An amputee was able to feel and differentiate textures in real-time thanks to an artificial fingertip surgically connected to his nerves in the upper arm. This advance in the sensitive technology can help to create prosthetics with the ability to feel, so millions of amputees can recover the sensitive-touch in their affected area.
The technology was developed by scientists from the Swiss Federal Institute of Technology (EPFL) and Sant’Anna School of Advanced Studies (SSSA) in Italy. They allowed amputee Dennis Aabo Sørensen to receive the sensitive information through their groundbreaking device, making him the first to try such advance.
“When the scientists stimulate my nerves I could feel the vibration and the sense of touch in my phantom index finger,” said Sørensen, according to Reuters. “The touching sensations is quite close to when you feel it with your normal finger; you can feel the coarseness of the plates, and the different gaps and ribs,” he added.
Sørensen’s arm nerves were wired to an artificial fingertip with sensors. A machine controlled the movement of the fingertip over different pieces of plastics, which each one had a different pattern, soft or rough ones, according to the EurekAlert.
As the bionic fingertip moved across the texture samples, the sensor generated electrical signals which were translated to electrical spikes imitating the language of the nervous system. After this translation, the electrical spikes were delivered to the nerves. The subject was able to distinguish between the different patterns in the plastic samples 96 percent of the time.
Further tests possible with no need for surgery
The nerves of non-amputees could be also stimulated without the need for surgery, this means that the prosthetic touch for amputees can now be developed and safely tested on intact individuals.
In the non-amputee subjects, the information was delivered through fine needles temporarily attached to the arm’s median nerve through the skin, and besides that the procedure was the same as Sørensen. The non-amputees were able to distinguish roughness in textures 77 percent of the time.
For the development of this kind of technology, scientists had to study through EEG (electroencephalogram) which nerves were stimulated from a real finger’s touch. Finally, to determine whether the feeling was the same, they compared the results of the EEG in the non-amputee subjects with the artificial fingertip and real ones.
They concluded from the EEGs that the activated regions in the brain from the artificial fingertip and the real one were analogous.