Apple Plans to Add Blood-Oxygen Feature to Watches
By Reuters | 14 Aug, 2025

Having put behind the dispute with Maximo over pulse-oxymetry technology Apple will use a software update to add the feature to several of its watches.

View of an Apple logo at an Apple store in Paris, France, April 23, 2025. REUTERS/Abdul Saboor/File Photo

Apple will bring a blood oxygen measurement feature to some of its watch models via a software update after receiving approval from the U.S. government amid a protracted legal dispute over the technology, it said on Thursday.

The move will allow users of Apple Watch Series 9, Series 10, and Apple Watch Ultra 2 in the United States to view their blood oxygen levels on a paired iPhone.

It comes after years of legal wrangling with Irvine, California-based Masimo, which has accused Apple of hiring its employees and stealing its pulse oximetry technology after discussing a potential collaboration.

Masimo won a ruling at the U.S. International Trade Commission to block imports of watches with the feature, which prompted Apple to remove the feature and set off a lengthy appeals process. Its shares were down 4.5%.

The watch models affected Thursday did not have the blood oxygen feature when shipped, but Apple said U.S. Customs had approved the software update. 

With the update, a user can start a session in the blood oxygen app on Apple Watch, and the Apple Watch sensors will collect data that will be used by the iPhone to calculate and display the levels, Apple said.

Apple first introduced pulse oximetry in its Series 6 Apple Watches in 2020. Masimo released its blood oxygen tracking W1 watch in 2022.

Masimo convinced the ITC to block imports of Apple's Series 9 and Ultra 2 smartwatches in 2023, based on the commission's determination that Apple's technology for reading blood oxygen levels infringed upon Masimo's patents.

Apple temporarily resumed sales of the watches the next day after persuading the Federal Circuit to pause the ban.

The Federal Circuit reinstated the ban the next month, leading Apple to remove pulse oximetry capabilities from its watches in the United States.

Masimo did not immediately respond to a request for comment.

(Reporting by Stephen Nellis in San Francisco; Additional reporting by Blake Brittain in Washington, Puyaan Singh and Akash Sriram in Bengaluru; Editing by Anil D'Silva)