Brain Chip, Electro-Sleeve Help Paralyzed Man Move His Hand
For the first time, a person living with paralysis has regained movement with recorded signals from the brain.
The goal of restoring movement to victims of paralysis, stroke or brain injury has consumed medical researchers for the past century. In recent years, they've deployed a variety of electronic devices to build a "brain-computer interface" that could harness the power of brainwaves to move muscles or other objects.
President Obama has discussed the science of spinal cord research this week on the Science Channel and Discovery News.
Today, a team of scientists says they made another step toward that goal by recording and translating brain signals to bypass a spinal cord injury and allow a 24-year-old man to move his hand again.
"This study marks the first time that a person living with paralysis has regained movement with recorded signals from the brain," said Chad Bouton, division leader at the Feinstein Institute for Medical Research in Manhasset, N.Y. "It's an important pathway for other patients in the future. For stroke and spinal cord and traumatic brain injury patients, this will help."
Bouton and colleagues from Batelle Research and Ohio State University report in the journal Nature on an experiment in which they implanted a small chip in a section of the brain called the motor cortex of a paraplegic male patient.
The chip recorded some of the electronic brain signals that were activated when the patient, Ian Burkhardt, was shown images of various hand movements -- processing more than three gigabytes of information every minute. It used machine-learning algorithms to translate and relay the signals to a electro-stimulation device worn on the Burkhardt's forearm. This system allowed him to make six different wrist and hand motions, including picking up a bottle and using a stick to stir the contents of a jar.
"The first time I was able to open and close my hand I felt a sense of hope for the future," said Burkhardt, who broke his neck while diving into a wave when he was 19 years old. "Now within last two years since then, things are moving better than I imagined."
Of course, Burkhardt can only move his arm while connected to the device inside the laboratory at Ohio State. And he has a chip implanted into his brain, a chip that the researchers said will degrade over time and could become infected or rejected by the body. Still, Burkhart hopes that he can one day leave the lab with functioning limbs. He says the electro-stimulation device, which is basically a series of wires and electrodes attached to his skin, is easier to wear than a bulky prosthetic.
"You're not going to be looked on as a cyborg with this big thing on your arm," Burkhart said. "It's a lot more natural and you are normal. It's a lot easier to use and fits in with your everyday life."
Ali Rezai, a co-author on the new report and director of Ohio State's Center for Neuroregeneration, said the team wanted something easy to wear.
"It's important for the patient to move their own limb," Rezai said. "We want the patients to use their own body parts that have become dysfunctional."
Other researchers are not convinced by this experiment, saying the brainwave translation model is unnecessarily complex and has been done before.
"This is not a new idea," said Robert Winograd, a hand surgeon at Massachusetts General Hospital and assistant professor of surgery Harvard Medical School. "This control scheme adds that level of control that we are all seeking. It does it at considerable risk to the patient. I don't know a clear enhanced benefit."
Winograd has been working with Emilio Bizzi, principal investigator at the McGovern Institute for Brain Research at the Massachusetts Institute of Technology to activate large groups of brain cells that control movement in many muscle groups. Bizzi said he wasn't impressed with the new paper, saying that the experiment only activates a relatively small number of brain cells with the six movement patterns.
"They are recording from a small area of the cortex that doesn't convey signals to do normal complex movements of everyday life," Bizzi said. "The discrepancy is too big."
The authors of the new paper acknowledged that other groups are working on other systems to restore movement, some using exoskeletons controlled by brain signals, for example, or a three millimeter stent that is inserted into the brain without surgery that could wirelessly control an wheelchair.
Nick Langhals, program director for neural engineering t the National Institutes of Health, said the Nature paper takes two existing techniques and puts them together in a new way.
"This is one of the first example of combining the two together," Langhals said.
Despite recent headlines about new advances, progress in the field of brain computer interface has been slow, according to Langhals. There are few eligible patients to work with, and many systems don't work well yet outside the laboratory, where signals from cell phones, radios or other forms of communication can interfere with the human-computer connection.
"The only way we are going to implement these things is studies like this is to get to practical implementation," he said. "You can only do it so many times in the lab when you have to get into the human population."
A computer chip in Ian Burkhart`s brain reads his thoughts, decodes them, then sends signals to a sleeve on his arm, that allows him to move his hand.
If we can think it, we can control it.