Wearable Aid for the Visually Impaired
From: IEEE Pervasive Computing - 09/2004 - Vol. 3, No. 3, P. 6
By: Danna Voth

Guide dogs, canes, and other traditional navigational aids for visually
impaired people cannot prevent collisions with certain obstacles, but a team
of University of Washington students led by Human Interface Technology Lab
assistant director Eric Seibel has invented a cheap wearable device that
alerts users to the proximity of stationary objects. The proof-of-concept
device integrates a video camera equipped with infrared light-emitting diodes
(LEDs), a scanner headset, a laptop worn in a backpack, and software, and
Seibel observes that the laptop could be multifunctional, given that many
visually impaired people regularly use computers in a variety of
applications. The camera is mounted on one side of the headset's eyeglass
frame, while the scanning fiber display and optics are positioned on the
opposite side; potential collision objects are identified by a machine vision
program included in the software, which also incorporates a display control
program and a graphical user interface that establishes parameters for the
embedded processor and produces warning icons. Video captured by the camera
is analyzed by the software, which measures the relative luminance of objects
to determine the ones that are getting closer, and then signals the processor
to display a warning icon that is beamed into the wearer's left eye when a
potential collision object is spotted. University of Washington student
Ryland Bryant explains that a visual display was chosen over an auditory
signal because subjects often depend on their hearing to get around. The
device boasts a working range of approximately 10 feet. Testing drew
attention to several problems, such as the low sensitivity people have to red
light used in the device and distracting noise caused by the vibration of a
ceramic piezoelectric actuator; the researchers solved the second problem
with the addition of a second piezo, while the first problem could be
remedied with blue or green LEDs. One future upgrade Seibel envisions is the
installation of optical character readers so that users can read documents
such as prescription labels.  

http://www.computer.org/pervasive/pc2004/b3006.pdf