Dane Dennis Aabo Sorensen lost his left hand and lower arm during a fireworks accident nine years ago. Now a new type of prosthesis has made it possible for him to feel sensation in his hand for the first time since then.
“When I hold an object, I can feel if it’s hard or soft, round or angular,” he said after tests at the Lausanne branch of the Swiss Federal Institute of Technology.
Experts from several European universities and clinics were involved in the development of the prosthesis, and the results have been published in Science Translational Medicine magazine.
To prompt sensation, researchers surgically implanted four electrodes in Sorensen’s upper arm. Focal points were the median nerve, which transmits feelings from the thumb and index finger to the brain, and the ulnar nerve that manages signals in the pinky finger. Specially developed software translated the pressure sensors’ electric signals into impulses on the nerve endings.
Initially, researchers were unsure whether the hand would work. “We were afraid that the sensitivity of the patient’s nerves would have decreased since he hadn’t used them in nine years,” said Stanisa Raspopovic of the Scuola Superiore Sant’Anna in Pisa, Italy. The patient won’t be able to keep the prosthetic for the time being, as the scientists wish to test it on other patients first.