The U.S. International Trade Commission (ITC) has initiated an investigation into Apple's blood oxygen sensing technology in its latest Apple Watch models, following allegations of patent infringement by Masimo. The investigation, which began recently, could result in an import ban on models such as the Series 10 and Ultra 2 within six months. This action comes after a 2023 decision that stopped sales of earlier models featuring the technology. Apple contests the infringement claims, asserting that its redesign, which shifts some processing to the iPhone, does not violate Masimo's patents. However, Masimo argues that Apple is attempting to bypass previous rulings. The outcome of this investigation could significantly affect Apple's U.S. holiday sales, potentially impacting up to 20% of its revenue during this period, as estimated by Bloomberg.