Igor Spetic, who lost his right hand to an industrial accident four years ago, can now feels his arm hairs rise when someone brushes the back of his prosthetic hand with a cotton ball.
Patterns of electric signals are sent by a computer into nerves in his arm and to his brain.
“I knew immediately it was cotton,” he said.
That’s one of several types of sensation Spetic, of Madison, Ohio, can feel with the prosthetic system being developed by Case Western Reserve University and the Louis Stokes Cleveland Veterans Affairs Medical Centre.
Spetic was excited just to “feel” again, and quickly received an unexpected benefit.
The phantom pain he’d suffered, which he’s described as a vice crushing his closed fist, subsided.
A second patient, who had less phantom pain after losing his right hand and much of his forearm in an accident, said his is nearly gone.
Despite having phantom pain, both men said that the first time they were connected to the system and received the electrical stimulation, was the first time they’d felt their hands since their accidents.
Watch the hand in action:
The system, which is so far limited to the lab, uses electrical stimulation to give the sense of feeling.
The nerves that used to relay the sense of touch to the brain are stimulated by contact points on cuffs around major nerve bundles in the arm.
Surgeons implanted three electrode cuffs in Spetic’s forearm, enabling him to feel 19 distinct points.
A blindfolded Vonderhuevel has held grapes or cherries in his prosthetic hand, the signals to his brain enabling him to gauge how tightly he’s squeezing, and pulled out the stems.
“When the sensation’s on, it’s not too hard,” he said. “When it’s off, you make a lot of grape juice.”
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