Researchers in the US have managed to create for the first time a prosthetic artificial hand that allows people who wear it in place of their own that was cut off to feel the sense of touch, and with great sensitivity and naturalness.
For about four decades, it has proven very difficult to artificially reproduce the sense of touch in prosthetic limbs, which are worn by people who have lost limbs in work accidents, in war, or after illness.
Researchers, led by associate professor of biomedical engineering Dustin Tyler of Case Western Reserve University in Ohio, who published the relevant work in the medical journal “Science Translational Medicine,” according to “Science,” “Nature,” and “New Scientist,” have found a way to transmit realistic tactile sensations to the human nervous system.
The amputee can now grasp something as soft as a piece of cotton with his artificial hand and feel it, feel a drop of water fall on his artificial hand, put toothpaste on his toothbrush, and grab a cherry without melting it.
For two years, the American research team has been developing the new technology, which uses pressure sensors, electrodes and a computer that (with the appropriate algorithms) processes and simulates the electrical signals that are generated when the prosthetic hand touches something, then converting them into tactile sensations in the nervous system.
For now, however, the new technology has only been tested on two people in laboratory conditions and not in everyday life by a volunteer. One disadvantage is that at present the simulation device is large and external, so it would have to be made small enough so that it could be inserted under the skin of the hand, like a pacemaker. On the other hand, researchers are already working to further expand the range of tactile sensations that the owner of the artificial hand can have.
In the same medical journal, another team of scientists reported that the first person, a 42-year-old amputee Swedish truck driver who in early 2013 was fitted with a mind-controlled prosthetic hand that also has a rudimentary sense of touch, continues to use it with great success. He ties shoelaces, carries eggs, and chops wood with his artificial hand, among other things.
He is the first person to have a prosthetic limb connected directly to his bones (with titanium connectors), nerves (with appropriate electrodes), and muscles. He can now control the movements of his artificial hand with his mind and have some basic tactile sensations when he touches something.
"This is the first time that a prosthetic device that can sense both touch and movement has been worn outside the laboratory for more than 30 days," said the head of the research team, biomedical engineer Max Ortiz Catalan of Chalmers University of Technology in Gothenburg. He said there is no need for the patient to remove their artificial arm, and the scientists' next step will be to make their sense of touch more natural.
Other scientists welcomed these advances in the field of biomedical technology and neuroprosthetics, while expressing the wish that the two pioneering teams from the US and Sweden would collaborate to combine and thus further advance their research. The ultimate goal is to create an artificial - robotic limb that will be completely integrated harmoniously into the human body, so that it can be worn comfortably all day long, while at the same time allowing freedom of movement and having a wide range of natural tactile sensations.
For the two original scientific publications (with subscription) at the addresses:
https://stm.sciencemag.org/content/6/257/257ra138
and https://stm.sciencemag.org/content/6/257/257re6
https://www.youtube.com/watch?v=PeA2cnanqyg
Source: skai.gr
