Robots help stroke victims
01:00 AM EDT on Saturday, April 17, 2010
PROVIDENCE — Using custom-designed robots strapped to the weakened arms of stroke patients, a team led by a Brown University researcher has demonstrated that intensive physical therapy can improve movement in people whose strokes occurred many years earlier.
The evidence is in a study, released Friday by the New England Journal of Medicine, in which Dr. Albert Lo and his colleagues randomly assigned 49 volunteers to robot-assisted therapy.
The computer-controlled robots, first developed at the Massachusetts Institute of Technology two decades ago, allow a patient to sit at a table with his arm strapped to a mechanical arm. As the patient tries to use the arm to play a rudimentary video game, the robotic arm guides the patient, when necessary.
“We looked at very severe, very chronic people who had been living with the aftereffects of a stroke for a very long time,” said Lo. “We now know if you provide this therapy, they can get better.”
But it wasn’t just the robot that made the difference.
A group of 50 stroke survivors showed similar improvement, compared with those who only received limited physical therapy, when human therapists helped move the arms to the same degree the robot did.
In all cases, the three-times-a-week therapy sessions extended over three months.
“We thought the robots would do a lot better,” said Lo. “So the good news is, if you can get a person to help you do that kind of movement, you can get fairly comparable results.”
The problem is, few therapists have the patience to do what the robot routinely did — make 1,024 repetitive movements per session.
During a traditional therapy session, the arm is moved only 45 times.
As a result, Lo said, using the custom-built robot should have its advantages, despite its current $180,000 price tag.
The discovery, if embraced by the medical community, would offer new hope to at least some of the 6.4 million stroke survivors still living with movement problems.
The conventional medical wisdom has been that, after about six months of treatment, most patients have regained as much muscle control as possible.
“When I was in medical school, if you saw someone a year after their stroke and they asked you how much movement they could get back, you would not be very optimistic about it,” Lo said. “Now, we’re not talking about curing the disease or transforming everything in their life, but we are talking about meaningful change.”
Some of the volunteers who showed improvement had suffered from multiple strokes. Some had experienced their stroke nearly two decades earlier, although the researchers are still analyzing whether the degree of improvement depended on how recent the stroke was.
The study was funded by the U.S. Department of Veterans Affairs and conducted at four VA medical centers. When Lo moved from the VA center in West Haven, Conn., to the center in Providence, he brought that robot with him.
Lo said even if the robots were widely used, it would not put physical therapists out of business.
In previous studies, patients preferred working with humans instead of a robot. In this study, a therapist was always there to encourage stroke victims as they worked with the robot.
“Human engagement is very important,” said Lo. “The therapist does the coaching and the robot does its job, which is the high-repetition movement part.”