FDA approves Fitbit's AFib detection algorithm

The US Food and Drug Administration has approved Google's Fitbit photoplethysmography algorithm to identify atrial fibrillation (AFib).

The AFib detection assesses the user's heart rhythm in the background while they're still or asleep. The feature works using a Fitbit's PPG optical heart-rate sensor that looks at how blood vessels under the wrist expand and contract based on changes in blood volume.

The detection algorithm analyzes these changes for irregularities and signs of possible atrial fibrillation. Fitbit says AFib detection is compatible with its Sense, Versa, Versa Lite, Charge 4 and Inspire 2 devices.

There are two ways to detect AFib with Fitbit, including via the ECG app and via the PPG-based algorithm. The ECG app lets users take a spot check while the PPG-based algorithm takes a measure of heart rhythm over a longer term to help spot asymptomatic AFib.

Google says the AFib detection feature will be coming soon to some of its devices that can measure heart rates. It said that the PPG algorithm will be available soon to customers in the US across a range of Fitbit's heart-rate enabled devices. Fitbit devices still use Fitbit OS but the company is planning to release a device with Google's Wear OS.