Smart speakers like Amazon’s Alexa or Google Home could detect if people are having a cardiac arrest at home, to alert loved ones or call the emergency services, a study has shown.
In the UK, 100,000 people die each year from cardiac arrest - when the electrical activity of the heart stops.
Without immediate CPR nine in 10 people die, but 24,000 attacks happen at home, often when people are on their own, or at night when family members are sleeping.
Now researchers at the University of Washington have shown that smart speakers could detect the tell-tale gasping for air that occurs during cardiac arrest, known as agonal breathing.
“It’s sort of a guttural gasping noise, and its uniqueness makes it a good audio biomarker to use to identify if someone is experiencing a cardiac arrest,” said author Dr Jacob Sunshine, an assistant professor of anesthesiology and pain medicine at the University of Washington’s School of Medicine.
“This kind of breathing happens when a patient experiences really low oxygen levels.”
The researchers gathered sounds of agonal breathing from real 911 calls to Seattle's Emergency Medical Services.
Bystanders were asked to record breathing by putting their phones up to the patient's mouth so that the dispatcher could determine whether the patient needed immediate CPR.
The team collected 162 calls between 2009 and 2017 and extracted 2.5 seconds of audio at the start of each agonal breath to come up with a total of 236 examples.
“We played these examples at different distances to simulate what it would sound like if it the patient was at different places in the bedroom,” said first author Justin Chan, a doctoral student.
“We also added different interfering sounds such as sounds of cats and dogs, cars honking, air conditioning, things that you might normally hear in a home.”
The algorithm was able to detect agonal breathing events 97 per cent of the time from up to 20 feet (or 6 meters) away.
The team also the algorithm to make sure that it would not accidentally classify a different type of breathing - such as snoring - as agonal breathing.
“We don't want to alert either emergency services or loved ones unnecessarily, so it's important that we reduce our false positive rate,” added Mr Chan.
The team envisions the algorithm could function like an app that runs passively on a smart speaker or smartphone while people sleep.
“A lot of people have smart speakers in their homes, and these devices have amazing capabilities that we can take advantage of," said co-corresponding author Dr Shyam Gollakota, an associate professor at Washington’s Paul G. Allen School of Computer Science & Engineering.
“We envision a contactless system that works by continuously and passively monitoring the bedroom for an agonal breathing event, and alerts anyone nearby to come provide CPR. And then if there's no response, the device can automatically call 911”
Agonal breathing is present for about 50 per cent of people who experience cardiac arrests, according to 911 call data, and patients who take agonal breaths often have a better chance of surviving.
“Cardiac arrests are a very common way for people to die, and right now many of them can go unwitnessed,” added Prof Sunshine.
“Part of what makes this technology so compelling is that it could help us catch more patients in time for them to be treated.”
The research was published in the journal Digital Medicine.