A team of researchers and engineers at the Swiss Ecole polytechnique fédérale de Lausanne (EPFL) Center for Neuroprosthetics and SSSA (Italy) have developed a revolutionary sensory feedback that allowed an amputee named Dennis Aabo Sørensen to feel sensory-rich information, in real-time, using a prosthetic hand wired to nerves in his upper arm.
A prototype of this bionic technology was tested a year ago during a clinical trial in Rome. The study is published in the February 5, 2014 edition of Science Translational Medicine, and represents a collaboration called Lifehand 2 between several European universities and hospitals.
In a laboratory setting wearing a blindfold and earplugs, Sørensen 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.
The researchers enhanced the artificial hand with sensors that detect information about touch by measuring the tension in artificial tendons that control finger movement and turning this measurement into an electrical current. The sense of touch was achieved by sending the digitally refined signal through wires into four electrodes that were surgically implanted into what remains of Sørensen’s upper arm nerves.
They say 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.
The next step involves miniaturizing the sensory feedback electronics for a portable prosthetic. In addition, the scientists will fine-tune the sensory technology for better touch resolution and increased awareness about the angular movement of fingers.