Smartwatches can track COVID-19 symptoms, study finds
University of Michigan researchers found that new signals embedded in heart rate indicated when individuals were infected with COVID-19 and how ill they became.
If a COVID-19 infection develops, a wearable device may eventually be able to clue you in. A study at the University of Michigan found that a smartwatch can monitor how symptoms progress.
The study evaluated the effects of COVID-19 with various factors derived from heart-rate data. This method also could be employed to detect other diseases, such as influenza and the common cold, at home or when medical resources are limited, such as during a pandemic or in developing countries.
Tracking students and medical interns across the country, the University of Michigan researchers found that new signals embedded in heart rate indicated when individuals were infected with COVID-19 and how ill they became.
For instance, they discovered that individuals with COVID-19 experienced an increase in heart rate per step after the onset of their symptoms. Meanwhile, people who reported a cough as one of their COVID-19 symptoms had a much more elevated heart rate per step than those without a cough.
“We previously developed a variety of algorithms to analyze data from wearable devices. So, when the COVID-19 pandemic hit, it was only natural to apply some of these algorithms to see if we can get a better understanding of disease progression,” says Caleb Mayer, a doctoral student in mathematics at the University of Michigan and a co-first author of the study.
People may not internally sense COVID-19’s direct impact on the heart, but “heart rate is a vital sign that gives a picture of overall health," says Daniel Forger, a University of Michigan professor.
Millions of people are tracking their heart rate through wearable devices. This information is already generating a tremendous amount of data for researchers to analyze, says co-author Daniel Forger, professor of mathematics and research professor of computational medicine and bioinformatics at the University of Michigan.
“Heart rate is affected by many different physiological signals,” Forger explains. “For instance, if your lungs aren’t functioning properly, your heart may need to beat faster to meet metabolic demands. Your heart rate has a natural daily rhythm governed by internal biological clocks.” While people may not internally sense COVID-19’s direct impact on the heart, he adds that “heart rate is a vital sign that gives a picture of overall health.”
Among the total of 2,164 participants who enrolled in the student study, 72 undergraduate and graduate students contracted COVID-19, providing wearable data from 50 days before symptom onset to 14 days after. The researchers also analyzed this type of data for 43 medical interns from the Intern Health Study by the Michigan Neuroscience Institute and 29 individuals (who are not affiliated with the university) from the publicly available dataset.
Participants could wear the device on either wrist. They also documented their COVID-19 symptoms, such as fever, shortness of breath, cough, runny nose, vomiting, diarrhea, body aches, loss of taste, loss of smell, and sore throat.
Experts not involved in the study found the research to be productive. “This work is pioneering and reveals exciting new insights into the many important ways that we can derive clinically significant information about disease progression from consumer-grade wearable devices,” says Lisa A. Marsch, director of the Center for Technology and Behavioral Health and a professor in the Geisel School of Medicine at Dartmouth College. “Heart-rate data are among the highest-quality data that can be obtained via wearables.”
Beyond the heart, she adds, “Wearable devices are providing novel insights into individuals’ physiology and behavior in many health domains.” In particular, “this study beautifully illustrates how digital-health methodologies can markedly enhance our understanding of differences in individuals’ experience with disease and health.”
Previous studies had demonstrated that COVID-19 affects cardiovascular functions. Capitalizing on this knowledge, the University of Michigan endeavor took “a giant step forward,” says Gisele Oda, a researcher at the Institute of Biosciences at the University of Sao Paulo in Brazil and an expert in chronobiology—the science of biological rhythms. She commends the researchers for developing a complex algorithm that “could extract useful information beyond the established knowledge that heart rate increases and becomes more irregular in COVID patients.”
Wearable devices open the possibility of obtaining large-scale, long, continuous, and real-time heart-rate data on people performing everyday activities or while sleeping. “Importantly, the conceptual basis of this algorithm put circadian rhythms at the center stage,” Oda says, referring to the physical, mental, and behavioral changes that follow a 24-hour cycle. “What we knew before was often based on short-time heart rate measured at any time of day,” she adds, while noting that heart rate varies between day and night and also changes with activity.
However, without comparison to a control group of people having the common flu, it is difficult to determine if the heart-rate signals are unique to COVID-19 or also occur with other illnesses, says John Torous, an assistant professor of psychiatry at Harvard Medical School who has researched wearable devices. In addition, he points to recent data showing that many wearables, which work by beaming light through the skin, may be less accurate in people with darker skin due to variations in light absorption.
