While prosthetic limbs are increasingly complex and restoring both capability and dignity to people who deal with mobility issues, there’s a frontier even the top engineers struggle with: Touch.
We need touch in our limbs in order to use them to their full effectiveness. Touch is the difference between picking up a glass and cracking it. Nathan Copeland, a man who lost the use of his body below the neck after a car accident, is the first to feel touch in his paralyzed hands, thanks to surgically-implanted electrodes and a robotic arm he can control with his mind. (It’s important to note that Copeland retained all his limbs after the accident, and the electrodes allow him to feel touch in his own hands when the robotic arm is touched.)
The limb pulls it off by being wired directly to the parts of the brain where Copeland processes touch. Using microimagining techniques, Copeland’s touch centers were found and four microelectrode arrays were implanted. When connected to the robotic arm, Copeland can feel each individual finger being touched. It’s not perfect: Copeland can’t sense temperature, and it’s more of a squeezing or tingling sensation in each finger than what we identify as touch. But it’s an enormous step forward. Copeland recently even shook President Obama’s hand:
The experiment with Copeland was a featured stop Thursday when President Obama visited Pittsburgh for a White House Frontiers Conference on advances in science, medicine and technology. The researchers described how neuroscience has been able to build a technology where simply imagining a motion translates into motion, in this case a robotic arm.
“It’s amazing. Pretty cool,” Obama said, before asking Copeland to “blow it up” with a handshake, where they each pulled their hand away at the end. “I couldn’t be prouder of all of you.”
There’s far more work to do, of course. There’s some debate, for example, about whether brain surgery should be used for this technique, or whether the prosthetic should be wired to nerves. And there is the issue that this technique involves major surgery, which carries a risk, however small, of complications. None of that, however, can detract from the fact that this is a life-changing breakthrough, first for Copeland, and likely soon for many others.