Sudden paralysis on one side of the body can afflict anyone. This reality is increasing demand for a particular kind of robot.
While Toyota’s rehabilitation assistance robot has given rise to some inspiring stories, the list of improvement requests from doctors and therapists currently runs to more than 100…
Reducing the burden on therapists
Even as the rehabilitation assistance robot has become a regular feature on the front lines of medical care, opinions differ between Japan and other countries.
Dr. Satoshi Hirano, Nanakuri Memorial Hospital
Whereas many models designed overseas forcibly make users walk, Professor Eiichi Saito, who has led the development of this robot, advocates for rehabilitation based on motor learning theory.
Simply put, this approach regards the whole body as a single system, harnessing the good parts to try and forge new motions that differ from those before the illness.
In other words, this “human-centered” robot seeks to tailor the recovery to each individual’s situation.
Dr. Ken Tomida, Physical Therapist, Nanakuri Memorial Hospital
Using the robot not only reduces the physical burden on therapists but also allows them to objectively analyze various aspects of the patient’s stride.
By adjusting different parameters, it is also simple to tailor exercise settings for individual patients.
I tell my colleagues that we are “exercise designers,” and we are creating more effective methods of rehabilitation.
After undergoing repeated improvements, the latest model of the rehabilitation assistance robot was completed in December 2024. We asked developers at Toyota which aspects had evolved.
Norihiko Kawata, Group Manager, Healthcare Business Department, New Business Planning Division
A key point is that the robot attached to the leg has been made lighter. That part of the robot previously housed sensors, but these have been moved to the floor. This not only reduces the weight but also allows us to check the load on both legs, including the side not fitted with anything.
This has opened up possibilities for the robot to be used not just by patients with paralysis, but in walking exercises for all kinds of people.
Takuma Nakamura, Group Manager, Healthcare Business Department, New Business Planning Division
On the software side, based on hospital requests, we had a mission of improving the function that detects walking abnormalities. We asked the doctors for their detailed opinions on what should be detected as abnormal.
As a result, we have revamped the detection logic to cover 13 types of walking abnormalities, and increased the granularity of severity assessments, from three levels to five. It feels more like a newly built system than a version update.
Other improvements include easier size adjustment when attaching the robot and a smaller frame that allows for more natural strides.
“Toyota always has about 100 improvement requests from us,” says Dr. Hirano. “Actually, it’s more like 500,” corrects a smiling Toyota developer. Their exchange highlighted the fact that the improvement process is never-ending.
The next step
After regaining a degree of walking ability, patients may sometimes find their knee buckling dangerously under them during exercises.
KNEAR is worn on the knee of the paralyzed leg. While bearing weight, that knee is prevented from buckling by a hydraulic lock, which is then released by sensor controls as the knee bends, allowing it to do so without resistance.
“I was afraid to put weight on my leg when walking, but this has given me confidence,” commented one trial participant.
Akira Nishida, Healthcare Business Department, New Business Planning Division
We can support the walker by controlling aspects like knee angle and tilt with respect to the ground. Collecting data also allows for analysis and feedback.
Unlike with larger machines, we can reach more people at low cost, offering great potential for use at smaller hospitals. We are continuing development with our sights set on a commercial release.
Toyota’s work on the rehabilitation assistance robot is driven by a desire to “get everyone where they want to go.”
As long as there are people in need, these efforts will continue, with Toyota striving for further evolution.
