The Geek Pub guide will help get you started with an Arduino pulse sensor. While sensors like this are reliable, it's worth keeping in mind that your heart rate can tell you a lot of different things.

This is a breadboard friendly breakout board for the Maxim MAX30105 reflectance, particle, and pulse ox sensor. This library should work with other MAX3010x sensors including the MAX30102, MAX30101, ...

This is an Arduino-based Proximity Sensor circuit wired using the popular HC-SR04 Ultrasonic ranging module,used here for non-contact object detection purpose. The HC-SR04 module includes ultrasonic ...

The organic optoelectronic pulse oximetry sensor described here demonstrates the potential for the application of organic electronics to thrive in the medical device field.