Last week, when Apple announced the release of a “redesigned blood oxygen feature” on the Apple Watch, many thought Masimo (which was suing Apple over patents related to this feature) would find a way to fight back. Today, the company did just that, filing a new lawsuit. But this time, they are in violation of U.S. Customs and Border Protection. Here’s why:
a little background
When Apple released blood oxygen functionality on the Apple Watch, medical device maker Masimo filed a lawsuit for alleged patent infringement.
The litigation dragged on for years, culminating in an import ban in December 2023, barring Apple from selling Apple Watch models with blood oxygen functionality in the United States.
Since then, after several days of suspension of sales, Apple has been selling the Apple Watch Series 9 and Apple Watch Ultra 2 without blood oxygen functionality, although it did not remove the hardware. Rather, this feature was disabled by software.
Last Thursday, Apple announced a “redesigned blood oxygen feature” that calculates blood oxygen on your iPhone instead of the Watch.
So will Masimo file another lawsuit?
yes. Massimo filed a new complaint Wednesday in the U.S. District Court for the District of Columbia.
The company claims that U.S. Customs and Border Protection (CBP) overstepped its authority and violated due process when it reversed its previous decision on August 1 and allowed Apple to restore the feature. Additionally, Masimo said he learned about the decision when Apple officially announced the return of the feature.
“It is now clear that CBP subsequently reversed its policy without any meaningful justification, without any material change in circumstances, and without any notice to Masimo, much less an opportunity to hear Masimo’s opinion.” iPhones already in the United States perform the same functions that the ITC found to infringe Masimo’s patents. Masimo learned of this ruling on Thursday, August 14, 2025, when Apple publicly announced that it would reintroduce pulse oximetry functionality through a software update.
The company is now asking the court for a temporary restraining order and a preliminary injunction to halt CBP’s decision and reinstate the original ruling, which “determined that Apple’s redesigned watch could only be imported to the extent that the infringing features were completely disabled.”
According to reports bloomberg lawMasimo says in its support brief:
“With each passing day, this unlawful ruling irrevocably deprives Masimo of its right to be free from unfair trade practices and remain competitive in the U.S. market.”
Masimo further asserted that CBP’s actions “effectively nullified” the ITC’s exclusion order against Apple. Apple’s appeal of this ban is still pending in the Federal Circuit Court.
Do you think Masimo could newly ban blood oxygen level measurements on Apple Watch? Let us know in the comments.
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