Jurors found that the smartwatch’s functions that notify wearers of unusually high or low heart rates infringed Masimo’s US patent No. 10,433,776, Masimo announced in Nov. 14 statement. The verdict was not yet entered into the docket as of Monday morning.
“We are pleased by this outcome, and appreciate the time and attention given to our case by the court and the jury,” Masimo said in its statement. “This is a significant win in our ongoing efforts to protect our innovations and intellectual property, which is crucial to our ability to develop technology that benefits patients.”
An Apple spokesperson said the company disagrees with the verdict, “which we believe is contrary to the facts,” and plans to appeal.
“Masimo is a medical device company that does not sell any products to consumers,” Apple said. “Over the past six years they have sued Apple in multiple courts and asserted over 25 patents, the majority of which have been found to be invalid. The single patent in this case expired in 2022, and is specific to historic patient monitoring technology from decades ago.”
The patent, which covers a power-saving system that uses light to track pulse and oxygen levels, expired in June 2022. Apple withdrew its arguments for invalidating the patent during the trial, leaving jurors to consider infringement by the device’s heart-rate alerts.
Jurors agreed with Masimo that the Apple Watch’s alert feature serves as a patient monitor—a device meant to detect and report abnormal readings even when the wearer isn’t moving. Masimo said Apple used its low-power light-sensing method and motion-filtering design for that purpose.
Apple argued the accused feature is a fitness aid, not a medical tool. Its lawyers told jurors that alerts activate only after 10 minutes of inactivity and are disabled in workout mode—showing the watch was never intended to capture every medical event.
The trial in the US District Court for the Central District of California pitted Irvine, Calif.-based Masimo against one of the world’s largest consumer-electronics companies in a fight over where wellness technology ends and medical monitoring begins. Masimo had sought as much as $981 million for alleged infringement from January 2020 through the patent’s June 2022 expiration.
The victory for Masimo is just one part of broader clash with Apple over wearable-sensor innovation. Masimo awaits a trade-secret bench ruling from Judge James Selna, is challenging a US Customs and Border Protection decision allowing imports of redesigned Apple Watches, and is defending an import ban it won at the US International Trade Commission that’s under review at the US Court of Appeals for the Federal Circuit.
Sullivan & Cromwell and Knobbe Martens represent Masimo and Cercacor. Wilmer Cutler Pickering Hale & Dorr LLP, Lewis and Llewellyn LLP, Pillsbury Winthrop Shaw Pittman LLP, Haynes & Boone LLP, and Gibson Dunn & Crutcher LLP represent Apple.
The case is Masimo Corp. v. Apple Inc., C.D. Cal., No. 8:20-cv-48, verdict issued 11/14/25 .
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