A New Era in Prosthetics
A revolutionary brain-controlled bionic leg is changing the landscape for amputees, allowing them to walk faster, navigate stairs and obstacles more easily, and experience a more natural gait. This groundbreaking trial, conducted by a team at the K Lisa Yang Center for Bionics at Massachusetts Institute of Technology (MIT), has demonstrated significant improvements over traditional prosthetics.
The brain-controlled bionic leg enables users to flex, point, and rotate the foot of the prosthetic using their thoughts alone. This innovation leads to a more natural gait, enhanced stability on stairs and uneven terrain, and a remarkable 41% increase in walking speed compared to traditional prosthetics. The bionic leg achieves this by reading activity in the patient's residual leg muscles and using these signals to control an electrically powered ankle.
Natural Movement and Improved Stability
Professor Hugh Herr, co-director of the K Lisa Yang Center for Bionics at MIT and senior author of the study, highlighted the uniqueness of this development:
No one has been able to show this level of brain control that produces a natural gait, where the human’s nervous system is controlling the movement, not a robotic control algorithm. Not only will they be able to walk on a flat surface, but they’ll be able to go hiking or dancing because they’ll have full control over their movement.
Personal Inspiration
Prof. Herr, a double amputee who lost both legs to frostbite during a rock climbing trip in 1982, expressed his hopes of benefiting from similar bionic legs in the future. He said:
I’m thinking of doing that for both of my legs in the coming years.
Clinical Trial Success
Nature Medicine recently published a study of seven patients equipped with the bionic leg were compared with seven patients using traditional prosthetics. Those with the bionic leg reported less pain and muscle atrophy, feeling more integrated with their prosthetic limb. Herr said:
[With] a prosthesis not controlled by the brain, patients view it as a tool, like a carpenter would view their hammer. When the person can directly control and feel the movement of the prosthesis it becomes truly part of the person’s anatomy. That can be quite emotional for the subjects that undergo this procedure.
Advanced Surgical Techniques
The device requires patients to undergo a new form of below-the-knee amputation surgery called agonist-antagonist myoneural interface (AMI). This surgery preserves two pairs of muscle connections, which are typically severed during conventional amputations. By reconnecting the residual muscles, the patient's muscle contractions can be monitored and translated into movements of the electrically powered ankle.
Expert Opinions and Future Prospects
Dr. Sigrid Dupan, an expert in prosthetics at University College Dublin, praised the study for leveraging the body's inherent abilities. She said:
The study shows impressive results for the walking speed, but I think the results related to how people are able to cope with differences in terrain will have a more profound impact on people’s lives. I’m looking forward to seeing how this research develops, and would love to see a broader implementation of this surgical approach.
The MIT team is optimistic about the future of this technology, aiming for a commercial version of the leg to be available within five years. Herr noted:
It’s going to lead to a step-change in clinical care for so many patients around the world. We’re very passionate about getting this technology out to the patients who need it.
MIT
