Hi everyone,

Today we'd like to share a look at what's coming next for Circular.

Over the past year, much of our work has focused on improving the foundation of the platform: stability, synchronization, connectivity, and overall reliability. That work is allowing us to move into the next phase, bringing more advanced health features and a better overall experience.

Sleep Algorithm V3

We've developed a completely new sleep algorithm trained on more than 800 polysomnography (PSG) recordings, the clinical gold standard for sleep studies.

In our internal testing, it reaches approximately 78% agreement with PSG for sleep staging while significantly improving detection of more complex and atypical sleep patterns that were challenging for previous models.

A validation study is currently underway, and we expect to submit it for publication in the coming months.

ECG & Heart Rhythm

We're also introducing major ECG improvements, which are essential for supporting more accurate Blood Pressure Monitoring. 

This includes cleaner ECG signals with significantly reduced noise, improved AFib detection, and additional clinical metrics such as PR interval, QRS duration, and QT/QTc intervals available in the downloadable PDF report

We're also expanding rhythm categorization beyond AFib, with support for additional rhythm classifications planned where regulatory approvals allow.

A validation study for these ECG improvements is also in progress.

Blood Pressure

Blood Pressure is getting closer. We are now testing the feature in a development environment on the app.

The rollout will happen in two stages:

• A free version available to all Circular users, including systolic and diastolic readings and full history.
• A premium version released later, with trend analysis, report exports, and target range insights.

Blood Pressure measurements will require an initial calibration using a standard cuff and a monthly recalibration to maintain accuracy.

A Redesigned App

Nearly every Circle inside the app has now been redesigned to create a cleaner and more intuitive experience.

Sport Session is the final area still being redesigned and will be the next to receive the updated interface.

More Reliable Connectivity

The latest firmware also introduces major Bluetooth improvements.

We've addressed the root causes behind intermittent disconnections, resulting in a more reliable connection between your ring and your phone across both Android and iPhone.

Looking Ahead

These improvements represent much more than individual features.

Throughout 2026 we've been investing heavily in the technical foundations that make all of this possible. As those pieces come together, we're able to deliver more advanced health insights while continuing to improve reliability and performance across the entire Circular ecosystem.

Thank you for your continued feedback, patience, and trust. Your input continues to shape the future of Circular, and we're excited to share the next chapter with you.

— The Circular Team