Apple Loses Bid to Overturn $634 Million Masimo Patent Verdict

A U.S. federal judge rejected Apple’s attempts to overturn a jury verdict that found the Apple Watch infringed a Masimo Corp. pulse-oximetry patent. The judge also denied Apple’s request for a new trial, leaving the $634 million damages award in place.

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In early 2020, medical-technology firm Masimo filed a lawsuit accusing Apple of misappropriating trade secrets and infringing patents covering pulse-oximetry and other optical health-monitoring technologies used in the Apple Watch. The dispute expanded to include an International Trade Commission (ITC) ruling in 2023 that temporarily barred imports of Apple Watch models with blood-oxygen monitoring, prompting Apple to suspend sales of those models before re-launching them with the feature disabled. In 2025 Apple introduced a redesign that moved sensor data processing to the paired iPhone and displayed results in the Health app, leading Masimo to sue U.S. Customs and Border Protection over the continued import of the revised watches. The patent-related portion of the California lawsuit proceeded separately, and a November 2025 jury concluded that Apple’s heart-rate monitoring and notification features infringed a different Masimo pulse-oximetry patent, resulting in the $634 million judgment.

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Apple’s legal team challenged the jury instructions and the exclusion of testimony from an Apple expert, arguing that the patent’s “patient monitor” term should apply only to conventional medical equipment. Judge James V. Selna found no reversible error and upheld the jury’s interpretation that the Apple Watch qualifies as a patient-monitoring device. When asked for comment, Apple directed reporters to a prior statement noting that Masimo, a medical-device company that does not sell directly to consumers, has pursued more than 25 patents against Apple over six years, most of which have been invalidated, and that the patent at issue expired in 2022. Apple indicated it will appeal the decision.

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Apple has signaled its intention to appeal the verdict, keeping the litigation active while the $634 million award remains enforceable. The outcome of the appeal will determine whether the damages are reduced, upheld, or potentially overturned.

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