Scientists have demonstrated an amazing proof-of-concept, using a technique called intracortical micro stimulation (ICMS) that allows amputees to feel sensory-rich information in real time. The technology is a remarkable breakthrough, and represents a huge stop toward creating devices that give amputees a sense of touch; the introduction of more life-like assistive devices has the potential to greatly increase the quality of life for users.
The ICMS method was first proven by researchers from the University of Chicago, who were able to project sensations associated with brain patterns to specific areas of a body. A variation of that technique has been implemented with an artificial limb, tested by 36-year-old Dennis Aabo Sorensen, allowing him to sense sensations such as how strongly he was grasping an object, as well as the shape and consistency of what he picked up.
"I could feel round things, and hard things, and soft things—and the feedback was totally new to me," Sorensen said. "Suddenly, when I was doing the movements, I could actually feel what I was doing instead of looking at what I was doing." Sorensen, by the way, was blindfolded during clinical tests, relying on the technology only during the trials.
Researchers were able to equip the artificial hand with sensors, giving the wearer the ability to detect information about touch. Measurements would then be turned into electrical currents, interpreted into scripted algorithms by the researchers, and in turn allowing Sorensen to feel the level of force when grasping an object. Four electrodes were actually surgically implanted into the ulnar and median nerves in Sorensen's upper arm, which gave the artificial arm a bridge to communicate.
While the news is huge for the future of prosthetics, it'll likely be a long time before something is commercially available. At the moment, the arm isn't even portable, and it's just a proof-of-concept more than anything. Additionally, the electrodes that were implanted into Sorensen's upper arm were removed after one month due to safety concerns. However, scientists are confident the electrodes would be functional for years, and wouldn't pose a threat to the nervous system.