Why researchers want to read the minds of spinal cord injury patients.
Imagine a wheelchair with robotic arms that move on command by reading the paralyzed occupant’s mind, some say why the idea is not so far fetched.
There are up to 400,000 people in the United States struggling with paralysis from spinal cord injuries. They can’t move when or how they want because their brain no longer gets the message to their body.
Miguel Nicolelis M.D. said, “If we have a Lesion that is like a lesion in the highway, so signals cannot cross.”
But doctors at Duke Medical Center are working on a “detour”, for brain signals so they can bypass the lesion, or injury, in the spinal cord.
“We hope that we can create what I like to call a brain pacemaker,” Dr. Nicolelis said.
The pacemaker would separate Motor commands from brain activity, sort of read the patient’s mind if you will, and send the information to a computer.
“Let’s say a laptop would be under the wheelchair. That laptop would then very quickly extract the motor commands and transmit it to a robot that would be in the arms of the wheelchair,” he stated.
Then just by “thinking” it, the patient could make the robotic arms perform tasks the patient’s own arms cannot.
“To feed the patient, grab objects, type in a computer, control a computer that would be in the chair, that controls appliances or other utilities,” Dr. Nicolelis explained.
Sound impossible? Although its years from a reality, preliminary tests in humans show a brain pacemaker is feasible.
Dr. Nicolelis added, “A few years ago, we had people tell us no, it’ll never happen, so I think that barrier of the impossible and the feasible has been crossed now.”
Researchers said the brain pacemaker could be a reality in five years.
The spinal cord is a network of nerve fibers that run the length of the spine from the brain down to about the waist. Nerve signals travel back and forth through the spinal cord, allowing the brain to “communicate” with the rest of the body.
When the spinal cord is injured, the communications pathway is disrupted. Like a disconnected telephone line, transmission of nerve signals in the area at and below the point of injury is cut off. The closer the injury is to the top of the spinal cord, the greater the loss of function. Paraplegia is the loss of sensation and/or movement in the lower parts of the body. Depending upon the exact location and degree of injury, the condition may affect the feet, legs, hips, stomach and/or chest. Tetraplegia (also called Quadriplegia) is the loss of sensation in the lower and upper areas of the body.
According to the Spinal Cord Injury Information Network, about 243,000 Americans are living with some degree of spinal cord injury (SCI). About 11,000 new cases occur every year. The most common cause of SCI is a motor vehicle crash (nearly 41 percent of cases), followed by falls (22.4 percent), acts of violence (21.6 percent – primarily gunshot wounds) and recreational sports activities.
Pathways to the Brain
When a spinal cord injury occurs, the signals to and from the brain are healthy and intact, but can’t get through. Researchers are searching for ways to regenerate spinal tissue and restore the connection, but it will be many years before treatments may become available. In the meantime, some investigators are looking at other ways to restore some degree of motor control to paralyzed patients.
One new technology is a brain-machine interface. Scientists have learned how to enable computers to analyze and interpret brain electrical signals that control motor function. Those signals could then be used to control a mechanical device.
At Duke University, researchers attached electrodes to the heads of monkeys. The brain signals from the monkeys were fed into a computer, which used the signals to control the motion of a robot arm. The monkeys eventually learned how to control the arm of the robot and play the video game solely by thought.
In a small human study, researchers placed an array of 32 tiny electrodes into the brains of 11 Parkinson’s patients. Then, researchers recorded the brain’s electrical signals while the participants squeezed a ball to control play in a video game. By analyzing the signals, the investigators could effectively predict the degree of grip strength.
Much work still needs to be done. Eventually, scientists hope to be able to develop a method to accurately enable humans to control a mechanized device using brain signals. The technology may help a patient to control a wheelchair, grasp an object or, with the aid of special body armor or suits, walk or move a prosthetic arm.