**Masimo vs. Apple: A Legal Clash Over Blood Oxygen Feature**
Last week, Apple unveiled a revamped Blood Oxygen feature for the Apple Watch, sparking speculation about how Masimo, the medical device company currently engaged in a patent infringement lawsuit against Apple, would respond. In an unexpected development, Masimo has initiated a new lawsuit, this time directed at the U.S. Customs and Border Protection (CBP), contesting the agency’s recent choice to permit Apple to reinstate the contentious feature.
### A Brief Background
The dispute between Apple and Masimo commenced when Apple launched the Blood Oxygen feature on the Apple Watch. Masimo accused Apple of violating its patents associated with this technology and subsequently filed a lawsuit. The legal battles reached a climax in December 2023 when an import ban was implemented, barring Apple from selling Apple Watch models that included the Blood Oxygen feature in the United States.
After the ban, Apple momentarily ceased sales before resuming with the Apple Watch Series 9 and Apple Watch Ultra 2, which had the Blood Oxygen feature deactivated through software, even though the hardware remained the same. On August 14, 2025, Apple revealed a redesigned Blood Oxygen feature that assesses blood oxygen levels using the iPhone instead of the watch.
### So Masimo is Suing Again?
Indeed, Masimo has intensified its legal maneuvers by submitting a complaint to the U.S. District Court for the District of Columbia. The company contends that the CBP overreached its authority and breached due process by reversing its prior decision on August 1, which had barred Apple from reinstating the Blood Oxygen feature. Masimo asserts it was unaware of this reversal until Apple’s public disclosure concerning the feature’s comeback.
In its lawsuit, Masimo underscores that the CBP altered its position without offering sufficient justification, significant changes in circumstances, or notifying Masimo. The company argues that the CBP’s ex parte decision on August 1 permitted Apple to import devices that replicate the functionality deemed to infringe Masimo’s patents.
Masimo is now pursuing a temporary restraining order and a preliminary injunction to thwart the CBP’s decision, seeking to revert to the original ruling that restricted Apple’s capacity to import redesigned watches unless the infringing functionality was completely disabled.
### Ramifications of the Lawsuit
Masimo’s legal position stresses that the continued enforcement of the CBP’s ruling irreparably damages its competitive position in the U.S. market. The company claims that the CBP’s decision essentially nullifies the International Trade Commission’s (ITC) exclusion order against Apple, which is still under appeal in the Federal Circuit.
As the legal confrontation develops, the pivotal question remains whether Masimo will manage to secure a new ban on the Apple Watch’s Blood Oxygen measurement feature. The outcome could have major ramifications for both companies and the wider market for health monitoring technologies.
### Conclusion
The ongoing legal contention between Masimo and Apple accentuates the intricacies of patent law and the competitive dynamics within the technology and medical device industries. As both entities navigate this contentious terrain, the resolution of this case will be keenly observed by industry participants and consumers alike.
