These emotional robotic touches have inspired researchers now recruiting volunteers for soon-to-start yearlong experiments.
“It was awesome,” is the decidedly unscientific description from the normally reserved Dr. Michael Boninger, rehabilitation chief at the University of Pittsburgh Medical Center. “To interact with a human that way. … This is the beginning.”
Hemmes‘ journey began in 2004. He owned an auto-detailing shop and rode his motorcycle in his spare time. Then one summer evening he swerved to miss a deer. His bike struck a guardrail. His neck snapped.
His determination didn’t. Paralyzed below the shoulders, he’s tried other experimental procedures in hopes, so far unrealized, of regaining some arm function.
“I always tell people your legs are great … but they just get you from here to there,” Hemmes says as his caregiver waits to feed him a bite of a cheeseburger near his home in Butler, north of Pittsburgh. “Your arms and fingers and hands do everything else. I have to get those back, I absolutely have to.”
His ultimate goal is to hug his 8-year-old daughter. “I’m going to do whatever it takes, as long as it takes, to do that again.”
Hemmes entered an operating room at UPMC with a mix of nerves and excitement.
“It’s good anxiety,” he says. “There is so much riding on this.”
Think “I want that apple,” and your arm reaches out and grasps it. You’re not aware that neurons are instantaneously firing in patterns that send commands down the spinal cord _ make the shoulder raise the arm, extend the elbow, flex the wrist and all five fingers.
A very similar firing occurs when you imagine movement or watch the movement you’d like to perform, explains Boninger, who with Schwartz is leading the Pittsburgh research together with a team of bioengineers, neuroscientists and physicians.
The DARPA arm was developed primarily for amputees. Separate research is under way to help them move it by using transplanted nerves to sense those brain commands. The paralyzed pose a more difficult challenge: getting those signals around a broken spinal cord.
For quadriplegic patients, scientists use implanted electrodes, called a “brain-computer interface” or BCI, to record that electrical activity. The signals move down through wires that tunnel under the skin and out by the collarbone, and are plugged into a computer or a robotic arm.
Until now, researchers mostly have tested miniature electrodes that poke inside the brain’s motor cortex and record from individual cells, presumably allowing for precise movements. Pittsburgh’s next test-patient will have two penetrating grids implanted in different parts of the cortex for a year to record from 200 cells altogether.