Any of us that saw the 1980 sci-fi movie “The Empire Strikes Back” will remember at the end of the movie we see Luke Skywalker aboard the medical ship getting his hand replaced with a realistic looking prosthetic. We were all amazed at how Luke could feel the pain of the needle as it poked each finger of the artificial hand. We wondered how long it would be before actual artificial limbs would be able to restore the sensation of touch? Apparently the answer to that question is 35 years.
Now, 35 years after that movie, DARPA (Defense Advanced Research Project Agency) has created such an artificial arm that can restore the sense of touch. The arm was successfully tested earlier this month allowing the recipient to feel the sensation of touch after a spinal cord injury he suffered a decade ago.
“We’ve completed the circuit,” Justin Sanchez, Darpa program manager, said in announcing the most recent results of the Revolutionizing Prosthetics program earlier this month at a conference in St. Louis, according to a press release from the agency.
The arm, that was developed at John Hopkins University’s Applied Physics Laboratory, works by a sending electronic impulses through an array of sensors that are connected directly to the brain. Those signals are then sent through the spinal cord to the artificial limb. The process created by the sensor array mimics the same electronic pulses sent through a healthy nervous systems.
“Prosthetic limbs that can be controlled by thoughts are showing great promise, but without feedback from signals traveling back to the brain it can be difficult to achieve the level of control needed to perform precise movements,” he said. “By wiring a sense of touch from a mechanical hand directly into the brain, this work shows the potential for seamless bio-technological restoration of near-natural function.”
After successfully attaching the arm they tested it much the same way that the robot medics test Luke Sywalker’s hand back in that 1980 movie.
“At one point, instead of pressing one finger, the team decided to press two without telling him,” said Sanchez, who oversees the Revolutionizing Prosthetics program. “He responded in jest asking whether somebody was trying to play a trick on him. That is when we knew that the feelings he was perceiving through the robotic hand were near-natural.”