May 2017 Medical News Today

Neuroprosthetics, also known as brain-computer interfaces, are devices that help people with motor or sensory disabilities to regain control of their senses and movements by creating a connection between the brain and a computer. In other words, this technology enables people to move, hear, see, and touch using the power of thought alone. How do neuroprosthetics work? We take a look at five major breakthroughs in this field to see how far we have come - and how much farther we can go - using just the power of our minds.

neuroprostheticsUsing electrodes, a computer, and the power of thought, neuroprosthetic devices can help patients with motor or sensory difficulties to move, feel, hear, and see.

Every year, hundreds of thousands of people worldwide lose control of their limbs as a result of an injury to their spinal cord. In the United States, up to 347,000 people are living with spinal cord injury (SCI), and almost half of these people cannot move from the neck down. For these people, neuroprosthetic devices can offer some much-needed hope.

Brain-computer interfaces (BCI) usually involve electrodes - placed on the human skull, on the brain's surface, or in the brain's tissue - that monitor and measure the brain activity that occurs when the brain "thinks" a thought. The pattern of this brain activity is then "translated" into a code, or algorithm, which is "fed" into a computer. The computer, in turn, transforms the code into commands that produce movement.

Neuroprosthetics are not just useful for people who cannot move their arms and legs; they also help those with sensory disabilities. The World Health Organization (WHO) estimate that approximately 360 million people across the globe have a disabling form of hearing loss, while another 39 million people are blind. For some of these people, neuroprosthetics such as cochlear implants and bionic eyes have given them back their senses and, in some cases, they have enabled them to hear or see for the very first time.

Here, we review five of the most significant developments in neuroprosthetic technology, looking at how they work, why they are helpful, and how some of them will develop in the future.

Ear implant

Probably the "oldest" neuroprosthetic device out there, cochlear implants (or ear implants) have been around for a few decades and are the epitome of successful neuroprosthetics.

The U.S. Food and Drug Administration (FDA) approved cochlear implants as early as 1980, and by 2012, almost 60,000 U.S. individuals had had the implant. Worldwide, more than 320,000 people have had the device implanted. Although imperfect, cochlear implants allow users to distinguish speech in person or over the phone, with the media abound with emotional accounts of people who were able to hear themselves for the first time using this sensory neuroprosthetic device.

Eye implant

The first artificial retina - called the Argus II - is made entirely from electrodes implanted in the eye and was approved by the FDA in February 2013. In much the same way as the cochlear implant, this neuroprosthetic bypasses the damaged part of the retina and transmits signals, captured by an attached camera, to the brain. This is done by transforming the images into light and dark pixels that get turned into electrical signals. The electrical signals are then sent to the electrodes, which, in turn, send the signal to the brain's optic nerve. While Argus II does not restore vision completely, it does enable patients with retinitis pigmentosa - a condition that damages the eye's photoreceptors - to distinguish contours and shapes, which, many patients report, makes a significant difference in their lives. Retinitis pigmentosa is a neurodegenerative disease that affects around 100,000 people in the U.S. Since its approval, more than 200 patients with retinitis pigmentosa have had the Argus II implant, and the company that designed it is currently working to make colour detection possible as well as improve the resolution of the device.

Neuroprosthetics for people with SCI

Almost 350,000 people in the U.S. are estimated to live with SCI, and 45 percent of those who had an SCI since 2010 are considered tetraplegic - that is, paralysed from the neck down. We recently reported on a groundbreaking one-patient experiment that enabled a man with quadriplegia to move his arms using the sheer power of his thoughts. Bill Kochevar had electrodes surgically fitted into his brain. After training the BCI to "learn" the brain activity that matched the movements he thought about, this activity was turned into electrical pulses that were then transmitted back to the electrodes in his brain. In much the same way that the cochlear and visual implants bypass the damaged area, so too does this BCI area avoid the "short circuit" between the brain and the patient's muscles created by SCI. With the help of this neuroprosthetic, the patient was able to successfully drink and feed himself. "It was amazing," Kochevar says, "because I thought about moving my arm and it did." Kochevar was the first patient in the world to test the neuroprosthetic device, which is currently only available for research purposes.

However, this is not where SCI neuroprosthetics stop. The Courtine Lab - which is led by neuroscientist Gregoire Courtine in Lausanne, Switzerland - is tirelessly working to help injured people to regain control of their legs. Their research efforts with rats have enabled paralysed rodents to walk, achieved by using electrical signals and making them stimulate nerves in the severed spinal cord. "We believe that this technology could one day significantly improve the quality of life of people confronted with neurological disorders," says Silvestro Micera, co-author of the experiment and neuroengineer at Courtine Labs. Recently, Prof. Courtine has also led an international team of researchers to successfully create voluntary leg movement in rhesus monkeys. This was the first time that a neuroprosthetic was used to enable walking in nonhuman primates. However, "it may take several years before all the components of this intervention can be tested in people," Prof. Courtine says.

