Robotic Road to Recovery

By Mark Dwortzan

Americans suffer three-quarters of a million strokes every year. For those who survive, recovery can be long and arduous. It doesn’t help that rehabilitation techniques are, for the most part, still remarkably low-tech. Therapists typically exercise patients’ impaired limbs using repetitive hands-on maneuvers and mark improvements on clipboards. Because it’s labor-intensive, the process is also expensive. Indeed, the annual price tag for the U.S. economy of stroke treatment is $30 billion and will likely escalate as Baby Boomers reach the peak stroke ages and drugs improve survival rates.

One solution: robots to boost the effectiveness and productivity of rehab. Systems designed by Neville Hogan and Hermano I. Krebs of MIT simultaneously deliver therapy and measure recovery of limb control. Playing specifically designed video games, the patient maneuvers the robot’s mechanical arm horizontally, moving it like an oversized computer mouse to work the wrists, elbows and forearms at graded levels of resistance. A computer records the robot arm’s position, velocity and the force the patient exerts.

Hogan and Krebs developed their devices at MIT’s Newman Laboratory for Biomechanics and Human Rehabilitation. They have tested them at the Burke Rehabilitation Center in White Plains, N.Y. Those tests, including a recently completed trial involving 60 stroke victims, show that, on average, patients receiving robotic therapy regained control of their shoulders and elbows at twice the rate of those limited to standard therapy. “These results are encouraging,” says Larry Goldstein, head of the Stroke Policy Program at Duke University Medical Center. “There appears to be some improvement of stroke-related impairments that is long lasting.”

Hogan envisions a clinician working a room full of robot-assisted inpatients, or even demonstrating exercises online and monitoring patients at home who are rigged with robot and modem. The MIT scientists are fine-tuning the system and devising new versions to work with legs and move in three dimensions. Says Krebs: “Our work opens up a vast area of research not only for us, but also for other groups to develop new tools to be used in stroke rehabilitation.” <