As you know, spinal cord injuries cause the brain and spinal cord to no longer communicate. This means that the brain is no longer able to send signals to the spinal cord for movement to occur because of a severe injury which results in a person's inability to move his limbs. Scientists and bioengineers hope to restore motion through the brain controlled wheelchair.
The idea of the brain controlled wheelchair is thought to be far from possible. But recently, scientists revealed that they have tested a mechanical exoskeleton on monkeys (rhesus macaques) that is controlled by the wearer’s thoughts. The test amazingly worked and bioengineers are overwhelmed by this achievement.
So how does this work? Hundreds of electrodes or sensors are implanted onto the rhesus macaque’s motor cortex. The motor cortex is the part of the cerebral cortex that is involved in the planning, control and execution of voluntary movements.
The electrodes, with the width of a human hair, are arranged in arrays like the bristles of a toothbrush. Numerous electrode or sensor arrays are implanted to the motor cortex of the monkey wherein every single array monitors 500 neurons.
The electrode arrays send signals to a CPU or central processing unit in a helmet of the mechanical exoskeleton wherein the helmet compiles the signals received into coherent commands. The commands compiled or collected are then transmitted wirelessly to a backpack computer.
Through the backpack computer, the commands are coordinated to produce complex motion. Movements of the joints and limbs occur as the tiny motors on the exoskeleton pick up the commands compiled and sent by the computer.
This experimental exoskeleton is created and designed by the well-known neuroscientist from Duke University Miguel Nicholelis. Nicholelis and his team have been working on this project, developing and improving it in order to give movement to individuals with paralysis.
Nicholelis presented at the Society of Neuroscience meeting their latest findings and development regarding the brain-machine interface. He stated in the meeting that two trained rhesus monkeys with sensors or electrodes implanted deep in their motor cortex were able to steer a wheelchair with their thought alone.
This achievement serves as a stepping stone for Nicholelis and his team as well as other scientists and bioengineers to develop a machine or a wheelchair that gives people with paralysis the option of voluntary motion.