EMU Prof Offers Innovative Design For Amputees

YPSILANTI -- A wireless device that measures stress on artificial limbs that was invented by an Eastern Michigan University researcher and a Michigan company has won top honors in a NASA design competition.

The small device, called an iPecs or Intelligent Prosthetic Endo-Skeletal Component, won in a "Create the Future" design competition sponsored by NASA. The iPecs was an entry in the electronics category, a competitive group that drew more than 900 entries from around the world.

Frank J. Fedel, an assistant professor and research director for the Prosthetic and Orthotics Program at EMU, said that he and his colleagues saw a need to accurately measure their patients' gait, in order to determine what is happening to them and their prosthetic device while walking.

"By measuring what is happening directly with a device installed as part of their prosthesis, you can identify uneven forces and twisting motions that make walking difficult or painful," Fedel said.

Armed with this information, researchers and clinicians will able to better prescribe and align prosthetic devices, according to Fedel.

Typically, a person with a lower limb prosthesis might have limited motion and other problems that can only be diagnosed in a gait laboratory, Fedel says.

A typical gait or walking lab, such as the new facilities at EMU, incorporates multiple high-speed video cameras, floor-mounted load transducers (platforms that measure force), and a walkway or treadmill connected to a computer to assess and treat individuals who have problems walking.   Patients perform walking trials in the lab, but it's an artificial setting in a controlled environment, says Fedel.  While the patient walks, the system collects information on various movements including step and stride length, cadence, speed and foot angle.

Measuring these same variables on amputees wearing a prosthetic device introduces several additional challenges. Individuals with an amputation often compensate for the absence of a portion of their limb by altering their gait. This creates subtle changes that aren't visible to the human eye, but which can be damaging to the patient over the long run, Fedel says.

That's where the iPecs comes in. The device, which is the size of an apple, is innovative because it is wireless and portable, Fedel says. It doesn't require expensive laboratory equipment dedicated to one particular room.

"The iPecs is like a gait lab without walls," Fedel says. "It combines well-established technologies like strain gauges, which measure stress or fatigue on the limb, with newer cell phone technology, so the device can provide accurate measurements anywhere -- all without heavy battery packs and wires. It is a lightweight wireless design, and has a plug-in-and-play simplicity."

When the iPecs is fitted to the artificial limb, data is captured throughout each step a patient takes. It can monitor the amount and direction of force being applied to a patient's limb socket, as well as identify the twisting motions as they occur. This helps clinicians and researchers refine the way a prosthetic limb fits and performs. The data is then transmitted wirelessly to a nearby computer or recorded on a micro SD memory card to be downloaded later by flash memory.

"Uneven forces and twisting motions, which make walking difficult or painful, can be identified, so researchers and clinicians alike will able to better prescribe and align prosthetic devices," Fedel said. "Even the best gait labs can't offer that on an everyday basis."

The device was co-invented by Fedel; Richard Harrington, director of design and development, at Sensor Tek in Dexter; and a team of engineers from College Park Industries, led by Michael Leydet, the company's director of research. The project was partially funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development.

College Park Industries, located in Fraser, has been designing and manufacturing prosthetic feet for the worldwide market since 1988. That expertise spurred Fedel to work with the company to develop the device.

The iPecs is now sold internationally and shipped to various research labs around the world.   Fedel would like to see the device become as commonplace for amputees as heart rate monitors are for cardiac patients, or blood sugar monitors are for diabetics. Plans to launch the first clinical version of the iPecs system are under way for mid-year 2012.

Fedel can't wait to test the device on patients.

"It would help those with a prosthesis detect and head off potential problems, as well as helping them get back to doing the things they want to do," Fedel said.

For more information about the iPecsTM go to www.college-park.com/ipecs

For additional information about Eastern Michigan's orthotics and prosthetics program, go to www.emich.edu/hphp/orthotics_index.html