Yes. Circular Ring 2 estimates your systolic and diastolic blood pressure from the app, and the feature is live now.
Circular Ring 2 offers estimates for blood pressure.
⚠️ Note: These are not medically certified features and are intended for wellness tracking only, not for diagnosis or treatment.
🧠 How Blood Pressure Estimation Works
The Circular Ring 2 is the first smart ring equipped with both a PPG sensor and a single-lead ECG sensor. This powerful combination allows us to estimate blood pressure using a technique called Pulse Transit Time (PTT) — a method widely used in clinical research for trend tracking without a cuff.
PPG alone cannot do this.
Here's how it works:
- The ECG sensor detects the electrical signal of your heartbeat (R-peak).
- The PPG sensor detects the arrival of that pulse at your finger.
- The time delay between those two signals is called Pulse Transit Time (PTT).
- PTT is inversely proportional to your systolic blood pressure.
- Based on this delay, the Circular app calculates an estimated blood pressure value.
🕒 You’ll perform a 60-second spot test to capture this measurement.
During the test, rest a finger from your opposite hand lightly on top of the ring to close the ECG circuit.
Light contact is important. Pressing hard compresses the tissue under the sensor and adds noise to the PPG signal.
The session ends once 20 consecutive high quality beats have been captured. The on-screen counter only advances on beats that pass the quality filter, so if your hand moves, the measurement simply takes a little longer.
🔁 Calibration for Accuracy
To keep estimates accurate, you’ll need to calibrate your ring once per month using a standard cuff-based blood pressure monitor. This step personalizes the measurement based on your cardiovascular profile.
Transit time tells the ring how fast your pulse wave travels. It does not tell it millimetres of mercury.
- At setup: take three readings with a standard cuff monitor and enter them. Those three points establish your personal relationship between transit time and mmHg.
- Every 30 days: one further cuff reading re-anchors the model, because arterial properties drift with age, weight, medication and season.
Think of it as setting the time on a watch. The mechanism is precise from the factory. It still needs to be told what time it is.
📈 Daily Wellness Insight
Once enabled, Circular will provide a daily estimated blood pressure reading as a wellness indicator — ideal for monitoring lifestyle trends, stress, and recovery patterns.
What is free and what is paid
Blood Pressure is a freemium feature. The essential score is free for every Ring 2 owner, with no subscription.
Free, for everyone
- Unlimited measurements
- Systolic, diastolic and heart rate for every session
- Daily view with your average across every reading that day, plus the full list of the day's sessions
- A contextual health tip on each result
- The in-app education library on what the two numbers mean
Included with Premium
- Advanced insights on your readings
- Long-term trends, including time in target range
- PDF export of your history to share with your doctor
🧷 FDA Status
We're currently in the regulatory process with our partner for FDA clearance of the blood pressure estimation feature.
🚫 Not a Diagnostic Tool
Please note: These features are not medical devices. They’re meant for informational purposes only and should not be used for medical decisions. Always consult a healthcare professional for clinical evaluations.
An issue with your blood pressure measurement?
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