First responders must sometimes go underground or into facilities where GPS doesn't work, but Swedish researchers are developing a new kind of shoe that could solve that problem. Researchers at the KTH Royal Institute of Technology in Stockholm are developing sensor-laden shoe soles that can transmit location information using ultra-wideband radio and do not require a communications infrastructure.

Peter Händel, professor of signal processing, John-Olof Nilsson, a researcher at KTH, and Jouni Ranta Kokko, a KTH researcher and research leader at the Swedish Defence Research Agency, are building a body of research that's being put into an open source project called OpenShoe. By collaborating with the Swedish Defence Research Agency, Swedish rescue services and the Indian Institute of Science in Bangalore, researchers are honing their real-time location tracking system.

The system uses accelerometer and gyroscope sensors similar to those found in today’s smartphones and transmits the data via a wireless module worn on the shoulder of each worker. Researchers are now working to integrate all the components into the shoe, including electronics that will generate power for the shoe’s data-gathering and transmission functions. The system also has a GPS sensor, to be used when GPS coverage becomes available, although the system does not require it to function.

The OpenShoe system, which has been field tested, allows for precise, simultaneous location tracking of multiple workers in the field, and the data is output to a nearby display. An Android app was developed that allows monitoring of those wearing the sensors, and it works no matter if workers are walking, running, crouching or crawling.

While originally conceived for use by firefighters, police officers and search and rescue teams, the system could have other applications, such as medicine and sports, Händel told Government Technology.

Swedish firefighters tested the system in the KTH Experimental Performance Space. So far the feedback has been very positive, Händel said, and they are continuing to gather feedback as they do more testing.

For a system that uses three units, the approximate cost is between $40,000 and $70,000, Händel reported.