Robotic therapy for stroke patients appears to significantly improve patients' short- and long-term recovery of arm movement, MIT researchers and colleagues report in the November 10 issue of Neurology.
Three years ago the researchers ran the first clinical trial of the new therapy, which uses a robot to move a person's arm through a variety of exercises. Initial results were promising: patients who used the machine improved further and faster than a second group of patients that did not receive robot-assisted therapy.
The Neurology paper reports significant improvements over the long term as well. The researchers recently reevaluated 12 of the 20 original patients and found that those in the robot group again showed greater improvement than those with no robotic therapy.
Professor Neville Hogan, who holds joint appointments in mechanical engineering and brain and cognitive sciences, notes that the robot offers a variety of advantages over traditional therapy. For example, it can quantify forces and movements that until now have been judged by "touch and feel." Such data would provide a permanent, objective record of a patient's progress that could be used in many ways.
He emphasized, however, that "we don't want to replace [human] therapists, and I don't think we ever could. Rather, we'd like to provide a tool to increase their productivity." He also noted that the robot is an evolving technology. "Realizing its full potential will require an ongoing dialog between the technology creators and interested users, the clinicians and patients."
Professor Hogan led the work on the development of the robot. The clinical trial was led by Dr. Hermano Igo Krebs, an MIT research scientist in mechanical engineering, and Dr. Bruce Volpe of the Burke Medical Research Institute in White Plains, NY, and Cornell University Medical College.
In the robot-aided therapy, a person sitting at a table puts the lower arm and wrist into a brace attached to the arm of the robot, dubbed MIT-Manus for the link between its therapeutic focus and MIT's motto "mens et manus," or mind and hand. A video screen prompts the person to perform an arm exercise such as connecting the dots or drawing the hands of a clock. If movement does not occur, MIT-Manus moves the person's arm. If the person starts to move on his own, the robot provides adjustable levels of guidance and assistance to facilitate the person's arm movement.
The clinical trial lasted slightly over a year. In it, two groups of 10 stroke patients received standard therapy. People in the experimental group received an additional hour per day of robot-aided therapy. The others received "sham" robot therapy once a week; they were exposed to the robot but it didn't guide them through exercises. (They moved the robot manually, using their good arm to guide the disabled arm to perform exercises.)
Although it's not clear whether it was the robot or the additional exercises that led to the improvements in movements, "these results show the feasibility of the robotic technique," Professor Hogan said.
The researchers continue to study MIT-Manus and its application to stroke therapy. In March 1999 they concluded a larger clinical trialat Burke with 60 patients. This month they installed a second-generation robot at the Spaulding Rehabilitation Hospital in Boston, where they initiated a third clinical trial.
In related work, they are studying robotic therapy for patients with other neurological disorders such as Parkinson's disease, and are building new machines to work with limb segments including fingers, wrists and ankles. Finally, they are working on home-based robot therapy supervised by a clinician via the internet.
Additional authors of the Neurology paper are Lisa Edelstein and Christa Diels of Burke, and Dr. Mindy L. Aisen (SB 1976) of the Department of Veterans Administration. The work was sponsored by the Burke Medical Research Foundation, the National Parkinson'sFoundation and the National Science Foundation.
A version of this article appeared in MIT Tech Talk on November 24, 1999.