Advances in assistive technology have removed many barriers to entry for people with visual impairment. But it is the development of visual prostheses that has the potential to offer a whole new way of ‘seeing’ the world.
The incredibly complex structure of the human eye – with more than 2 million interacting parts – makes restoring someone’s vision a formidable challenge. But it is not impossible, as the bionic eye, or the visual prosthesis, to use the medical term that has been featured for decades in sci-fi fantasy films and TV shows, is now a reality.
“Enabling a patient to see again is our dream. A dream that we believe can come true,” said Serge Picaud, director of the Institut de la Vision, a leading eye research center in Paris, France.
As one of the world’s leaders in the development of retinal prostheses (a layer of cells on the back of the eyeball that are sensitive to light), Picaud coordinates ENTRAIN VISION, a network of experts from all key disciplines related to visual restoration. – from neuroscience and engineering to pathology and machine learning. Together with 15 early researchers, they are working on new technologies to restore patients’ vision.
“It might sound a bit like science fiction,” Picaud said, describing the prostheses at the retinal and cortical level (the cerebral cortex or the outermost layer of the brain). “Currently, there are no commercial cortical prostheses, so this research provides a great opportunity to develop them, and we have a team working on this.”
For millions of patients who lose their vision or are already blind due to a damaged connection between the retina and the visual cortex, a cortical prosthesis is the only option.
To see is to believe
The idea of electrically stimulating the human visual system is not new – it was first described more than 200 years ago. But rapid advances in neural engineering and microelectronics have paved the way for more advanced cortical-based visual prostheses.
“The idea is to use a type of electronic device to electrically stimulate the remaining nerve cells. So after losing part of the ‘circuit’, you replace it with an electronic device,” Picaud said.
One of the ENTRAIN VISION partners recently implanted a microelectrode array consisting of 100 microneedles in the visual cortex of a blind woman. With the implant, she was able to identify lines, shapes and simple letters. “These results are very exciting because they demonstrate both the safety and effectiveness of this technology and can help achieve a long-lasting dream for many scientists: to transfer information from the outside world directly to the visual cortex of blind individuals and restore a rudimentary form of vision. , “Picaud explained. “This work is likely to be a milestone in the development of new technologies that may help transform the treatment of blindness. However, more research is still needed.”
The use of electrical stimulation to restore an individual’s vision is just a new approach being studied, but there are others.
Optogenetics was developed in the 2000s and is a biological technique that uses light to control nerve cells or other cell types.
“There is already a patient in France who can see using this,” Picaud said.
The patient to whom Picaud refers was diagnosed with the neurodegenerative eye disease retinitis pigmentosa, which affects more than two million people worldwide and destroys their retinal photoreceptors. Thanks to groundbreaking research with Gensight Biologics, the patient’s vision has been partially restored using light-sensing proteins that were first found in algae.
The third exciting technology that researchers have turned their attention to is virtual reality.
“In Paris, we have surroundings like a cinema (Streetlab) where we can test a patient’s vision,” Picaud explained. “For example, it could be a room full of obstacles. So once the patient has a device implanted, we can test it using this platform. However, it is not easy to validate a device in other centers outside Paris because the platform “can not be easily recreated elsewhere because of its size. This is where virtual reality comes in.”
For example, a virtual reality headset can allow users anywhere in the world to experience the same conditions as those in the theater in Paris. “It can also help us understand what the most important parts of an image are for a patient so they can recognize their friends or ways of moving in a room,” Picaud added.
Such technologies will help people suffering from vision loss to regain their independence. But what happens if both sight and hearing – our two most important senses – are severely impaired?
Solutions for life without light and sound
For the millions of people living with deafblindness, the sense of touch is central to perceiving and interacting with the world.
“Being informed and able to communicate is central to everything we do, but you can not interact with your environment if you are not able to get information about it or communicate with people and your surroundings. So we focused on improving communication for people with deafblindness. “noted Nasrine Olson, associate professor at the University of Borås and coordinator of the SUITCEYES project.
The result was a smart, tactile interface that expands the user’s perception and spatial orientation, enabling them to interact with others. The technology was nominated for an Innovation Radar Prize.
Capture the environment using computer vision
Describing the ins and outs of technology, Olson said: “First, our haptic intelligent personalized interface, also known as the HIPI, captures the environment using computer vision and sensor technologies. The camera, sensors and computer vision algorithms together detect and recognize objects, scenes and faces. “object can be a chair or a cup, a scene can be a corridor or an office or a bathroom. The system also detects faces and whether they are known by the user or not. The sensor technologies also observe the distance between things.” For example, if the user is looking for his cup of coffee, the HIPI will see that it is on a table three meters away, to the left of the user.
Once the platform has all this information, what does it do with it? How do we communicate this information to the person who needs it? “We have created haptograms to convey messages to users. A haptogram is basically a haptic pattern that has a meaning for the user, for example ‘happy’.” It does this by using vibro-tactile actuators, which are small electronic devices that vibrate. They can be placed on different parts of the body, “Olson explained.
Prototypes have been developed that integrate the technology into clothing. “This includes a series of vests as well as a dress that shows how the technology can be worn while looking fashionable,” Olson said. There is also a version called “chairable” that can be mounted on the back of an office chair to convey messages to the seated person.
The possibility of smart wearables and soft interfaces that enable people with deafblindness to get information about the environment will facilitate an independent life. The project even added a COVID-19 feature that allows face recognition with masks.
New features include the ability to send the same haptic information to multiple people at the same time, whether it is near or across long distances.
“This was tested by our colleagues in the Netherlands by sending haptic messages to colleagues in Germany,” Olson said. But what is completely unique about the project is its holistic approach, which included extensive user and policy surveys, networking, technological innovations and gamification for enriched user experience and learning opportunities.
Although it will probably be some time before the benefits of this technological breakthrough are widely experienced, the future prospects are exciting. Meanwhile, researchers continue to envision a future where vision can be restored.
Bionic eye study paves the way for human experimentation
Provided by Horizon: The EU Research & Innovation Magazine
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