The FDA often serves as the pace-setter for other regulators around the globe. Apple anticipates approval in most territories by the end of September.

Sleep apnoea is a disorder where muscles in the throat relax, leading to a complete obstruction of the throat, prohibiting breathing. In response, the brain is woken – or goes through an arousal – and breathing is restored briefly before the process begins again, NZ Respiratory and Sleep Institute respiratory and sleep specialist Dr Andrew Veale told the Herald after an accident that saw a sleep apnoea sufferer fall asleep at the wheel, cross the centre then crash into another vehicle – earning him a careless driving causing injury charge.

Even though the person is often not woken during this process, it caused repeated sleep fragmentation, leading to people becoming sleepy during the day.

“That can range from people who just aren’t firing on all cylinders, right through to people you have to wake two or three times in the midst of a conversation,” Veale said.

Conversation starter

The new Apple Watch sleep apnoea detection is part of a broader new feature called Breathing Disturbances and is not billed as a medical diagnosis. But it does alert you to a potential problem you might otherwise be unaware of, and Apple says results from the Watch’s app – which can be viewed on your iPhone or printed out as a PDF – can serve as a “conversation starter” with your family doctor.

Your GP can in turn refer you to a sleep clinic in the public health system for an overnight test – although I know from personal experience that you can wait around six months for an initial assessment then around a year for the test, unless you’re a truck driver or in another profession where there’s an immediate risk to the public from the daytime weariness that sleep apnoea induces. After learning the wait times, I skipped the queue by going private (which was covered by my basic health insurance plan).

Doctors at private clinics also work with wearables for at-home testing.

Whether you go public or private, the end result is the same if you’re diagnosed with sleep apnoea: Being issued with a CPAP (continuous positive airway pressure) machine (NZ’s Fisher & Paykel Healthcare is one of the biggest players worldwide in this market; it’s also the second-largest publicly-listed NZ firm with its $22.5 billion market cap).

“I don’t think it’s an exaggeration to say that there is no part of our health and wellbeing that isn’t connected to sleep in some way,” Apple research scientist Dr Matt Bianchi told the Herald.

“Sleep apnea is an incredibly common problem. You heard that eye-popping 1 billion people affected number during the [Apple Glowtime event] keynote. It’s treatable. That’s the good news. But the challenge we’re trying to meet here is that 80% of those people don’t know they have it.

“And that’s where we think we can make any impact by offering people overnight tracking to look for disturbances in their normal breathing pattern and introducing a new metric called Breathing Disturbances. If we find consistent evidence of an elevated breathing disturbances, we can alert you to the possibility of sleep apnoea.”

The Apple Watch already features a three-axis accelerometer, used for fitness apps, plus fall and crash detection.

It can be used to track the fine motions of your respiratory rate overnight as well.

“Apple Watch can see those breathing patterns reflected from the chest down in the wrist. We use that same accelerometer; that high-frequency oscillation that tracks breathing in our sleep-staging algorithm to give REM, core deep and wake stages in the [existing] sleep tracking feature for sleep apnoea notification.”

The new feature is aimed at those over the age of 18 who have not been diagnosed with sleep apnoea. Breathing disturbance results are delivered daily. But to avoid false positives, an alert for potential sleep apnoea is only delivered after a month of monitoring during which 50% of nights are classified as elevated.

“A user might see some night-to-night fluctuation, maybe with alcohol, sleeping on their back instead of on their side or just a brief illness,” Dr Bianchi said.

“We want that holistic, 30-day view because if we send you a notification, we want you to have confidence that we’ve got an accurate set of data to support a decision to go to your doctor and talk about the possibility of sleep apnoea.”

Three key principles

“Our focus for health is grounded in these three key principles. And we always think it’s important to re-emphasise these because I think that’s what makes us different,” Apple Watch senior director Deidre Caldbeck said.

“First, we make sure the information is meaningful and actionable for you.

“Secondly, we take the science of health very seriously. We collaborate with the medical community, academic institutions and researchers, but we also have clinicians like Matt and scientists and researchers on our teams here at Apple, and they work alongside engineers and designers to develop health features. So we’re able to sort of combine the best science with the best technology and create the most impactful experience for users.

“And thirdly and maybe most importantly, our priority is to really have the trust of our users in keeping with our belief that privacy is a fundamental human, right. Every user should have control over their health data.”

Series 10 tops tests

Beyond the signature sleep apnoea feature, the Apple Watch Series 10 is getting some strong notices.

The Herald will have a review after the September 20 local release, but the Wirecutter crew at our syndication partner the New York Times has already had a hands-on look. It found:

“The Apple Watch Series 10 offers the best combination of style, health and fitness features, app selection, battery life, and price of any smartwatch for any platform.

“It’s Apple’s thinnest smartwatch ever, with more active screen area than the Series 9, but smartwatch size creep is getting noticeable: The smallest Series 10 is 42 mm, which was once Apple’s largest watch size. (The larger Series 10 is 46 mm.)

“The Series 10 supports the Series 9′s Double Tap gesture [where you tap your index finger and thumb together twice to initiate common actions, like answering a call or replying to a message], and it includes two temperature sensors, car-crash detection, emergency SOS, an always-on display, ECG, and faster charging than previous models.”

READ MORE: Can smart watches help curb anxiety about health and safety

You might have read about the popular blood oxygen measuring feature being temporarily disabled on the Series 9, Series 10 and Ultra in the US while Apple appeals a patent case. The feature is still available outside the US, including New Zealand, for the new Series 10, plus earlier models that support the feature, first introduced with the Series 6.

The FDA approval for Apple Watch sleep apnoea detection was Apple’s second big win with the regulator this month. On September 13, it approved a software upgrade that will transform the latest model of Apple’s AirPods Pro earbuds into over-the-counter hearing aids.

Chris Keall is an Auckland-based member of the Herald’s business team. He joined the Herald in 2018 and is the technology editor and a senior business writer.