"What's available commercially is woefully inadequate," Col. Geoffrey S.F. Ling, a physician and war veteran who manages the military program, told The Baltimore Sun that year. "We also set the bar really high. We want to give them back their lives."
Since then, McLoughlin and researchers have tallied up 3,000 hours of experience with the device, fine-tuning the technology that directs its movement. Sensors placed around an amputated arm detect patterns in firing muscles when subjects are told to imagine making particular movements. Once a pattern is established, it can be assigned to an action; the more complex the pattern data collected, the more lifelike the movement.
"It's almost more important than coloring it right," said Bobby Armiger, one of the physics lab researchers, of amputees' need for prosthetics that mimic human motion as much as possible.
Such thought-controlled robotic motion has been achieved in the past. Under an earlier project sponsored by the military research agency, Duke University researchers taught monkeys to operate a robotic arm by thought alone, but that was through wires implanted in their brains. In another venture, a patient at the Rehabilitation Institute of Chicago was able to operate an arm using sensors attached to his chest muscles, to which arm nerves had been grafted.
But the modular prosthetic limb project goes beyond both, the Hopkins researchers said, because it doesn't require any sensors to be implanted, and, as in Burke's case, doesn't even require surgery.
Elsewhere, projects include efforts to build a thought-controlled, whole-body exoskeleton for paralyzed patients and to create a substance that would fuse severed nerves with robotic limbs.
After six years of development, the researchers say they are ready to put the technology to use. Along with Burke, a second patient will also soon be outfitted with a thought-controlled device — a West Virginia man who, along with Chi, will be featured in an upcoming segment devoted to the breakthrough on CBS' "60 Minutes."
But there are hurdles to giving more amputees such an opportunity.
For one, the technology is relatively unknown and the pool of potential patients with amputations above the elbow is small enough that few realize it's an option. Burke had no idea until last January, when her father spotted the magazine feature. But just over a year later, she'll have her own version.
Chi said he hears from interested patients every few months, gaining a handful each year. Recent calls have come from California and Arizona, but hopping on a plane to spend weeks working with Chi, McLoughlin and their colleagues isn't so simple. Testing of the prosthetic technology with patients has been going on at the University of Pittsburgh and Walter Reed National Military Medical Center, and more patients will be recruited soon at the California Institute of Technology in Pasadena, McLoughlin said.
Most amputees would need to go through the nerve surgery that Burke didn't require, Chi said, but that could change if her case is any lesson.
"This is a game-changer for all trauma surgeons," Chi said.
If more doctors took the extra few minutes to reattach nerves to muscle during amputation surgeries, it could make the later surgery unnecessary, Chi said. It also would help patients avoid the phantom limb pain that can occur when nerves remain detached. The fact that Burke didn't need it means she will get her prosthetic at least six months earlier than she might have otherwise.
Still, the prosthetic itself remains cost-prohibitive for commercial production. The goal is to reduce the cost per arm to less than $30,000, but it's nowhere near that now. The researchers are exploring whether production could be paid for by a philanthropic organization or nonprofit — "something not looking for a return on investment but for the good of our soldiers and others who need limbs," McLoughlin said.
While they continue to refine the device, the researchers say they are finally getting to the point where the goal of their work is being realized.
"We will always continue to develop the technology, but now we're able to focus on the really important part of this," McLoughlin said.
Burke's long journey began 14 years ago when an estranged friend confronted her and her future husband outside a Central Pennsylvania bar one August night. The man shot her and her companion, then himself.
As she waited for paramedics, she didn't even feel the pain in her arm, but could smell the blood and the gunpowder. Her side, near where her elbow met her abdomen, was blown open, she said.
When she awoke in a hospital, she didn't understand the severity of her injuries at first. Immobilized, she couldn't see that her arm was missing, nor could she feel it.
"You should be on 'Oprah,'" Burke recalled a hospital worker telling her. "I said, 'Why?" And she said, 'Because you lost your arm.'"
Now she talks about visiting the doctors who saved her life to share her opportunity for a new limb. And despite the tragedy in her past, she doesn't see herself as a victim. She said she is only looking to the possibility ahead.
"It's the closest to two-handed I've been in 14 years," Burke said. "Put a price tag on that. I can't."