Researchers from Mount Sinai have found that the Apple Watch can detect small changes to a user’s heartbeat that may indicate they have the coronavirus, a full week before they feel sick, as CBS News reported.

The participants wore Apple Watches equipped with special apps that measured changes in their heart rate variability (HRV).

A similar study done by Stanford University found that participants wearing a variety of trackers from Garmin, Fitbit, Apple and others found that 81 percent of patients testing positive for coronavirus had changes in their resting heart rate up to nine and half days prior to the onset of symptoms.

Feeding that information into CovidDeep, they found they could detect the virus at a rate of 90 percent — more accurately than typical temperature screenings.