Apple is once again looking to redefine wearable health technology. A newly published patent from March 18 reveals the company is working on an innovative blood pressure monitoring system using a liquid-filled sensor, possibly paving the way for a future Apple Watch that can deliver more precise health insights.
The patent, titled “Blood Pressure Monitoring System Including a Liquid-Filled Sensor,” was first reported by PatentlyApple. It outlines a device built into a watch strap, which includes an inflatable chamber, an air pump, and a liquid-filled pressure sensor positioned between the strap and the user’s wrist.
Rethinking the Traditional Cuff
Current blood pressure monitors rely heavily on inflatable cuffs that restrict blood flow to measure pressure. Apple’s patent points out the limitations of this method, including varying accuracy due to inflation and deflation rates, as well as inconsistencies in cuff design.
Apple proposes a more refined solution. The patent describes a system where a strap, equipped with a liquid-filled chamber and a sensitive pressure sensor, can monitor blood pressure more accurately and potentially in a less invasive way. The sensor detects pressure changes in the liquid, which correlate to the user’s blood pressure.
Beyond the Apple Watch
Interestingly, the patent also mentions that the sensor could function independently of the Apple Watch or be used in combination with an iPhone. This hints at broader ambitions for modular health devices within Apple’s ecosystem.
What to Expect in 2025 and Beyond
Apple is expected to unveil the Apple Watch Ultra 3 and Series 11 this September. While rumors suggest these models might introduce some form of blood pressure detection, it is unlikely to include the advanced liquid-sensor system described in this patent. Instead, the upcoming models may offer more basic features such as detecting abnormal blood pressure trends, similar to how they currently detect potential signs of sleep apnea.
If this patented technology ever makes it to market, it would place Apple in direct competition with devices like the Huawei Watch D2, which already offers a form of blood pressure monitoring via a miniaturized cuff. However, Apple’s vision points to a more integrated, seamless experience for users.
The Road Ahead
Though still in its early stages, this patent offers a clear indication of Apple’s long-term vision for health monitoring. A future Apple Watch equipped with a liquid-based blood pressure sensor could represent a major breakthrough in wearable wellness tech — one that combines accuracy, usability, and elegance.
