In a recent blog post, Fitbit unveiled three new devices in its product line. One of the newly debuted watches, the Sense 2, includes an atrial fibrillation (AFib) detection algorithm that recently received FDA clearance.

The AFib detection technology relies on a photoplethysmography (PPG) optical heart-rate sensor that reads the heart rhythm of its wearer periodically throughout the day, or on demand. These readings are then applied to the algorithm in order to detect irregularities. The device will notify the wearer if any irregularities are detected, and prepare readings that can be sent to healthcare providers.

Fitbit conducted a clinical study of more than 455,000 users in order to test the PPG algorithm. Results of the study, shared at the American Heart Association’s annual scientific sessions in 2021, showed that nearly one-third of those who received notification of irregular heart rhythm were later diagnosed with AFib. When the sensor was used alongside a wearable ECG patch monitor, detection of AFib cases was 98% accurate.

The Sense 2 adds to Fitbit’s list of heart health tracking modalities, including heart rate variability (previously discussed here).