Will Circular Ring 2 Measure Blood Pressure and Blood Glucose?

Yes — and it's coming soon!

We’ve officially announced that the Circular Ring 2 will offer estimates for both blood pressure and blood glucose via a firmware update.

⚠️ 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.

Here's how it works:

1. The ECG sensor detects the electrical signal of your heartbeat (R-peak).
2. The PPG sensor detects the arrival of that pulse at your finger.
3. The time delay between those two signals is called Pulse Transit Time (PTT).
4. PTT is inversely proportional to your systolic blood pressure.
5. 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, you’ll be asked to touch the ring with a finger from your opposite hand to complete the ECG circuit.

🔁 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.

📈 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.

🧷 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.

Updated on: 17/10/2025