For a full decade, Gudmundur Olafsson was unable to move his right ankle. That's because it wasn't there. Olafsson's amputated lower leg was the delayed casualty of an accident from his childhood in Iceland, when he was hit by an oil truck. “I lived in pain for 28 years,” says Olafsson. “After 50-plus operations, I had it off.” For years after the operation he wore a Proprio Foot, a prosthetic with a motorized, battery-powered ankle, sold by the Reykjavik-based company Ossur. The Proprio is essentially a wearable robot, with algorithms and sensors that automatically adjust the angle of the foot during different points in its wearer's stride. Olafsson's ankle moved on autopilot.
But 14 months ago Ossur upgraded his hardware. Now, at age 48, Olafsson can move his right ankle by thinking about it. When the electrical impulse from his brain reaches the base of his leg, a pair of sensors embedded in his muscle tissue connect the neural dots, and wirelessly transmit that signal to the Proprio Foot. Since the command reaches the foot before the wearer's residual muscles actually contract, there's no unnatural lag between intention and action. That makes Olafsson part of a highly exclusive club. Along with David Ingvasson, a fellow Ossur tester, he's one of the only people on the planet who owns a brain-controlled bionic limb. Ossur unveiled its implanted myoelectric sensor (IMES) technology today at an event in Copenhagen, and is now preparing large-scale clinical trials, in the hopes of reaching the market in three to five years.
“The first time, to be honest, I started to cry."
This is a bigger breakthrough in the field of robotics and advanced prosthetics than it might appear. Brain-controlled bionic limbs make headlines on a regular basis, with the implication that the science has been solved, and experimental systems are already transitioning to products. But most of those devices are confined to laboratories, and many require complex surgery, such as transplanting muscle tissue or implanting electrodes in a subject's brain. These devices look like the real thing in brief, sometimes compelling video clips. But so far, prosthetics that respond to thoughts are not so much a reality as a promise.