Device may offer alternative for stroke patients

Mar 30 2005

As the most common cause of adult disability in the United States, stroke leaves many survivors unable to perform tasks that were once part of their daily routine. Much of the time the disabilities are treatable, but the high cost of rehabilitation therapy leaves many patients to cope on their own.

Now, a new device has the potential to reduce the cost of therapy while increasing access by performing many of the therapists’ tasks robotically. Jay Alberts, assistant professor in the Georgia Institute of Technology School of Applied Physiology, and colleagues from Emory University are beginning a two-year study to see if the Hand Mentor is a feasible complement to individual therapy.

"The question we’re trying to answer is ‘can we get the same level of improvement while cutting the time a patient spends with a therapist in half?'” said Alberts. “If we can, that could make treatment more accessible by making it more affordable for insurance companies to cover.”

Stroke patient Herbert Brooks has difficulty controlling his right hand. A pre-trial participant, he slips his arm into the Mentor, resting his fingers on the hand grip. His therapist punches a few buttons on the device’s computer. The Mentor’s air muscles contract, extending his wrist to a programmed angle.

The rest is up to Brooks. The machine stops pulling and the therapist asks Brooks to extend his wrist the rest of the way. All the while the Mentor is measuring how far he extends, how much force he is using and how much electrical activity his muscles are experiencing. It also records the resistance he gives as the machine pulls his hand into position. If he’s improving, the resistance should decrease.

Developed by Kinetic Muscles, Inc. in Tempe, Ariz., the Hand Mentor is used with a type of therapy known as repetitive task practice. Typically, patients who have difficulty controlling a part of their body after a stroke learn to compensate with another limb. This acquired behavior, known as learned non-use, can prevent patients from improving the functioning of the affected limb. Repetitive task practice works by forcing patients to use the impaired limb.

"Active therapy may help the brain rewire itself to use different neurons for muscle movements that were impaired by stroke,” explained Alberts. “In essence, we’re training the brain as well as the muscles.”

Alberts is collaborating with Steve Wolf and Andrew Butler in Emory’s Department of Rehabilitation Medicine on the NIH-funded preliminary clinical trial. The 24 participants will spend four hours a day, five days a week for three weeks undergoing traditional repetitive task training, using just the Mentor, or both. Patients will undergo brain scans before and after the therapy regimen.

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