New arterial implant allows thought-control of bionic limbs
Collaboration in Melbourne leads to ‘holy grail’ mobility device for disabled.
“We have been 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,” explains Dr. Thomas Oxley, principal author and Neurologist at The Royal Melbourne Hospital and Research Fellow at The Florey Institute of Neurosciences and the University of Melbourne.
“Our vision, through this device, is to return function and mobility to patients with complete paralysis 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. In essence this a bionic spinal cord.” Currently, the minimally invasive brain-machine interface is set to be implanted in the first in-human trial at The Royal Melbourne Hospital in 2017.
The concept is similar to an implantable cardiac pacemaker—electrical interaction with tissue using sensors inserted into a vein, but inside the brain, explains Dr. Nicholas Opie, co-principal investigator and biomedical engineer at the University of Melbourne. The device itself measures only three millimeters wide and
“Utilizing 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,” Dr Opie said.
The development of the stentrode has been the “holy grail” for research in bionics, says Professor Terry O’Brien, Head of Medicine at Departments of Medicine and Neurology, The Royal Melbourne Hospital and University of Melbourne.
“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,” Professor O’Brien said.
“The device has gone through a number of iterations; there have been a large number of challenges that we’ve had to overcome to manufacture the device that is suitable and safe for implementation,” Opie adds. The stentrode is made of nitinol, a nickel-titanium composite, which provides greater resilience when being flexed and compressed over other more commonly used materials.
The possibilities for such a device are endless, with O’Brien adding that it has the potential to be used in people with a wide range of diseases, not just spinal cord injuries, but epilepsy, Parkinson and other neurological disorders.