Scientists develop prosthetic hand with sense of touch

Washington: European researchers said Wednesday they have created a “revolutionary” prosthetic hand that helped an amputee who had not experienced the sensation of touch for over nine years to feel differences again in real-time.

The findings were published in the US journal Science Translational Medicine, Xinhua reported.

Researchers from Italy, Switzerland, Germany, Britain and Denmark used electrical stimulation to jumpstart residual sensory fibres in the stump of an amputated hand of a 36-year-old patient from Denmark called Dennis Aabo Sorensen.

The information from the prosthetic sensors was communicated through four ultra-thin, ultra-precise electrodes that were surgically implanted into what remains of Sorensen’s upper arm nerves.

The researchers performed a series of experiments with the prosthetic hand, testing its ability to increase or decrease grasp force, and gauge the shape and stiffness of objects.

“This is the first time in neuroprosthetics that sensory feedback has been restored and used by an amputee in real-time to control an artificial limb,” lead author Silvestro Micera of the Ecole Polytechnique Federale de Lausanne in Switzerland and the Scuola Superiore Sant’Anna in Italy said in a statement.

They found that the hand allowed the patient to experience almost natural sensory feeling, without any particular training.

“The sensory feedback was incredible,” said Sorensen. “I could feel things that I hadn’t been able to feel in over nine years.”

In a laboratory setting wearing a blindfold and earplugs, Sorensen was able to detect how strongly he was grasping, as well as the shape and consistency of different objects he picked up with his prosthetic.

“When I held an object, I could feel if it was soft or hard, round or square,” said Sorensen, who lost his left hand while handling fireworks during a family holiday.

The electrodes were removed from Sorensen’s arm after one month due to safety restrictions imposed on clinical trials, although the scientists are optimistic that they could remain implanted and functional without damage to the nervous system for many years.

A sensory-enhanced prosthetic is years away from being commercially available and the bionic hand of science fiction movies is even further away, but the clinical study provides the first step towards a bionic hand, the researchers said.

The next step is to test the prosthetic hand in a pilot clinical study with more patients, as well as study the long-term usability of the technology, they added.

Src:IBN