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Abstract | I. Business Opportunity | II. Current Technology | III. Technology Requirements | IV. References AbstractDetailed driving directions from one location to another can easily be obtained and downloaded at no cost from the internet. In fact, the directions can be customized to provide the shortest route, the fastest route and a route that avoids toll roads and highways. However, there is no internet site for planning a travel route as a pedestrian, or as a user of public transportation. Travel route planning by a person with a visual impairment is made even more difficult as basic navigation, orientation, and signage information, including street signs, building address signs, directional signs, public transportation signs, and print maps, are often not accessible. A need exists for a travel route planning device. The device should be portable, incorporate a cell phone, work equally well indoors and out, provide travel route directions for pedestrian and public transportation systems, and it should calculate the distance, time, cost and level of difficulty of the route. At any point on a route, simple commands should result in information about the immediate surroundings, including current location, nearby buildings and public facilities. The availability of an easy to use, portable, low cost travel route planning device would benefit millions of visually impaired persons worldwide and enable them to plan and navigate travel routes, traverse new surroundings, independently access previously unknown facilities, and provide equal access to bus and other transit systems. [ Top of Page ] Business OpportunityPeople who have visual impairments must have the ability to plan comprehensible routes, follow those routes, and maintain orientation along the way. Fortunately, the need for wayfinding methods and devices exists not only for the 7.2 million people with visual impairments, but also for the general population (Lighthouse Inc., 1995). These needs have spurred the development of navigation systems for use by the government, business, and civilians. Enhancing the capabilities of systems that enable people to retrieve information about travel routes will ease the burden of travel for all persons, whether they are traveling on foot, in a car, by bus, or stepping off a train in an unfamiliar city. Over the past 30 years, mapping and navigation applications have been increasingly sophisticated and become more prevalent, moving from paper based documentation to electronic databases accessible through network connections. This trend, coupled with advancements in useful business applications has stimulated development in the GPS industry to the tune of more than 12% annual growth, which is projected to continue through 2008 (Microwave Journal, 2003). Originally designed for use by the military, GPS is now readily available to the civilian population in many forms. The number of GPS receivers produced has exceeded 1.4 million units per year since 1997 (Myers, Wikle, Helmer, Demers, and Jiangming, 2003), and current figures reflect an approximated 200,000 GPS receivers purchased by civilian users every month (Parkinson, 2003). Projections state that the GPS market will exceed $22 billion by 2008 (Microwave Journal, 2003), and there will be an estimated 50 million GPS users by the year 2010 (Parkinson, 2003). GIS is equipping users with powerful levels of detail to enhance their mapping and navigation abilities. The GIS service market in North America alone has an estimated value of $2.5 billion (Gupta, 2003), with some companies experiencing annual growth rates as high as 25% (Michelsen, 2004). Growth in the GPS industry is promising for assistive technology applications. Increased sales have lead to lower cost units, with some GPS receivers currently selling for as little as $100 or less (Microwave Journal, 2003). As the development of these technologies for mainstream America continues, the price of these components will fall and availability will increase, enabling assistive technology manufacturers to incorporate these features into their devices while maintaining reasonable price points. As a result, people with visual impairments will be able to take full advantage of their surroundings. This will benefit people with visual impairments, the businesses they patronize and the community as a whole. [ Top of Page ] Current TechnologyDespite the advancements made in wayfinding technology over the past few decades, people with vision impairments continue to rely on multiple navigation techniques and technologies. Wayfinding products include the Braille Note GPS (Pulse Data, 2004), Victor Trekker™ (VisuAide, 2004), Talking Signs® (Talking Signs, 2004) and Ping! (Touch Graphics, 2004). The Braille Note GPS and Victor Trekker™ are built around the global positioning system (GPS) / global information system technology (GIS). While GPS/GIS systems offer great promise, there are significant limitations. GPS signals are interfered with by buildings, terrain, and inclement weather. GPS systems generally lack sufficient positional accuracy (about 10 meters) for safe obstacle avoidance. GPS generally does not work indoors and therefore cannot provide a wayfinding solution for important public venues such as airports, schools, libraries, courts and bus terminals. GIS datasets are often developed around roadways and urban environments rather than parks, hiking trails and urban areas. GIS datasets typically address the needs of sighted individuals – complementing rather than replacing the rich visual information available to