Blood oxygen tracking is returning to the Apple Watch after an 18-month hiatus, through a software update effective today.
Apple had been forced to disable the pulse oximetry functions of its watches in January 2024 following the threat of a federal import ban and a years-long patent dispute lodged by patient monitor maker Masimo.
The tech giant described it as a redesigned feature for certain models—including the Series 9, 10, and Ultra 2, all of which debuted after Masimo first filed a complaint at the International Trade Commission, and were sold after the import ban took effect. Apple said it received a new green light through a recent U.S. Customs ruling.
According to Apple, sensor data from the watch will now be “measured and calculated” separately on the user’s paired iPhone, with results being viewed in the respiratory section of the phone’s Health app, instead of on the wrist.
Masimo’s three patents at the heart of the case governed “user-worn devices” for noninvasively capturing a biomarker, including using light-based sensors. Previously, Apple had unsuccessfully argued that the construction of its sensors differed from the patents’ claims, which are set to expire in August 2028.
Masimo had also filed a trade secrets suit related to pulse oximetry, claiming that Apple poached the company’s former employees. That case led to a hung jury in 2023. Meanwhile, Apple has lobbed lawsuits of its own over design similarities in Masimo’s W1 smartwatch.