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Breakthrough paves the way for next generation of vision implants

Key Takeaways

  • Researchers have created an exceptionally small brain implant, with electrodes the size of a single neuron.
  • The new implant, which can remain intact in the body over time, holds promise for future vision implants for the blind.

Often when a person is blind, some or part of the eye is damaged, but the visual cortex in the brain is still functioning and waiting for input. Thus, one option for restoring vision to the blind is to bypass the eye and directly stimulate the brain with an implant. By sending electrical impulses via an implant to the visual cortex of the brain, an image can be created, with each electrode representing one pixel. “This image would not be the world as someone with full vision would be able to see it. The image created by electrical impulses would be like the matrix board on a highway, a dark space and some spots that would light up depending on the information you are given. The more electrodes that ‘feed’ into it, the better the image would be,” says Maria Asplund, leader of a new study on vision implants published in Advanced Healthcare Materials.

When considering brain stimulation for sight restoration, there needs to be thousands of electrodes in an implant to build up enough information for an image. Thus, Asplund and colleagues created an exceptionally small implant, with electrodes the size of a single nerve cell. The researchers have the potential to fit lots of these electrodes onto a single implant and build up a more detailed image for the user.

Creating an electrical implant on such a small scale came with challenges. The major obstacle was not to make the electrodes small, but to make such small electrodes last a long time in a moist, humid environment. Corrosion of metals in surgical implants is a huge problem.

In the past, this problem has not been possible to solve. But now, the research team have created a unique mix of materials layered together that do not corrode. “We now know it is possible to make electrodes as small as a neuron (nerve cell) and keep this electrode effectively working in the brain over very long timespans, which is promising since this has been missing until now. The next step will be to create an implant that can have connections for 1000s of electrodes,” says Asplund, something that is currently being explored within a larger team in the ongoing EU project Neuraviper.

Often when a person is blind, some or part of the eye is damaged, but the visual cortex in the brain is still functioning and waiting for input. Thus, one option for restoring vision to the blind is to bypass the eye and directly stimulate the brain with an implant. By sending electrical impulses via an implant to the visual cortex of the brain, an image can be created, with each electrode representing one pixel. “This image would not be the world as someone with full vision would be able to see it. The image created by electrical impulses would be like the matrix board on a highway, a dark space and some spots that would light up depending on the information you are given. The more electrodes that ‘feed’ into it, the better the image would be,” says Maria Asplund, leader of a new study on vision implants published in Advanced Healthcare Materials.

When considering brain stimulation for sight restoration, there needs to be thousands of electrodes in an implant to build up enough information for an image. Thus, Asplund and colleagues created an exceptionally small implant, with electrodes the size of a single nerve cell. The researchers have the potential to fit lots of these electrodes onto a single implant and build up a more detailed image for the user.

Creating an electrical implant on such a small scale came with challenges. The major obstacle was not to make the electrodes small, but to make such small electrodes last a long time in a moist, humid environment. Corrosion of metals in surgical implants is a huge problem.

In the past, this problem has not been possible to solve. But now, the research team have created a unique mix of materials layered together that do not corrode. “We now know it is possible to make electrodes as small as a neuron (nerve cell) and keep this electrode effectively working in the brain over very long timespans, which is promising since this has been missing until now. The next step will be to create an implant that can have connections for 1000s of electrodes,” says Asplund, something that is currently being explored within a larger team in the ongoing EU project Neuraviper.

Edited by Miriam Kaplan, PhD

Source: Chalmers University of Technology, ScienceDaily, May 7, 2024; see source article