DP2: Demand Pull Program

Abstract | I. Business Opportunity | II. Current Technology | III. Technology Requirements | IV. References

Abstract

All people need the ability to "visualize" their local and immediate environment for activities of daily living, work, school, and recreation. To accomplish this, people with visual impairments require technology that identifies obstacles in their immediate path both inside and outside of buildings, and helps them to navigate around those obstacles. For example, the basic challenges of navigating streets and sidewalks are worsened by unanticipated factors such as construction work, poor weather and irregular traffic. Improved obstacle detection and avoidance capabilities will support safe independent travel, increasing access to schools, work and the community overall.

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Business Opportunity

Unlike people who have full use of their vision, many people with visual impairments are unable to easily scan their environment for potentially dangerous situations. Pedestrian accidents occur everyday in America. In 2001, almost 5,000 pedestrians in the U.S. died, including an estimated 500 children under the age of 16. Another 78,000 persons were injured while crossing the street, walking to school, or waiting for a bus (Ernst and McCann, 2002). People with visual impairments lose their lives to pedestrian accidents far more frequently than their non-disabled peers ( Martinez, 2000). The American Council of the Blind conducted a study indicating that cars at intersections had hit almost 8% of visually impaired respondents. 28% of respondents reportedly had their white canes, used to locate obstacles in their path of travel, run over by careless motorists (Carroll and Bentzen, 1999).

Traffic is not the only concern facing pedestrian travelers. Sidewalks in need of repair, head-high tree limbs, uneven terrain and debris are everyday hindrances to sighted individuals but significant safety threats for persons with visual impairments. In New York City there were nearly 2,800 claim settlements for sidewalk injury cases in 2002 which cost the city $67.9 million ( Taylor, 2004). Considering the high rate of injury during pedestrian travel for all citizens, and the higher rate for persons with visual impairments, (American Council of the Blind, 2003), injuries to persons with visual impairments resulting from simply walking about their communities may seem inevitable.

Older Americans experience visual impairment at a greater rate than any other age group. Lighthouse International (1995) states that the visually impaired population of persons over the age of 65 is expected to grow to be 8.3 million people by the year 2010 and 4.3 million people, ages 65 and over will have a severe visual impairment (Lighthouse International, 1995). As a result, many older Americans lose their ability to drive, and will rely more on walking as a mode of transportation.

Finally, the market for wayfinding technologies that incorporate Global Positioning Systems (GPS) and Global Information Systems (GIS) technology is growing at an astounding rate. According to the U.S. Department of Commerce, approximately four million people were using GPS technology in 2000. The $8 billion industry was projected to have doubled in value in three years, bringing the current market value to $16 billion (Avery, 2000). As the production of GPS/GIS units continues to increase, prices will fall, making this technology an affordable component of assistive technology devices. An obstacle avoidance technology incorporating GPS/GIS capabilities would not only enable people with visual impairments to safely avoid obstacles but also to plan and follow routes and obtain location specific information.

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Current Technology

Despite the advancements made in wayfinding technology over the past few decades, people with vision impairments continue to rely on multiple navigation techniques and technologies. These "technologies" include white canes, laser canes, clear path indicators, ultrasonic binaural sensing, and guide dogs. 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 off two rechargeable AA batteries. The LaserCane™ is used in an identical manner to a white cane.

The Polaron™ (Nurion-Raycal, 2004) is a secondary mobility aid typically used in conjunction with a cane or guide dog. In use, Polaron™ is 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. A special vibratory unit, worn at the neck, can be used with the neck hung Polaron™. The Polaron™ is powered from 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 both 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 as well as 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 that measures 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.

Complementary, 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 ten 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. They serve to complement rather than replacing the rich visual information available to these individuals. GPS/GIS systems currently do not integrate rapidly changing, local information such as roadway construction, warning signs or today's menu specials.

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 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 a product under development 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, as they select a personal "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.

