Your Apple watch may soon be able to warn you of a coming stroke

[NEW YORK] A device that's embedded in a new wristband for the Apple Watch marries two existing features - the heart rate monitor and activity sensors - and takes them to a new level using artificial intelligence.

The KardiaBand from AliveCor uses a neural network to predict and analyse the wearer's heart rate based on his or her history and a trove of cardiovascular data from both sick and healthy people. The device measures the heart rate every five seconds and tells users when it's out of their expected range. It doesn't apply a generic range - instead, it determines what's abnormal for you.

The Apple Watch already uses machine learning to identify when the heart rate spikes abnormally, but this personalised approach goes a step further. When the device realises you're out of range, it will prompt you to record the heart's electrical rhythm, using electrocardiogram (EKG) technology built into the wristband.

The process involves placing a thumb over the sensor for 30 seconds while the results appear on the face of the watch. A recording is then available to send to a doctor.

Portable EKG readers that work with smartphones have been around for years, allowing consumers to check their heart's electrical activity at will using a separate device. The crucial issue was knowing exactly when to do it. For people in danger of cardiovascular-related complications such as stroke, devices like this may soon play a critical role in helping wearers avoid a health emergency.

"This is continuously monitoring your heart rate to let you know if something is potentially off track," said Eric Topol, director of the Scripps Translational Science Institute and a professor of molecular medicine who isn't involved with the technology.

"That's the big difference."

"This is the first time I've seen artificial intelligence on a smart watch," said Topol, who is also a cardiologist.

"It's definitely a step in the right direction."

The reading could help detect dangerous electrical abnormalities such as atrial fibrillation. The condition, marked by an erratic rhythm that can lead to deadly blood clots and strokes, develops in about one-quarter of people over age 40. The technology, however, doesn't come cheap. The KardiaBand, the first medical device accessory approved by the US Food and Drug Administration for use with the Apple Watch, sells for US$199. Users also have to subscribe to AliveCor's premium service at a cost of US$99 a year. Of course, they also have to have an Apple Watch, Series 3. They are on sale at Macy's for US$399.

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