In 2023, blood oxygen sensing was disabled on all newly sold Apple Watches in the United States. This was due to a court ruling that Apple had violated a patent from digital health company, Masimo.
This feature was brought back this week, thanks to a workaround that allows this data to be processed on the iPhone instead of directly on the Watch.
From the press release:
Apple will introduce a redesigned Blood Oxygen feature for some Apple Watch Series 9, Series 10, and Apple Watch Ultra 2 users through an iPhone and Apple Watch software update coming later today.
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.
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.
This is great news for those who have missed out on this feature.