Apple reintroduces Blood Oxygen monitoring on new Apple Watch models after resolving legal issues.

Apple is reintroducing a redesigned Blood Oxygen feature for the Apple Watch Series 9, Series 10, and Ultra 2 in the U.S. through a software update. Users need to update their iPhone to iOS 18.6.1 and their Apple Watch to watchOS 11.6.1 to access the feature, which calculates blood oxygen levels on the paired iPhone and displays results in the Health app's Respiratory section. This follows a legal dispute with Masimo and a U.S. Customs approval.