After a prolonged legal battle with Masimo over pulse oximetry technology, Apple on Thursday announced it will introduce a redesigned blood oxygen feature for some Apple Watch Series 9, Series 10, and Apple Watch Ultra 2 users through an iPhone and Apple Watch software update. The blood oxygen feature was removed in 2023 after the United States International Trade Commission found that Apple violated US laws by incorporating Masimo’s patented light-based pulse oximetry technology in its products. Following this update, sensor data from the blood oxygen app on Apple Watch will be measured and calculated on the paired iPhone, and results can be viewed in the Respiratory section of the Health app. There will be no impact to Apple Watch units previously purchased that include the original blood oxygen feature, nor to Apple Watch units purchased outside of the United States. Apple Watch Series 9, Series 10, and Apple Watch Ultra 2 also offer users sleep apnea notifications, irregular rhythm notifications, the ECG app, fall detection, sleep tracking, wrist temperature sensing, the Vitals app, the Noise app, the Medications app, and the Mindfulness app, among many health tools.