http://www.digitaljournal.com/tech-and-science/science/prosthetic-arm-created-that-enables-patients-feel-touch-again/article/554635

Prosthetic arm created that enables patients to feel touch again

Posted Jul 25, 2019 by Tim Sandle
Prosthetics enables those who have lost a limb to regain a degree of functioning in terms of movement but not with touch. This could be about to change, as scientists have developed technology that can return some degree of feeling.
This photo released by Lifehand2 shows amputee Dennis Aabo Sorensen wearing a sensory feedback enabl...
This photo released by Lifehand2 shows amputee Dennis Aabo Sorensen wearing a sensory feedback enabled prosthetic in Rome in March 2013
Patrizia Tocci, Lifehand2/AFP/File
The breakthrough comes from the University of Utah where researchers have developed technology that can deliver a degree of feeling to people with with prosthetic limbs. While there have been previous attempts at this, previous advances with prosthetics aimed at delivering sensations have been limited and often imprecise. These previous attempts used automated neural-machine interfaces which vibrate the muscles used for control of prosthetic hands. The new innovation brings the sensation of touch via an artificial limb far closer to mimicking how a hand feels and senses the external environment.
The new technology is based on a process called Utah Slanted Electrode Array (USEA). The USEA, according to Gizmodo, provides an interface between what a prosthetic hand can detect and the user’s remaining sensory and motor nerves in their arm. It is a combination of these nerves and the patient's own thoughts which assist in driving the device. This furthers the development of neural interfaces for neuroprosthetics.
The connection of the array to the person requires a lengthy and complex procedure. The process requires the surgical implantation of hundreds of electrodes directly next to the patient's nerve fibers. These electrodes are designed to “record from (listen to) or stimulate (talk to) small subsets of nerve fibers very selectively, and reasonably comprehensively,” according to lead researcher Gregory Clark.
This human-computer system enables a wide range of specific sensory and motor signals to be received and then sent back between the prosthesis and the body's nervous system. The research opens up new scenarios in the research on artificial prostheses and their ability to recover as much as possible the naturalness of the missing limb.
The research into the sensitive prosthetic has been published in the journal Science Robotics, with the research headed "Biomimetic sensory feedback through peripheral nerve stimulation improves dexterous use of a bionic hand."