December 17, 2012
Quadriplegic Woman Uses Robotic Arm To Eat Chocolate For First Time
[Watch Video: Woman Uses Mind To Move Robotic Arm]
Lawrence LeBlond for redOrbit.com - Your Universe OnlineReaching for an object, shaking someone´s hand, sending a text message–these are all things that most of us take for granted every day. But for people who are quadriplegic (paralyzed from the neck down), like Jan Scheuermann, tasks such as these are not possible because of paralysis. That is until now.
Researchers from University of Pittsburgh School of Medicine and UPMC have given Ms. Scheuermann the ability to do things that quadriplegia victims have not before been able to do. The team of scientists hooked Scheuermann up to a mind-controlled, human-like robot arm and watched as she performed several natural and complex motions of everyday life.
Using the robotic arm like she would a regular one, she reached out to perform a “high five,” grasped and moved objects around and even fed herself a piece of dark chocolate. Scheuermann, 53, of Whitehall Borough in Pittsburgh, Pennsylvania, was ecstatic to be able to use her brain power to move, turn and bend her arm, as well as make a fist for the first time in nine years.
Ms. Scheuermann lost the use of her limbs to a degenerative disease that first struck in 1996. Over time, the disease damaged her spinal cord which led to her paralysis–the disruption to her nervous system was the equivalent of a broken neck. But by using the robotic arm, she learned quickly to make fluid movements, reaching levels of performance not even the scientists expected.
In the study, published in The Lancet online, the team described how the brain-computer interface (BCI) technology and training program allowed Scheuermann to operate the robotic arm. Specialized brain implants were used for Scheuermann to control the arm. Instead of thinking where the arm should go and what it should do, the brain implants allowed Scheuermann to focus just on the goal to make the arm work.
The technology has been implemented by other research groups around the world, but the Pitt/UPMC team said no one has achieved such impressive results as they have.
The team said Ms. Scheuermann was able to move the arm forward, backward, right, left, up and down in just two days of training. Within weeks she could reach out and change the position of the hand to pick up an object on a table and put them down at another location.
When Scheuermann first used the arm, she maintained that she was “going to feed [herself] chocolate before this is over.” And less than a year later she accomplished her goal, savoring the taste and saying: “One small nibble for a woman, one giant bite for BCI.”
“This is a spectacular leap toward greater function and independence for people who are unable to move their own arms,” noted senior investigator Andrew B. Schwartz, Ph.D., professor, Department of Neurobiology, Pitt School of Medicine. “This technology, which interprets brain signals to guide a robot arm, has enormous potential that we are continuing to explore. Our study has shown us that it is technically feasible to restore ability; the participants have told us that BCI gives them hope for the future.”
Scheuermann first heard about the research in October 2011 after a friend pointed out a video of another paralyzed man, Tim Hemmes, from Butler, Penn., who moved objects on a computer screen and reached out and touched his girlfriend with a robotic arm during Pitt/UPMC BCI research.
“Wow, it´s so neat that he can do that,” Scheuermann thought as she watched him. “I wish I could do something like that.” She had her attendant call the trial coordinator immediately, and said, “I´m a quadriplegic. Hook me up, sign me up! I want to do that!”
To wire Scheuermann up to the arm, doctors had to perform a four-hour operation to implant two tiny electrode grids into her brain. Each grid has 96 little electrodes and was positioned just under the surface of the brain, near neurons that control hand and arm movement in the motor cortex.
Once the implants were in place, the surgeons replaced the part of the skull they had removed to expose the brain. Wires from the electrodes ran to connectors on the patient´s head, which doctors could then use to plug the patient into a computer system and robotic arm.
Before the arm was ready to test, the team had to record her brain activity imagining various arm movements. They asked her to watch the robotic arm as it performed various maneuvers, and then got her to imagine she was moving her own arm in the same way. While thinking of these maneuvers, the computer recorded her electrical activity in the brain through the electrode grid.
Neurons that control movement tend to have a preferred direction of travel, and fire their electrical pulses more frequently to perform movements in that direction. “Once we understand which direction each neuron likes to fire in, we can look at a larger group of neurons and figure out what direction the patient is trying to move the arm in,” said Schwartz.
Then, the team programmed the arm to help Scheuermann´s movements. At first, the computer assisted in the movements, correcting any small mistakes that were made during the process. But Scheuermann quickly progressed to controlling the arm with no help whatsoever. After three months of training, she could complete tasks with the arm 91.6 percent of the time, and 30 seconds faster than when the trial began.
"This bio-inspired brain-machine interface is a remarkable technological and biomedical achievement," said GrÃ©goire Courtine, at the Swiss Federal Institute of Technology in Lausanne, in an accompanying article.
Schwartz told BBC News´ James Gallagher that the movements seen in this study have not been achieved on any scale beforehand.
“They're fluid and they're way better, I don't know how to say it any other way, they're way better than anything that's been demonstrated before,” he rejoiced. “I think it really is convincing evidence that this technology is going to be therapeutic for spinal cord injured people.”
“They are doing tasks already that would be beneficial in their daily lives and I think that's fairly conclusive at this point,” he added.
The field of harnessing a healthy brain to overcome a damaged body is quickly gaining traction in the science world.
Another study earlier this year allowed a stroke victim to use a robotic arm to drink a cup of coffee for the first time in 15 years.
While these studies are significant, they are also impractical in their current settings. The arms are bulky, heavy and take up a lot of room. But researchers are looking to make it practical. The Pitt team is now trying to figure out a way to mount the arm on to Ms. Scheuermann´s wheelchair so she will be able to use it in her everyday life.
There are other obstacles as well. Though Scheuermann´s performance continued to improve after the study was written, she has since plateaued because scar tissue that forms around the tips of the electrodes degrades the brain signals the computer receives.
Schwartz said thinner electrodes may solve this problem, stating they would be too small to trigger the scarring process in the body.
The next goal for the team is to build sense into the robotic arm, so the patient can feel the texture and temperature of the objects they are touching. To accomplish this, sensors on the fingers of the robotic hand could send information back to the sensory regions of the brain. The team are also looking further ahead, thinking of how they can make the system wireless, so the patient doesn´t have to be physically plugged into a computer to control the arm.
For now, Scheuermann is expected to continue to offer her services to the BCI team for two more months, and then the implants will be removed in another operation.
“This is the ride of my life,” she said. “This is the rollercoaster. This is skydiving. It´s just fabulous, and I´m enjoying every second of it.”