Medical Researchers in Melbourne, Australia have created a new bionic spine that will give those suffering from spinal cord injuries hope to walk again using the power of thought. The minimally-invasive brain-machine interface consists of a stent-based electrode implanted within a blood vessel next to the brain, which then records the type of neural activity that pre-clinical trials have shown to move limbs through an exoskeleton or bionic limbs.
The concept is similar to a cardiac pacemaker-electrical interaction with tissue using sensors inserted into a vein-but inside the brain. Nicholas Opie, co-principal investigator and biomedical engineer at the University of Melbourne, said that, by using stent technology, “our electrode array self-expands to stick to the inside wall of a vein, enabling us to record local brain activity. By extracting the recorded neural signals, we can use these as commands to control wheelchairs, exoskeletons, prosthetic limbs or computers.”
The stent-based electrode (dubbed stentrode) is smaller than a paper-clip and was called “revolutionary” by Thomas Oxley, principal author and neurologist at The Royal Melbourne Hospital where the study was mainly conducted. Oxley said that the 39 academic scientists from 16 departments were able to “create the world’s only minimally invasive device that is implanted into a blood vessel in the brain via a simple day procedure, avoiding the need for high-risk open brain surgery.” The main goal of the project was to “return function and mobility to patients with complete paralysis” from a spinal cord injury “by recording brain activity and converting the acquired signals into electrical commands, which in turn would lead to movement of the limbs through a mobility assist device like an exoskeleton.”
Exoskeletons are currently controlled by the manual manipulation of a joystick to transfer from the various stages of walking (for example: sit, stand, etc.). However, the stentrode would be the first device to allow direct thought-control of these devices, making the fact that the device does not require major brain surgery even more impressive. The device is instead implanted via angiography (a procedure performed to view blood vessels after injecting them with a radiopaque dye that outlines them on x-ray), which greatly decreases the risks involved with open brain surgery.
The first in-human trial is planned to take place in 2017 at The Royal Melbourne Hospital. Pre-clinical tests have been positive, showing the device was safe for long-term use, successfully recording brain activity over many months, and the quality of the recordings improved over time as the device was eveloped into tissue.
Terry O’Brien, head of Medicine at the departments of Medicine and Neurology at The Royal Melbourne Hospital and University of Melbourne, said the stentrode was “the holy grail” for research in bionics. “To be able to create a device that can record brainwave activity over long periods of time, without damaging the brain is an amazing development in modern medicine.” O’Brien also pointed out the possible advancements in treatments of other diseases besides spinal cord injuries, such as Parkinson’s and epilepsy, that could benefit from the stentrode.
With the success of the trials, the researchers at the Royal Melbourne Hospital look forward to the benefits the stentrode can provide in modern medicine, and hope to one day be able to provide independence to those suffering from paralysis.
Dr. Banco is a board-certified, fellowship-trained orthopaedic spinal surgeon. He attended medical school at Jefferson Medical College followed by an orthopaedic surgery residency at Thomas Jefferson University Hospital, both in Philadelphia. Dr. Banco performed his spinal fellowship at The New England Baptist Hospital in Boston, MA. Dr. Banco is on the Editorial Review Board for “The Journal of Spinal Disorders and Techniques.”