The sensor still works on your wrist—you just check your iPhone for the result
For nearly two years, a patent dispute quietly erased a health feature from millions of American wrists — a reminder that the tools we come to rely on exist within legal and commercial ecosystems as much as technological ones. Apple has now restored blood oxygen monitoring to its newest US Apple Watch models through a software update that shifts the computational work from watch to iPhone, satisfying import restrictions while returning a capability many users had come to depend on. The resolution, enabled by a fresh US Customs ruling, closes a chapter that began in 2023 when the International Trade Commission sided with health technology firm Masimo over pulse oximetry patents. What returns is not quite what was taken, but it is close enough to matter.
- A 2023 patent ruling forced Apple to strip blood oxygen monitoring from new US Apple Watches right before the holiday season, briefly pulling the devices from shelves entirely.
- The dispute with Masimo left American buyers of the Series 9, Series 10, and Ultra 2 without a health feature their counterparts abroad continued to enjoy.
- Apple engineered a technical workaround — offloading sensor data processing from the watch to the paired iPhone — that redraws the line of what the watch itself computes.
- US Customs approved the redesigned technology for import, clearing the legal path for Apple to restore the feature via iOS 18.6.1 and watchOS 11.6.1 software updates.
- The feature is back, but with a changed workflow: readings are taken on the wrist, results appear in the iPhone's Health app — a compromise most users are likely to accept.
Apple has found its way around a legal obstacle that kept blood oxygen monitoring off American smartwatches for nearly two years. Starting this week, owners of the Apple Watch Series 9, Series 10, and Ultra 2 in the United States can measure their blood oxygen levels again — though the experience works a little differently than before.
The trouble began in 2023, when the International Trade Commission ruled that Apple had infringed on a patent held by Masimo, a digital health company, related to pulse oximetry technology. Apple contested the finding, but the ruling held. The company was forced to remove the feature from new US Apple Watches — a painful blow that briefly pulled the devices from American store shelves ahead of the holiday season. Existing owners kept their feature, and watches sold outside the US were never affected.
Apple's solution shifts where the processing happens. Rather than calculating blood oxygen levels on the watch itself, sensor data now travels to the paired iPhone, where the computation occurs. Results appear in the Health app's Respiratory section instead of on the watch face. A recent US Customs ruling approved the import of Apple Watches with this redesigned approach, allowing Apple to deliver the restoration through software: iOS 18.6.1 and watchOS 11.6.1, available as over-the-air updates.
The practical change is modest — you take the reading on your wrist, then check your phone for the result. For most users, that is a reasonable trade. The update applies only to the three newest models that lost the feature; older watches and all devices purchased outside the United States are unaffected. After years of legal navigation, Apple has recovered the functionality its customers wanted, even if the path there required reimagining where the work gets done.
Apple has found its way around a legal obstacle that kept one of its most useful health features off American smartwatches for nearly two years. Starting Thursday, owners of the Apple Watch Series 9, Series 10, and Ultra 2 in the United States can measure their blood oxygen levels again—but not quite the way they could before the patent dispute began.
Back in 2023, the International Trade Commission ruled that Apple had infringed on a patent held by Masimo, a digital health company, related to pulse oximetry technology. Apple contested the finding, but the ruling stuck. The company was forced to remove the blood oxygen feature from new Apple Watches sold in the US, a particularly painful blow that came right before the holiday shopping season and briefly pulled the watches from American store shelves entirely. The ban applied only to new devices sold domestically; existing owners kept their feature, and watches sold outside the US were unaffected.
Now Apple has engineered a technical workaround that satisfies the import restrictions while restoring the capability. The solution shifts where the actual processing happens. When you measure your blood oxygen on the watch itself, the sensor data no longer stays on your wrist. Instead, it travels to your paired iPhone, where the calculation occurs. The results then appear in the Health app on your phone, specifically in the Respiratory section, rather than displaying directly on the watch face.
The path to this solution required a fresh ruling from US Customs, which recently approved the import of Apple Watches with this redesigned version of the technology. That clearance opened the door for Apple to roll out the feature through software updates: iOS 18.6.1 on iPhones and watchOS 11.6.1 on the watches themselves. Users can download both updates over the air through their device settings.
The practical effect is that American Apple Watch owners regain access to respiratory health monitoring, though with a workflow change. You'll still be able to take a reading on your wrist, but you'll need to check your iPhone to see the actual number. For many users, this represents a reasonable compromise—the data is still there, the health insight remains available, just accessed through a different device. The update applies only to the three newest models that lost the feature; older Apple Watches with the original blood oxygen capability are unaffected, as are all watches purchased outside the United States.
This resolution marks the end of a frustrating chapter for Apple and its customers. The company has spent years navigating patent law to restore a feature that users valued, and the legal path forward required not just a workaround but explicit customs approval. The redesigned approach suggests Apple found a technical distinction that satisfied the patent holder's claims while still delivering the core functionality users wanted back.
Citações Notáveis
Apple Watch users in the US can once again measure their blood oxygen levels directly on their watch, but the detailed results will only appear on the iPhone— Apple statement
A Conversa do Hearth Outra perspectiva sobre a história
Why did Apple need to move the processing from the watch to the iPhone? Couldn't they have just designed around the patent entirely?
The patent covers the specific technology for measuring blood oxygen on the watch itself. By moving the calculation to the iPhone, Apple created enough technical separation that US Customs approved it as a different implementation. It's not elegant, but it works.
So users have to pull out their phone every time they want to see their blood oxygen number?
Not exactly. You still take the measurement on your wrist—the sensor still works. You just can't see the result there. You open the Health app on your iPhone to view it. For someone checking their respiratory health regularly, it's an extra step, but the data is still being collected.
How long did this legal battle actually take?
Nearly two years from the 2023 ruling until now. Apple pulled watches from shelves right before the holidays, which was brutal timing. They've been working on this workaround the whole time.
Does this affect people who already owned the watches with the feature?
No. If you bought an Apple Watch Series 9 or 10 before the ban, your blood oxygen feature never went away. This update only restores it to people who bought after the ban took effect and never had it.
What about people outside the US?
They were never affected. The ban was US-specific, so international users kept the original feature all along.