At the end of 2023, competitor Masimo’s patent lawsuit caused considerable waves: Apple had to stop selling the smartwatch shortly after Christmas. Although the sales ban was lifted after three weeks, a newly purchased Apple Watch was no longer allowed to carry out blood oxygen measurements in the United States. Apple revised the function and released it again in August 2025. Masimo sued again – but this time the court decided differently: According to Judge Bhattacharyya, the revised version does not infringe any of the competitor’s patents. The court confirmed a previous decision that the method originally integrated into watchOS had violated the patents of the plaintiff company. However, the software version currently used by Apple in the USA is unaffected. Regarding the latter assessment, the company thanked the judge for her “careful assessment” and expressed satisfaction. However, this only represents a recommendation for the International Trade Commission (ITC), which makes the final decision. If the ITC agrees with the judge’s recommendation, the preliminary approval will remain in effect and the company will be allowed to continue selling the Apple Watch in the USA; US users who already own such a smartwatch can also continue to measure oxygen saturation in the blood.
Banned in the USA: Measurement results directly on the Apple Watch.
Transfer to iPhone
Apple bought this opportunity through a certain loss of convenience for users: In the USA, users have to check what a measurement revealed on their smartphone. The software developers moved the calculation of the oxygen concentration and the display of the result to the iPhone. In this way, Apple circumvents the Masimo patent. The sensor remains the same; Apple didn’t have to make any changes to the hardware. A jury decided in the fall that the patent infringements of previous implementations would cost Apple $643 million. Apple said it disagreed with this decision and was considering further legal action.
