As it turns out, nowadays you can make your own fingertip pulse oximeter using an Arduino microcontroller and an appropriate pulse oximeter sensor module. There’s nothing to be afraid of, so go ahead ...

A pulse oximeter is a device that clips on your finger, toe, or earlobe to measure blood oxygen saturation. Here's how it works and how to read it.

A pulse oximeter measures both your pulse and the oxygen saturation in your blood. You’ve probably had one of these on your finger or earlobe at the doctor’s office or a hospital.