Context: Medical device maker Masimo never really believed it could make it big in the smartwatch business, but it created a “product” only for the purpose of seeking a limited exclusion order (U.S. import ban) from the United States International Trade Commission (USITC or ITC). Apple appealed the ITC ruling, not only but primarily on the basis that this was not a case of someone seeking to protect a genuine domestic industry in the United States. ITC complainants must meet the domestic industry requirement (DIR) to be entitled to remedies, and the ITC has frequently been accused, not only by Apple, of vitiating that criterion in order to expand its jurisdiction. The United States Court of Appeals for the Federal Circuit heard Apple’s appeal against the ITC (with Masimo intervening on the ITC’s behalf) last month (July 7, 2025 MP3 file). If Apple prevailed, for which the hearing gave no strong indication, it could bring back pulse oxymetry in the original form by means of a software update (March 12, 2024 ip fray article).
What’s new: Apple just announced that U.S. Customs and Border Protection (CBP) has cleared a designaround by Apple that puts its new implementation of pulse oxymetry outside the scope of both import ban patents. The measurements are performed by the sensors in the Apple Watch, but evaluated on a paired iPhone, which also displays the result in the Respiratory section of the Health app. On that basis, Apple can import Apple Watches into the U.S. market with pulse oxymetry while complying with the ITC decision. It can also make that functionality available over the air to those who had bought the Apple Watch since the import ban entered into effect last year. Users just need iOS 18.6.1 and watchOS 11.6.1.
Direct impact:
- Masimo’s leverage over Apple, even in the event the Federal Circuit upholds the ITC’s final determination, has been reduced massively. Should there still be a settlement, Masimo could not expect the bonanza it once hoped for. At best, all it would have to offer Apple is that customers could again see their blood oxygen saturation level on their Apple Watches (and as explained further below, it’s not 100% clear that Apple couldn’t do that even without a license deal with Masimo). In three years from now, the patents will expire anyway. Then Apple can even reactivate its old implementation.
- Masimo could try to challenge the CBP ruling that clears the workaround, especially since both the iPhone and the Watch are Apple products that now provide the accused functionality together, but it would be an uphill battle as we’ll explain further below.
Wider ramifications: The ITC case, with respect to which a Supreme Court petition may very well follow the Federal Circuit decision, is going to remain interesting with a view to the ITC’s application of the DIR. Also, Apple will presumably continue its lobbying efforts, alongside other large companies, against the ITC’s expansive jurisdiction. Furthermore, Apple has once again demonstrated its resilience. In patent litigation, 99% of targets are “soft” compared to Apple, and none is harder.
ip fray has been skeptical of Masimo’s case from the beginning, both with a view to how it sought to satisfy the DIR and the leverage it would ultimately have over Apple. The latest development validates that bearish perspective, which ip fray took despite knowing that it was an unpopular view in large parts of the IP enforcement community. It was all about an accurate assessment of the situation.
So, what claim limitations does Apple work around by means of the workaround? This article may also be read by people from the Apple ecosystem who are not familiar with patent law to the extent ip fray‘s core readership is, we refer anyone unfamiliar with the concept of claim limitations to games fray‘s IP Lingo dictionary. As the name of that website indicates, it’s not a legal dictionary, but a reference for people with an interest in computer games who are following the Nintendo & The Pokémon Company v. Pocketpair dispute and other games-related patent cases.
The ITC held that “Apple has violated section 337 as to claims 22 and 28 of [U.S. Patent No. 10,912,502] and claims 12, 24, and 30 of [U.S. Patent No. 10, 945,648].” Instead of reciting the entire claims here, let’s just list the ones that Apple argued and U.S. CBP agreed are not implemented when the Watch merely performs the measurements and the iPhone evaluates the data and displays the result:
- ‘502 patent
- Claim 22 is derived from claim 1, a claim that starts with lots of sensor-related elements, but ends with “one or more processors configured to receive one or more signals from at least one of the photodiodes and calculate a measurement of the physiological parameter of the user.”
- Claim 28 has even two relevant claim limitations related to
- receipt of measurement data and calculation (“one or more processors configured to receive one or more signals from at least one of the photodiodes and calculate an oxygen saturation measurement of the user, the one or more processors further configured to receive the temperature signal”) as well as
- display (“a user interface comprising a touch-screen display, wherein the user interface is configured to display indicia responsive to the oxygen saturation measurement of the user”).
