Happitech has validated the SDK with third party support of Lifeguard and the Vrije Universiteit of Amsterdam late 2016. The tests were done using the validated VU – Ambulatory Monitoring System (specifications can be seen here)

The SDK was approved for the use with the ONVZ insurance company app NRGY.

The correlation of the measurements between the iPhone & AMS System are shown below. Average correlation for RMSSD (HRV) is 86.7%
Average correlation for Heart Rate is 94.9% on a low end model

New studies are being conducted at VU Amsterdam University and started in October 2020.