Android heart rate monitor how to implement?

Question

Android

Greetings!
You need to automatically receive heart rate in the application. Every smartphone has a camera and a flash. The question is how is it implemented? Is it necessary to somehow analyze the video?
Or maybe there is a link to an open source project?

Answer 1

Finger on the camera, the camera captures the transmitted light. There is not much of it, but with sufficient illumination for detection it will be enough.
Fix the darkening peaks in relation to time intervals.
According to these data, count the pulse.