Robotic skin gives back sense of touch to arm amputee

‘After many years, I felt my hand, as if a hollow shell got filled with life again’

‘Phantom limb’ is a common side-effect of amputation where patients feel like the limb is still there. File image: Brenda Fitzsimons

‘Phantom limb’ is a common side-effect of amputation where patients feel like the limb is still there. File image: Brenda Fitzsimons

 

A man whose arms were amputated has regained the sensation of touch and pain through a robotic skin developed by US researchers.

The man (29), who had both his arms amputated five years prior to the study due to a blood infection, said “after many years, I felt my hand, as if a hollow shell got filled with life again”.

The biomedical research team at Johns Hopkins University developed the robotic skin called e-dermis.

“We’ve made a sensor that goes over the fingertips of a prosthetic hand and acts like your own skin would,” said Luke Osborn, one of the developers.

Colleague Nitish Thakor said: “For the first time, a prosthesis can provide a range of perceptions, from fine touch to noxious to an amputee, making it more like a human hand.”

During the experiments, the amputee was blindfolded and asked to identify the shape of different objects by pressing the tips of his prosthetic thumb and little finger against them. Brain scans (electroencephalographies or EEGs) allowed the scientists to confirm the bionic skin was conveying tactile sensations across the body.

Speaking about why they included pain sensation as one of the features of the robotic skin, Osborn said “pain is, of course, unpleasant, but it’s also an essential, protective sense of touch that is lacking in the prostheses that are currently available. Advances in prosthesis designs and control mechanisms can aid an amputee’s ability to regain lost function, but they often lack meaningful, tactile feedback or perception”.

The researchers said e-dermis could be installed on any prosthetic hand and was capable of stimulating the nerves of the arm bringing to life the “phantom limb”, a common side-effect of amputation where patients feel like the limb is still there.

This occurs because there is a group of neurons in the brain for each part of the human body designed to manage sensations and movements. When a limb is cut off, the brain area that controls it remains intact causing the phantom limb syndrome.

According to the authors of the study, published on Wednesday in the journal Science Robotics, the bionic skin could also be installed on astronaut gloves and space suits.