Just a few months after Fitbit roped in FDA clearance for an algorithm that could be embedded into its eponymous health-tracking wearables to detect atrial fibrillation, the technology is ready to hit the ground running.
In a blog post this week, Fitbit unveiled a trio of new additions to its smartwatch lineup. While all three will include the afib algorithm, two are predominantly fitness-focused devices. The third, dubbed the Sense 2, has been categorized as the tech developer’s “most advanced health-focused smartwatch.”
Fitbit’s afib detection technology relies on a photoplethysmography (PPG) optical heart-rate sensor. It passively collects heart rhythm readings throughout the day, which are then analyzed by an algorithm to spot any irregularities. If any are detected, the device automatically notifies the wearer, who can then share the collected readings with a healthcare provider.
The Google-owned devicemaker validated the PPG algorithm in a large-scale clinical study of more than 455,000 Fitbit users. Trial results shared at the American Heart Association’s annual scientific sessions late last year showed that about one-third of those who received irregular heart rhythm notifications went on to be diagnosed with afib. Additionally, when the sensor was used in tandem with a wearable ECG patch monitor, it was 98% accurate in detecting afib cases.
The algorithm has been cleared for use only by wearers who are at least 22 years old and have no known history of irregular heart rhythm.
The new Sense 2 wearable includes both the PPG algorithm, which monitors heart rate around the clock, and the previously FDA-cleared ECG app that allows users to perform on-demand spot checks for afib. The device boasts a battery life of more than six days on a single charge, which Fitbit says is especially helpful for the heart-monitoring technology since afib is often best spotted when the body is at rest.
Beyond those new features, according to another company post, the Sense 2 includes other health-tracking capabilities that were integrated into past models of Fitbit’s wearables: measurements of heart rate and its variability, breathing rate, skin temperature and oxygen saturation.
The device also introduces a new sensor dubbed Body Response, which continuously tracks electrodermal activity—an indicator of changes in the sympathetic nervous system. Those cEDA readings, plus heart rate, heart rate variability and skin temperature measurements, are combined to assess stress levels. The Sense 2 device then uses those findings to nudge wearers toward stress relief activities like deep breathing, practicing mindfulness and more.
The Sense 2 smartwatch starts at $300 and is slated to begin shipping out by the end of September.