Aabo Dennis Sorensen, Danish 36, lost his left hand 10 years ago when a firecracker exploded during the celebration of New Year. He never expected to regain feeling or to feel something. But now he has recovered the sense of touch thanks to a bionic hand that allows him to catch and identify objects even blindfolded.
The prototype is connected to the nerves of Dennis' left arm and serves as a link between his body and the machine. Scientists from Italy, Switzerland, Germany, Britain and Denmark have participated in the project - developed at the Gemelli hospital in Rome and published today in the journal Science Translational Medicine' - and they are confident that this prosthesis will revolutionize the lives of many people with amputations.
In their daily life, Sorensen used a prosthesis that detects muscle movements and allows him to open and close the hand but it doesn't allow to have any sense of touch, so he needs to be careful not to break the stuff he tries to grab. The new prosthesis, named LifeHand 2 is more sophisticated as it combines intranervous connections, robotics and computer science to recreate the sense of touch.
The patient was implanted tiny electrodes with the thickness of a human hair in the ulnar and median nerves of the arm before putting the bionic hand, which is equipped with several artificial sensors. These sensors measure the strain on the tendons of each finger to find the force required to catch every object. Computer algorithms transform this information into electrical signals that the nerves can interpret.
The result is a feeling very near to real touch, including different intensities that have allowed Sorensen distinguish shapes and textures of different objects. In a series of experiments blindfolded, he can recognize the basic forms of a series of objects and notice the differences between and orange and a baseball. Scientists will now work to ensure that the hand is able to differentiate between more refined textures and between hot and cold and get the patient to live "several months" with the device.
"It was a great experience. It was amazing to feel something after feeling nothing for so many years ," said Sorensen. "I have been pretty close to the same feeling as if I had a normal hand", he assured.
The device is still experimental and it won't be available for a few years yet. Researchers still have work ahead to reduce components and the amount of cables which limit its current use to the lab. Nevertheless, it is a fantastic advancement of technology that surely someday many people will be enjoying around the world.