While the results sound interesting, they lack the level of conclusive evidence that would be needed to transform how physicians care for patients. “But it is a good step in learning more about what these wearables can tell us,” says Torous, who is also director of digital psychiatry at Beth Israel Deaconess Medical Center, a Harvard affiliate, in Boston. A follow-up step would entail replicating the results in a different pool of people to “help us realize the full value of this work.”
It is important to note that this research was conducted in university settings during the early phases of the pandemic, with remote learning in full swing amid strict isolation and quarantine mandates in effect. The findings demonstrate that physiological monitoring can be performed using consumer-grade wearable sensors, allowing research to continue without in-person contact, says Sung Won Choi, a professor of pediatrics at the University of Michigan who is principal investigator of the student study.
“The worldwide COVID-19 pandemic interrupted a lot of activities that relied on face-to-face interactions, including clinical research,” Choi says. “Mobile technology proved to be tremendously beneficial during that time, because it allowed us to collect detailed physiological data from research participants remotely over an entire semester.” In fact, the researchers did not have any in-person contact with the students involved in the study. “Everything was done virtually," Choi explains. "Importantly, their willingness to participate in research and share data during this historical time, combined with the capacity of secure cloud storage and novel mathematical analytics, enabled our research teams to identify unique patterns in heart-rate data associated with COVID-19.”
Is Carbon Dioxide the New Black? Yes, If These Fabric-Designing Scientists Have Their Way
The entrepreneurs Tawfiq Nasr Allah (left, standing) and Benoit Illy (right, sitting down) at Fairbrics' lab in Clichy, France.
Each year the world releases around 33 billion tons of carbon dioxide into the atmosphere. What if we could use this waste carbon dioxide to make shirts, dresses and hats? It sounds unbelievable. But two innovators are trying to tackle climate change in this truly unique way.
Chemist Tawfiq Nasr Allah set up Fairbrics with material scientist Benoît Illy in 2019. They're using waste carbon dioxide from industrial fumes as a raw material to create polyester, identical to the everyday polyester we use now. They want to take a new and very different approach to make the fashion industry more sustainable.
The Dark Side of Fast Fashion
The fashion industry is responsible for around 4% of global emissions. In a 2015 report, the MIT Materials Systems Laboratory predicted that the global impact of polyester fabric will grow from around 880 billion kg of CO2 in 2015 to 1.5 trillion kg of CO2 by 2030.
Professor Greg Peters, an expert in environmental science and sustainability, highlights the wide-ranging difficulties caused by the production of polyester. "Because it is made from petrochemical crude oil there is no real limit on how much polyester can be produced...You have to consider the ecological damage (oil spills, fracking etc.) caused by the oil and gas industry."
Many big-name brands have pledged to become carbon neutral by 2050. But nothing has really changed in the way polyester is produced.
Some companies are recycling plastic bottles into polyester. The plastic is melted into ultra-fine strands and then spun to create polyester. However, only a limited number of bottles are available. New materials must be added because of the amount of plastic degradation that takes place. Ultimately, recycling accounts for only a small percentage of the total amount of polyester produced.
Nasr Allah and Illy hope they can offer the solution the fashion industry is looking for. They are not just reducing the carbon emissions that are conventionally produced by making polyester. Their process actually goes much further. It's carbon negative and works by using up emissions from other industries.
"In a sense we imitate what nature does so well: plants capture CO2 and turn it into natural fibers using sunlight, we capture CO2 and turn it into synthetic fibers using electricity."
Experts in the field see a lot of promise. Dr Phil de Luna is an expert in carbon valorization -- the process of converting carbon dioxide into high-value chemicals. He leads a $57-million research program developing the technology to decarbonize Canada.
"I think the approach is great," he says. "Being able to take CO2 and then convert it into polymers or polyester is an excellent way to think about utilizing waste emissions and replacing fossil fuel-based materials. That is overall a net negative as compared to making polyester from fossil fuels."
From Harmful Waste to Useful Raw Material
It all started with Nasr Allah's academic research, primarily at the French Alternative Energies and Atomic Energy Commission (CEA). He spent almost 5 years investigating CO2 valorization. In essence, this involves breaking the bonds between the carbon and oxygen atoms in CO2 to create bonds with other elements.
Recycling carbon dioxide in this way requires extremely high temperatures and pressures. Catalysts are needed to break the strong bonds between the atoms. However, these are toxic, volatile and quickly lose their effectiveness over time. So, directly converting carbon dioxide into the raw material for making polyester fibers is very difficult.
Nasr Allah developed a process involving multiple simpler stages. His innovative approach involves converting carbon dioxide to intermediate chemicals. These chemicals can then be transformed into the raw material which is used in the production of polyester. After many experiments, Nasr Allah developed new processes and new catalysts that worked more effectively.
