Google researchers use off-the-shelf headphones to measure heart rate

Typical heart rate monitoring in wearable tech, like smart watches or wireless earbuds, relies at least partially on photoplethysmography (PPG), which uses light pulses to measure blood activity. It works generally well, but it has its limitations.

in a new research blog spotted by 9to5Google yesterday that they had tried a different approach, called audioplethysmography (APG), that uses ultrasound to measure heart…