When it happened, when the robotic hand that Tim Hemmes willed to move only with his mind reached out and touched girlfriend Katie Schaffer's outstretched palm, emotions flashed like lightning.
It was the first time a person with quadriplegia has used his mind to control a robotic arm so masterfully. The 30-year-old man hadn't moved his arms, hands or legs since a motorcycle accident seven years ago. But Hemmes had practiced six hours a day, six days a week for nearly a month to make history.
That successful act in a Pittsburgh hospital laboratory increases hope for people with paralysis or loss of limbs that they can feed and dress themselves and open doors, among other tasks, with a mind-controlled robotic arm. It's also improved the prospects of wiring around spinal cord injuries to allow motionless arms and legs to function once again.
"I think the potential here is incredible," said Dr. Michael Boninger, director of the University of Pittsburgh Medical Center's Rehabilitation Institute and a principal investigator in the project. "This is a breakthrough for us."
Experiments in electrocorticography or ECoG —- in which an electronic grid is surgically placed against the brain without penetration — had raised a tantalizing question in mind control: Could someone with quadriplegia use ECoG's capability to control a robotic arm? ECoG picks up an array of brain signals that a computer algorithm can interpret and then move a robotic arm based on the person's intentions. But researchers didn't even know whether the brains of people with long-term paralysis still produced signals to move their limbs.
Hemmes became quadriplegic July 11, 2004, apparently after a deer darted onto the roadway, causing him to swerve his motorcycle onto gravel where his shoulder hit a mailbox, sending him flying headfirst into a guardrail. The top of his helmet became impaled on a guardrail I-beam, rendering his head motionless while his body continued flying, snapping his neck at the fourth cervical vertebra.
A passerby found him with blue lips and no signs of breathing. Hemmes was flown to the hospital by rescue helicopter to and diagnosed with quadriplegia -— he had lost use of his limbs and his body below the neck or shoulders. He had to learn how to breathe on his own. His doctor told him it was worst accident he'd ever seen in which the person survived.
But after the process of adapting psychologically to quadriplegia, Hemmes pursued a full life, especially after he got a device to operate a computer and another to operate a wheelchair with head motions.
Since January, he has operated a website — www.Pittsburghpitbullrescue.com — to rescue homeless pit bulls and find them new owners.
The former hockey player's competitive spirit and willingness to face risk were key attributes in his being chosen for this test. Elizabeth Tyler-Kabara, the neurosurgeon who would install the ECoG in Hemmes' brain, said he had strong motivation and a vision that paralysis could be cured.
Ever since his accident, Hemmes said, he's had the goal of hugging his daughter Jaylei, now 8. This could be the first step.
Hemmes underwent several hours of surgery to install the ECoG at a precise location against the brain. Wires running under the skin down to a port near his collarbone -— where wires can connect to the robotic arm — caused him a stiff neck for a few days.
Two days after surgery, he began exhaustive training on mentally maneuvering a computer cursor in various directions to reach and make targets disappear. Next he learned to move the cursor diagonally before working for hours to capture targets on a three-dimensional computer.
The U.S. Food and Drug Administration allowed the trial to last only 28 days, when the ECoG is removed. The project, initially funded by UPMC, has received more than $6 million in funding from the Department of Veterans Affairs, the National Institutes of Health, and the U.S. Defense Department's Advanced Research Projects Agency.
Initially Hemmes tried thinking about flexing his arm to move the cursor. But he had better success visually grabbing the ball-shaped cursor to throw it toward a target on the screen. The "mental eye-grabbing" worked best when he was relaxed.
Soon he was capturing 15 of 16 targets and sometimes all 16 during timed sessions. The next challenge was moving the robotic arm with his mind.
The same mental processes worked, but the arm moved more slowly and in real space. Time was ticking away as the experiment approached its final days last month. With Hemmes finally moving the arm in all directions, Wei Wang —- assistant professor of physical medicine and rehabilitation at Pitt's School of Medicine who also has worked on the signalling system —- stood in front of him and raised his hand.
The robotic arm that Hemmes was controlling moved with fits and starts but in time reached Wang's upheld hand. Hemmes gave him a high five.
The big moment arrived.
Katie Schaffer stood before her boyfriend with her hand extended. "Baby," she said encouraging him, "touch my hand."
It took several minutes, but he raised the nearby robotic hand and pushed it toward Schaffer until its palm finally touched hers. Tears flowed. "It's the first time I've reached out to anybody in over seven years," Hemmes said. "I wanted to touch Katie. I never got to do that before."
"This was way beyond what we expected," Tyler-Kabara said. "We really hit a home run, and I'm thrilled."
Hemmes was taking part in one of two brain-computer interface studies under way at the University of Pittsburgh School of Medicine and UPMC Rehabilitation Institute. The unique robotic arm and hand was designed by the Johns Hopkins University Applied Physics Laboratory.
The next phase will include up to six people tested in another 30-day trial with ECoG. A yearlong trial will test an electrode array that shallowly penetrates the brain. Goals during these phases include expanding the degrees of arm motions to allow people to "pick up a grape or grasp and turn a door knob," Tyler-Kabara said. Anyone interested in participating should call 1-800-533-8762.
Hemmes says he will take part in future research. "This is something big, but I'm not done yet," he said. "I want to hug my daughter."