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Rehab's robotic revolution

Researchers envision a day when robots will become therapeutic equipment. Stroke victims could especially benefit.

January 30, 2006|Chris Woolston | Special to The Times

NINE years after suffering a major stroke, Chicago resident Bill Journey finally put away his cane.

That cane was supposed to be a fixture in his life. Stroke patients generally have a three-month window for rapid recovery of limb function. After six months, progress tends to be slow or nonexistent.

Journey, 67, a retired electrician, found new strength and balance by working with a 500-pound, four-wheeled robot named KineAssist. A few times each week, he would take tentative steps while the robot supported and guided his body. Three weeks later, he was surprised to discover that he could walk on his own -- with neither robot nor cane.

KineAssist is just one of a legion of smart machines poised to bring physical therapy, a field that relies heavily on rubber bands, exercise mats and dumbbells, into the high-tech age. Researchers envision a day when robots will become standard equipment in rehabilitation centers, giving stroke patients -- and possibly patients with spinal cord injuries -- a chance to take their recovery further than previously possible.

The KineAssist, developed at the Rehabilitation Institute of Chicago, is essentially a hip brace and harness that connects to a rolling bank of wires and motors. The whole thing could fit in the back of a minivan with the seats down.

When a patient steps forward, backward or to the side, the robot follows, using sensors in the brace to detect the patient's speed and position. If the patient leans too far or loses balance, the brace catches him.

"Think about how you learned to walk," says James Patton, co-director of the rehabilitation institute's robotics lab. "You have to fall many times before you learn." Human therapists, he adds, aren't always able to prevent or break such falls, despite their dedication: "They just don't have enough hands to do the therapy," he says. Sessions must thus be less aggressive and will usually end should a patient fall even once.

The machine, in contrast, "lets him 'fall' over and over again without worry," Patton says.

Journey admits he was skeptical about the KineAssist at first: "I didn't think it could hold me," he says. But after working with it off and on for two years, he now thinks robots have certain advantages. "I know that machine ain't going to drop me, but a person might," he says.

Using Journey and other patients as consultants, Patton has tweaked the robot to make it more comfortable and responsive. Patients will begin using the improved KineAssist on Wednesday. The machine already has Food and Drug Administration approval as an exercise device, and formal clinical studies are in the planning stage.

Stroke-damaged arms are the target of another kind of robot: the MIT-Manus, which was designed by engineers at the Massachusetts Institute of Technology, the pioneers of robot therapy.

As part of their rehabilitation, patients play video games while wearing the MIT-Manus. The robot uses sensors to track the arm's motion. If a patient can't make a certain movement, the robot will guide his arm or rotate his wrist. The first versions were a bit herky-jerky, but the current robot is nearly as gentle as a guiding hand, says Dr. Bruce Volpe of the Burke Rehabilitation Hospital in White Plains, N.Y., a site where the robot is being tested.

With the robot in place, a patient can repeat a motion more than 1,500 times in 45 minutes. The sheer repetition seems to sear the routine into the brain, which gradually learns to compensate for stroke damage.

So far, more than 700 patients at various sites have used the MIT-Manus. Studies have found the therapy can improve arm function by 25% to 30% -- about double the improvement of standard physical therapy. In many cases, a 25% improvement in arm function could make it possible for patients to bathe or dress themselves for the first time in years, Volpe says.

The first large-scale, randomized clinical trial of MIT-Manus will start this spring, comparing the robot with intense physical therapy. This should go a long way toward answering important questions, says Pamela Duncan, a professor of physical therapy at the University of Florida. Robots hold "tremendous potential" for stroke rehabilitation, she says, but it's not yet clear which patients are most likely to benefit, or how improvements in laboratories translate to everyday tasks.

Questions aside, the robots continue marching forward. MIT has recently developed an "ankle-bot" designed to give strength and flexibility to stroke-damaged ankles. The ultimate goal, researchers say, is to create a team of robots to cover all of the major joints -- a shoulder-bot, a hip-bot and more.

"I see it as nothing but an inevitability that robots will be playing a major role in physical therapy," Patton says. "They just have so much to offer."



Benefits out of step with care

At a time when researchers are developing high-tech therapeutic robots to aid stroke patients, many patients are losing access to basic care.

On Jan. 1, Medicare put a $1,740 annual cap on outpatient physical or language therapy. Therapy for a victim of a severe stroke can easily cost more than $10,000.

Pamela Duncan, a professor of physical therapy at the University of Florida, says the limits could hamper recovery for many patients.

Stroke is already the No. 1 cause of serious disabilities in the United States. According to the American Heart Assn., about 700,000 Americans have a stroke each year, and 15% to 30% of survivors will have trouble getting back to the basic tasks of living.

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