Special Report: A Touching Movement
A quadriplegic man moved neuromodulation a step forward.
Declaring it a first in medicine, researchers at The Ohio State University have completed a procedure that has allowed a paralyzed man to move his fingers and hand with his own thoughts. The breakthrough was made possible by a technology called Neurobridge developed by researchers at Battelle, working with doctors at Ohio State. The researchers implanted a microchip sensor in the patient’s brain that essentially read his thoughts and sent signals to a wearable high-tech sleeve placed on his forearm to control muscle movements.
The overall aim of this study is to advance the field of the brain machine interface and its application for patients with spinal cord and brain injuries to be more connected to their environment, according to Ali Rezai, MD, director director of The Ohio State University Wexner Medical Center’s Neuroscience Program, and director of Neuromodulation at Ohio State’s Wexner Medical Center. The study will last six months.
“Specifically, we are able to use the brain signals of a patient with quadriplegia to voluntarily move the muscles in his paralyzed hand via a brain-device interface that bypasses the patients damaged spinal cord,” he said. “The technology utilizes a multi-array neuronal signal sensor that is implanted in the upper extremity motor cortex of the brain.”
The brain signals linked to repeated visualization and thoughts about movement are chronically recorded, filtered, amplified, processed, analyzed and interpreted using various decoding computer algorithms. The decoded brain signals from the visualization and thoughts of movements are then re-coded and linked to an external high definition muscle stimulation sleeve that the patient wears around their arm.
“This technology allows a patient who has not moved his hands for four years since the injury to have consistent voluntary multi-dimensional hand and finger movement linked to his thoughts,” he said.
Researchers inserted a chip smaller than a pea onto the motor cortex of the patient’s brain during a three-hour surgery. The surgical procedure required precise localization of the motor cortex hand area. In order to achieve this, they utilized computerized anatomical and physiological image guidance using pre-operative high-resolution structural and functional MRI studies delineating the location of the upper extremity motor cortex. Further location verification was accomplished during surgery via physiological mapping of the motor and sensory cortex. Once the exact location of the hand motor cortex was determined, the recording micro array chip was implanted on the upper extremity motor cortex, and connected to a pedestal signal-recording interface on the surface of the skull.
Neuroscientists and engineers at the Battelle Corporation developed the Neurobridge technology. “This technology consists of software that combines algorithms that learn and decode the user’s direct brain activity and links it to a high definition and high resolution super flexible muscle stimulation electrode sleeve that translates neural signals to move the muscles of a paralyzed limb on demand,” Dr. Rezai. “The stimulation cuff/array is comprised of small circular hydrogel electrodes that allow for stimulation of small and large muscles and a wide variety of spatial patterns and associated movements.”
The brain microchip senses and records neuronal electrical signals, which are subsequently decoded, analyzed and interpreted, and re-coded and linked to the external high definition stimulation sleeve that the patient wears around their arm. “This technology allows for a direct communication between ones brain and an external device,” he said. The technology also employs machine learning paradigm, whereby repeated trials of visualizing and thinking about a movement or a task, that signal becomes standardized and clear over time and can be linked more consistently and accurately to electrodes that externally stimulate muscles.
“This is the first step in what we hope to be a brighter future for those living with disabilities from spinal cord and brain injuries. We are now able to harness one’s thoughts of movements and link it to devices that will allow them to function better,” Dr. Rezai said. “The current systems are complex and require wired connections and significant analytic and computing capabilities as well as having a significant costs and a need for multidisciplinary teams. I believe that in the future these systems will become wireless with more advanced decoding and recoding, analytic and feedback capabilities that will result in more precise, complex, smooth, and natural movements which will also be tailored to individuals disabilities.”
Overall, he says, there is a need for significant additional research and development activity to advance brain device interface technology, applications, expertise and equipment to help patients and their families. “I am hoping that there will be a day coming soon where those with brain or spinal cord injury and disability can more routinely utilize brain device interface technologies, to use their thoughts, to move their arms and legs and to more effectively interact with their surroundings and improve their function.”
Watch video of the patient online at PracticalNeurology.com.