Since v2.2.9, AIRS provides heart rate measurements using the built-in camera and flash of a compatible phone. How does this work?
First, you will have to place the AIRS heart rate widget on your launcher screen. Then, you will need to subscribe to the IH sensor in local recording. When pressing the widget on your launcher screen, a window will now appear that shows a camera preview and Start/Cancel buttons.
Using the camera and the built-in flash, AIRS grabs the current preview and calculates the changes in red color, caused by the pulsing blood in your finger (assuming that you indeed placed the finger over the camera lens, also covering the flash light!). These changes are averaged over 10 seconds of recording, after which you can see the estimate of your beats per minute in the upper left corner of the window. You can take up to 3 measurements before AIRS switches off the measurement in order to spare your flash light from burning too long.
Sure, the measurements are not as accurate as using a proper heart rate monitor (such as the one supported by AIRS, namely the AliveTech ECG monitor). However, these values will hopefully provide approximate insights into your heart rate for scenarios such as stress monitoring. Given that the flash light is used, it is not meant for continuous monitoring!
Enjoy this new feature!