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Fitbit wearers asked to join a study to see if smartwatches can detect signs of coronavirus

Fitbit wearers are being asked to join a study to see if smartwatches can detect the coronavirus.

King’s College London believe changes in heart rate, activity and sleeping patterns might be able to raise red flags in possible coronavirus cases.

Using a free app called Mass Science they will track thousands of peoples’ vital signs with the hope of an alert system inside the watch further down the line.  

It can take several days for viruses to cause symptoms but a growing body of evidence suggests wearables may be able to spot invisible signs of infection early on. 

Covid-19 patients with smartwatches have shown tiny changes in their health indicators days before the tell-tale symptoms of a cough, fever or loss of taste and smell start. 

A tool that can find Covid-19 cases before symptoms start would be ‘game changing’, scientists say.

The majority of transmission of the coronavirus happens in the pre-symptomatic stage, or from people who never show symptoms at all. 

Fitbit wearers are being asked by scientists to join a study to see if smartwatches can detect the coronavirus

Scientists at King’s College London (KCL) have designed a new app, called the Mass Science app, that allows volunteers to connect their wearable devices and automatically share their data.

The data will be assessed by the researchers over time to match any patterns in vitals with people who later test positive for Covid-19.

The researchers, funded by the NHS National Institute for Health Research, believe they will eventually be able to use the data to develop a tool to spot infection early on. 

Study leader Dr Amos Folarin said: ‘With a lack of information on who is infected in the population, especially asymptomatic, we are investigating how wearable data can be used to detect Covid-19.

‘Having a cheap, continuous digital test for infection could be a game-changer.


Resting heart rate (RHR) is the steady pace your heart beats at when you are motionless or sitting quietly.

Maximum heart rate is the rate at which your heart is beating when it is working its hardest to meet your body’s oxygen needs.

During the day, the heart rate changes from minute to minute depending on what you’re doing. It will shoot up while doing exercise, as the heart pumps oxygenated blood to the muscles, for example.

The usual range for RHR is anywhere between 60 and 100 beats per minute. Above 90 is considered high, according to Harvard Health.

RHR is influenced by many factors. Age, fitness, smoking, sleep, stress, medical conditions, genetics and weight all play a role.

Does illness affect RHR?

Doctors have long known that a higher resting heart rate can be a sign that the body’s immune system is ramping up. 

Research has previously shown that young men with fevers had increases in their resting heart rate of about 8.5 beats per minute for about every 2°F increase in body temperature.

Some early research shows that resting heart rate data and other key health indicators from wearables have the potential to identify flu-like illness before symptoms emerge. 

But because there is such a huge variation in what’s normal from person to person, it’s not possible at this stage to measure someone’s heart rate and diagnose them because the doctor would need data on what is typical for that person.

Scientists know heart rate can flag viral respiratory infections, including asymptomatic infections – those that do not have obvious symptoms. And smartwatches could one day be used to help with this.

But scientists haven’t been able to hone an alert system in a wearable yet. 

‘When you indicate you are experiencing symptoms in the app, we’ll be able to look at your data before, during and after this period and compare it to your healthy baseline data.

‘Passive monitoring of symptoms coupled with movement data could be very useful as lockdown is cautiously lifted across the country.  

‘As shops, schools and other businesses reopen we expect an overall increased movement of population and potential for a second wave of COVID-19.’

Professor Richard Dobson added: ‘There are more than eight million regular wearable device users in the UK and the data generated from these devices could be really important in helping our understanding of disease onset and disease trajectories, provide regional disease surveillance and support a safe lockdown release.

‘This is a really important project that builds on our previous and ongoing experience in remotely monitoring disease and mental health, and development of our open-source platforms.’ 

Some early research shows that resting heart rate data and other key health indicators from wearables have the potential to identify flu-like illness before symptoms emerge. 

Doctors have for years known a higher resting heart rate could be a sign the body’s immune system is ramping up in response to a pathogen even in the absence of obvious symptoms.   

But scientists haven’t yet been able to make an effective alert system within a wearable watch.

They would first need to identify exactly how the disease alters heart rate or other parameters, which would likely differ from person to person.  

One study by Stanford University in California analysed data from 31 Fitbit users who had caught Covid-19.

They found changes in heart rate, number of steps taken and sleep were evident in 80 per cent of the cases, suggesting the virus is detectable before it takes hold.

In some cases, signs of infection were clear nine days before the tell-tale symptoms of a cough, fever or loss of taste and smell started.

The researchers said wearables that measure health vitals could be the way out of the Covid-19 pandemic.

And they designed an algorithm that works to spot Covid-19 infection in smartwatch wearers — but cautioned it needs fine-tuning before it is reliable. 

Such a tool would be beneficial for curbing the spread of the virus because it would catch infectious people as early as possible, and limit how many people they can transmit the virus to while contagious.  

It could catch the carriers of the virus who don’t have symptoms yet, and unaware they have the virus, even though they are contagious to others.

This is what governments globally are trying to do with a test and trace system, whereby people are alerted if they are suspected to have the coronavirus and therefore at risk of passing it on to others. 

Tests for the coronavirus are only undertaken when someone presents with symptoms, which is problematic because carriers are able to unknowingly spread the virus before they even are aware they have it. 

Some never show symptoms at all, called asymptomatic, believed to account for as many as 50 per cent of transmission.