Tag: bionic eye

Recipients of Bionic Eyes Blindsided by Obsolescence

Source: Daniil Kuzelev on Unsplash

After the manufacturer of a bionic eye ended support, hundreds of recipients of the vision-improving implants have been left without support – “literally in the dark”, as one of them put it.

IEEE Spectrum, which first broke the story, reported that Second Sight discontinued its retinal implants in 2019. The retinal implants serve as the source of artificial vision for the users.

The publication wrote that the firm’s focus is currently on developing a brain implant known as the Orion, which also provides artificial vision. However, it only offers very limited support to the 350 or so who have the now-obsolete Argus II implants.

The system consists of a camera mounted on glasses worn by the user, which transmits video to a video processing unit (VPU), which then encodes the images into arrays of black and white pixels. The VPU then relays the pixel to an electrode array behind the retina, which creates flashes of light corresponding to the white pixels. The technology has had a long and costly road from experiment to product, starting with a lab experiment in the 1990s where stimulation of a single electrode in the retina was discovered to create a visible flash of light perceived by a blind patient. It is hugely expensive, with an estimated cost of $150,000 (R2.25 million) even before the surgery and post-surgery training. 

Implantation surgery typically takes a few hours, followed by training to help users interpret the new optical input from their implants. It is not a replacement for sight; rather it is more like a new sense. Users of the system see fleeting changes of grey which some can then use to assist with basic locomotion. However, the technology is still crude and not all benefit to the same degree. While some can make out the stripes on a pedestrian crossing, others never achieve that level of ability.

The technology also comes with some risk. In the postapproval period, 17% experienced adverse events, though this was an improvement over the 40% in the preapproval period. Since the implant can interfere with MRI scans, some have had to consider removal.

IEEE Spectrum contacted a number of patients, who voiced concern over their future. One patient, Ross Doer, said he was delighted when Second Sight told him in 2020 he was eligible for software upgrades. Yet, he heard troubling rumours. When he called his Second Sight vision-rehab therapist, “She said, ‘Well, funny you should call. We all just got laid off,’ ” he recalled. “She said, ‘By the way, you’re not getting your upgrades.’ ”

“Those of us with this implant are figuratively and literally in the dark,” he said.

Second Sight, when contacted by the publication, said that it had to reduce its workforce because of financial difficulties, and though it attempted to provide “virtual support” was unable to assist with repairs or replacements.
Benjamin Spencer, one of the six patients to receive the new Orion implant, said that it was “amazing” and he was able to see his wife for the first time. But knowing what he does now about Second Sight makes him apprehensive, and plans to have his implant removed at the end of the study period.

Speaking to the BBC, Elizabeth M. Renieris, professor of technology ethics at the University of Notre Dame, in the US, described the development as a cautionary tale.

“This is a prime example of our increasing vulnerability in the face of high-tech, smart and connected devices which are proliferating in the healthcare and biomedical sectors,” she said.

“These are not like off-the-shelf products or services that we can actually own or control. Instead we are dependent on software upgrades, proprietary methods and parts, and the commercial drivers and success or failure of for-profit ventures.”

She added that in future, ethical considerations concerning such technology should include “autonomy, dignity, and accountability”.

Source: IEEE Spectrum

Bionic Eye Demonstration Paves the Way to Human Trials

The Phoenix99 Bionic Eye. Credit: University of Sydney

A bionic eye under development has shown to be safe and stable for long-term implantation in a three-month animal study, paving the way towards human trials.

The Phoenix99 Bionic Eye, being developed by University of Sydney and UNSW, is an implantable system, designed to restore a form of vision to patients living with severe vision impairment and blindness caused by degenerative diseases, such as retinitis pigmentosa. The device consists of two main implants: a stimulator attached to the eye and a communication module positioned under the skin behind the ear.

Published in Biomaterials, the researchers used a sheep model to observe how the body responds and heals when implanted with the device, with the results allowing for further refinement of the surgical procedure. The biomedical research team is now confident the device could be trialled in human patients and have applied for ethical approval.

The Phoenix99 Bionic Eye works by stimulating the retina which, in healthy eyes, the cells in one of the layers turn incoming light into electrical messages. In some retinal diseases, the cells responsible for this crucial conversion degenerate, causing vision impairment. The system bypasses these malfunctioning cells by stimulating the remaining cells directly, effectively tricking the brain into believing that light was sensed.

“Importantly, we found the device has a very low impact on the neurons required to ‘trick’ the brain. There were no unexpected reactions from the tissue around the device and we expect it could safely remain in place for many years,” said Mr Samuel Eggenberger, a biomedical engineer who is completing his doctorate with Head of School of Biomedical Engineering Professor Gregg Suaning.

“Our team is thrilled by this extraordinary result, which gives us confidence to push on towards human trials of the device. We hope that through this technology, people living with profound vision loss from degenerative retinal disorders may be able to regain a useful sense of vision,” said Mr Eggenberger.

Professor Gregg Suaning said the positive results are a significant milestone for the Phoenix99 Bionic Eye.

“This breakthrough comes from combining decades of experience and technological breakthroughs in the field of implantable electronics,” said Prof Suaning.

A patient is implanted with the Phoenix99, and a stimulator is positioned on the eye and a communication module implanted behind the ear. A tiny camera attached to glasses captures the visual scene in front of the wearer, and the images are processed into a set of stimulation instructions which are sent wirelessly through to the communication module of the prosthesis.

The implant then transfers the instructions to the stimulation module, which delivers electrical impulses to the neurons of the retina. The electrical impulses, delivered in patterns matching the images recorded by the camera, trigger neurons which forward the messages to the brain, which interprets the signals as seeing the scene.

Source: University of Sydney