these individuals. GPS/GIS systems allow limited note taking for points of interest along the travel route, however the database itself cannot be edited. In particular, these systems cannot download and integrate local (rapidly changing) information such as roadway construction, warning signs or today's menu specials. As with any voice output system, environmental noise (traffic, wind) can interfere with comprehension. In addition, voice output can interfere with other auditory cues used for mobility and orientation. Talking Signs® is a wireless system that consists of infrared transmitters located throughout an environment (e.g., bus terminal, museum, city streets) and infrared receivers carried by the user. Each transmitter is programmed with and broadcasts a short message, usually pertaining to the local environment. Talking Signs® receivers are handheld, directional and local. The infrared signal is stronger and detectable when the receiver is pointed at and near to a transmitter. The receiver delivers auditory information to the user through speakers or a headset. The system is effective for both interior and exterior applications provided that the transmitted signal is not overwhelmed by a very powerful infrared light source (e.g., pointing the receiver directly at the sun). Recently, WiFi (802.11 standard) networked Talking Signs® transmitters have been developed. This innovation makes it possible to quickly reprogram transmitter messages from one or more remote locations thereby greatly extending system flexibility. Ping! is being developed by Touch Graphics for wayfinding in public exhibit spaces such as science and technology museums. Ping! employs a network of wireless audio beacons at key destinations in the exhibit space. Cell phones are used to select and trigger beacons that emit audible tones for navigation to exhibits. Once an exhibit is reached, the cell phone is used to access exhibit content. Users call a toll-free phone number and interact with a human-voice computer attendant. They can use the automated system to select a "ping" sound from a catalog of available chirps, whistles and chimes. A notable characteristic of the Ping! system is reliance upon the user's training in and personal experience with mobility and orientation. Complementary technologies used for obstacle avoidance, mobility and orientation include white canes, laser canes, clear path indicators, ultrasonic binaural sensing, and talking tactile maps. White canes are used to identify holes in the ground and steps down. The LaserCane™ (Nurion-Raycal, 2004) projects three laser beams: upward angle (range 30"), straight ahead (adjustable range 5'-12') and downward angle (range 30"). Reflected light identifies head high (e.g., branches), straight ahead (e.g., people) and downward (e.g., step) obstacles. The user receives auditory (low, medium and high tones) and vibratory cues (low, middle and combined) to the index finger. Auditory cues can be turned off. The LaserCane™ is powered by two rechargeable AA batteries. The LaserCane™ is used in an identical manner as a white cane. The Polaron™ (Nurion-Raycal, 2004) is a secondary mobility aid typically used in conjunction with a cane or guide dog. Polaron™ is either hand held (used like a flashlight) or hung from the user's neck. The Polaron™ projects an ultrasonic cone whose reflection indicates the presence or absence of obstacles in the path. Range can be set at 4, 8 and 16 feet. The user can chose between auditory and vibratory feedback. The vibratory feedback device is worn at the neck. The Polaron™ is powered by a single 9 volt battery. The Pathfinder™ (Nurion-Raycal, 2004) is a mobility aid typically mounted onto wheelchairs. The Pathfinder™ employs both ultrasound and lasers. Ultrasound cones project forward (range 8') and to the left and right (range 16"). The side beams assist navigation through doorways and around furniture. Two laser beams project downward to detect drop offs. Auditory tones indicate obstacles to the left, right and front in addition to drop offs ahead. Sonar vision glasses (RJ Cooper, 2004) is a secondary mobility aid typically used in conjunction with a white cane or guide dog. Sonar Vision Glasses employ an ultrasound cone extends 40 degrees in the direction of "gaze." A low pitched tone is generated as an object comes into view with a range of about 3-4 meters. The pitch rises as the user gets closer to the object. An absence of sound means that there is no nearby obstacle. Obstacles on both sides and up and down, can be detected if the user orients his or her head. Both of the user's hands remain free during use (Text News, 2003). Considerable training is required to master the sonar vision glasses. As with any device employing auditory feedback, the user may have difficulty attending to auditory cues from the environment or attending to conversation. The Talking Tactile Tablet (Touch Graphics, 2004) provides auditory feedback to users exploring an appropriately constructed tactile map. Information can be structured and accessed in a hierarchical fashion to allow quick exploration of broad features and detailed exploration of particular points of interest. Development systems to produce tactile maps and databases are available from the same company. [ Top of Page ] Technology RequirementsConsumers, manufacturers, clinicians, researchers and other stakeholders have identified technology requirements that would significantly improve travel route planning through the use of a single device. These specifications include:
[ Top of Page ] References
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