Although it might be tempting to rely on your fitness tracker to catch early signs of COVID-19, researchers caution that consumer wearables are not sophisticated enough to monitor the complicated illness.

The team published a perspective in the journal Science Advances, in which they differentiate between popular consumer electronics and clinical-grade monitoring systems.

"According to the Journal of the American Medical Association, the three most important early symptoms for COVID-19 are fever, shortness of breath and coughing," the senior author said. "For a wearable technology, you want to track those key symptoms. A conventional wearable device, such as a fitness tracker, sits on the wrist or finger -- not the anatomical location that is most relevant to COVID-19."

This past spring, the group introduced a novel wearable device and set of data algorithms specifically tailored to catch early signs and symptoms associated with COVID-19 and to monitor patients as the illness progresses. About the size of a postage stamp, the soft, flexible, wireless device sits just below the suprasternal notch, the visible dip at the base of the throat -- an ideal location for monitoring respiratory health.

More recently, the team added a wearable, flexible pulse oximeter to pair with the suprasternal-mounted device. This allows physicians to continuously monitor for silent hypoxia, an often asymptomatic feature marked by alarmingly low blood oxygen levels. Adding this feature will help the device, and accompanying algorithms, give a fuller picture of the disease's onset, progression and response to treatment.

"The device measures very tiny vibrations on the skin and has an embedded temperature sensor for fever," the senior author said. "As you cough and breathe, it counts coughs, monitors the intensity of cough and senses labored breathing. The location on the throat also is close enough to the carotid artery that it can measure mechanical signatures of blood flow, monitoring heart rate."

"This sensor system targets key symptoms for COVID-19, with the goal to identify the infection earlier in patients," the lead author said. "It's a suite of clinical-grade sensors wrapped into one small device. And once it's placed on the throat, people don't even realize that it's there."

Since launching the device in April, the team has tested it on 52 COVID-19-positive physicians, nurses, rehabilitation specialists and patients. The device was tested both in the hospital and in the home.

From these tests, the team have collected 3,000 hours of data, which will continue to strengthen the device's algorithms. Eventually, the machine-learning algorithms will become smart enough to distinguish between a COVID-like cough and more benign coughs from allergies, colds or dryness. The team expects to test 500 subjects by the end of the year.

"We are already seeing clear vital sign differences collected by the sensor between patients with COVID-19 and healthy-matched controls," said the author who leads the algorithm development. "We're working together to develop predictive algorithms for detecting the disease earlier."

The device wirelessly transmits data to a HIPAA-protected cloud, where automated algorithms produce graphical summaries tailored to facilitate rapid, remote monitoring. This allows the doctors to continue monitoring the patients well after they have been dismissed from the hospital.

"It has provided valuable information about each patient's respiratory status," the author said. "We hope that as we gain experience with this device, it will greatly enhance our ability to monitor patients remotely. Under the circumstances of the pandemic, remote monitoring capabilities improve efficiency in medical care while increasing protection to health care workers against the virus."

To accelerate manufacturing and deployment, the authors launched technology startup Sonica Health, based on intellectual property (IP) jointly developed by Northwestern and the Shirley Ryan AbilityLab. The IP related to this project has been optioned through Northwestern's Innovation and New Ventures Office.

https://news.northwestern.edu/stories/2020/07/clinical-grade-wearables-offer-continuous-monitoring-for-covid-19/

https://advances.sciencemag.org/content/early/2020/06/30/sciadv.abd4794

http://sciencemission.com/site/index.php?page=news&type=view&id=publications%2Fcontinuous-on-body&filter=22