This article provides far more information about this project and a
direct URL to a demo/description site than I've seen in any other
article.



http://www.uwnews.org/article.asp?articleID=4459

May. 27, 2004 |
Wearable low-vision device gives the sight-impaired a cyber helping hand

FROM:
Rob Harrill
[log in to unmask]

206-543-2580

nav/enlarge

HIT Lab, University of Washington

A visually impaired volunteer uses a Wearable Low Vision Aid prototype
to maneuver around a chair while researcher Ryland Bryant looks on. The
device uses
a laser to paint an image inside the user's eye and generates icons that
warn of upcoming obstacles.

What do you get when you cross a computer and a seeing-eye dog?

That's easy, according to a group of student researchers at the
University of Washington's Human Interface Technology Laboratory: a
first-of-its-kind Wearable
Low Vision Aid. And, they add, the digital helper does have some
distinct advantages over a canine:

• You don't have to feed it.
• It doesn't drool.
• There's no need to worry about keeping a pooper-scooper handy.

But the biggest advantage is that, in many ways, the computer has the
potential to do a better job identifying walking hazards.

"Even with a cane or a guide dog, low-vision people can have a difficult
time identifying obstacles that can be hazardous," said Eric Seibel,
research assistant
professor in mechanical engineering at the lab, who for the past four
years has overseen the student team that developed the device. "This is
another set
of eyes looking out for them."

The group will demonstrate the latest prototype of the technology today
at the Society for Information Display's annual conference, being held
at the Washington
State Convention and Trade Center in downtown Seattle. The work is
funded by the National Science Foundation.

The Wearable Low Vision Aid was designed to be both portable and low
cost, according to Seibel. A laptop computer that provides the "brains"
for the system
is carried in a backpack, and can be used for other tasks once the user
gets to work or school. The imaging system is mounted on a pair of
glasses and
combines a ring of light-emitting diodes that fire bursts of infrared
light in coordination with a small camera that collects images of the
infrared-illuminated
landscape.

Software created by the student team compares that infrared scene with
the normally lit scene. Since closer objects reflect more light than
distant ones,
the system can "see" which objects remain in the field of view and grow
in size, indicating a possible collision. The computer assesses the
situation and,
if appropriate, generates a flashing icon to warn the wearer of the
danger.

The device can be programmed to generate different icons for different
hazards, so it not only warns of a hazard, but also lets wearers know
exactly what
they are dealing with.

"One of the beauties of this is that we can customize it for different
users," Seibel said. "For some people, overhanging branches might be a
big problem,
and we can customize for that. In the city, it might be something else.
All of these people have specific obstacles that they regularly
encounter that
are quite hazardous to them and we can cater the device to fit their
unique needs."

The device's display consists of a vibrating crystal fiber --
constructed of parts that cost less than $1 -- attached to a laser
diode. The fiber vibrates
very fast, more than a thousand times a second, to trace a series of
horizontal lines and form a complete, translucent "screen." That image
is beamed into
the user's eye and painted onto the retina. The brightness of the
display is adjustable so it can be seen both indoors and outside in full
sunlight.

The method also bypasses many users' visual problems.

"Because this can be very bright, directed laser light, it actually goes
straight through optical problems of the eye and paints a bigger,
brighter image
on the retina, even for people with retinal problems," Seibel said.

By using visual prompts, Seibel added, the device leaves intact another
sense key to people with low vision -- hearing.

"We talked with a number of visually impaired people, and they
absolutely did not want anything interfering with their hearing," he
said. "They really depend
on that."

While portable, the current prototype is still a bit bulky, Seibel said.
A smaller version is already in the works, according to Ryland Bryant, a
recently
graduated master's degree student who was lead author of the Seattle
conference paper. He has built a new circuit board that drops the
overall weight of
the system by about a half-pound. Currently, the backpack and computer
weighs in at just under 10 pounds.

In addition, the team will use an improved micro-optical scanner that
has higher resolution (50 times more pixels) but is one-tenth the size
of the one
in the low-vision aid prototype.

The next step for the team, according to Seibel, could be to investigate
using laser light to "tickle," or directly stimulate, neurons in the
eye, which
could allow people to see even if the photoreceptors in their eyes are
dead. It's an exciting prospect for a far-out, futuristic device, and
Seibel and
his collaborators have worked out some ways to possibly do it, but the
concept is still preliminary.

"It's in the proposal-writing stage and we need exploratory research
funding to continue," he said.

###

For more information, contact Seibel at (206) 543-5075 or
[log in to unmask]
An overview of the project, including animations depicting how the
Wearable Low Vision Aid works, are available on the Web at
http://www.hitl.washington.edu/projects/wlva/

Pratik Patel
Managing Director
CUNY Assistive Technology Services
the City University of New York


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