Over the past decade, DARPA’s work on brain-controlled prosthetic limbs has led to some impressive breakthroughs, but with the development of novel neuromuscular interfaces, it’s making real headway toward mainstream bionic limbs in the near term. Today, the agency released some new information about its ongoing research, showing off arms that amputees can control with their remaining nerve and muscle tissue, and that even communicate back with the wearer, restoring a sense of touch.
TMR is getting close to the performance of brain interfaces
In a press release, DARPA writes that TMR is getting close to the performance of cortical, or brain, interfaces, and because installing them is less invasive, these "peripheral interfaces" have more potential for prosthetics over the next several years. TMR uses surgery to reroute signals from nerves that were severed during amputation to muscle tissue elsewhere, which then serves as an amplifier to control the artificial limb. The procedure made big news last year when Zac Vawter used a TMR-controlled bionic leg to climb the 103-story Willis Tower in Chicago, and below, Army Staff Sergeant Glenn Lehman gives a demonstration of the accurate motor control possible with the technology.
In another video, DARPA shows a technique called FINE (flat interface nerve electrode) can be used to send direct sensory feedback to the arm’s owner. FINE (pictured top) flattens out nerve fibers so that several of them can be exposed to the electrical currents that provide feedback, restoring the patient’s sense of touch. The agency writes that the technology lets patients "move a hand without keeping their eyes on it — enabling simple tasks, like rummaging through a bag for small items, not possible with today’s prosthetics."