An arm that feels has also led other projects on neuroprosthetics. In 2014, MNT reported on the first artificial hand that was enhanced with sensors. Researchers measured the tension in the tendons of the artificial hand that control grasping movements and turned it into electric current. In turn, using an algorithm, this was translated into impulses that were then sent to the nerves in the arm, producing a sense of touch. Since then, the prosthetic arm that "feels" has been improved even more. Researchers from the University of Pittsburgh and the University of Pittsburgh Medical Centre, both in Pennsylvania, tested the BCI on a single patient with quadriplegia: Nathan Copeland. The scientists implanted a sheath of microelectrodes below the surface of Copeland's brain - namely, in his primary somatosensory cortex - and connected them to a prosthetic arm that was fitted with sensors. This enabled the patient to feel sensations of touch, which felt, to him, as though they belonged to his own paralysed hand. While blindfolded, Copeland was able to identify which finger on his prosthetic arm was being touched. The sensations he perceived varied in intensity and were felt as differing in pressure.

Neuroprosthetics for neurons? 

We have seen that brain-controlled prosthetics can restore patients' sense of touch, hearing, sight, and movement, but could we build prosthetics for the brain itself? Researchers from the Australian National University (ANU) in Canberra managed to artificially grow brain cells and create functional brain circuits, paving the way for neuroprosthetics for the brain. By applying nanowire geometry to a semiconductor wafer, Dr. Vini Gautam, of ANU's Research School of Engineering, and colleagues came up with a scaffolding that allows brain cells to grow and connect synaptically.

Project group leader Dr. Vincent Daria, from the John Curtin School of Medical Research in Australia, explains the success of their research:

We were able to make predictive connections between the neurons and demonstrated them to be functional with neurons firing synchronously. This work could open up a new research model that builds up a stronger connection between materials nanotechnology with neuroscience."

Neuroprosthetics for the brain might one day help patients who have experienced a stroke or who live with neurodegenerative diseases to recover neurologically. Every year in the U.S., almost 800,000 people have had a stroke, and more than 130,000 people die from it. Neurodegenerative diseases are also widespread, with 5 million U.S. adults estimated to live with Alzheimer's disease, 1 million to have Parkinson's, and 400,000 to experience multiple sclerosis.

May 2017 PLOSone

Many people with severe or severe-profound hearing loss in the high frequencies have functional residual hearing in the low frequencies. For such people, electric-acoustic-stimulation (EAS) or hybrid systems, which combine the use of CI (electric stimulation, ES) and a hearing aid (acoustic stimulation) into one device, are advisable and can significantly benefit users, especially in difficult listening environments. For EAS candidates and for CI candidates with less residual hearing, CI manufacturers developed thin and straight electrodes with lengths between 16 mm and 31 mm. The aim of these developments was to preserve residual hearing, even when it is marginal, by minimising intraoperative damage to the sensitive intracochlear structures; while at the same time offering good speech understanding with electrical hearing only. If a CI recipient does lose residual hearing due to surgery, his/her electrically stimulated hearing must be superior to his/her preoperative speech understanding results or he/she will not have derived benefit from implantation.

This investigation evaluated the effect of cochlear implant (CI) electrode length on speech comprehension in quiet and noise and compare the results with those of EAS users.

91 adults with some degree of residual hearing were implanted with a FLEX20, FLEX24, or FLEX28 electrode. Some subjects were postoperative electric-acoustic-stimulation (EAS) users; the other subjects were in the groups of electric stimulation-only (ES-only).

Speech perception was tested in quiet and noise at 3 and 6 months of ES or EAS use. Speech comprehension results were analysed and correlated to electrode length.

Conclusions: Among ES-only users, the FLEX28 ES users had the best speech comprehension scores, at the 3- months appointment and tendentially at the 6 months appointment. EAS users showed significantly better speech comprehension results compared to ES-only users with the same short electrodes.

May 2017 , Derek Parker (writer and critic), The Weekend Australian

It says much that surgery to implant the bionic ear is no longer considered newsworthy. Thousands of people in Australia are walking around with one, and that is largely due to Bill Gibson, known widely as “the Prof” by many of those he has helped to achieve a normal life.

He is not widely known outside medical circles, and this book is meant to remedy that. Gibson readily co-operated with Tina Allen, an experienced medical scientist and writer, but he sometimes seems a bit bemused about the project. He simply is not the celebrity type. He is the type who goes fishing with mates and dresses up as Santa Claus for children’s parties.

