Scientists have developed a wearable sensor system—a watch-like wristband and a chest patch—that monitors the wearer’s environment, heart rate, respiratory rate, and other factors in order to predict and prevent asthma attacks.
The system, called the Health and Environmental Tracker (HET), is composed of a suite of novel, ultralight sensor devices that are powered only by the body’s heat and movement, according to a report published online May 26, 2016 in the IEEE Journal of Biomedical and Health Informatics.
“Our goal was to design a wearable system that could track the wellness of the subjects and in particular provide the infrastructure to predict asthma attacks, so that the users could take steps to prevent them by changing their activities or environment,” said principal investigator Alper Bozkurt, PhD, MSc, Assistant Professor of Electrical and Computer Engineering at North Carolina State University, in Raleigh, NC.
“Preventing an attack could be as simple as going indoors or taking a break from an exercise routine,” said lead author James Dieffenderfer, a PhD student in the joint biomedical engineering program at NC State and the University of North Carolina at Chapel Hill.
The system’s two wearable components are the wristband and the chest patch. The wristband monitors environmental factors such as volatile organic compounds, ozone in the air, as well as ambient humidity and temperature. The wristband also has sensors to monitor the wearer’s motion, heart rate, and blood oxygen level.
The chest patch includes sensors that track a patient’s movement, heart rate, respiratory rate, blood oxygen level, skin impedance, and wheezing in the lungs.
The system also has one non-wearable component: “For HET, we developed a customized self-powered spirometer, which collects more accurate information on lung function and feeds that data into the system,” Dieffenderfer explained.
Data from all of these sensors is continually streamed wirelessly to a computer, where custom software collects and records the data, which is then transferred to a dedicated server for cloud storage.
“We have tested the system in the benchtop and on a limited number of human subjects for proof of concept demonstration and have confirmed that all of the sensors work, and that the system accurately compiles the data,” said study co-author Veena Misra, PhD, Professor of Electrical and Computer Engineering at NC State.
Dr. Misra added, “This summer, we plan to begin testing HET in a controlled environment with subjects suffering from asthma and a control group, in order to identify which environmental and physiological variables are effective at predicting asthma attacks.”
“Once we have that data, the center can begin developing software that will track user data automatically and give users advance warning of asthma attacks,” said Dr. Bozkurt, who is overseeing HET system integration. “And that software will allow users to synch the HET to their smartphones so that they can monitor their health on the go. After these tests are completed, and the prediction software created, we are hoping that a fully functional HET system will be available.”