First Clinical-Grade Diagnostic Wrist-Worn Device Designed for Long Term Monitoring of Atrial Fibrillation

Wearable technology has the potential to significantly aid in the detection and management of atrial fibrillation (AF), a common heart rhythm disorder. However, current consumer wrist-worn devices using photoplethysmography-based algorithms are limited to intermittent checks and are not designed for clinical decision-making. Recognizing this gap, researchers have developed a wearable wristwatch that offers continuous monitoring of heart rhythm and employs an innovative algorithm for AF detection.

Developed by a team at the University of Michigan, the Verily Study Watch stands out as a clinical-grade device. It operates on a principle similar to other wearables, using photoplethysmography to monitor heart rhythm changes. Unique to this device, if AF is detected, it prompts the wearer to take a single-lead ECG for confirmation. This result is then verified by a cardiographic technician before being communicated to the patient's doctor. This device constantly analyzes data, checking every 15 minutes. Over a period from September 2020 to May 2021, it was tested on over 100 participants, proving its effectiveness in identifying AF with an accuracy rate comparable to other photoplethysmography-based devices. While there was a noted dip in performance for detecting AF in participants with darker skin, it nonetheless was successful in identifying AF cases in these patients.

Image: The clinical smart watch has been found to successfully identify atrial fibrillation (Photo courtesy of 123RF)

This research is the first to evaluate the performance of a photoplethysmography-based algorithm in detecting AF across all physical activity levels. The Verily Study Watch maintained its accuracy in detecting AF during both low and moderate physical activities. Unlike consumer-oriented devices like the Apple Watch and Fitbit, which are FDA-approved only for pre-diagnostic use, the Verily Study Watch bridges the gap, potentially enabling healthcare providers to leverage wearable data for patient management. The FDA has granted 510(k) clearance to Verily, acknowledging the device's efficacy and its comparability to other legally marketed medical devices.

“Right now, we typically manage patients with atrial fibrillation using electrocardiogram, or ECG, patches that we put on the chest, but the future of Afib management will be on the wrist,” said Hamid Ghanbari, M.D., M.P.H., a cardiac electrophysiologist the University of Michigan Health Frankel Cardiovascular Center. “It is not intended to replace interval ECG monitoring for patients who need it. However, the multistage system may also limit the burden on clinicians and avoid the deluge of notifications generated by other wrist-worn devices that rarely result in clinically actionable findings.”

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