Is it possible to get PPG(Photoplethysmogram) data from a smart watch via android?

Question

I want to develop a health care app using Android smart watch devices that have an optical heart rate sensor. Examples of such devices are: Samsung gear live, Moto360, LG G

Answer 1

Yes, it is possible (at least on a Samsung mobile device such as the S5, S6 etc.).

See this link: http://developer.samsung.com/galaxy#sensor-extension

From the Samsung website:

The HRM Sensor is located on the rear panel of the phone. If you place your finger, measurement starts. The photoplethysmogram(PPG) signal means the amount back of IR / RED light that reflected from blood vessel in the finger.

Use Samsung's SDK and it will give you the raw values (values range from 0 to ~64600 if I remember correctly).