Redesigned Blood Oxygen Feature for Apple Watch Returns to US Market
Apple announced on August 14, 2025, that it will reintroduce a redesigned Blood Oxygen feature for Apple Watch Series 9, Series 10, and Ultra 2 users in the United States through a software update. The new feature works by collecting sensor data on the Apple Watch but processing and calculating the results on the paired iPhone, with results viewable in the Health app’s Respiratory section.
This workaround comes after a lengthy legal dispute with medical technology company Masimo, which accused Apple of patent infringement on pulse oximetry technology. In 2023, the International Trade Commission found that Apple’s blood oxygen sensors violated Masimo’s intellectual property, forcing Apple to pause sales and remove the feature from watches sold in the US after January 2024.
The update was enabled by a recent US Customs ruling and arrives through iOS 18.6.1 and watchOS 11.6.1. Apple emphasizes that previously purchased watches with the original Blood Oxygen feature and international models remain unaffected by these changes.
Source: Apple Newsroom