Smartwatches as COVID-19 Detectors

Smartwatch manufacturers are looking closer at data that suggests wearing a device that measures heart rate variability (HRV) may identify COVID-19 several days before a person experiences symptoms. If so, activity tracking devices could play an important role in slowing the spread of the disease by indicating when individuals should consider self-isolating.

HRV is a measure of the variation in the interval between heartbeats. These fluctuations are normal and occur in response to things like respiration, blood pressure, sleep cycles, stress and anxiety. When HRV is reduced, it can signal a variety of issues, including a reduction in the body’s immune response.

One study followed about 300 healthcare workers who wore Apple Watches equipped with an app to monitor HRV for a period of five months. A retrospective review of the data revealed that those who tested positive for COVID-19 during that period showed significant changes in HRV up to a week before the onset of symptoms. Another study, using a variety of fitness tracking devices, found that changes in resting heart rate occurred up to nine and a half days prior to symptoms.

Although these preliminary results are far from conclusive, and are not necessarily limited to COVID-19, augmenting traditional testing with noninvasive monitoring devices could provide for earlier detection and more timely intervention, leading to better outcomes.