Experimental Prosthetic Hand Can "Feel"

Recent clinical trials of a new prosthetic hand have been concluded with some impressive results. The prototype prosthetic has sensors in the tips of its fingers that can simulate "touch" for the brain.

Thirty-six year old Dennis Aabo Sorensen had had his injured left arm amputated below the elbow ten years ago. Now, after the guidance of researchers over the course of four months, Sorensen can once again pick up objects with his left arm, bending a prosthetic forearm and hand to his whim -- with a little concentration. According to the latest reports of over 700 trials published in Science Translational Medicine, sensors on the subject's stump interpreted motor signals sent by the brain, and responded appropriately, bending fingers and a wrist on command.

More impressive still is that after numerous trials Sorensen could also "feel" the surface of the objects his prosthetic hand held.

According to the report, after weeks of trails, the Sorensen was able to distinguish between the surfaces of a pack of cotton, a stack of plastic glasses, and a chunk of wood. This was done through a pair of electrodes that interpreted signals from force sensors on the prosthetic's finger tips and then carried appropriately strengthen electrical charges to the subject's upper-arm. Soft resistance against the fingertips would yield a light charge, and increased resistance would yield progressively stronger charges just short of painful. In the same way a subject could theoretically determine the texture of a surface, where a consistent charge meant he was feeling something smooth, and a charge of staggered strength meant he was feeling something rough.

In an interview with École Polytechnique Fédérale De Lausanne News Sorensen talked about how fantastic it was to feel -- even in a roundabout way -- with his left hand once more. His children, he said, even developed a new nickname for him, "the cable guy."

The most recent report on these clinical trials was published by Translational Medicine.