RAPID advancement in the field of neurobionics and brain–computer interface (BCI) may see the restoration of vision in people with acquired blindness or assistance for people with spinal cord injuries to walk, but many technical and ethical challenges lie ahead, say experts.
In a Narrative Review published in the MJA, Professor Jeffery Rosenfeld, director of the Monash Institute of Medical Engineering and senior neurosurgeon at Alfred Health, and Dr Yan Tat Wong, biomedical engineer and neuroscientist at the University of Melbourne, reviewed international research efforts in BCI applications over the past decade.
BCI technology involves linking the brain to computers through scalp, subdural or intracortical electrodes. These electrodes transmit computer-generated electrical signals to the brain; or receive, record and interpret electrical signals from the brain.
The authors wrote that BCIs were being developed to provide ambulation for patients with paraplegia, through controlling robotic exoskeletons; restore vision in people with acquired blindness; detect and control epileptic seizures; and improve control of movement disorders and memory enhancement.
The authors pointed to several reports of the application of BCI in both motor and sensory interfaces, including a report in Nature in 2016 of the use of BCI in a 24-year-old US man with quadriplegia, allowing him to move his fingers to grasp, manipulate and release objects in real time.
In an MJA InSight podcast, Professor Rosenfeld said that implanting an electrode inside the brain provided the most precise stimulation or recording, but that this was also the most invasive option, which presented several challenges.
“Most of the reports, as you will see in the review, have been on patients who have had a wire cable coming out of the head through a plug arrangement in their skull – that’s clearly not a practical proposition … so we need to create wireless devices,” he said, adding that advances in battery technology would also assist in the development of BCI.
Professor Rosenfeld said that other challenges arose with the long term implantation of a device in the brain.
“Micromovements in these electrodes … lead to scarring, and that impairs the signal over time,” he said. “So, we’re looking at new types of electrode design that minimise those effects … they may have an anti-inflammatory coating on them, they may be polymer-based rather than metal-based, they may be nanotechnology-type designs with carbon nanotubes. These are all the things that are being looked at experimentally to try to increase the longevity of these electrodes.”
Professor Robert Shepherd, Director of the Bionics Institute and Professor of Medical Bionics at the University of Melbourne, told MJA InSight that it was “highly likely” that a person confined in a wheelchair today could be walking via assistive technologies controlled by a BCI within a decade.
However, he agreed that there were many hurdles to overcome.
“In addition to the challenges outlined in the review, additional challenges include the ability of weakened muscles to support the body – muscle strengthening or exoskeletons to support the body weight would be needed to overcome this problem,” he said.
“I also see the pathway to commercialise these technologies as problematic as the number of potential end-users is not huge and the technology is invasive (at least using microelectrodes).”
Professor Shepherd said that BCI technology could only be developed in a multidisciplinary environment, with scientists, engineers and clinicians working very closely together, and added that there were also great opportunities in combining bionics with regenerative medicine.
“For example, combining an electrode array with slow-release neurotrophins to maximise the health of the target neural population.”
A key ethical challenge in the development of BCI is the potential for the technology to be applied to enhance normal physical or cognitive function, perhaps even in the creation of a “‘super’ soldier”, the MJA authors suggested.
Professor Shepherd said that this was a potential concern, particularly if BCIs were used in association with exoskeletons to allow soldiers to carry huge weights or cover vast distances.
“But the best BCI devices currently being developed involve invasive surgery to place microelectrodes in the brain – a procedure that may be acceptable for a patient who had a severe stroke, but not for an able-bodied soldier,” he said.
“Other ethical concerns include the careful management of patients’ expectations and the care that needs to go into the informed consent prior to clinical application.”
Professor Rosenfeld told MJA InSight that there was a concentration of bionic engineering expertise in Australia.
“The quality of the research [in Australia] is at a world-leading level and it would be great if our government could give this effort greater financial support,” Professor Rosenfeld said.
He said that the Rudd government had invested $50 million into the development of bionic vision and a continuation of such largesse could pay dividends across several sectors.
“Further development of [this] advanced technology in Australia … leads to not only improving the lives of people with disabilities, but it also leads to new high-tech industry for Australia, new export industry and new jobs,” Professor Rosenfeld said.
The Bionic Institute conducted its first trial of a bionic eye in three patients from 2012 to 2014, and along with its clinical partner, the Centre for Eye Research Australia, the institute will commence a second trial in the next 4 months.
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