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Device enables blind people
to ‘see’ with their tongue


Neuroscientists in the US have developed and are in the middle of testing an innovative device that enables blind people to ‘see’ with their tongue. Sound bizarre? Well the theory behind it is, but the reality is that it works remarkably well. Callan Emery spoke to Aimee Arnoldssen, PhD, one of the neuroscience researchers involved in the project.

If all goes to plan, and looking at the current experimental track record it is, then sometime next year blind people in the US, and presumably in several other countries around the world, will be able to buy a small device called BrainPort Vision that will enable them to use their tongue to “see” the world about them. They will, in a sense, have their sight miraculously restored enabling them to perceive their environment in a completely new and previously unimaginable way. They will be able to identify objects, orientate themselves and be mobile in their environment giving them a completely new lease on life.

The idea of sensory substitution is not new. It originated in the late 1960’s when Dr Paul Bach-y-Rita a US neuroscientist whose work focused on neuroplasticity introduced the idea of swapping sensory stimulation to aid rehabilitation by substituting touch for sight.

Aimee Arnoldssen, PhD, one of the neuroscience researchers at Wicab, the biomedical engineering company developing BrainPort Vision, worked with Dr Bach-y-Rita until his death in 2006. She explained that the device they are developing consists of a head-mounted camera with zoom lens that serves as the “eyes” to gather black, white and gray pixels of visual information and a small postage stamp-sized electrode array that sits on the tongue of the user. The visual information from the camera is converted by computer to mild electrical impulses which are sent to the electrode array which stimulates nerves on the tongue. In the same way that electrical impulses from the eye are sent to the brain via the optic nerve, electrical impulses are sent to the brain via nerves on the tongue.

Dr Arnoldssen explained that learning to use the BrainPort is like learning a new language. Strong vibrations on the tongue represent white pixels, mediumstrength vibrations represent gray pixels and no vibrations represent black pixels. She said users describe the sensation as pictures drawn on their tongue with champagne bubbles.

“About 80 people have worked with our device in research studies over the past few years,” she said. Learning how to use the device is relatively quick and takes about 8- 10 hours.

Initially, users must consciously translate the pattern of impulses on the tongue to the idea of an object in space. But as a person becomes fluent in this process, the translation becomes automatic.

“You learn to ignore what’s happening on the tongue because that’s not the most important piece of information,” she explained, and added that the most critical step in the process is for the brain to perceive these impulses as a representation of the surrounding environment.

Dr Arnoldssen said that while BrainPort does not replace the sense of sight, it adds to other sensory experiences to give users information about the size, shape and location of objects. She said that within an hour, most users can point to different shapes. After a few more hours, they can identify familiar objects and avoid obstacles.

“We have had great success with our investigation device used for research at our site as well as a handful of other institutions,” Dr Arnoldssen said.

“We will be submitting an application for FDA (US Food and Drug Authority) approval later this year,” she added.

Following FDA approval the company can begin commercial production of BrainPort Vision.

Dr Arnoldssen said that one of their biggest challenges is funding and although they have received some funding from the US National Eye Institute, they are actively seeking more.

The electrode array device that sits on the tongue is wired to the head-mounted camera. “This could be a wireless device,” she explained, “But we do not currently have funding to pursue this expensive endeavour.”

However, even with limited funding, these researchers have developed a remarkable device which has vastly improve the lives of blind people.

● On the Web: BrainPort on YouTube


ate of upload: 10th Dec 2009

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