Apple Watch health monitoring patent dispute

On January 9, 2020, Masimo and its subsidiary, Cercacor Laboratories, filed a lawsuit in the United States District Court for the Central District of California, alleging that Apple violated the company's light-based health monitoring patents. Masimo and Cercacor claimed that Apple's hiring of Cercacor chief technology officer Marcelo Lamego and Masimo chief medical officer Michael O'Reilly allowed Apple to gain a competitive advantage through their knowledge of Masimo's. The lawsuit seeks to block the use of Masimo's patents in the Apple Watch Series 4 and 5 and to seize seven patents issued to Lamego.^[6] Apple repeatedly filed to dismiss the allegations of obtaining trade secrets and filed petitions to invalidate Masimo's patents at the Patent and Trademark Office in September; Masimo accused these efforts of being attempts to delay the case in order to garner a greater share of the smartwatch market.^[7] In April 2023, deliberations began in the case. Judge James V. Selna^[8] dismissed the business and marketing claims against Apple and set the maximum fine against Apple at US$1.85 billion.^[9] The trial ended with a no jury verdict; the jury favored Apple, but a holdout juror refused to compromise.^[10]

In June 2021, Masimo expanded its lawsuit to encompass the Apple Watch Series 6, filing a complaint to the International Trade Commission to state that the Series 6 infringes five patents for Masimo's light-based pulse oximeters.^[11] The complaint was prompted by delays in the lawsuit, according to Masimo chief executive Joe Kiani.^[12] On October 26, 2023, the International Trade Commission issued an import ban against the Apple Watch Series 6, 7, 8, and 9 models set for December 26.^[13] Apple announced that it would halt sales of Apple Watch Series 9 and Ultra 2 models in retail locations on December 24 and online on December 21.^[14] The company has attempted to overturn the ban through software updates that would alter how oxygen saturation is determined.^[15] Apple lost an attempt to stay the ruling while awaiting an appeal^[16] and appealed the ruling to the Court of Appeals for the Federal Circuit.^[17] The federal appellate court granted Apple a temporary reprieve.^[18]

In November 2025, a federal court in California awarded $634 million to Masimo from Apple. It was a jury decision. The issue concerns the pulse oximetry technology in used in the Apple Watch.^[19][20]

Apple stated that it disagrees with the verdict and will appeal this decision.^[19]

• Brown, Dalvin; Tilley, Aaron (December 28, 2023). "Apple Keeps Chasing the Ultimate Health-Tracking Watch—but It Could Take Years". The Wall Street Journal. Retrieved December 28, 2023.