New prosthetic hand can sense objects’ form and position

The newly developed prosthetic hand can sense the position of an object in a purse, for example. Luca Rossini

A robotic hand developed by researchers from Swiss and Italian universities allows amputees to sense the limb’s position in space and to regain their sense of touch.

The device, which took a decade to complete, was developed by scientists at the Federal Institute of Technology EPFLExternal link in Lausanne as well as the Sant’Anna School of Advanced Studies in PisaExternal link and the A. Gemelli University Polyclinic in Rome. It enables amputees to sense an object’s shape, consistency, size and position without needing to look at it.

Two types of information

Until now, prosthetic hands have used remaining muscle function in the forearm to allow patients to regain motor control. However, those so-called myoelectric prostheses did not allow for true sensory function in the hand.

+ Read about earlier prosthetics research out of the University of Geneva

The new device developed by the Swiss and Italian team works by stimulating nerves in the forearm, which then provide sensory feedback in a similar way to a natural hand.

Silvestro Micera from the EPFL, who helped coordinate the research, explains that the discovery “can deliver both position feedback and tactile feedback simultaneously and in real time” – an improvement on other recent advances allowing patients a basic sensory knowledge of items.

“The brain has no problem combining this information, and patients can process both types in real time with excellent results,” Micera says.

The results have been published in the journal Science Robotics.External link  So far, with proper training on how to transfer nerve pulses to sensation in the prosthetic hand, two amputees have been able to benefit from the technology. They were able to determine the size and shape of four objects with about 75% accuracy.