Amputee feels with bionic hand in real-time
Published Wednesday, February 5, 2014 2:24PM EST
Last Updated Thursday, February 6, 2014 5:33PM EST
After losing his hand while handling fireworks nearly a decade ago, a Danish man has become the first amputee to feel -- in real time -- through a prosthetic hand.
Dennis Aabo Sorensen volunteered to test the sensory-enhanced bionic hand in a four-week clinical trial last year.
“For the first time we were able to restore a real-time sensory feeling in an amputee while he was controlling this sensorized hand,” said Silvestro Micera, professor at the Ecole Polytechnique Federale de Lausanne and member of the team that developed the prosthetic hand, in an EPFL video.
Scientists equipped the artificial hand with sensors that detect touch, and surgically implanted “transneural” electrodes into Sorensen’s upper arm nerves. Sorensen was able to regain a sense of touch through a digitally refined signal that was sent to the electrodes in his arm.
“It was quite amazing because suddenly I could feel something that I haven’t been feeling for nine years,” Sorensen said in the video. “The feedback was totally new to me and suddenly when I was doing some movements, I could feel actually what I was doing instead of looking (at) what I was doing.”
Sorensen was able to detect the shape and consistency of different objects while wearing a blindfold and earplugs. He was also able to detect how strongly he was grasping the objects. “When I held an object, I could feel if it was soft or hard, round or square,” he said.
The results of the clinical trial were published in the journal Science Translational Medicine on Wednesday.
While scientists were at first concerned about the reduced sensitivity in Sorensen’s nerves since they hadn’t been used in more than nine years, they were relieved when they were able to reactivate his sense of touch.
“I would love to have the new prosthetic because it’s so amazing to feel something that you haven’t been able to feel for so many years,” he said.
Since losing his hand, Sorensen has been wearing a commercial prosthetic that detects muscle movement, which allows him to open and close his hand. But without sensory information being fed into his nervous system, Sorensen constantly has to make sure he doesn’t crush objects with his prosthetic.
But he’ll have to wait a few more years before the hand becomes commercially available.
The next step involves “miniaturizing the sensory feedback electronics for a portable prosthetic” and fine-tuning the sensory technology, EPFL said in a statement.