the Apple Watch is getting a new health feature to detect signs of sleep apnea, a potentially serious condition where you stop breathing momentarily during the night. Let's dig into how all of this works. It's estimated that close to 1 billion people around the world between the ages of 30 and 69 may have obstructive sleep apnea. Left untreated, it could increase the risk of cardiovascular or metabolic health problems. Normally, sleep apnea is detected on a polysomnography, otherwise known as a sleep study. This could be in a sleep clinic, or there are at-home tests that you can do. A sleep study measures your brain activity, heart rate, movement, and blood oxygen, among other metrics, to assess your sleep. Now you can get some of this data from your wrist just by wearing a smartwatch to bed. The Apple Watch uses the accelerometer and machine learning to detect interruptions in your breathing pattern by monitoring small movements on the wrist. You wear the watch to sleep for at least 10 nights in a 30-day period. And it

measures a new metric that Apple calls breathing disturbances. I spoke with Apple to dive into more about how this all works and how it was tested. My name is Matt Bian. I'm a neurologist and sleep disorder specialist, and I work in a research unit called Health Technologies at Apple. My name is Dedra Caldbek, and I'm the senior director of Apple Watch and health product marketing. Each night you wear your watch, we're tracking that breathing sensor signal through accelerometer. We quantify that number, and you get to see your breathing disturbance value and whether it's elevated or not elevated each night in the health. Now, even a person without sleep apnea can have some interruptions in breathing at night. Sometimes it's a little too much alcohol. Sometimes it's you're sleeping more on your back than on your side. We want to actually tackle that night-to-night variability issue head-on by having the notification logic look at 30 days of data, so we get a holistic view of what's going on. Can you

elaborate a bit more on what the specific wrist movements are when that differs essentially from regular breathing to a breathing that might indicate sleep apnea. Imagine that when you breathe, it's an oscillation of movement in your chest. That oscillation in and out is actually seen through the Apple Watch accelerometer at the wrist. And so, when you have an interruption in breathing where you're either taking more shallow breaths or you stop breathing for 20 or 30 seconds, that can be read out and detected through machine learning algorithms in the wrist. How does the Apple Watch determine the difference between someone just tossing and turning in bed, having a restless night, compared to an actual breathing disturbance? So, one of the ways we make sure that we don't make mistakes or misconstrue movements like that is to collect an incredible amount of ground truth data across a huge variety of people sleeping in the lab, in a Sleep Center, sleeping at home in their natural environment. In fact, our internal work involved over 11,000 nights of ground

truth recordings alongside watch to train these algorithms. We partnered with academic medical centers, hospital systems, through patient care settings, as well as clinical research organizations, which are private research organizations, to recruit patients. And then there was an additional 1,500 nights collected through C for the valid study submitted to the FDA and will be submitted to other regulatory bodies as well. What Matt is describing, of course, is what we used for development and the clinical validation. But we do have a little Leap lab on campus, and you know, of course, to do this continued prototyping and iteration of all of our features, including the continued enhancements of our features for sleep tracking and sleep stages. Sleep apnea notifications are coming to the Series 10, Series 9, and Ultra 2 for people 18 years and older in over 150 countries. So, you may be wondering if this sleep apnea feature relies on the accelerometer. Why didn't Apple roll it out on earlier Apple

watches for this feature to meet our performance objectives. We needed that processing power that we introduced with the S9 SIP last year. So, and that same processing power is in the S10 SIP and in Ultra 2. So, it's the ability to use the accelerometer data, process that data on device, and ensure that we get, you know, accuracy and ensure we meet our performance objectives. And so, we really needed that combination. Sleep apnea notifications are now available in the US following FDA clearance. You'll go through a quick setup process and then wear the watch to sleep. After each night of sleep, you'll see that breathing disturbances metric show up in the health app listed either as elevated or not elevated. The Apple Watch is the second smartwatch to get sleep apnea notifications following the Samsung Galaxy Watch earlier in 2024. Apple takes a different approach to Samsung's sleep apnea feature because the Galaxy Watch only needs two nights of sleep data versus 30 days on the Apple Watch, and Samsung's watches use blood oxygen as

part of this measurement, regardless of methodology. It's really important to note that no smartwatch is able to give a medical diagnosis of sleep apnea or any other condition. The idea is that you take the data from your watch, which in the case of Apple's Health app, lets you export it as a PDF. Then, you present it to your doctor. Thanks to Deardra and Matt from Apple for chatting with us about all things Apple Watch, and thanks to the Clancy in San Francisco for letting us film. And thank you for watching.

How Apple Watch Sleep Apnea Detection Works

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