Technology Holds Promise for Paraplegics, Others with Limited MovementSaturday, December 31st, 2011
Lizzeth Davila, 8, was peering at a picture on her doctor’s office wall when the it hit.
Her eyes rolled. Her arms, legs and head thrashed back and forth. Her mother cupped her ears with both hands, gently held her head and whispered: “Are you OK?”
Lizzeth, 8, had battled epileptic seizures for three years. Over that time, the seizures had become more intense and prolific with as many as four dozen each day.
She underwent surgery more than two months ago in an attempt to limit the seizures. And as part of a study that could have implications far beyond her condition, the neurosurgeons at Phoenix Children’s Hospital implanted a grid of electrodes to test a technology that one day could marry humans and machines in seamless movement.
The experiment seeks to further develop technology that could allow paraplegics, stroke patients and others with limited movement to think commands to a prosthetic limb or device and recapture a full range of motion.
While neurosurgeons conducted surgery for Lizzeth’s epilepsy, they implanted electrodes along the surface of her brain and tracked activity as she moved a cursor for a video-game-like device. The computer would later replicate Lizzeth’s movements based on the data gathered from measurement of her brain waves.
Children who require surgery for epilepsy are good subjects because surgeons need a medical reason to implant the electrodes in a child’s brain. In the case of the epilepsy patients, the electrodes are needed to monitor a child’s brain activity during seizures.
The brain-computer interface technology could one day be used to help people with limited mobility regain their movements, said David Adelson, a Phoenix Children’s Hospital neurosurgeon who is conducting the experiment with Arizona State University researchers.
Adelson provided some examples of how the technology could be useful. A quadriplegic could flip a light switch or type an e-mail, an amputee could use a prosthetic arm to reach for a cup or a stroke patient could regain movement.
“What we’re trying to see is can you create learning in the brain in areas that don’t have that function,” Adelson said.
So far, four children who required surgery for epileptic seizures have participated in the study at Phoenix Children’s Hospital. Adelson said he plans to test the technology on four to six additional children.
The research is partly funded by a three-year grant of nearly $500,000 from the Arizona Biomedical Research Commission.
Adelson said some patients are alert during the experiment and generate a high degree of motor activity. Others are tired and less active in manipulating the video-game device. Still, those less-active patients provide valuable information. Researchers can measure sensory information such as how they respond to vibration, temperature or soft touch, Adelson said.
Stephen Helms Tillery, a professor at Arizona State University’s school of biological and health-systems engineering, is working with Adelson. He has conducted more advanced studies using this technology on animals.
Tillery said that the technology needs to be developed and refined before it can be useful to a person who uses a wheelchair or an amputee who needs a prosthetic arm, leg, hand or finger.
Scientists are trying to figure out how to relay sensory information back to a person using the prosthetic limb. For example, a person would be able to pick up a cup of coffee, but a prosthetic hand would not be able to send signals back to the person’s brain to inform them that the coffee was hot or cold.
Tillery said there are practical reasons for refining the technology. Consider an artificial hand developed by scientists at Johns Hopkins University. The hand can grab an egg, for example, but users cannot control whether to use a strong or gentle grip. Think of the Terminator crushing an egg.
Another limitation is reaching for items a user cannot see. So if a person wants to grab a file from a briefcase while staring at a computer screen, the existing technology does not allow a person to make such a transfer.
Tillery said another important development will be refining wireless technology so users are not tethered by wires. This would allow someone with an implanted device to seamlessly control an arm or a leg and feel that the prosthetic limb is a natural extension of their body.
The research field into such brain-controlled prosthetics is mushrooming, with both university scientists and private businesses investing in the field.
One year ago, the University of California-Berkeley and the University of California-San Francisco launched the Center for Neural Engineering and Prostheses.
ASU is collaborating with a Los Angeles-based company, SynTouch, which has developed an artificial finger.
“The technology is getting ripe,” Tillery said. “The costs are a little high now, but within five years, some of these things will be available for purchase.”
Need for volunteers?
Arizona’s contribution to the technology, however, will hinge on patients such as Lizzeth who are willing to participate.
Since the September surgery, Lizzeth has been seizure-free. She has slowly begun to talk more and interact with others.
Lizzeth, who lives in Mesa, also is back at school and striving to catch up in math and reading. She fell behind even before the surgery, as the seizures struck more often.
“This is what we were hoping for,” said Yesica Aguilar, Lizzeth’s mother. She is back to her normal activities, riding bikes and scooters.
It is the second surgery that Lizzeth has had for her seizures, and Aguilar hopes it is the last time.
“Hopefully it’s done and over with and that she comes back to her normal happy, confident self,” Aguilar said.
Reach the reporter, Ken Alltucker at firstname.lastname@example.org or 602-444-8285.