In the winter of 2004, a teenager named Nathan Copeland was in a car wreck that rendered him tetraplegic - that is, unable to move his four limbs. His physicians assumed he would never be able to reverse the effects of paralysis and regain sensation. However, thanks to researchers at the University of Pittsburgh Medical Center and the University of Pittsburgh, he is achieving exactly that.
A team of biomedical engineers, surgeons, and doctors worked together for over five years to build a robotic arm for Copeland that would work in tandem with his brain to restore, in some measure, his sense of touch. Put simply (and simplistically), chips implanted in his brain enabled him to control the prosthesis, even though it was not physically connected to his body. In a follow-up procedure, surgeons implanted miniscule electrodes into the region of Copeland's brain that is responsible for tactile sensation in his right hand and fingers. Theoretically, these electrodes would interact with corresponding electrodes on the prosthetic limb, allowing him to "feel" when it was touched or manipulated.
Bringing The Future Nearer
Theory, last month, led to reality. In an account published recently in the Washington Post, Copeland reports that he "can feel just about every finger" on the limb. "Sometimes it feels electrical," he said, "and sometimes it's pressure, but for the most part, I can tell most of the fingers with definite precision."
This represents a major advance over previous prosthetics. While earlier robotic limbs allowed their operators to manipulate objects and, as such, regain a modicum of motor function, none had endowed their users with a sense of touch or facilitated such complex feedback between the limb and the operator's brain. Such an achievement gives hope to victims of all manner of accidents and illnesses who have lost the use of their limbs.