World’s first ‘feeling’ leg prosthesis offers amputees new hope

VIENNA: The world’s first artificial leg capable of simulating the feelings of a real limb and fighting phantom pain has been unveiled by researchers in Vienna.
The innovation is the result of a two-fold process, developed by Prof. Hubert Egger at the University of Linz in northern Austria.
Surgeons first rewired remaining foot nerve endings from a patient’s stump to healthy tissue in the thigh, placing them close to the skin surface.
Six sensors were then fitted to the foot sole of a lightweight prosthesis, and linked to so-called stimulators inside the shaft where the stump sits. “It’s like a second lease of life, like being reborn,” Austrian amputee Wolfgang Rangger, told AFP ahead of Monday’s media launch.
The former teacher, who lost his right leg in 2007 after suffering a blood clot caused by a cerebral stroke, has spent the last six months testing the new prosthesis.
“It feels like I have a foot again. I no longer slip on ice and I can tell whether I walk on gravel, concrete, grass or sand. I can even feel small stones,” he said.
The 54-year-old also runs, cycles and goes climbing. When he moves, the limp is barely noticeable. Every time Rangger takes a step or applies pressure, the small sensor devices send signals to the brain.
“In a healthy foot, skin receptors carry out this function but they are obviously missing here. However, the information conductors — the nerves — are still present, they’re just not being stimulated,” Egger said.
“The sensors tell the brain there is a foot and the wearer has the impression that it rolls off the ground when he walks. All things considered, the procedure is a very simple one given the results.”
This is not the first time the Austrian scientist has caused a stir with his research.
In 2010, he presented a mind-controlled prosthetic arm, which the user directed with motor neurons previously connected to the lost limb.
For the artificial leg, the principle remains the same except that the process works in reverse: information is guided from the prosthesis to the brain, rather than the other way around.