Note: Descriptions are shown in the official language in which they were submitted.
CA 02898387 2015-07-27
This invention relates to a hand-held mobility aid for the visually impaired.
Currently,
visually impaired persons rely on white guide canes or guide dogs for
navigation. However, it is
necessary to know the destination in order to provide efficient and safe
navigation, and these
methods are not capable of doing so. They provide short term obstacle
detection, and do not find
efficient routes to the destination. Guide dogs are also very expensive,
costing upwards of
$40,000. Other prototypes include head-mounted cameras that are connected to
Simultaneous
Localization and Mapping (SLAM) software. This triggers vibrations on a vest
to direct users
through environments. However, this system does not provide accurate
navigation, but only
indicates "left" or "right" orientation. Headsets are also being used to
provide audible tones in
increasing frequencies that alert users to obstacles. However, it is very hard
to distinguish
different frequencies for a non-musically trained user, and this results in
unsafe and inefficient
navigation.
These disadvantages were overcome by providing precise tactile feedback using
an omni-
directional toggle system. The toggle system can rotate accurately to direct
the user to a
destination. Tactile sensory feedback to the hands is more sensitive than
elsewhere in the body.
Unlike cumbersome head-mounted gear, the system is small, mobile, and hand-
held. The system
can show distance to the destination through tilting of the toggle system.
This is an improvement
over systems that only show orientation to the destination. Wide field
horizontal scanning of the
immediate environment using proximity sensors is then used to provide
additional input over
shorter distances. The wide field scanning mimics the broad visual field of a
normal-sighted
person. Users are alerted to immediate obstacles through an audible beep that
occurs at a
constant frequency, so users are not required to interpret different
frequencies
In the drawings which illustrate components of the invention, Figure 1 is a
depiction of
the proximity sensors, Figure 2 shows the schematic, and Figure 3 shows the
tilting and
horizontal rotational components of the toggle system.
In Figure 1, the illustrated invention scans a wide range using proximity
sensors (2a and
2b). They are attached to a belt-like strap (4) using appropriate measures,
like screws (3). The
strap can be attached to the user's belt using Velcro-like straps (la and lb).
The wires (6)
connecting the proximity sensors to the microcontroller are contained in a
rubber-like covering
(5), indicated in the cross-sectional area depicted. The proximity sensors are
used to determine
the longest unobstructed path.
This data is fed to the microcontroller shown in Figure 2. A buzzer is
attached to the
system to alert users to immediate obstacles within a customizable range.
Outdoors, a GPS
module determines the location of the destination, and a compass module
determines the bearing
to the destination. The microcontroller uses the information to move the
toggle system (Figure
3). The toggle system can be powered by a 9V battery.
Depicted in Figure 3, the toggle system rotates to indicate the longest
unobstructed path.
It is comprised of two pan/tilt brackets on a hand-held device. One bracket
rotates horizontally to
indicate direction (2), while the other rotates vertically to indicate
distance (3). Miniature servos
are used to facilitate rotation (1 and 8), but other motors may also be used.
The brackets are
CA 02898387 2015-07-27
attached to the servos using appropriate measures, such as screws (4 and 5),
with washers in
between the brackets (6). The servo motor used to power the vertical-moving
bracket is held in
place by an L-bracket (7). A joystick is attached to the top of the vertical-
moving bracket using
screws for user comfort (9). The power, ground, and signal wires from the two
servos (10) are
contained in a rubber-like sheath (11), and are connected to the
microcontroller.
