Background and figures on sleep apnea detection › iphone-ticker.de

Apple has published a new document entitled “Identifying Breathing Disorders and Sleep Apnea Risk with Apple Watch.” In it, the company describes how certain models of the Apple Watch – specifically the Series 9, the new Series 10 and the Apple Watch Ultra 2 – can monitor sleep interruptions and possible signs of sleep apnea.

The new feature of watchOS 11 is expressly not aimed at patients who have already been diagnosed and is based on the collection of movement data during sleep using an accelerometer.

Sleep apnea often goes undetected

Sleep apnea is a widespread sleep disorder that causes breathing to stop while sleeping. It is estimated that this disorder remains undetected in around 80 percent of those affected, which can lead to long-term health risks such as high blood pressure, but also heart attacks or strokes. Apple has therefore developed an algorithm that uses movement data to identify breathing interruptions and indicate an increased risk of moderate to severe sleep apnea. The data is displayed in the Health app on the iPhone, where notifications can also be sent about possible abnormalities.

Apple conducted several studies to validate the technology. In a first step, the company collected data from over 2,100 participants who underwent both laboratory and home sleep tests. In addition to the Apple Watch, a clinical reference method was also used that recorded pauses in breathing and hypopnea events. The results of these studies were used to develop the algorithm that converts movement data from the watch into a pattern of breathing disorders.

As part of the clinical validation, Apple conducted another study with nearly 1,500 participants. They wore an Apple Watch for up to 30 nights and performed parallel sleep apnea tests. The results of these tests show a sensitivity of 66.3% and a specificity of 98.5%, meaning that the Apple Watch was able to correctly detect sleep apnea in most cases, while largely avoiding false alarms.

Time window of 30 days

The Apple Watch uses a time window of 30 days to analyze breathing disorders. If abnormalities are detected for at least 10 nights within this period, the user will be informed. However, Apple emphasizes that the lack of a notification does not automatically mean that sleep apnea is not present. Rather, the function is intended as a tool that monitors possible abnormalities over longer periods of time.

For users who do not yet have a diagnosis, the feature may provide a starting point to monitor their sleep quality and consult a doctor if necessary. However, Apple expressly points out that the Apple Watch remains a tool for rough assessment and is not a substitute for a clinical diagnosis.