Wolfang Rangger, who received the artificial leg, said: “It feels like I have a foot again. It’s like a second lease of life.” Rangger lost his right leg in 2007.
Professor Hubert Egger developed the innovation in a two-fold process. The first step was to attch remaining foot nerve endings from a patient’s limb stump to healthy tissue in the thigh close to the skin surface.
In the second step, he fitted six sensors to the foot sole of a lightweight prosthesis, linking to artificial stimulators inside the shaft where the stump sits. The sensors send signals to a micro-controller, which relays them to the the stimulators.
“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 in an AFP interview.
“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.”
Becuase of the neural interface, a patient can now have feeling on the sole of the prosthetic foot. As a result they are much better able to recognize the terrain he/she is walking on.
A heightened awareness of obstacles, which greatly reduces the risk of falling, is another of the device’s benefits. The re-established transfer of information also contributes to a more natural integration of the prosthesis into the body concept of the patient and, in Wolfang Rangger’s case, has led to the complete disappearance of previous long lasting pains.
Photo: Screenshot of AFP video, courtest APF
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