The Apple Watch blood oxygen patent dispute reached a critical inflection point on November 15, 2025, when a California federal jury awarded Masimo a $634 million verdict against Apple for patent infringement. The ruling keeps alive one of tech’s longest-running intellectual property fights, yet Apple’s existing software workaround means the company can continue selling full-featured Apple Watches in the United States without interruption.
Key Takeaways
- Masimo won a $634 million patent infringement verdict on November 15, 2025, in California federal court
- The disputed patent (no. 10,433,776) expired in mid-2022 but covered 43 million Apple Watch units already sold
- Apple’s August 2025 workaround processes blood oxygen data on the paired iPhone rather than the Watch itself
- The ITC is reopening its import ban review after Masimo challenged the workaround’s validity
- Apple plans to appeal, calling the patent “historic patient monitoring technology from decades ago”
How the $634 Million Verdict Changes the Game
Masimo’s $634 million award represents the largest financial judgment in the six-year dispute, though it falls short of the company’s $634–749 million damage range. The verdict hinged on whether Apple Watch qualifies as a “patient monitor” under Masimo’s patent—a classification Apple has contested throughout the litigation. The jury sided with Masimo, citing specific features like heart rate alerts that activate after 10 minutes of motionless detection and integrated workout tracking as evidence the device performs clinical functions.
The core of Masimo’s case rested on internal Apple documents labeling the Apple Watch “the most used heart monitor in the world,” according to court filings. This language became central to proving Apple understood it was building a device with medical monitoring capabilities—and therefore infringing Masimo’s low-power pulse oximeter patent. Apple’s counterargument—that these are consumer wellness features, not clinical tools—failed to persuade the jury, though the company has signaled it will challenge the verdict on appeal.
Why Apple’s Workaround Keeps Watches Selling
Despite the verdict, Apple Watch sales in the United States have not faced disruption since August 2025. That is because Apple engineered a software solution that sidesteps the patent entirely: blood oxygen data is now processed on the paired iPhone rather than on the Watch itself. U.S. Customs approved this workaround, allowing Apple to resume full-feature sales without the software restrictions that had been in place since December 2023.
This technical pivot matters enormously. The original patent dispute triggered an International Trade Commission (ITC) import ban that forced Apple to disable blood oxygen features on U.S. Apple Watch models for over a year. The new architecture—offloading the computation to the iPhone—appears to satisfy the import restrictions because the Watch no longer performs the infringing function independently. However, Masimo has already challenged whether this workaround truly avoids the patent’s scope, prompting the ITC to reopen its review of Apple Watch imports with blood oxygen sensors.
What Happens Next in the Apple Watch Blood Oxygen Patent Fight
The legal landscape remains unsettled. Apple has announced plans to appeal the $634 million verdict, arguing that the patent covers “historic patient monitoring technology from decades ago” and should carry minimal weight. Over the past six years, Masimo has asserted more than 25 patents against Apple, with the majority invalidated in court, according to Apple’s statement. This history suggests Apple believes it has strong grounds to overturn or reduce the damages award.
The simultaneous ITC review adds another layer of uncertainty. If regulators determine that Apple’s iPhone-based workaround still infringes the patent, a new import ban could be imposed—this time potentially without a viable software fix. Such a ruling would force Apple to redesign the feature more fundamentally or remove it entirely from U.S. models. Masimo has framed the dispute as essential to protecting innovation in patient monitoring technology, stating it remains “committed to defending our IP rights moving forward”.
Why This Matters Beyond Apple and Masimo
The Apple Watch blood oxygen patent case illustrates the friction between consumer electronics and medical device patent regimes. Masimo positions itself as a medical technology innovator protecting decades of research into low-power pulse oximetry. Apple counters that it is building consumer wellness tools, not clinical instruments. The jury’s verdict suggests courts may lean toward Masimo’s interpretation—that a device performing medical-adjacent functions, even in a consumer context, can infringe medical device patents.
This precedent could influence how other tech companies approach health monitoring features. Smartwatch makers, fitness trackers, and smartphone manufacturers now face a clearer signal that integrating certain biometric sensors carries patent risk, particularly if the underlying technology traces back to older medical patents. The workaround approach—offloading sensitive computations to paired devices—may become a standard design strategy to mitigate infringement liability.
Does the verdict mean Apple will lose access to blood oxygen monitoring?
No. Apple’s iPhone-based workaround has already allowed U.S. Apple Watches to function with blood oxygen features since August 2025. Even if the verdict stands, this technical architecture appears to satisfy current import restrictions. The ITC review could change that, but for now, U.S. customers can purchase and use Apple Watches with full blood oxygen capabilities.
How much will Apple actually have to pay?
The jury awarded $634 million, but that figure is not final. Apple plans to appeal, and courts may reduce damages based on legal arguments about patent validity or infringement scope. The patent itself expired in mid-2022, which Apple’s legal team will likely cite to argue for minimal damages. The final amount—if any—depends on how appeals courts rule.
Why is Masimo pushing back on the workaround?
Masimo argues that processing blood oxygen data on the iPhone still uses Masimo’s patented low-power pulse oximeter technology, just with the computation shifted to a different device. The company is asking the ITC to examine whether the Watch’s sensor hardware alone—independent of where the data is processed—infringes the patent. If regulators agree, Apple would need to either redesign the sensor entirely or disable the feature in U.S. models again.
The Apple Watch blood oxygen patent dispute is far from over. A major verdict has landed, but Apple’s technical workaround keeps the feature alive for now, and the company’s appeal machinery is already in motion. The next critical moment arrives when the ITC concludes its reopened review, which will determine whether Apple’s iPhone-based solution truly escapes Masimo’s patent reach or faces a new import restriction. Until then, U.S. Apple Watch owners can continue using blood oxygen monitoring without interruption—though the legal uncertainty hovering over the feature underscores how fragile consumer tech features can be when they brush against medical device patents.
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Edited by the All Things Geek team.
Source: T3
