Amputee Successfully Feels Prosthetic Grip Strength Via Arm Electrodes
Amazing
http://spectrum.ieee.org/tech-talk/biomedical/bionics/sensitive-prosthetic-hand-gets-a-grip
For decades, amputees have been able to open and close prosthetic hands by twitching muscles and activating a superficial electromyogram (sEMG), but they had no way of feeling what the prosthetic was encountering and little control over the strength of their grasping grip. It was a clunky, incomplete solution.
But recently, an amputee who allowed European researchers to plug electrodes into a bundle of his wrist nerves was able to control the strength of a prosthetic hand's grip and to distinguish the shapes and stiffness of three kinds of objects. The 30-day trial marks a success for one of several new experimental ways of giving amputees a better sense of touch and control over their prosthetics. A different group has conveyed sensations of temperature and vibrations by moving arm nerves into intact muscles of the chest, which act as biological amplifiers of the nerves' tiny signals. Another team tapped into nerves in the lower spine of cats to control their limbs. The Defense Advanced Research Projects Agency, is also seeking to improve sensation and control of its advanced prosthetics.
In the latest trial, appearing in Science Translational Medicine today, biomedical engineer Silvestro Micera of the Swiss Federal Institute of Technology in Lausanne (EPFL) and a large team surgically attached electrodes from a robotic hand to a 36-year-old volunteer's median and ulnar nerves. Those nerves carry sensations that correspond with the volunteer's index finger and thumb, and with his pinky finger and the edge of his hand, respectively. The volunteer controlled the prosthetic with small muscle movements detected by sEMG, a method that dates to the 1970s and measures electrical signals through the skinunlike the electrodes attached to his nerves, sEMG is not invasive.
"They make an important contribution to show that direct electrical feedback through the peripheral nerve is important for improved control of a prosthetic hand," says biomedical engineer Dustin Tyler of Case Western Reserve University in Cleveland, Ohio, who is working on other neural prosthetics.
That is awesome.