Apple has released the iOS 18.6.1 update to iPhone users. The update comes with a significant change that directly affects Apple Watch users. Released simultaneously with watchOS 11.6.1, iOS 18.6.1 includes a redesigned Blood Oxygen feature specifically for Apple Watch Series 9, Series 10, and Apple Watch Ultra 2 owners in the United States.

iOS 18.6.1 Officially Released

The new feature was developed after a patent dispute that began approximately 18 months ago in the US forced Apple to disable the Blood Oxygen feature on some Apple Watch models. Following this legal action with health technology company Masimo, a software solution was developed for users whose Apple Watches lacked this measurement function.

With the redesigned system, users can initiate measurements using the Blood Oxygen app on their Apple Watch. During measurements, the sensors on the Apple Watch collect the necessary data, but this data is no longer interpreted directly on the watch.

Measurement results are transferred to the iPhone, and the analysis is performed on the phone. Results can only be viewed in the Respiration tab of the Health app on the iPhone. Measurement results are not accessible on the Apple Watch.

According to Apple’s update notes, this new Blood Oxygen experience will only be available on Apple Watch models sold in the US that do not include the original Blood Oxygen feature. There are no changes for watches equipped with the original feature or for models outside the US.

The update does not introduce any other system updates or changes within the iOS 18 series. Users can upgrade to iOS 18.6.1 by going to Settings > General > Software Update on their iPhones. This version, a technical workaround developed by Apple to address legal restrictions, offers special functionality to a limited group of users.