Health trackers worn on wrists could detect Covid-19 days before symptoms begin appear, new research suggests.
Such health trackers monitor changes in the skin's temperature as well as heart and breathing rates. When combined with artificial intelligence (AI), it could provide a diagnosis of Covid-19.
An AVA bracelet - a fertility tracker - was tested by a research team who wrote in the journal BMJ Open. Like many other health trackers, it monitors breathing rate, heart rate, heart rate variability, wrist skin temperature, and blood flow.
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In the study, 1,163 people under the age of 51 in Lichtenstein were asked to wear the AVA bracelet at night from the start of the pandemic. The device would save data every 10 seconds with participant needing to sleep at least four hours for it to work.
The health trackers were paired with a smartphone app while participants recorded any activity which could affect results, such as drinking alcohol and taking prescription medications and recreational drugs. Potential Covid-19 symptoms, such as a fever, were also recorded.
Regular antibody tests for Covid were regularly taken by the participants while those with symptoms also took a PCR swab test. Throughout the study, 1.5 million hours of physiological data were recorded while Covid infection was confirmed in 127 people.
The study discovered that there were significant changes in the body during the long incubation period for the infection, the period before symptoms appeared, when symptoms appeared and during recovery, compared to non-infection.
Conclusively, the tracker and computer algorithm identified 68 per cent of Covid-19 positive people two days before their symptoms appeared. The team, which consisted of those from the Cardiovascular Research Institute of Basel, concluded there were limits to the research since it didn't detect all Covid cases.
But they added: “Wearable sensor technology can enable Covid-19 detection during the pre-symptomatic period. Wearable sensor technology is an easy-to-use, low-cost method for enabling individuals to track their health and wellbeing during a pandemic.
“Our research shows how these devices, partnered with artificial intelligence, can push the boundaries of personalised medicine and detect illnesses prior to (symptom occurrence), potentially reducing virus transmission in communities.”
However, the algorithm is now being tested with a much larger group of 20,000 people in the Netherlands. Results are expected to be published later this year.