Announced at the "It's Glowtime" event, this health feature marks a significant step for Apple Watch's health-tracking capabilities, which now includes monitoring breathing disturbances linked to sleep apnea.
A detailed 10-page report titled "Estimating Breathing Disturbances and Sleep Apnea Risk from Apple Watch" outlines the development and verification of this new feature. The report explains that Apple Watch uses its triaxial accelerometer to track not only coarse body movements but also fine motions, including those related to breathing. These accelerometer signals are used by a custom algorithm to detect breathing disturbances, such as temporary interruptions in breathing that occur during sleep.
Apple collaborated with sleep researchers to validate the accuracy of its detection. Testing was conducted on a diverse group of participants, with 3,936 nights of data from 2,160 volunteers who were either in a sleep lab or using home sleep apnea tests. An additional 7,220 nights of data from 2,542 volunteers were used to further validate the algorithm.
The detection process is rooted in well-established clinical methods for diagnosing sleep apnea, such as polysomnography (PSG), which tracks apnea and hypopnea events—key components of the apnea-hypopnea index (AHI). Apple used strict scoring standards set by the American Academy of Sleep Medicine (AASM) to ensure the accuracy of its detection system.
The sleep apnea detection feature will be available in a future update to watchOS 11 for the Apple Watch Series 9, Apple Watch Series 10, and Apple Watch Ultra 2. Initially, the feature will be available in the US, with potential expansion to other regions later on.