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Technology Requirements

Consumers, manufacturers, clinicians, researchers and other stakeholders identified desirable performance characteristics of an obstacle avoidance device that will significantly improve the ability of a person with visual impairment to avoid obstacles in their immediate environment. The characteristics include:

• able to locate obstacles overhead (e.g., tree branches);
• able to identify obstacles below (e.g., curbs, steps);
• able to recognize and notify the user of an obstacle's relative position (e.g., left/right/up/down);
• able to detect objects that have a wide range of sizes and orientations (e.g., twigs, roller skates, cars, light standards);
• able to estimate (in addition to detecting) the size of the obstacle (e.g., width and length of traffic cones, caution tape or plywood barrier);
• able to detect rapidly approaching objects (e.g., cars);
• able to detect peripheral obstacles (e.g., what lies to both sides);
• able to detect the indentation typical of doorways;
• able to identify inaccessible terrain at a distance corresponding to a street width (able to discern problems before crossing a street);
• able to identify extreme changes in elevation, a block away (roughly 800 feet);
• able to scan the environment at a customizable distance (e.g., when moving, perhaps scan at 30 feet ahead);
• should not interfere with auditory cues used for navigation (e.g., horns, car motors);
• should support output in tactile, speech, audio and Braille formats;
• should not be demanding to use (e.g., low cognitive load, low vigilance, intuitive);
• should allow hands to remain free (e.g., for canes, guide dogs);
• should be user customizable (e.g., specify the distance at which obstacles are identified, set how often the feedback is provided);
• should be portable and lightweight (size of cell phone, pager or PDA);
• should operate on a battery that lasts at least one day;
• should be waterproof;
• should work indoors and outdoors;
• should work in all lighting conditions;
• should work with all materials (e.g., glass, brick, wood);
• should incorporate all features within one device;
• should employ a smart universal interface (e.g., WiFi (802.11), USB) that supports integration with other wayfinding technology [Note: this capability would allow devices to access and integrate local and perhaps rapidly changing information, download GIS data sets or transmit information about the local environment to others];
• should have integrated GPS/GIS capabilities (e.g., detect doorway and GPS/GIS identifies street address).

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References

1. American Council of the Blind. (2003). Pedestrian safety fact sheet. Retrieved January 13, 2004, from http://www.acb.org/pedestrian/factsheet-copy1.html

2. Avery, S. (2000). People tracking device may be on market soon. Retrieved December 16, 2003, from http://www.csi-wireless.com/public_relations/5_2000_people.shtml

3. Carroll, J. & Bentzen, B. L. (1999). Survey of blind pedestrians and orientation and mobility specialists. Retrieved January 13, 2004, from http://www.walkinginfo.org/aps/2-3.cfm

4. Ernst, M., & McCann, B. (2002). Mean streets 2002. Retrieved January 13, 2004, from http://www.transact.org/PDFs/ms2002/MeanStreets2002.pdf

5. Lighthouse International. (1995). Statistics on vision impairment. In Projected estimates of vision impairment. Retrieved January 22, 2003, from http://www.lighthouse.org/vision_impairment_projected_estimates.htm

6. Martinez, D. (2000). From the president's desk. Retrieved January 13, 2004, from http://www.acb.org/arizona/fsjanja.html

7. Nurion-Raycal. (2004). Makers of the LaserCane™, Pathfinder™ and Polaron™ mobility products. Retrieved February 12, 2004, from 2004, http://www.nurion.net/

8. Pulse Data Inc (2004). Maker of the Braille Note™ GPS. Retrieved February 12, 2004, from http://www.pulsedata.com/

9. RJ Cooper (2004). Distributor for sonar vision glasses. Retrieved February 12, 2004, from http://cdd.unm.edu/at/products/resources.htm

10. Talking Signs ® Inc (2004). Maker of the Talking Signs^® infrared communication system. Retrieved February 12, 2004, from http://www.talkingsigns.com/

11. Taylor, C. L. (2004). Slip and fall claims decrease: City shifts liability, goes after fraud. Retrieved January 13, 2004 from, http://www.nynewsday.com/news/local/queens/nyc-nywalk043609941jan04.story

12. Text News. (2003). Sonar article. Retrieved February 20, 2003, from http://www.tnauk.org/uk/TextSite/NewsSub/sonar.htm

13. Touch Graphics. (2004). Maker of the Talking Tactile Tablet and Ping!. Retrieved February 12, 2004, from http://www.touchgraphics.com/

14. VisuAide. (2004). Maker of the Victor Trekker™. Retrieved February 12, 2004, from http://www.visuaide.com/

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