A pioneering new device to allow the blind access to sight is being researched and developed by leading scientist Sheila Nirenberg. The device is making waves, and could be used on humans within the coming few years.
Sheila Nirenberg’s field is the study of how the brain processes information. This study refers to the ability of the brain to take inputs from the external world and create an output within the brain. This is done using any or all of the five senses: sight, touch, hearing, taste and smell. These senses are used to capture information from the outside world. Our bodies are able to convert this captured information into electrical activity. This electrical activity is then able to be read by the brain, enabling an action to be performed as a result of the new information.
Disease and injury are unfortunately able to damage or completely destroy vital parts of the bodies used to collect or process this data. The retina is the light-sensitive part of the inner surface of the eye. It is as a result of the retina that we can see. There are approximately 10 million registered blind in the US as a result of retinal disease or damage. There are drug treatments available but they only seem to show an effect in a very small number of those prescribed with the drug. For those who see no improvement, their best hope to be able to see is by using a prosthetic device.
A prosthetic device is a man-made artificial replacement for part of the human body that fails to perform correctly. Unfortunately, current prosthetic devices aimed at sight don’t work very well at all. They allow the user to see major difference in contrast and bright lights, but not much more. There is currently nothing close to normal vision possible for these people.
When a healthy person looks at something, the light travels into the eye, landing on the photo-receptors of the retina. The circuitry of the retina then performs actions on it, converting the visual information into a code. This code is then converted and sent to the brain. It is this code, or set of pulses, that the brain is able to read, and allows us to understand visual data. The patterns change all the time, in a dynamic fashion, as our field of view changes.
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These photo-receptors can unfortunately be damaged or lost altogether as a result of a retinal disease, such as macular degeneration. The cells in the retinal circuitry then die away too. The only cells left are the output cells that create the code for the brain to understand. As a result of the degeneration, these cells receive no input. They are therefore unable to provide an output to the brain, and this causes the resulting blindness.
Sheila Nirenberg and her team are working on a device that takes performs the function of the degenerated cells, allowing the brain to once again process visual information. This device is comprised of an encoder and a transducer.
The encoder mimics the actions of the front end circuitry that take the images in and convert them to the retinas code. The transducer then takes this converted code and sends it to the brain in a pattern of pulses. This results in a retinal prosthetic that is able to produce a normal visual output.
No other device is currently able to do this. The potential impacts of this revolutionary device would mean that, for the first time ever, a blind mother would be able to recognise the face of her own child.
Image Source: idealsociety.org.in
