Masimo Sues US Customs Over Apple Watch Blood Oxygen Return

Medical device company Masimo has filed a lawsuit against U S Customs and Border Protection, challenging the agency’s recent move to allow Apple to reactivate the blood oxygen monitoring feature on Apple Watches.

Masimo’s legal action stems from a longstanding patent dispute with Apple. In late 2023 the U S International Trade Commission issued an import ban on certain Apple Watch models after finding they infringed on Masimo’s patents related to pulse oximetry.

Apple responded by disabling the feature and later pushing software that shifted the oxygen calculation to the wearer’s iPhone rather than the watch itself.

The company learned of the Customs reversal in August only after Apple announced a software update re-enabling blood oxygen tracking via paired iPhones. According to Masimo the agency issued a ruling on August 1 but failed to notify Masimo or allow it to respond before reversing its earlier ban decision.

In its complaint filed in federal court in Washington D C Masimo argues that Customs acted improperly under the Administrative Procedure Act and violated its due process rights under the Fifth Amendment. The company is seeking a temporary restraining order and a preliminary injunction to restore the earlier ban that prohibited the import of Apple Watches equipped with the infringing blood oxygen function.

In its filings, Masimo notes the timing of Apple’s substantial public investment pledges in the United States, which preceded the Customs reversal a move that it suggests may have influenced the agency’s decision.

Apple introduced the blood oxygen feature in 2020 and has relied on it as a central health measurement capability. The ITC ruling led to temporary disruption in Apple Watch sales as Apple disabled the feature in models including the Series 9 and Ultra 2 while the legal fight unfolded.

Physically the decision now at issue allows Apple to distribute the oxygen functionality through software updates that offload processing to the iPhone rather than the watch itself. Masimo argues that this is a superficial workaround designed to evade the spirit of the exclusion order and that the underlying infringing technology remains present.

the court’s decision on Masimo’s motion for injunctive relief will determine whether Apple can continue offering blood oxygen sensing through its current update or if the feature must remain disabled in US models.