Circular has introduced blood pressure monitoring for the Circular Ring 2, allowing users to estimate systolic and diastolic blood pressure from their finger in approximately 60 seconds.
The new capability is available through the Circular app at no additional cost or subscription charge. It is intended to help users monitor blood pressure trends rather than provide a medical diagnosis or guide treatment decisions.
Unlike a conventional blood pressure cuff, which measures pressure by temporarily compressing an artery, Circular Ring 2 estimates blood pressure by analyzing cardiovascular signals captured from the finger.
The ring simultaneously records electrocardiogram, or ECG, and photoplethysmography, or PPG, signals and uses those measurements to calculate Pulse Wave Transit Time.
PWTT measures how quickly the pressure wave generated by each heartbeat travels through the cardiovascular system to the finger.
Circular said pulse waves generally move faster when arteries are stiffer and under greater pressure, giving the company a signal that can be used to estimate blood pressure when combined with the ring’s ECG and PPG measurements.
The system requires an initial calibration using a traditional blood pressure cuff.
Users take three conventional blood pressure readings and enter those values into the Circular app. The readings establish a personalized baseline that the Ring 2 can use when calculating later estimates.
Once that calibration is complete, users can perform regular measurements directly from the Ring 2 without using a cuff every time.
Circular recommends repeating the cuff-based calibration approximately every 30 days to help maintain the accuracy of the estimates.
To perform a measurement, the wearer places a finger from the opposite hand on the Ring 2.
That contact completes the ECG circuit while the device records 20 consecutive high-quality heartbeats. The ring then combines the resulting ECG and PPG information to estimate systolic and diastolic pressure.
The addition expands the role of Circular Ring 2 from general wearable health monitoring toward more cardiovascular-focused tracking.
Blood pressure has traditionally been more difficult to monitor through consumer wearables than metrics such as heart rate because accurate measurement generally requires either an inflatable cuff or an alternative technique that has been calibrated against one.
Circular’s approach does not eliminate the cuff entirely. Instead, the traditional measurement provides the personal reference point needed for the ring’s subsequent estimates.
That model could make blood pressure tracking more convenient for users interested in observing changes over time without repeatedly setting up a conventional monitor.
The company is emphasizing trend monitoring rather than positioning the Ring 2 as a replacement for clinical blood pressure measurement.
Circular specifically states that the feature should not be used to diagnose medical conditions or make treatment decisions.
The feature arrives as Circular continues developing its smart ring lineup following the company’s recent announcement of the Circular Ring 3.
For Ring 2 owners, however, blood pressure monitoring is being added through the existing app without an additional subscription, extending the capabilities of hardware already in use.
By combining ECG and PPG signals with individualized calibration data, Circular is attempting to provide another cardiovascular metric within the compact form factor of a smart ring while keeping the measurement process relatively simple for consumers.
The broader value proposition is convenience: after calibration, a user can take a blood pressure estimate from the finger in around one minute, potentially making it easier to build a regular record of blood pressure trends over time.
