Sensor technology designed to prevent diabetic foot amputations

University of Arizona researchers working to reduce foot amputations among diabetics think they may have found a way to increase adherence to prescribed footwear.

In concert with a Cambridge, Mass.-based wearable technology company and using a $400,000 small business innovation research grant from the National Institutes of Health, they have created an interactive sensor that alerts patients when they forget to wear removable cast walkers that reduce pressure on the bottom of the foot.

The sensor--which currently takes the shape of a small, black box--will be worn inside the cast walker. It works in conjunction with a special watch that buzzes to alert patients when they aren't wearing the footwear.

To test the sensor's effectiveness, Bijan Najafi, an associate professor of surgery at UA's Department of Surgery, and colleagues have recruited 30 patients from the school's Southern Arizona Limb Salvage Alliance Clinic to wear the device inside their cast walkers. The patients also will wear a 'smart' shirt that uses sensors that measure physical activity. Combine data from the shirt and the sensor will help Najafi and his team to determine adherence to the footwear.

The study is expected to last one year.

"People sometimes don't realize how important it is to wear [a cast walker]," Najafi said in an announcement. "Maybe they think they are walking just a few steps around the home, and they don't need it."

David Armstrong, a professor of surgery and the SALSA director, thinks the technology can work for non-diabetic patients, as well.

"We imagine integrated devices that can help assist patients, nurses and doctors fit and wear anything that is put in their body," he said.

Medication adherence technology has been shown to be effective with regard to patients ingesting medicine. The MediSafe Project announced last month that use of its mobile "pillbox app" resulted in patients taking their medication on time at a 31 percent higher rate than the World Health Organization's estimated average medication adherence rate of 50 percent.

A 'smart' cast developed in 2010 by a graduate of the Copenhagen Institute of Interaction Design uses electromyographic (EMG) sensors that track muscle activity around a fracture site to determine how much mobility a patient has in an affected area, and how physical therapy and daily activity are affecting the area. That, then, enables clinicians to adjust treatment accordingly.

To learn more:
- here's the University of Arizona announcement