Brain-Controlled Prosthetic Limbs - Mayo Centre for Innovation - Healthcare Design

Prosthetic Limbs Controlled by Patient’s Brain

Post Written By Megan Zimmerman

I recently came across an article from the New York Times entitled: “Prosthetic Limbs, Controlled by Thought.” Intrigued by the title, I read the article and became exposed to a whole new generation of biotechnology and prosthetic limbs. The article told the story of Les Baugh. Thirty years ago, Mr. Baugh lost both of his arms after he was severely injured in an accident as a teenager. Ever since then, he has learned to adapt to life without his arms. The video displayed alongside the article showed Mr. Baugh cooking in his kitchen, driving his pickup truck, starting a fire in his fireplace, and feeding his dog. It was really interesting to see his dry humor and how resourcefully he adapted to his situation.

Engineers at the Allied Physics Lab at John Hopkins University developed a robotic arm that has 26 joints and is controlled by a person’s brain. To make the prosthetic communicate with his brain, Les Baugh had surgery to remap the remaining nerves in his shoulders. This ensures that when the brain sends a signal down to the shoulder, it is received by the socket of the prosthetic limb, and the limb then responds by performing the movement that Mr. Baugh thought about. Each arm has over a hundred sensors that receive sensory input from the environment. This means that Mr Baugh might soon be able to feel texture through the limb as the remapped nerves in his shoulder develop. This prosthesis is called Modulatory Prosthetic Limb (M.P.L.). The term modulatory is important because it means that it can be built to fit people with different needs (just a hand, or an entire arm).

On the same day that the New York Times released the article on Les Baugh, Popular Science published an article entitled “Brain-Controlled Bionic Legs are Finally Here.” This article tells the story of Gudmundur Olafsson. Mr. Olafsson was in an accident as a child that left him in extreme pain. After over fifty surgeries that failed to relieve his pain, he had his foot amputated. Initially, Mr. Olafsson was fit with a motorized and battery-powered prosthetic foot sold by a company called Ossur. This Proprio foot has special sensors and technology that adjusted the angle of the foot while he walked, which allowed Mr. Olafsson to have better mobility and significantly less pain than he experienced with his foot. A little over a year before this article was published, Mr. Olafsson was fit for a new prosthesis that is controlled by his brain. This prosthesis is very similar to the prosthetic arms Les Braugh worked with. The electrical signals sent from Mr. Olafsson’s brain reach a pair of sensors embedded in his muscle tissue and this sends a signal to the Proprio Foot. This foot is better than this first model because it is not battery-dependent (meaning it does not need to be charged) and because it communicates with the nerves in his leg. Mr. Olafsson’s gate is normal because the signals that are sent from his brain reach his prosthesis and his other foot at the same time.

The technological advances behind the M.P.L. and the Proprio Foot are incredibly beneficial to patients all over the world. Unfortunately, these prosthetic limbs are far from being available to patients like Les Baugh. Each M.P.L. costs at least $500.000.00 and they have not been approved by the FDA. The Popular Science article does not specify the cost of the Proprio limb, but I would think it safe to assume that the cost is high as well. So, now the question is, what can we do to make these cutting-edge prosthetic limbs available for all patients regardless of socioeconomic status or access to resources and insurance.

For more information about the M.P.L. or Proprio Foot, I have included links to the articles I read:

http://www.popsci.com/brain-controlled-bionic-legs-are-here-no-really

http://www.nytimes.com/2015/05/21/technology/a-bionic-approach-to-prosthetics-controlled-by-thought.html

{Photo Credit :: Popsci.com}