Mobile robot helps with retinal prosthesis research
MyVisionTest
created a remote-controlled robot that is able to simulate the
"visual" experience of a blind person who has been implanted with a
visual prosthesis, such as an artificial retina. An artificial retina
consists of a silicon chip studded with a varying number of electrodes
that directly stimulate retinal nerve cells. It is hoped that this
approach may one day give blind persons the freedom of independent
mobility.
The robot - or, rather, the mobile robotic platform, or rover - is
called CYCLOPS. It is the first such device to emulate what the blind
can see with an implant, says researcher Wolfgang Fink.
An artificial retina, also known as a retinal prosthesis, may use
either an internal or external miniature camera to capture images. The
captured images then are processed and passed along to the implanted
silicon chip's electrode array. The chip directly stimulates the eye's
functional retinal ganglion cells, which carry the image information
to the vision centers in the brain.
CYCLOPS fills a void in the process of testing visual prostheses,
explains Fink. "How do you approximate what the blind can see with the
implant so you can figure out how to make it better?" he asks.
One way is to test potential enhancements on a blind person who has
been given an artificial retina. And, indeed, the retinal implant
research team does this often, and extensively. But few people
worldwide have been implanted with retinal prostheses, and there is
only so much testing they can be asked to endure.
Another way is to give sighted people devices that downgrade their
vision to what might be expected using artificial vision prostheses.
And this, too, is often done. But it's a less-than-ideal solution
since the brain of a sighted person is adept at taking poor-quality
images and processing them in various ways, adding detail as needed.
This processing is what allows most people to see in dim light, for
example, or through smoke or fog.
"A sighted person's objectivity is impaired," Fink says. "They may not
be able to get to the level of what a blind person truly experiences."
Enter one more possible solution: CYCLOPS. "We can use CYCLOPS in lieu
of a blind person," Fink explains. "We can equip it with a camera just
like what a blind person would have with a retinal prosthesis, and
that puts us in the unique position of being able to dictate what the
robot receives as visual input."
The results of tests on the CYCLOPS robot should also help researchers
determine whether a particular version of a prosthesis, say, or its
onboard image-processing software, are even worth testing in blind
persons. "We'll be coming in with a much more educated initial
starting point, after which we'll be able to see how blind people work
with these implants," Fink notes.
Fink points out, "Blind people using a cane or a canine unit can move
around impressively well. For an implant to be useful, it has to have
the implicit promise that it will surpass these tools. The ultimate
promise - the hope - is that we instill in them such useful vision
that they can attain independent mobility, can recognize people, and
can go about their daily lives."
Medical News Today
http://www.medicalnewstoday.com/articles/168043.php
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