A new robotic hand developed by the Defense Advanced Research Projects Agency has developed a prosthetic hand that allows its user to feel physical sensations.
A 28-year-old man with paralyzation due to a spinal cord injury was equipped with the prosthesis, becoming the 1st person to “feel” touch-sensations through the prosthetic unit which is directly connected to his brain, according to DARPA.
“We’ve completed the circuit. 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. 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,” DARPA program manager Justin Sanchez said in a press release.
The new “feeling” prosthetic operates through the placement of electrode arrays into the paralyzed volunteer patient’s sensory cortex, to enable feeling, and motor cortex, to enable movement.
Wires connect the arrays to the mechanical hand, developed by the Applied Physics Laboratory at Johns Hopkins University. The new prosthetic hand allows the patient to control the new limb with their thoughts, something DARPA had achieved in a previous program for a patient with similar injuries, the agency said.
To test the hand, researchers gently touched each of the fingers while the subject was blindfolded. The researchers recorded a 100% accuracy in identifying which finger was being touched and the patient reported he felt as if it was his own hand being touched.
“At 1 point, instead of pressing 1 finger, the team decided to press 2 without telling him. 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,” Sanchez said in prepared remarks.
The new hand contains “sophisticated torque sensors that can detect when pressure is being applied to any of its fingers, and can convert those physical “sensations” into electrical signals,” according to the agency.
The findings were released last Thursday at a DARPA event in St. Louis, according to the agency. DARPA hopes the project will lead the way for future prosthetics that operate more similarly to natural limbs.
“DARPA’s investments in neurotechnologies are helping to open entirely new worlds of function and experience for individuals living with paralysis and have the potential to benefit people with similarly debilitating brain injuries or diseases,” Sanchez said in a prepared statement.