Apple has just scored an important – but very specific – win in its long‑running fight with medical‑device company Masimo over the Apple Watch’s blood oxygen feature. An ITC judge has ruled that Apple’s redesigned blood oxygen implementation, the so‑called “workaround,” does not infringe Masimo’s patents and therefore does not trigger a new import ban on current Apple Watch models in the United States.

To understand why this ruling matters, you have to rewind a bit. Back in 2023, the U.S. International Trade Commission found that earlier Apple Watch models infringed Masimo patents related to pulse oximetry, the tech that lets your watch estimate blood oxygen levels using light sensors on your wrist. That decision led to an import ban targeting Apple Watch models with the offending feature, which briefly forced Apple to halt U.S. sales of the Apple Watch Series 9 and Apple Watch Ultra 2 in December 2023 until it secured a temporary stay and then simply turned the feature off via software for U.S. buyers in early 2024.

For Apple Watch users, the first big consequence was pretty straightforward: if you bought your watch in the U.S. during that period, the Blood Oxygen app was effectively dead. The hardware was there, but the feature was disabled to comply with the ITC ruling and to keep watches flowing into the country. That meant Apple had to walk a tightrope between keeping its flagship health product legally sellable and avoiding the perception that one of its marquee health features had just vanished overnight.

In August 2025, Apple came back with what it described as a compliant workaround. Technically, the watch still uses its built‑in sensor to capture raw data, but the key change is where the processing happens and how the feature is exposed to the user. Under the new design, the Apple Watch collects the signal but offloads the heavy‑lifting analysis to a paired iPhone, and users see their blood oxygen information on the iPhone rather than directly on the watch display. In other words, Apple reframed the system as a more distributed setup – watch as data collector, iPhone as analyzer – instead of a single, monolithic device doing everything on the wrist.

That architecture change turned out to be crucial in the latest ITC review. Masimo argued that Apple’s workaround still violated its rights and pushed both U.S. Customs and Border Protection and the ITC to clamp down again. Customs initially signed off on Apple’s redesign, which prompted Masimo to sue CBP, accusing the agency of overstepping its authority by green‑lighting imports of the updated watches. Now, an ITC administrative law judge has essentially backed the CBP view, concluding that the paired Apple Watch plus iPhone system does not infringe the Masimo patents or violate the original import ban.

There are two important nuances here. First, the judge’s finding is preliminary – the full ITC commission still has to review and decide whether to adopt it, which is standard in these cases. Second, on the same day Apple received this favorable workaround ruling, the U.S. Court of Appeals for the Federal Circuit separately affirmed the original 2023 ITC decision that said the older Apple Watch design did infringe Masimo’s patents and that the initial import ban was valid. So Apple has effectively lost the fight over what it did in the past, but is winning, at least for now, on how it has redesigned the feature for the present.

From Apple’s point of view, this is about keeping the Apple Watch’s health story intact in its biggest market. The company has leaned heavily on metrics like heart rate, ECG, and blood oxygen as proof that the watch is more than just a notification screen, and having one of those pillars crippled in the U.S. for an extended period was never going to be sustainable. Apple has said it will continue to explore “all avenues for further review” of the Federal Circuit decision, while also welcoming the ITC judge’s confirmation that its current approach can stay on the market.

Masimo, meanwhile, has its own narrative. The California‑based company has long argued that Apple copied its pulse oximetry technology and even poached Masimo employees after talks about a possible collaboration years ago. It successfully persuaded the ITC to impose the initial import ban, and in November 2025, a federal jury in California awarded Masimo $634 million in damages after finding that Apple’s blood oxygen‑related features, including workout mode and certain heart‑rate notifications, infringed one of its patents. Apple is appealing that verdict, but from Masimo’s perspective, the message is clear: courts and regulators have, at least in part, validated its claims that Apple used its intellectual property without permission.

What makes this fight especially interesting is how it exposes the gray zone where consumer tech and regulated medical tech collide. Masimo builds professional‑grade monitoring gear for hospitals and clinicians, where accuracy, reliability, and regulatory approvals are paramount. Apple, on the other hand, designs a mass‑market smartwatch that frames blood oxygen as a wellness metric rather than a medical diagnostic, but the underlying sensing principles overlap heavily with what companies like Masimo have been refining for years. When a general‑purpose gadget starts nibbling at the edges of the medical device market, patent boundaries suddenly matter a lot more.

The workaround ruling also highlights how much of patent law, especially at the ITC, comes down to claim language and system architecture. Masimo’s key claims here have been interpreted as covering a single device that performs specific sensing and processing functions. Apple’s workaround essentially splits those functions between two devices – watch plus phone – and that distinction was enough for the ITC judge to say, at least preliminarily, that this paired configuration is outside the scope of the patents that underpinned the 2023 ban. It is a reminder that sometimes, re‑wiring where code runs and how a feature is presented can be as powerful as changing hardware.

For users, though, the legal nuance mostly fades into the background. What matters is that blood oxygen sensing has already started to return in the U.S., with readings collected on Apple Watch and surfaced through the iPhone’s Health app instead of being treated as a first‑class citizen on the watch itself. That is slightly less convenient – you may need to grab your iPhone to dig into trends and details – but it is a lot better than having the feature entirely switched off, especially for people who like to keep an eye on metrics like sleep‑related oxygen dips or altitude acclimatization.

Looking ahead, timing is quietly working in Apple’s favor. The Masimo patent at the center of the 634‑million‑dollar verdict has already expired, and other patents tied to the import ban are due to run out in roughly the next couple of years. Once those rights lapse, Apple will have more freedom to revert to a simpler implementation that processes blood oxygen data directly on the watch, without needing the legal gymnastics of offloading to the iPhone. Until then, the company looks set to maintain its paired‑device workaround while it battles Masimo in appeals courts and resists any fresh attempts to block imports of future Apple Watch models.

The broader industry will be watching this saga closely. If Apple can successfully defend a carefully engineered workaround and keep a flagship health feature alive despite a hostile patent landscape, it could become a playbook for other consumer tech firms that run into similar conflicts with established medical‑device players. At the same time, the sheer size of the damages in the Masimo verdict shows that jumping into quasi‑medical territory without a bulletproof IP strategy can be an extremely expensive gamble, even for a company the size of Apple. For now, though, Apple Watch owners in the U.S. get to keep their blood oxygen readings – with a little extra help from the iPhone and a lot of behind‑the‑scenes lawyering.