A collaborative effort between researchers at the University Campus Bio-Medico (UCBM), Rome, Italy and the Italian Workers’ Compensation Authority (Istituto Nazionale per l’Assicurazione, INAIL), has produced a system of sensors and algorithms that will improve the dexterity of and provide sensory perception to bionic prosthetic hands. They said the system will be able to be used with any advanced upper-limb prosthesis.
“This is not actually a brand new ‘bionic hand,’ but a complex hardware and software system that makes upper-limb prostheses smarter, by controlling their motors in a more sophisticated way,” said Eugenio Guglielmelli, PhD, a bioengineering professor and vice-rector for research at UCBM. “This will allow modulating brain inputs so that the patient can simultaneously move all five fingers, just a few of them, or even one finger at a time.”
Called the Prosthesis Research Project 2 (Progetto Protesi Ricerca 2, PPR2), it is the third phase after LifeHand 2, a thought-controlled upper-limb prosthesis that provides the user with sensory perception, which was also developed in Italy.
The PPR2 will allow users of bionic upper-limb prostheses to feel the consistency of objects touched, command movements for neural pathways, modulate grip strength, and improve the user’s ability to manipulate objects, write, use smartphones, or even react in real time to “clumsy” moves such as the sliding of a bar of soap while washing.
Further, compared to LifeHand 2, after an initial adjustment period, the PPR2 system will no longer need a computer connection via external cables to send impulses to the brain that are picked up by the electrodes and, in the other direction, send the intentions of moving from the brain to the prosthesis. The algorithm will be managed onboard the hand through electronic chips the size of a credit card.
The new smart system will be tested for the first time in 2016 on a volunteer who will undergo neurosurgery to implant neural interfaces in the nerves of the residual limb. This should enable the connection of the nervous system with the sensors of the new prosthetic hand. The same project will also test the ability to perform delicate grasps and manipulate commonly used objects (e.g., turn a key, rotate a ball in the palm of the hand, and point a finger to open an app on a tablet or browse web pages). Moreover, the new system could also help reduce phantom limb pain, the researchers said.