Apple has been ordered to pay $634 million to Masimo after a federal jury in California found that the Apple Watch’s blood-oxygen-related features infringed one of Masimo’s patents, marking the most significant victory yet for the medical-technology company in its sprawling legal war with the iPhone maker.
The jury concluded on Friday that Apple violated Masimo’s patent rights through the Apple Watch’s workout mode and heart-rate notification features. Masimo confirmed the verdict in a statement, calling the decision “a significant win in our ongoing efforts to protect our innovations and intellectual property.”
Apple said it disagrees with the jury’s findings and will appeal. “Over the past six years (Masimo has) sued Apple in multiple courts and asserted over 25 patents, the majority of which have been found to be invalid,” an Apple spokesperson said. “The single patent in this case expired in 2022, and is specific to historic patient monitoring technology from decades ago.”
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The ruling caps a major chapter in a contentious, years-long legal feud between the two California-based companies, one that has stretched across federal courts, the U.S. International Trade Commission (ITC), and now U.S. Customs and Border Protection.
A Multi-Front Fight Over Pulse-Oximetry Technology
Masimo, headquartered in Irvine, has accused Apple of hiring away its employees and using its proprietary pulse-oximetry technology—traditionally used in medical devices—for the Apple Watch. That claim has spawned multiple lawsuits and regulatory battles since 2018, turning the conflict into one of Apple’s most persistent patent fights.
The most dramatic escalation came in 2023 when the ITC blocked imports of Apple’s Series 9 and Ultra 2 watches after determining that Apple’s blood-oxygen technology infringed Masimo’s patents. Apple responded by stripping the blood-oxygen feature from certain watches in the U.S. market to avoid running afoul of the ban. The company later reintroduced an updated oxygen-sensing technology in August after receiving approval from U.S. Customs and Border Protection.
Even with the workaround, the regulatory tug-of-war remains in motion. The ITC said on Friday that it will hold a new proceeding to determine whether Apple’s updated watch models should still fall under the import ban. That decision could again disrupt Apple’s sales depending on the outcome.
Masimo has an ongoing lawsuit against Customs over the agency’s clearance of Apple’s revised watches. Apple, meanwhile, is challenging the original ITC import ban in the federal appeals court.
A Dispute With No Clean Ending in Sight
Friday’s $634 million verdict represents one of the largest single judgments Apple has faced in a patent case in recent years, though the company is already signaling a lengthy appeal process. Because the patent in question expired in 2022, the dispute centers on earlier Apple Watch models and historic technology, not the company’s newest devices.
The two sides have split earlier rounds of litigation. A California judge declared a mistrial in 2023 in Masimo’s trade-secret case against Apple after jurors could not reach a unanimous verdict. Apple scored a symbolic win in Delaware last year when a jury ordered Masimo to pay just $250 over allegations that Masimo’s smartwatches infringed two Apple design patents.
Still, the broader battle over pulse-oximetry technology remains unsettled. The stakes go beyond the two companies, because the Apple Watch is one of the world’s most widely used health-monitoring devices. Any ruling that affects its features or availability tends to ripple across the wearables industry, health-tech suppliers, and regulators.
Friday’s verdict adds to that uncertainty. Masimo, emboldened by its win, is continuing to pursue claims across multiple venues. Apple is preparing for another round at the appeals court. And the ITC could once again determine whether Apple’s flagship watches stay on U.S. shelves.
For now, the only clarity is that the fight is far from over.