Scientists in Austria have unveiled an artificial leg which allows amputees to feel lifelike sensations from their foot.
One recipient, Wolfang Rangger, who lost his right leg in 2007, described the new artificial leg, saying, “It feels like I have a foot again. It’s like a second lease of life.”
Professor Hubert Egger of the University of Linz, said sensors fitted to the sole of the artificial foot, stimulated nerves at the base of the stump. He added it was the first time that a leg amputee had been fitted with a sensory-enhanced prosthesis, BBC reported.
Surgeons first rewired nerve endings in the patient’s stump to place them near the skin’s surface. Six sensors were fitted to the base of the foot, in order to measure the pressure of heel, toe and foot movement.
These signals were relayed to a micro-controller which relayed them to simulators inside the shaft where it touched the base of the stump, BBC reported. Through vibrations, nerve endings were stimulated under the skin, which relayed signals to the brain.
Professor 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.”
Wolfgang Rangger, a former teacher, lost his leg after a blood clot caused by a stroke. Rangger has been testing the device for six months, both in the lab and at home. He said, “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.”
The 54-year-old also cycles, goes climbing, and runs.
Another major benefit noted was a reduction in excruciating “phantom limb” pain felt by Rangger for years after the amputation. Egger said the brain now received real data rather than searching for information from the missing limb.