Researchers in Switzerland and Italy are developing and using interfaces that connect a bionic hand directly to the nerves in the residual limb that are responsible for controlling the lost limb. Photograph courtesy of LIFEHAND consortium.
At the 2013 Annual Meeting of the American Association for the Advancement of Science (AAAS) in Boston, Massachusetts, February 14–18, Silvestro Micera, PhD, an associate professor of neuroprosthetics at the École Polytechnique Fédérale de Lausanne (EPFL), Switzerland, Center for Neuroprosthetics, reported on the results of previous work in which he and his colleagues conducted a four-week clinical trial that improved sensory feedback in individuals with amputations by using intraneural electrodes implanted into the median and ulnar nerves. This interface holds promise because of its ability to create an intimate and natural connection with the nerves, and because it is less invasive than other methods. It also provides fast, intuitive, bidirectional flow of information between the nervous system and the prosthesis, resulting in a more realistic experience and ultimately improved function.
Micera said that the benefits of this interface are more versatile prosthetics with intuitive motor control and realistic sensory feedback—essentially, they could one day return dexterity and the sensation of touch to an amputee.
“We could be on the cusp of providing new and more effective clinical solutions to amputees in the next years,” said Micera, who is head of the EPFL Translational Neural Engineering Laboratory and head of the neural engineering group at the Scuola Superiore Sant’Anna, Pisa, Italy.
Micera and his colleagues tested their system by implanting intraneural electrodes into the nerves of an amputee’s residual limb. The electrodes stimulated the sensory peripheral system, delivering different types of touch feelings. Then the researchers analyzed the motor neural signals recorded from the nerves and showed that information related to grasping could indeed be extracted. That information was then used to control a prosthetic hand placed near the subject but not physically attached to the subject’s arm.
At AAAS, Micera also described his recent activities to improve the efficacy of this approach and announced a new clinical trial starting soon as part of the Italian Ministry of Health’s NEMESIS project. The new trial will carry this research a step further by connecting the prosthetic hand directly to the patient for the first real-time, bidirectional control using peripheral neural signals. The researchers said they hope to find still further improvement in the sensory feedback and overall control of the prosthesis with this new method.
Editor’s note: This story was adapted from materials provided by École Polytechnique Fédérale de Lausanne (EPFL), Switzerland.
