Every step which Wolfgang Rangger takes with his artificial leg is sending information to his brain. There is a hardly a hint of a limp in the Austrian’s walk and having the leg fitted has not prevented him pursuing many of his hobbies.
That’s because the artificial limb is fitted with small sensors on the foot which are in constant contact with the wearers brain transmitting sensitive information. It is the first such prosthesis in the world. The 54-year-old has spent the last six months testing his new leg.
“With the leg I can feel now if it is a graveled road or if it is paved. Or in winter, and that’s important, if the road is icy or slippery. I can react to it and so don’t slip or fall down,” said Wolfgang Rangger.
Remarkably it has helped eradicate the excruciating pain which he had experienced since his leg was amputated.
The innovation is the result of a two-fold process, developed by Professor Huber Egger at the University of Linz in Austria.
Surgeons first rewired remaining foot nerve endings from the patient’s stump to healthy tissue in the thigh, placing them close to the skin surface.
Six sensors were then fitted to the sole of the foot on the lightweight prosthesis and linked to so-called stimulators inside the shaft where the stump sits.
“With this sensitive artificial leg, there are pressure points built in on the sole of the prostheses and these points measure the contact to the surface and also the rolling movement of the artificial foot. And this information is transmitted technically to the nerve cells and then to the brain, where it generates a sensation,” explained Professor Hubert Egger.
The new technology, believes Professor Egger could improve life for amputees in third world countries. But a high-tech foot model costs between 10,000 euros and 30,000 euros. Reducing the cost is the next challenge which could happen if small companies start production of the prosthesis.