526821/

Edit:
Thanks for all the input: I get back with what results from this in a new message

EDIT:
WE REALLY NEED "LIKE" FOR THIS FORUM ...

You can measure it very simply by looking at the change in light that passes through your finger. For example this was a quick hack I did a while ago that uses your webcam to measure your pulse. It's not great, but in the right conditions (light behind your finger) it does work!

https://gfwilliams.github.io/HeartRate/

So just a light on one side, and a light sensor on the other.

However you can buy more professional units which (I believe) have two lights and sensors at different wavelengths. One is a wavelength that is affected by blood, one isn't - and you can then just compare the two sensor readings over time to get a pulse.

Breakout board with MAX30100
http://www.ebay.de/itm/182342028548

Thanks - that looks great! :)

@OwenBrotherwood, This sensor from Adafruit is small, and will work on a fingertip, or clipped to an earlobe:
https://www.adafruit.com/products/1093

It uses 4mA at 5v, and will also run at 3v, with just 3 wires – power, ground, and analog output.

The hardware is open source, and detailed here:
https://pulsesensor.com/pages/open-hardware

Some useful links:

https://github.com/xcoder123/MAX30100

https://github.com/sparkfun/SparkFun_MAX3010x_Sensor_Library

https://www.sparkfun.com/products/14045

Also lots of Max30100 boards on Amazon, prices all over the place.