"We use a catalyst to transform CO2 into the chemicals that are used for polyester manufacturing," Illy says. "In a sense we imitate what nature does so well: plants capture CO2 and turn it into natural fibers using sunlight, we capture CO2 and turn it into synthetic fibers using electricity."
The Challenges Ahead
Nasr Allah met material scientist Illy through Entrepreneur First, a programme which pairs individuals looking to form technical start-ups. Together they set up Fairbrics and worked on converting Nasr Allah's lab findings into commercial applications and industrial success.
"The main challenge we faced was to scale up the process," Illy reveals. "[It had to be] consistent and safe to be carried out by a trained technician, not a specialist PhD as was the case in the beginning."
They recruited a team of scientists to help them develop a more effective and robust manufacturing process. Together, the team gained a more detailed theoretical understanding about what was happening at each stage of the chemical reactions. Eventually, they were able to fine tune the process and produce consistent batches of polyester.
They're making significant progress. They've produced their first samples and signed their first commercial contract to make polyester, which will then be both fabricated into clothes and sold by partner companies.
Currently, one of the largest challenges is financial. "We need to raise a fair amount to buy the equipment we need to produce at a large scale," Illy explains.
How to Power the Process?
At the moment, their main scientific focus is getting the process working reliably so they can begin commercialization. In order to remain sustainable and economically viable once they start producing polyester on a large scale, they need to consider the amount of energy they use for carbon valorization and the emissions they produce.
The more they optimize the way their catalyst works, the easier it will be to transform the CO2. The whole process can then become more cost effective and energy efficient.
De Luna explains: "My concern is...whether their process will be economical at scale. The problem is the energy cost to take carbon dioxide and transform it into these other products and that's where the science and innovation has to happen. [Whether they can scale up economically] depends on the performance of their catalyst."
They don't just need to think about the amount of energy they use to produce polyester; they also have to consider where this energy comes from.
"They need access to cheap renewable energy," De Luna says, "...so they're not using or emitting CO2 to do the conversion." If the energy they use to transform CO2 into polyester actually ends up producing more CO2, this will end up cancelling out their positive environmental impact.
Based in France, they're well located to address this issue. France has a clean electricity system, with only about 10% of their electric power coming from fossil fuels due to their reliance on nuclear energy and renewables.
Where Do They Get the Carbon Dioxide?
As they scale up, they also need to be able to access a source of CO2. They intend to obtain this from the steel industry, the cement industry, and hydrogen production.
The technology to purify and capture waste carbon dioxide from these industries is available on a large scale. However, there are only around 20 commercial operations in the world. The high cost of carbon capture means that development continues to be slow. There are a growing number of startups capturing carbon dioxide straight from the air, but this is even more costly.
One major problem is that storing captured carbon dioxide is expensive. "There are somewhat limited options for permanently storing captured CO2, so innovations like this are important,'' says T. Reed Miller, a researcher at the Yale University Center for Industrial Ecology.
Illy says: "The challenge is now to decrease the cost [of carbon capture]. By using CO2 as a raw material, we can try to increase the number of industries that capture CO2. Our goal is to turn CO2 from a waste into a valuable product."
Beyond Fashion
For Nasr Allah and Illy, fashion is just the beginning. There are many markets they can potentially break into. Next, they hope to use the polyester they've created in the packaging industry. Today, a lot of polyester is consumed to make bottles and jars. Illy believes that eventually they can produce many different chemicals from CO2. These chemicals could then be used to make paints, adhesives, and even plastics.
The Fairbrics scientists are providing a vital alternative to fossil fuels and showcasing the real potential of carbon dioxide to become a worthy resource instead of a harmful polluter.
Illy believes they can make a real difference through innovation: "We can have a significant impact in reducing climate change."
Vaccine passports, if required by businesses and universities, may give people a false sense of security, one expert cautions.
Vaccines are one of the greatest public health accomplishments of all time. For centuries, public health has relied on vaccinations to prevent and control disease outbreaks for a plethora of infectious scourges, with our crowning achievement being the successful eradication of smallpox.
The purpose of vaccine documentation is to provide proof of an individual's protection from either becoming infected or transmitting a vaccine-preventable disease. Vouching for these protections requires a firm knowledge about the epidemiology of the disease, as well as scientific knowledge concerning the efficacy of the vaccine. The vaccines we currently require be documented have met these tests; the vaccine for COVID-19 has not yet been proven to do so.
