Over the last couple of years, Apple has been fighting a patent infringement case against Masimo. Masimo alleges that Apple infringed on its patents for the blood oxygen sensor that’s included on various Apple Watch models. That resulted in Apple being forced to turn that feature off on Apple Watches sold in the United States. Apple has now re-enabled the feature through a clever workaround.
Apple has redesigned the Blood Oxygen feature for Apple Watch Series 9, Series 10, and Apple Watch Ultra 2 users through an iPhone and Apple Watch software update. Once users update their iPhones to iOS 18.6.1 and Apple Watch to watchOS 11.6.1, they will have access to the Blood Oxygen feature.
It’s important to note that the import ban only applied in the United State of America. Australians have not lost access to the feature. Apple says:
There will be no impact to Apple Watch units previously purchased that include the original Blood Oxygen feature, nor to Apple Watch units purchased outside of the U.S.
Apple has been able to do this as they have changed how blood oxygen (also called SpO2) is calculated. The patent Apple is alleged to have infringed involved calculating SpO2 on the Apple Watch. Apple’s workaround shifts the calculation of SpO2 from the Apple Watch to the iPhone.
Blood oxygen is determined by shining a coloured light through the skin. The reflection of that light is measured and then an algorithm determines the oxygen level in the blood. That calculation was done on the watch before the import ban was imposed by the courts in the USA.
Now, the data collected by the watch is sent to the iPhone where it is available through the Health app.
Apple says:
Following this update, sensor data from the Blood Oxygen app on Apple Watch will be measured and calculated on the paired iPhone, and results can be viewed in the Respiratory section of the Health app. This update was enabled by a recent U.S. Customs ruling.
Anthony is the founder of Australian Apple News. He is a long-time Apple user and former editor of Australian Macworld. He has contributed to many technology magazines and newspapers as well as appearing regularly on radio and occasionally on TV.