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Restoring Touch

October 27, 2016

Scientists are learning the complex nerve signals that allow us to experience the sensation of touch.

Transcript

Graczyk et al., Science Translational Medicine 2016

Implanted peripheral nerve electrodes deliver stimulation directly to the nerve.* (Graczyk et al., Science Translational Medicine, 2016)

BOB HIRSHON (host):

The secrets of touch. I’m Bob Hirshon and this is Science Update.

By stimulating nerves in the upper arms of amputee volunteers, University of Chicago neuroscientist Sliman Bensmaia and his colleagues report producing realistic sensations of light and forceful fingertip touch. In the journal Science Translational Medicine, they report that a small number of nerve signals, or action potentials, produced the feeling of a light touch, while many action potentials felt like a hard poke. The work will help them design robotic hands that can feel.

SLIMAN BENSMAIA ( University of Chicago ):

It’s not enough to just be able to move the hand, even moving the hand by thought is not enough. You need to also be able to feel through the hand; you need to be able to restore these sensory signals that allow you to use your hands and manipulate objects dextrously.

HIRSHON:

Next, the team will try to discover what nerve patterns let us discern textures. The goal is robot hands that convey fully realistic feeling. I’m Bob Hirshon, for AAAS, the science society.

Story by Bob Hirshon

*Electrical stimulation was delivered by an external stimulator (top left) through percutaneous leads to flat interface nerve electrodes (FINEs) implanted on the median, ulnar, and radial nerves of an upperlimb amputee (bottom left). Stimulation consists of trains of square, biphasic, charge-balanced pulses delivered to individual contacts in the eight-channel FINE. The FINE reshapes the nerve and achieves close proximity between the fascicles and the stimulating contacts, improving selectivity. Each electrode contact evokes sensory percepts on small regions of the missing hand of the subject.