Rehab gets robotic help

BY NICK STREICHER
For the Daily
Published February 20, 2007

Using a new device developed by University researchers, people with spinal cord injuries who might otherwise be bound to a wheelchair for life could regain the ability to walk.

Sarah Royce
(Photo Courtesy of Dan Ferris)

Dan Ferris, an associate professor of kinesiology and biomedical engineering, and Keith Gordon, a graduate of the University's kinesiology Ph.D program and a post-doctoral fellow at the Rehabilitation Institute of Chicago, have developed a robotic exoskeleton to help patients regain movement in their legs.

Ferris described how damage to the spinal cord decreases nervous system activity and can prevent people from moving their leg muscles.

The prosthetic skeleton includes electrodes attached to the patient's ankle that detect nervous system activity. The prosthesis senses weak movements and amplifies them through an air-powered pneumatic muscle.

Ferris and Gordon have tested the device on healthy volunteers. After the prosthesis was placed on their ankles, volunteers gauged the comfort of the device while the scientists tested how effectively the prosthesis detected and assisted in muscle contraction.

Although healthy volunteers had trouble getting used to the prosthesis at first, Gordon said they were able to walk normally after about half an hour with the device on their ankles.

Now Ferris is testing how well the exoskeleton works for patients with spinal cord injuries. The technology is not meant as a permanent fix, though. Ferris said it serves as a training device that can amplify muscle movement to help patients regain their coordination.

It's possible that exercise using the exoskeleton could undo nerve damage, but Ferris would not say whether the machine has any impact on nervous system activity before the researchers publish their data.

Ferris said that although some spinal rehabilitation centers already use robotic prostheses to rehabilitate patients, most centers send patients home with support braces or wheel chairs. But most rehabilitation centers that use robotics control the devices with computers instead of the patient's own nerve impulses.

Using the patient's own nerve impulses to control the prosthesis gives the nervous system the feedback it needs to regain muscle coordination, Ferris said.

He called the device a safe and effective way to treat spinal cord patients.

Despite his high hopes, Ferris said there won't be just one solution for the estimated 250,000 Americans currently suffering from spinal cord injuries.

He said he hopes his work will be a major step forward for the study and treatment of spinal cord injuries.

"We are really at the tip of the iceberg," Gordon said.