Circular's New Smart Ring Can Detect AFib From Your Finger

Forget taking an electrocardiogram from your wrist; now you can take one from your finger. The Circular Ring Gen 2, which was announced on Jan. 5 just ahead of CES 2025, is one of few smart rings that can detect atrial fibrillation. It’s a feature that’s become common in smartwatches but is still relatively rare on smart rings.

The new ring will be available for $380 in February or March after a crowdfunding campaign in January. 

Read more: How Wearables Are Slowly Turning Into Personal Health Coaches in 2025

Watch this: Oura Ring 4: What’s New, and What I Liked and Don’t Like So Far

05:55

Atrial fibrillation is a condition in which a person experiences an irregular heartbeat. It can increase one’s risk of stroke and other heart-related conditions according to the Mayo Clinic. It’s estimated to affect 10.5 million US adults, or nearly 5% of the population, reports the University of California San Francisco. Circular says its Afib detection algorithm has been cleared by the US Food and Drug Administration.

Most Apple Watch models have been capable of taking an electrocardiogram since the Apple Watch Series 4 arrived in 2018, and the feature has become more common on wrist-worn wearables in recent years. While popular smart rings like those made by Oura and Samsung can’t detect Afib, Circular isn’t the first to put this functionality on your finger. Ultrahuman’s smart ring can measure signs of the condition overnight. 

The Circular Ring 2 will be available in gold, silver, black and rose gold and is made from titanium. It should last for eight days on a single charge, and Circular says it’s also redesigned the ring’s accompanying app.

Circular’s new ring is yet another sign that the smart ring market is growing and becoming increasingly competitive with traditional fitness trackers and smartwatches. 

Oura, broadly considered to be the leader in the smart ring category, released its latest model in October, which includes a new sensing system that should improve accuracy. Samsung, meanwhile, just launched its first smart ring in July 2024. 

According to the International Data Corporation, shipments of smart rings are estimated to have grown by 88.4% in 2024, far outpacing growth in other categories like watches, earbuds and glasses. 

Jack Leathem, a research analyst at Canalys, said in a previous interview that smartwatches could learn a thing or two from smart rings like those made by Oura.

“They’re actually pushing quite a bit of innovation within the smartwatch fields,” he said. “And vendors need to catch up.”