MIT professor Neville Hogan and his colleagues in the Newman Laboratory for Biomechanics and Human Rehabilitation have measured the stiffness of the ankle in various directions using a robot called the “Anklebot.” This measured data could aid in rehabilitation from strokes, other motor disorders.
Hogan and his Team developed the Anklebot as an experimental and rehabilitation tool.
Photos: Hyunglae Lee / MIT
The robot is mounted to a knee brace and connected to a custom-designed shoe. As a person moves his ankle, the robot moves the foot along a programmed trajectory, in different directions within the ankle’s normal range of motion. Electrodes record the angular displacement and torque in specific muscles, which researchers use to calculate the ankle’s stiffness.
The team has tested the Anklebot on stroke patients who experience difficulty walking. In daily physical therapy sessions, patients are seated in a chair and outfitted with the robot. Typically during the first few sessions, the robot does most of the work, moving the patient’s ankle back and forth and side to side, loosening up the muscles, “kind of like a massage,” Hogan says. The robot senses when patients start to move their ankles on their own, and adapts by offering less assistance.
“The key thing is, the machine gets out of the way as much as it needs to so you do not impose motion,” Hogan says. “We don’t push the limb around. You the patient have to do something.”
Many other robotic therapies are designed to do most of the work for the patient in an attempt to train the muscles to walk. But Hogan says such designs are often not successful, as they impose motion, leaving little room for patients to move on their own.
“Basically you can fall asleep in these machines, and in fact some patients do,” Hogan says. “What we’re trying to do with machines in therapy is equivalent to helping the patients, and weaning them off the dependence on the machine. It’s a little bit like coaching.”
According this old MIT article, it seems MIT had created initial version of Anklebot in the year 2005 itself.
