Use your mind to control the robot arm

US scientists have announced the world’s first brain-computer interface (BCI) technology that allows a paralyzed patient from the chest down to control a robotic arm with just his mind. far.

Nathan Copeland controls a robotic arm using electrodes implanted in his brain. Published in the journal Science, the team say their work demonstrates that adding sensation to the technology significantly improves the function of prostheses for quadriplegics, compared with based solely on visual cues. Nathan Copeland, 34, told AFP: “I am the first person in the world to have a device implanted in the sensory cortex that scientists can use to stimulate my brain directly. And then, I felt like I had a real feel in my flesh and blood hand.” In 2004, Copeland was involved in a car accident that left him with a severe spinal cord injury and quadriplegia. He volunteered for scientific research and six years ago he underwent major surgery to implant tiny electrodes in his brain. Two sets of 88 electrodes the width of a human hair are arranged like tiny combs and penetrate deep into the cortex, which controls motor function. According to Associate Professor Rob Gaunt of the Department of Physical Medicine and Rehabilitation at the University of Pittsburgh, co-leader of the study, fewer than 30 people in the world have received such a transplant. What’s unique about Copeland’s case is that an additional set of electrodes is connected to his dorsal cortex, which receives and processes sensations. The idea of ​​sending haptic feedback to the tactile sensory cortex dates back decades, but doing so in a controlled and understandable way by brain circuitry used to be a major challenge. After Copeland underwent surgery to install the electrodes, the team was truly thrilled. Then came the decisive moment, when they tried sending the first tactile signal. “It felt really fuzzy,” Copeland recalls. He asked them to try again to make sure it was real. Before the interface could work with the robotic arm, the scientists had to perform a series of tests on Copeland. First, they needed to learn which electrodes cause what sensation when activated and which fingers are associated with them in order to set up the robotic hand correctly. They also made him watch a video of the robotic arm moving left or right and recorded the electrodes lighting up when he was asked to “think” it was him controlling it. Copeland sat next to a black metal robotic arm and was asked to pick up a series of small objects such as rocks and spheres and place them in a box – when the tactile sensors were turned on or off. He can complete each task in an average of twice as fast when the sensors are activated, and can even perform more complex tasks like picking up a glass and pouring its contents into a glass. another cup. The team wanted to further refine the prosthetics because they didn’t want to just do science experiments in the lab, but wanted to actually make devices that would be useful to people. Copeland has set up his brain-computer interface at home when the Covid-19 pandemic shut down universities and has used his downtime to learn how to draw on a tablet and even play video games. death. He does this by using his mind to send signals directly to the computer, instead of using his arms to press buttons.