Brain-Controlled Bionic Leg Revolutionizes Mobility for Amputees: How Does This New Tech Work?

A groundbreaking new study finds that a bionic leg controlled by the brain has helped amputees walk faster and get around obstacles more easily.

This new prosthetic gives users a more natural gait and better stability, a step forward in movement technology.

Brain-Controlled Bionic Leg Revolutionizes Mobility for Amputees — (Photo: Pexels/ Lara Jameson)

Unveiling the Brain-Controlled Bionic Leg Technology: How Does it Work?

The robotic leg reads the patient's remaining leg muscles and controls an electrically powered ankle. This lets the person wearing it bend, point, and twist their foot just by thinking about it. Because of this, people who use them walk more naturally, are more stable on stairs and uneven ground and can walk 41% faster than when they used standard prosthetics.

Prof. Hugh Herr, co-director of the K Lisa Yang Center for Bionics at MIT and lead author of the study, said that no one has yet shown the level of brain control needed to achieve a natural gait in which movement is controlled by the nervous system instead of a robotic control program. Herr had lost both legs because they got badly frostbitten when he got caught in a blizzard while rock climbing in 1982. Even though he lost both legs decades ago, he hoped to get similar bionic legs.

The agonist-antagonist myoneural interface (AMI) is a new surgical method that is needed for the device. This surgery keeps two sets of muscle links important for moving the foot.

These connections are cut during normal amputations, but AMI surgery reconnects the remaining muscles. This lets the contractions of the muscles be tracked and turned into movements of the electrically powered ankle.

The study, published in Nature Medicine, compared seven people with bionic legs to seven with regular limbs. People who had surgery on a bionic leg said they had less pain and muscle loss. They also thought their artificial limbs fit better with their bodies.

Herr explained that prostheses become a part of a person's body when they can directly control and feel how they move them. He said this can be a very emotional event for the people going through it.

Real-World Applications and Future Prospects

As a para-athlete who had the surgery in 2018, Amy Pietrafitta talked about how happy she was with the technology. She feels like she has her leg back and that it has many useful uses. However, natural movements are still restricted when the prosthetic isn't connected to the nervous system.

Surface sensors pick up nerve activity from the brain to the calf and shin muscles. This activity shows that the person wants to move their lower leg. A small computer in the bionic leg reads these messages and moves the leg in response, making the limb's movement more natural.

Herr said that for people whose biological limbs are still working, things like going up and down stairs are automatic and can't be stopped. He said the same is true for their patients, even though their arms are made of titanium and silicone.

Patients who used the neural interface could walk 41% faster and more quickly on stairs and sloped surfaces. They also said the prosthetic didn't feel like a tool but like a normal part of their body.

The MIT team wants to introduce the bionic leg on the market within five years. They want it to change the way people worldwide are treated in hospitals.

Herr said that he thought the technology would make a big difference in the clinical care of many people worldwide. He stressed their dedication to making this technology available to everyone who needs it.

Dr. Sigrid Dupan, a prosthetics expert at University College Dublin, praised the study and said that the results about how people handle different types of terrain will improve their lives. She said the surgery can be done during the first amputation or as a follow-up. With progress made in neural interfaces, the future of prosthetics looks bright, with bionic arms that are easier to control and better integrated into the body.