Apple Blood Oxygen Feature Workaround Sparks Fresh Masimo Lawsuit
Medical technology company Masimo on Wednesday filed a lawsuit against U.S. Customs and Border Protection in which it challenged the agency's decision to allow Apple to restore blood oxygen monitoring to its Apple Watch models (via Bloomberg Law).

In a complaint filed Wednesday in the US District Court for the District of Columbia, Masimo said that Customs acted unlawfully when it ruled on August 1 that Apple can import watches with pulse oximetry technology – a reversal of the agency's decision from last year – without notifying Masimo. Masimo said it only discovered the ruling on August 14, when Apple publicly announced it would be reintroducing the pulse oximetry functionality through a software update.
The medical device maker claims Customs and Border Protection exceeded its authority when it issued the ruling permitting Apple's redesigned approach. Apple's workaround offloads blood oxygen calculations from the Apple Watch to a paired iPhone, where it performs similar functionality to what the ITC originally judged to have infringed Masimo's patents.
Masimo is seeking a temporary restraining order and preliminary injunction to block the Customs decision. "CBP's function is to enforce ITC exclusion orders, not to create loopholes that render them ineffective," Masimo said.
The dispute originates from an International Trade Commission ruling in December 2023 that found Apple's blood oxygen sensors infringed Masimo's patents, leading to an import ban on Apple Watch Series 9 and Ultra 2 models that have the feature enabled. 
Apple paused sales in the U.S. for several days before resuming them on January 18, 2024. The Series 9 and Ultra 2 models then went back on the market without blood oxygen monitoring, up until Apple's release of iOS 18.6.1 and watchOS 11.6.1 last week, which shifted the feature's calculations to paired iPhones.
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