Apple Watch Series 10 was introduced last year with a refreshed design. But when it comes to health sensors, Series 10 has pretty much the same capabilities as Series 9. Interestingly, a leaked prototype of Series 10 has just revealed that Apple may have had bigger plans for last year’s Apple Watch.

Apple Watch Series 10 prototype hints at new health sensors

The Apple leaker and collector known as “StellaFudge” has shared images of an intriguing prototype of the Apple Watch Series 10. That’s because this particular prototype has a “very unique health sensor arrangement” that differs not only from the sensors included in the final version of the Series 10, but from any other Apple Watch ever released.

According to the leaker, the heart rate and blood oxygen level sensors in this prototype are much smaller than in the sensor that Apple currently uses. But that’s not all, as the back of the leaked Apple Watch Series 10 prototype also includes a never-before-seen “extra light ring” between the ECG sensor and the heart rate sensors.

According to rumors, Apple has been working on blood pressure and blood glucose sensors for the Apple Watch. The company would have experimented with these new sensors during the prototyping phase of the Series 10, but ended up delaying them to focus on the new design. The leaker believes that the prototype was used for internal testing with the new health sensors.

Unfortunately, although the prototype is fully functional, it runs an internal build of watchOS 11.1 without the stock apps installed (because they can only be downloaded through Apple’s internal network). For this reason, there’s no way to explore whether the health apps on this Apple Watch Series 10 prototype have any new unreleased features.

• Prototype Apple Watch Series 10 with… A very unique health sensor arrangement.
  
• The health sensors got shrunk down a lot and there was an extra light ring around the perimeter. The watch is also running an unreleased build of watchOS11, somewhere between 11.1b5 and 11.1rc. pic.twitter.com/8n06JkQT39
  
• — Stella – Fudge (@StellaFudge) March 31, 2025

Another interesting detail is that the internal build installed on this prototype dates back to October 2024, which suggests that Apple is still running experiments with these new health sensors. Maybe we’ll finally see them in action on the next generation Apple Watch.

Source: 9to5mac