Covid-19 can be detected by wearing a smartwatch that detects the infection days before symptoms appear, scientists claim.
Researchers at Stanford University in California analyzed data from 31 people who had contracted the infection and were using Fitbits.
They found changes in heart rate, number of steps taken, and sleep were evident in 80 percent of cases, suggesting the virus is detectable before it catches.
In some cases, the signs of infection were evident nine days before the tell-tale symptoms of cough, fever, or loss of taste and smell.
The researchers now believe that wearables that measure health vitality may be the way out of the Covid-19 pandemic, which has killed 550,000 people worldwide.
And they designed an algorithm that detects Covid-19 infection in smartwatch wearers, but warned it needs to be adjusted before it’s reliable.
Such a tool would be useful in preventing the spread of the virus, as it would catch infectious people as early as possible and the number of people to whom they could transfer the virus, while it would be contagious.
Covid-19 can be detected by wearing a smartwatch (photo in the photo) that notices the infection days before the symptoms, scientists claim
The researchers narrowed the study group down to just 31 people who all reported a positive Covid-19 diagnosis and who all used the same smartwatch (Fitbit, photo)
Research scientist Tejaswini Mishra led the study, who said smartwatches can be useful in detecting whether someone’s typical health parameters are off.
Technology in watches can measure heart rate and skin temperature. Some have the added benefit of monitoring sleep quality over time.
WHAT IS A QUIET HEART RATE AND WHAT AFFECTS?
Resting heart rate (RHR) is the steady pace at which your heart beats when you are motionless or sitting still.
Maximum heart rate is the rate at which your heart beats when it works hard to meet your body’s oxygen needs.
During the day, the heart rate changes from minute to minute depending on what you are doing. It will skyrocket during exercise because, for example, the heart pumps oxygenated blood to the muscles.
The usual RHR range is somewhere between 60 and 100 beats per minute. Above 90 is considered high, according to Harvard Health.
RHR is influenced by many factors. Age is the most important because aging accelerates it.
Someone who is physically fit is more likely to have a low RHR.
Smoking, sleep, stress, medical conditions, genetics and weight also play a role.
The larger the body, the more the heart has to work to supply it with blood, so losing weight can help slow an increased RHR.
Does disease affect RHR?
Doctors have long known that a higher resting heart rate may be a sign that the body’s immune system is rising.
Research has previously shown that in young men with fever, resting heart rate increased by about 8.5 beats per minute with about every 2 ° F rise in body temperature.
But because there is such a huge variation in what is normal from person to person, at this stage it is not possible to measure a person’s heart rate and make a diagnosis, because the doctor needs data on what is typical for that person.
Scientists know that the heartbeat can signal viral respiratory infections, including asymptomatic infections – which have no obvious symptoms. And smartwatches could one day help with this.
But scientists have not yet been able to hone a warning system in a wearable.
How to measure your RHR
Press your index and middle fingers together on your wrist, in the neck of the inside of the elbow.
Feel light around until you detect banging – this is the wrist.
Count the number of beats in 60 seconds to get your beats per minute – that’s your RHR.
The best time to get your heart rate at rest is first thing in the morning, even before you get out of bed.
Doctors have known for years that a higher resting heart rate can be a sign that the body’s immune system is getting faster in response to a pathogen, even if there are no obvious symptoms.
Researchers have shown that commercial wearables can mark a viral infection in this way.
But scientists have not yet succeeded in creating an effective warning system to detect infections for any wearable technology.
To recognize Covid-19, they must first determine exactly how the disease changes the heart rate or other parameters, which would likely vary from person to person.
The researchers recruited a group of 5,322 individuals who completed surveys on their health.
They narrowed the study group down to just 31 people who all reported a positive Covid-19 diagnosis and who all used the same smartwatch (Fitbit).
They examined each person’s ‘baseline’ – their normal resting heart rate and typical fluctuations for that person.
Researchers analyzed whether baseline abnormalities of each person were detected around the disease period – 14 days before the symptoms and seven days after.
The first finding was that 87.5 percent of patients had elevated heart signals compared to their previous ‘healthy window’ before or at the time of symptoms.
In more than 85 percent of positive cases, these symptoms were evident in the days leading up to the symptoms.
The changes occurred three days before the patients developed an average cough or fever.
In some people, the signals were clear nine days or earlier. But these patients were unsure when they actually contracted the virus, so the findings are not concrete.
Around the same time, the heart rate changed, the number of steps a person took decreased significantly, and the duration of sleep increased, indicating fatigue.
The researchers said it was “interesting” that these changes are visible before a person actually reports symptoms.
Covid-19 was found to change heart rate, steps and sleep in 80 percent of cases.
This suggests that the disease is related to changes in physiology that can be detected via a smartwatch.
It gives hope that detecting changed parameters can help predict if someone will get Covid-19 sick before they realize they have it.
It can catch carriers of the virus that have no symptoms yet, even if they are contagious to others.
This is what governments around the world are trying to do with a testing and tracking system, alerting people if they suspect they have the coronavirus and thereby risk passing it on to others.
They need to isolate themselves to avoid going outside, mingling with others, and potentially infecting many more people. It allows governments to stay one step ahead of the coronavirus.
Tests for the coronavirus are only performed when someone shows symptoms, which is problematic because carriers can unknowingly spread the virus before they even realize they have it.
These are heart rates for two different patients (B and C) over a number of days (each gray vertical line is a new day). The red and purple vertical dotted lines indicate the day of onset of symptoms and the diagnosis of Covid-19, respectively. To see where the heart rate rises before the symptoms, look at the top panel (the black serpentine line) for each patient. The red horizontal arrow indicates where the heart rate was above the baseline for several days. It also appears to peak at other times after infection, which may be due to a relapse of symptoms
Some show no symptoms at all, called asymptomatic, which are believed to make up as much as 50 percent of cases.
The advantage of smart watches is that they are used by millions worldwide and are easily accessible.
“There is a great need and opportunity for population-scale technology solutions for infection detection and detection,” wrote Ms. Mishra.
“Since most infections only appear at the onset of symptoms, current testing methods cannot identify presymptomatic carriers, which is a major challenge for implementing early-stage interventions that reduce transmission.
“Therefore, there is an urgent need for accessible and inexpensive methods for early detection of COVID-19.”
The team developed an algorithm to detect Covid-19 by tracking heart rate in real time using the data they collected.
They tested their method on 24 Covid-19 patients – and found that detecting Covid-19 before or at the onset of symptoms worked in 67 percent of cases.
The most missed cases were in people with other pre-existing conditions such as chronic respiratory disease, which the algorithm may have been unable to distinguish from Covid-19.
Interestingly, the number of alarms after the Covid-19 infection is increasing significantly, indicating persistent complications from Covid-19 disease, the authors wrote.
They saw that in some people the symptoms came back after recovery and that the heart rate increases were consistent.
Other things that increase the heart rate, such as medication, alcohol, stress or travel, were picked up by the tool.
But their alarm system worked in a ‘layered’ way, so it didn’t cause a false alarm when someone just watched a scary movie or was exercising.
The findings have been published online and are yet to be explored by other independent scientists.
But Ms. Mishra and team are confident in the potential of wearables to mitigate the Covid-19 pandemic.
They added, “It should be noted that these portable devices have not yet been approved by the FDA and our study is still modest in size.
“It is currently unclear whether our approach can distinguish infections from SARS-CoV-2 from those caused by other diseases.”