An app that could turn any smartphone into a medical monitor for heart and lung patients


GaitTrack is the up-and-coming app that promises to turn just about any smartphone into a “sophisticated medical device.” Developed by researchers at the University of Illinois at Urbana-Champaign and the University of Illinois at Chicago, the application goes beyond basic step counting, relying on eight motion parameters to perform a detailed analysis of a person’s gait, or walking pattern, which can tell physicians much about a patient’s cardiopulmonary, muscular and neurological health.

Led by Bruce Schatz, the head of medical information science and a professor of computer science at the University of Illinois, the team published its findings in the journal Telemedicine and e-Health.

“Fitness apps and devices are tuned for healthy people,” said Schatz, who also is affiliated with the Institute for Genomic Biology at the University of Illinois. “They cannot accurately measure patients with chronic disease, who are the biggest medical market. A pedometer is not a medical device. But a cheap phone with GaitTrack software is.”

Relying on eight motion parameters to perform a detailed analysis of a person’s gait, the application turns any smartphone into a medical device.Schatz says that gait is often referred to as the “sixth vital sign,” after temperature, blood pressure, heart rate, respiratory rate and blood oxygen level. Gait speed involves several systems of the body working together in coordination, so changes in gait can be a sign of trouble in one or more systems.

Doctors often use an assessment called the six-minute walk test for patients with heart and lung disease; however, patients with chronic disease often cannot be measured with typical pedometers since they tend to walk with shorter, more careful strides, or to shuffle, so specialized medical accelerometers are used.

The Illinois team used GaitTrack to administer the same six-minute walk tests to 30 patients with chronic lung disease and found that it monitored more accurately than medical accelerometers. In addition, they discovered that analysis of the gait data could predict lung function with 90% accuracy, within an age group.

The GaitTrack app could run constantly in the background, periodically collecting data, analyze it while keeping tabs on the patient’s status.Schatz envisions the GaitTrack app running constantly in the background as a patient carries a phone. The phone would periodically collect data, analyze it and keep tabs on the patient’s status, alerting the patient or patient’s doctor when it detects changes in gait that would indicate a decline in health so that treatment could be adjusted responsively.

The researchers now are testing GaitTrack in larger trials within health systems. Schatz hopes to have the app available for download within months, and in the meantime – he and his team will demonstrate it at the annual meeting of the American Telemedicine Association this month.