Although he seems very Australian, he was in fact born in Britain. He comes from a family of doctors and there was never much doubt that he would become one. He studied in Britain, where he gained his qualifications, and was drawn to audiology because of the breakthroughs taking place in the field. In particular, Graeme Clark and his team in Melbourne were examining ways of using new technology to help deaf people, focusing on the cochlea, the part of the ear that passes sounds to the brain. There was already a primitive version of the bionic ear available but it provided only a dot-dash sort of sound. Developing this into a multi-channel device that could convert sounds into electronic impulses that the brain could “hear” was a huge step forward. Gibson came to Australia in 1983 to follow it up, seeing the opportunity to knit his surgical expertise to the device.

 Bill Gibson BiographyNewSouth Press 302pp, $35

Allen is adept at explaining the technology and how it evolved from its shaky beginnings, growing from rough experiments to a commercial model. In 1984 Gibson implanted the device in two women who had lost their hearing, with good results. Further refinements of the device followed and the surgical procedure became more routine. There were, inevitably, failures as the medical teams learned more about distinguishing between patients who were suitable for implants and those who were not but there was a sense of solid progress. The device became compact and Gibson developed a way to implant it using a small incision rather than a large C shaped one.

The first generation of recipients were people who had lost their hearing in adulthood. This meant they understood the concept of speech and of spoken communication. Gibson formed the view that while restoring hearing to adults was important, the focus should be on young people, even children, who had been deaf from birth and so had never learned to speak. By the age of seven or so the speech organs had effectively atrophied.

Gibson eventually chose a four-year-old girl for an implant, which involved convincing medical regulators that the process was ethical and practical. It worked, and the little girl learned to both understand and use speech. Gibson was able to leverage the success to push the age threshold downwards, to children under the age of two. Along the way he helped establish CICADA — Cochlear Implant Club and Advisory Association — a group than enables implant recipients to meet regularly, providing support to each other and feedback to doctors. (This biography was commissioned by CICADA.)

As the success rate improved it became easier to obtain funding for specialist facilities and post-op therapy. But there was one group that criticised and attacked Gibson, as well as others in the bionic ear circle. The Signing Deaf group took the view that congenital deafness should not be seen as a disease to be “cured”. Instead, the focus should be on teaching deaf children about signing, which should itself be seen as a valid alternative language. Allen notes this idea is difficult to understand but she acknowledges that it is deeply held by some. Gibson, for his part, listened to the view and was sympathetic to the idea of removing any trace of social stigma from deafness. But he looked more to the real-world picture, which was largely of people delighted to be able to participate fully in the world.

Eventually, Gibson notched up more than 2000 implant operations. As he nudged 70 he began to move out of the surgical side, but at 73 he still assists and consults. He thinks of retirement, apparently, as dropping down a gear rather than switching off the engine.

This is a fascinating story but, as biographies go, there is not much in the way of narrative tension. Basically, Gibson has lived a good life filled with good works. Nearly everyone who has had anything to do with him has only warm words to say. Judging from the photos included in the book, he and his wife of many years remain deeply bonded. So if you want to read about personal sturm und drang or this month’s celebuwreck, then this book is not for you. But if you want to find out about how the world was made a better place, then it is a good place to go.

June 2017 Canberra Times

Engineers Australia says it is on track to have a $2 million sculpture inspired by the cochlear implant in the ground at the National Arboretum Canberra by 2019. The year is significant as 2019 represents the centenary of Engineers Australia, the body representing engineers from all disciplines. The cost of the sculpture will be met by fundraising by Engineers Australia.

implant sculpture #1The design for the sculpture was decided in 2014 after a competition, with the winner, Queensland firm Bligh Tanner, inspired by the Australian-developed hearing device, the cochlear implant.

The design curls through the Freefall Pin Oak Forest at the arboretum, also known as the Engineers Forest. The pin oak is a popular street tree in Canberra, especially in the inner south. In 1926, the Institution of Engineers helped sponsor the plantings of trees around what is now known as Manuka Circle. The late Dr Robert Boden was responsible for developing the "Freefall" cultivar, which sheds its leaves on cue after autumn.

sculpture #2Rolfe Hartley, chairman of the steering committee behind the sculpture, said it was focused on final technicalities for erecting the sculpture, including works approval from the National Capital Authority, before fundraising would begin in earnest. "The fundraising is still very much in its early days," he said. Engineers Australia division manager Keely Quinn said fundraising would be through donations from members, corporate partners and the community.

The sculpture will be made from corten steel and have a rust-like exterior. 

arboretum3The design was also being finetuned, not in terms of how it looked, but more the logistics of building it, Mr Hartley said. "We didn't brief that we wanted a cochlear implant design but having chosen it, we think it's a really fantastic concept," he said. "The cochlear implant is an Australian engineering innovation that really transforms people's lives and showcases cutting-edge technology, which summarises what we want to say about Australian engineering."

Mr Hartley said the committee was "pretty comfortable" with meeting requirements for works approval and expected to have an application submitted to the NCA by October or November.