Scientists have developed a prosthetic leg controlled by the human brain which could make it easier for amputees to get up and down stairs. The ground-breaking new device allows patients to directly control their prosthetic using their thoughts. The device records signals from surgically preserved muscles which are carefully monitored and converted into controls for a robotic ankle. In a trial of 14 amputees, researchers from MIT found that the leg created a more natural gate, improved stability on uneven terrain, and a 41% increase in speed. Researchers now hope that a commercial version of the leg will be available within as little as 5 years. In traditional below-the-knee applications the muscles that normally control the foot are wrapped around the severed limb to create a soft padding. However, this process severs the normal connection between “antagonistic” pairs of pushing and pulling muscles in the leg. The new device requires patients to undergo a new form of below-the-knee amputation surgery, called agonist-antagonist myoneural interface (AMI). The ends of the muscles are connected together so that they can still communicate with each other within the residual limb.
