Masimo Fights Apple Bid to Undo $634 Million Apple Watch Verdict

Masimo Corp. urged a California federal judge to reject Apple Inc.’s bid to erase a $634 million patent-infringement verdict over Apple Watch heart-rate alerts, arguing trial evidence supported the damages award.

The jury heard sufficient evidence to back its finding that Apple Watch continuously measures pulse rate and issues high- and low-rate alerts, supporting its finding that Apple Watch meets the “patient monitor” limitation of US Patent No. 10,433,776, Masimo said in a redacted brief filed Jan. 23 in the US District Court for the Central District of California.

Responding in opposition to Apple’s bid for judgment as a matter of law or a new trial, Masimo pointed to doctors’ statements, Apple marketing, and testimony from Masimo’s expert and from Apple engineers, who said "[e]very single watch ever sold by Apple has been a heart rate monitor.”

“In fact, Apple’s Chief Operating Officer called the Watch ‘the most used heart rate monitor in the world,’” the brief said.

The November 2025 verdict was supported under both literal infringement and patent law’s doctrine of equivalents, Masimo said, arguing Apple’s claim-construction and evidentiary challenges don’t warrant throwing out the jury’s verdict. Masimo also said its survey and economic expert provided a non-speculative basis for damages, arguing against a new trial only on that question.

Apple in December asked Judge James Selna to overturn or reduce the $634 million award, saying the record can’t support the verdict and that trial errors and insufficient apportionment inflated the damages.

Sullivan & Cromwell LLP and Knobbe Martens represent Masimo. 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, opposition to motion for judgment as a matter of law and new trial filed 1/23/26.