Let's acknowledge that the term "vaccine passport" is a poor choice of words. Passports are a legal travel document created by nations and governed by law for identification of the bearer to control entry and exit from nation states. They often serve as legal forms of identification and as a record of international travel. They are generally very sophisticated documents that have been created in a secure manner and may include a range of electronic and, in some cases, biometric measures such as fingerprints to ensure the holder is indeed who they say they are. Vaccine passports are medical documents used to document the vaccination status of an individual. They do not undergo the same level of administrative scrutiny and cannot be used to verify that the presenter is indeed the vaccinated individual. Some companies do have electronic methods to address concerns about verification; however, most people currently have paper records that can be easily falsified.
"Vaccine passports" as currently proposed risk giving people a false sense of security.
Successful disease control from vaccination programs relies on the ability to vaccinate at a level that prevents large-scale disease spread and the ability to rapidly identify the presence of disease outbreaks. It requires reliable, safe, and effective vaccines that are easily delivered in clinical and nonclinical settings. Keeping vaccination information as a part of the medical record, and even having a separate specialized vaccine record for personal use, is a time-honored tradition.
Keeping a vaccination record provides a method to keep track of the many shots one receives and serves as a visual reminder to help ensure the appropriate vaccine shot schedule is maintained for vaccines requiring multiple doses. The vaccine record, when combined with vaccine safety monitoring systems, serves as a mechanism to track adverse events to monitor and ensure the safety of vaccines as a consumer product. The record also serves as the official record of vaccination when required for administrative or legally prescribed purposes.
"Vaccine passports" as currently proposed risk giving people a false sense of security. In the case of the COVID-19 vaccines currently approved for use, many of the essential questions remain unanswered. While we do know the current three vaccines are highly protective against severe disease and death, and there is some evidence that these vaccinations do reduce infections and virus transmission of SARS-CoV-2, we do not yet know the full degree to which this occurs.
For example, we know there have been some cases of people that have been infected in close proximity to getting their full vaccination and rare cases of breakthrough reinfections. A breakthrough infection in a restaurant is a challenge for contact tracing, but an outbreak from a movie theater exposure or a baseball game could spark a major outbreak at our current level of vaccination. Current CDC guidance recommends continued mask wearing in order to address these concerns.
We also do not yet know how long the protections will last and if or when a booster or revaccination is required. In effect, it is too soon to know. Should an annual booster shot be required, then a vaccine passport would require annual updating, a process more frequent than renewal of a driver's license.
We also know that the current SARS-CoV-2 virus is mutating briskly. While the current approved vaccines have remained effective overall, there is evidence of some degree of degradation in vaccine effectiveness against some of the circulating strains. We also have sparse data on many of the other emerging strains of concern because we have not had the surveillance capacity in the U.S. to gain an adequate sense of how the virus is changing to fully align vaccine effectiveness with viral capabilities.
The risk of people misusing these "passports" is troubling. The potential for using these documents for hiring, firing or job limitation is a serious concern. Unvaccinated workers are at risk of this form of discrimination even from well-meaning employers or supervisors. Health insurers are prohibited by the Affordable Care Act from discriminating based on preexisting conditions, but they could probably charge a higher premium for unvaccinated individuals. There also is a risk of stigmatizing individuals who are not vaccinated or have left their vaccine documentation at home. Another concern: the opportunity to discriminate based on race, gender, sexual orientation, or religion, using one's vaccination status as an excuse.
These "passports" are being discussed as a "ticket verification" for entry to many activities, including dining at restaurants, flying domestically and/or internationally, going to movie theaters and sporting events, etc. These are all activities we already are doing at reduced levels and for which wearing a mask, hand hygiene and physical distancing are effective disease control practices. COVID-19 vaccines are indeed the measure that will make the ability to totally reopen our society complete, but we are not there yet. Documentation of one's COVID-19 vaccine status may be useful in selected situations in the future. That remains to be seen.
Finally, inadequate vaccine supply and disparities in vaccine delivery have created enormous challenges in providing equal access to vaccination. Also, the amount of misinformation, disinformation, and lingering vaccine hesitancy continue to limit the speed at which we will reach the level of vaccination of the population that would make this documentation meaningful. The requirement for "vaccine passports" is already alienating people who are opposed to vaccinations for a variety of reasons, paradoxically risking reduced vaccine uptake. This politicization of the vaccination effort is of concern. There are indeed people who, due to medical contraindications or legal exemptions, will not be vaccinated, and we do not yet have a national framework on how to address this.
Vaccine passports are not the solution for reopening our society — a robust vaccination program is. The requirement to document one's vaccination status for COVID-19 may one day have its place. For now, it is an idea whose time has not yet come.
Editor's Note: This op/ed is part of a "Big Question" series on the ethics of vaccine passports. Read the flip side argument here.