In the October issue of Science Translational Medicine, researchers report that two men who lost hands in industrial accidents were able to feel long-term realistic tactile sensations over a two-year period. Similar methods have created tingling sensations for patients but the results only lasted a few weeks.
Amputees discern familiar sensations across prosthetic hand
Using electrodes implanted around nerves in the residual part of each man's arm, scientists at Case Western Reserve University produced the perception of touch across the entire hand. Patients could tell the difference between smooth and ridged textures, and could pull a cherry from its stem between 77% and 100% of the time.
Prosthetic hand recreates feeling of cotton bud touch - health - 08 October 2014 - New Scientist
Dennis Aabo Sorensen, of Denmark, was the first patient to try a hand that also used electrodes implanted into the nerves in his upper arm. During a four-week clinical trial in 2013, the hand let him distinguish the consistency and shape of objects, as well as how hard he was grasping them.
"This is the first time in neuroprosthetics that sensory feedback has been restored and used by an amputee in real-time to control an artificial limb."
Silvestro Micera, Director of the Translational Neural Engineering Laboratory and the Institute of Bioengineering
Several European hospitals and universities worked together to produce Sorensen's prosthetic hand. The research was published Feb. 2014 in the journal Science Translational Medicine.
"The sensory feedback was incredible. I could feel things that I hadn't been able to feel in over nine years."
Dennis Aabo Sorensen
During the trial, Sorenson wore a blindfold and earplugs and was tested on his ability to describe objects he handled. Scientists say it will take many more years until a "sensory-enhanced prosthetic" hand for commercial use will be available, but that research is going in the right direction.
The Food and Drug Administration on May 9 approved a prosthetic hand made by private New Hampshire company DEKA, which was founded by Segway creator Dean Kamen. The robotic prosthetic weighs and looks like an adult human hand, and is controlled by the user's thoughts.
Innovative Prosthetic Arm From Segway Inventor Cleared by U.S.