Robots Give Stroke Patients a Helping Hand
Computer-Assisted Techniques Help Patients to Better Grab, Release Objects
Feb. 20, 2009 (San Diego) -- Stroke patients who were lent a robotic hand
regained some lost strength and motor skills, researchers report.
Steven C. Cramer, MD, director of the Stroke Center at the University of
California, Irvine, and colleagues studied 15 stroke patients with partial
paralysis and weakness in their right hands and arms. Four months to 10 years
after their stroke, patients began a two-week course of robotic therapy.
All 15 could pick up and release objects more easily after treatment. And
the greater their disability at the start of the therapy, the greater their
recovery, according to the findings, presented at the American Stroke
Association’s International Stroke Conference 2009.
Edward J. Mendelsohn, MD, of Manhattan Rehabilitation Services in N.Y., says
that it’s noteworthy that patients experienced gains in motor function even
though they didn’t undergo treatment until months or years after their
“Usually, most return of function occurs within the first three months,”
says Mendelsohn, who wasn’t involved with the study. “But using [robots, video
games, and relaxation exercises], we’re now seeing improvements in range of
motion and in function in patients who had strokes five or six years earlier.
Seeing any improvement at all years after the stroke is significant.”
Sensory Feedback Helps Brain to Recall
In the study, seven patients were given a robotic technique called motor
therapy, in which computers guide patients while they relearn how to pick up
and release objects.
The other eight patients received a more complex robotic approach called
premotor therapy, which requires grasping, releasing, and resting in synch with
timed visual cues.
Cramer offers an example. “In response to one of three color cues, patients
try to open, then close, then rest, their weak hand. After they do the best
they can, the robot completes the movement to the extent the patient couldn’t,”
The reason the computer kicks in at that point, Cramer says, is because
“sensory feedback is a normal part of motor performance. We completed the
movement in these instances so the brain could experience the signals of a
completed correct movement. That helps the brain to recall what to do the next
time," he says.
On tests performed one month after treatment ended, people with less severe
damage to their motor skills showed bigger improvements after the premotor
therapy than the motor therapy. Patients with greater physical
impairments benefited equally from both robotic techniques.
“The status of a patient’s motor system at the beginning of therapy is very
much related to how treatment will affect them,” Cramer says.
Robots May Usher in Rehab Telemedicine
Although still experimental, robotic therapy offers a host of benefits,
“It’s very precise, and you can do the same thing over and over. Most
importantly, it enables telemedicine rehabilitation so we can help more
patients who now miss out on therapy because they live too far away [from a
rehab facility],” he tells WebMD.
Cramer says robotic therapy could “also help rewire, or reshape, the brain
in conjunction with other stroke therapies. One of the key points in the
current study is that the way we use robots to help people recover function
might differ according to how severe their stroke was,” he says.