- ‘648 patent
- Claim 12 adds nothing relevant in this context to claim 8, from which it is is derived and which comes with the following claim limitation: “one or more processors configured to receive one or more signals from at least one of the photodiodes and output measurements of a physiological parameter of a user”
- Claims 24 and 30 add nothing relevant in this context to claim 20, from which they are derived and which ends with “one or more processors configured to receive one or more signals from at least one of the photodiodes and determine measurements of oxygen saturation of the user.”
Here’s a table to show what relevant elements those claims involve:
| Patent Claim | Processor receives measurement data | Processor performs calculation | Display of measurement |
| ‘502, claim 2 | X | X | — |
| ‘502, claim 28 | X | X | X |
| ‘648, claim 12 | X | at least not explicitly | X |
| ‘648, claim 24 | X | X | — |
| ‘648, claim 30 | X | X | — |
The claims say “one or more processors”, but that doesn’t matter. It’s enough if one processor does it, so let’s simplify it.
Now, the Apple Watch does have a processor that receives measurement data from the sensors. The measurement data can’t go directly from the sensors to the iPhone.
Apple says “sensor data from the Blood Oxygen app on Apple Watch will be measured and calculated on the paired iPhone.” That wording is a bit strange. How can “sensor data . . . be measured”? Sensor data is already the result of a measurement because what a sensor does is that it measures and provides the result in the form of data. What a processor can do is to perform calculations using such data. But the claim language refers to the processor(s) “calculating” and “determining” (which in the case of a processor also means calculating) a “measurement”, so Apple carefully worded its announcement so as to eliminate any doubt that the iPhone gets nothing but raw sensor data. Still, the first column of the above table is irrelevant because the Watch will still have a processor that receives raw sensor data.
To avoid the two claims of the ‘502 patent and at least two of the three claims of the ‘648 patent, Apple must avoid that the Watch processor performs the calculation in question. That functionality has now been moved to the paired iPhone.
Apple’s announcement says the results will be displayed in the Health app, which is an iPhone and not Watch app. Accordingly, some have interpreted the announcement as meaning that the result will be shown only in the iPhone version of the Health app.
Why wouldn’t Apple display the result on the Watch anyway? It’s enough to avoid one claim limitation. Claim 28 of the ‘502 patent and claim 12 of the ‘648 patent talk about “display” (or “output”, which is synonymous with “display”). Claim 28 also requires the calculation to be performed on the Watch. But claim 12 doesn’t explicitly say so. Arguably, some calculation is implicitly meant there. But it’s not clear.
Another reason could be that, at least in a first step (Apple can always submit yet another proposal to CBP), Apple didn’t want to get into a debate over whether the pairing of a Watch with an iPhone really constitutes a good-faith workaround.
Let’s look at it this way:
- The Apple Watch is just an iPhone accessory from a commercial point of view; a very expensive one, but still. Apple makes the Watch and the iPhone, and every owner of a Watch needs an iPhone. It can’t be paired with other phones. Without an iPhone, even the initial setup is simply impossible. Apple Watch users don’t need to have their iPhone with them all the time. The Watch won’t stop working (though it will lose some functionality, especially if it’s not a cellular one) if the iPhone is not connected to the Watch. But most of the time, the iPhone will be around. If users have a need for pulse oximetry, they will make sure they have their iPhone with them.
- But the patent claims on which Masimo prevailed refer to a device, not a pair of devices.
It’s possible that Masimo tried to dissuade U.S. CBP from clearing the workaround based on the commercial logic, but lost because patent law is technical law, not business law.
The patent claims on which Masimo prevailed at the ITC do not talk about the possibility of one device having the sensors and a second device performing the calculations. To some extent, Masimo definitely had that scenario in mind when drafting the patents in question. There are claims with such wordings as “a network interface configured to wirelessly communicate at least the measurements of oxygen saturation to at least one of: a mobile phone or a computer network.” It could be that Apple didn’t want to make it too easy for Masimo to go back to the ITC and maybe seek an import ban, possibly with shortened timelines, based on different claims.
Masimo can try to appeal the CBP decision, but that will take time and the hurdle is high. Meanwhile, everyone is awaiting the Federal Circuit ruling.
The timing of Apple’s workaround suggests that Apple did not want there to be a debate over the workaround at the time of the Federal Circuit hearing.
This dispute is not over yet, but today’s announcement by Apple shows that Masimo is never going to get serious leverage.