A Robotic Elbow for Stroke Survivors

Continued from page 1

Physical therapists can adjust the robotic brace to provide just enough assistance to patients, so they use their own muscles as much as possible, preventing atrophy. The active involvement of the patient has another advantage: it may help promote nerve-cell growth, reestablishing connections damaged in a stroke, and helping patients move more on their own.

In a pilot trial of the device, six stroke survivors who had shown no improvement in their ability to move for at least six months improved by an average 30 percent on one physical therapy scale of arm function. For example, often with stroke, muscles involuntary tighten, causing a patient's arm to curl up and be difficult to extend. All of the patients were able to extend their arm to a greater degree after training with the robot. "It was beyond our dreams of what we might be able to accomplish," Sahney says. Future studies will feature more patients and rigorous controls.

Other robotic devices for helping stroke patients are being developed and tested, including a walking assistant by Chicago PT of Evanston, IL, and a range of rehabilitative robots for exercising arms, wrists, and legs by Interactive Motion Technologies of Cambridge, MA.