The Next Step for Smart Wearable Devices is Disease Warning Lights.


Harpreet Rye, CEO of smart ring company Oura, often tells the story of March 2020 Post to Facebook. Ring user Oura reported that the device reported that his overall health had dropped below his normal level, prompting him to get tested for COVID-19, and the test came back positive. The company has heard from other users as well.

Anecdotal reports prompted Ouru to collaborate with research groups to try to figure out how well the ring can predict who might be sick with COVID-19. Their research has been part of a wave of interest in wearable devices as disease detectors over the past year. Now filled with data, researchers and wearable companies are waiting for their next steps.

Research over the past year has shown that it can probably be noted that someone is sick. But differentiating which the an illness that someone might have will be much more severe. Experts think this will eventually be possible, but in the near future, disease detection programs may be more like warning lights: they can tell the user that they might get sick, but not with anything.

“It’s like a warning light for your car – take it to a mechanic, we don’t know what is wrong, but something looks wrong,” says Rai. “I think the industry is heading in that direction.”

Disease signatures

Even before the pandemic, researchers were checking data from wearable devices to see if they could find telltale signatures that could predict diseases. One study published in early 2020 showed that Fitbits data can predict, for example, trends in flu-like illness at the state level. Another study found that wearable devices can show signs of Lyme disease. A team of researchers from Mount Sinai Health System in New York has used wearable devices to predict exacerbations of disease in patients with inflammatory bowel disease (IBD), such as Crohn’s disease.

When COVID-19 broke out, many of these research groups shifted their focus. “We decided to shift some of our focus to how we can assess and identify COVID-19 infections using the same methods and technologies,” says Robert Hirten, a Mount Sinai gastroenterologist who has worked on wearable devices and IBD.

Hirten’s research showed that Apple Watch can detect changes in heart rate variability in healthcare workers seven days before they were diagnosed with COVID-19. Heart rate variability, which tracks the time between heart beats, is a good indicator of how the nervous system is working, he said. “It often seems like it is very telling that something is happening in the body, even before people realize that something is happening.”

Other data types were also helpful. A Stanford University study found that heart rate, daily steps, and sleep time measured by smartwatches changed in a small group of users before they developed symptoms of COVID-19. The first report from the TemPredict study at the University of California, San Francisco showed that the Oura ring can detect an increase in body temperature before wearers develop symptoms of COVID-19. Through a partnership with New York-based Northwell Health, Fitbit showed that its devices track changes in heart rate and respiration in the days before someone felt unwell.

Research is ongoing. Groups at UCSF and the Rockefeller Institute of Neuroscience at West Virginia University continue to conduct research with the Oura ring, and Fitbit is still working on research with Northwell Health. Fitbit is also part of the Scripps Translation Research Institute and the Stanford Medical and Healthcare Innovation Laboratory. Apple launched its Respiratory Disease Prediction Survey and Apple Watch in April.

There is a good reason for the large wearable companies to continue their research in this direction; the studies carried out to date are promising. “People are really learning the best ways to identify and predict conditions,” says Hirten. “It has really advanced the field of wearable technology significantly.”

Warning light

This does not mean that smartwatches will have apps that inform owners that they have COVID-19. There is a big difference between the ability to detect general changes in the body, which can be disease, and the detection specific disease, says Jennifer Radin, an epidemiologist at the Scripps Research Institute’s Digital Medicine Division, which conducts research on wearable devices and COVID-19.

“If your heart rate increases beyond your normal rate, it could be due to many other reasons besides a viral infection. Perhaps you drank too much yesterday, she says.

None of the indicators that researchers extract from wearable devices are direct indicators of respiratory illness. “They are all just indicators of whether the body is doing well,” says Hirten. These systems are very different from the function of wearable devices, which can detect atrial fibrillation, a type of abnormal heart rhythm. In this case, the wearable device directly measures a marker – heart rate – that changes clearly and uniquely when someone experiences atrial fibrillation.

“Something like COVID-19 is much more complicated. You are trying to find alternative markers in the body that track viral disease, ”he says. “But it’s much more difficult because these markers also track other things going on in the body.”

Fitbit saw an overlap with other diseases this year in one of its disease prediction projects, which asked participants to take flu tests. According to Conor Henegan, director of research at Fitbit, there were similar signals in the data when people got sick with the flu and COVID-19. “I feel it will be difficult to reliably distinguish between them,” he says.

The task becomes even more difficult as the level of coronavirus circulating in the community drops. All studies on wearable devices and COVID-19 were conducted in the last year, when coronavirus was the main factor causing the disease. The flu season was virtually non-existent. There was a pretty good chance that if someone had a specific signature on their wearables that tracked a respiratory illness, the respiratory illness could be COVID-19. As the disease becomes rare, it becomes more difficult. “It’s not that specific anymore as prevalence is declining,” says Hirten.

But tools that alert people that they might get sick are still useful, even if they can’t tell what someone is sick with. with… Henegan says this is the most likely route for Fitbit. “It will be common, hey, something has changed in your physiological characteristics, you might think you might get sick,” he says. “This is probably normal from our point of view.”

Oura’s Rai says the Oura ring already fulfills this function. The ring gives users a readiness score that includes metrics such as sleep quality, heart rate, and body temperature. If he discovers that someone’s body temperature is rising, he gives people the opportunity to pause the achievement of activity goals and go into rest mode. “This is a product warning light,” says Rai. He thinks this will be the main approach for the next few years.

“These devices cannot diagnose or treat, but they can tell that something is wrong with your baseline,” he says.

Adding such features to more wearable devices will require good communication with users, Radin said. “We don’t want to scare people,” she says. It would be a problem if people who wore smartwatches thought they had COVID-19 every time their data changed. But the devices can explain to users that there are a number of reasons why someone might notice a change, including illness, she says. “It’s just a warning that something is out of your normal range and it might be something to watch out for.”