In this paper, two assistive projects on the spatial cognition by blind and visually impaired (B&VI) people are presented using the sound patterns and ultrasonic sensing. The first device supports the sport activities of B&VI, the golf game specifically. Every golf flagstick has the sound marking device with the active buzzer and WiFi remote control by the person with good vision. The NodeMcu Lua ESP8266 ESP-12 WiFi boards in devices are controlled by the cross-platform HTML web-sites, and hence any WiFi smartphone and / or computer can be in use to start the HTML web-page. Mini portable WiFi router links all devices in the network. End-users are securely connected using the password to wireless router. Ten assistive devices were handed in Instituto para Ciegos y Débiles Visuales “Ezequiel Hernández Romo” together with WiFi router. The second device supports the orientation of B&VI by measuring the distance to the obstacle based on the ultrasonic sensor HC-SR04 and Arduino Uno. The distance is pronounced to the B&VI using headphone and MP3 player with SD card. Nowadays, Universidad Politécnica de San Luis Potosí is negotiating with several organizations to create a production line. All devices are of the budget price up to USD 10. All devices were tested successfully. This is joint work of Instituto para Ciegos y Débiles Visuales “Ezequiel Hernández Romo”, Universidad Politécnica de San Luis Potosí, and Tecnológico de Monterrey with ongoing project “Artificial Eyes” based on Raspberry Pi 3 Model B board with an ultrasonic sensor and camera for the image and/or video processing of the surrounding environment, as well as the friendly integration into the local networks using onboard WiFi and Bluetooth.
TopIntroduction
World Health Organization pointed that 285 million people are estimated to be blind and visually impaired (B&VI) worldwide in 2014 (Visual Impairment and Blindness, 2016). In particular, 39 million are blind and 246 have low vision, which means approximately 3.9% of the population (7.261 billion in 2014) around the world have the eyes problems. About 90% of the world's visually impaired live at low income. Besides the medical treatment, these people need the assistive devices for the spatial cognition. These devices play important role in the outdoor exploration of B&VI (Sonnier & Riesen, 1985). In particular, Golledge (1993) showed that an independent travel and interaction with the wider world is a significant problem for B&VI after the reading and writing. Bruce et al. (1991) found that approximately 20% of young B&VI people in the United Kingdom had not left their home, approximately 30% had travelled locally (Clark-Carter, Heyes, & Howarth, 1986), and only 41% left their home alone and walked. In addition, most of B&VI people who explore new routes feel disorientation, fear, stress, and panic associated with being lost (Golledge, 1993). To be mobile is a factor that contributes to the success of the blind adults because it directly corresponds with their employment (Goodwyn, Bell, & Singletary, 2009). The development of the assistive devices for B&VI increases the social responsibility about B&VI (Bell, 2010).
Nowadays, different hardware was developed converting the input info (images, videos, numbers, etc.) into the tactile and sound patterns. Some devices have already been released commercially, e.g. Sonicguide of price USD 500 (Marsh, 1978), iGlasses of price USD 100 (iGlasses Ultrasonic Mobility Aid, 2016), Brainport V100 of price USD 10,000 (BrainPort V100 Device, 2015). They work quite well but they are not accessible for poor people (i.e. for 90% of the visually impaired) because of the high price. Analysis of the B&VI minimum needs shows that the basic functionality includes the sound marking of the surrounding objects and the measurement of the distance to them. In Cappagli, Cocchi, and Gori (2015), a strong deficit in the audio distance evaluation for early blind children and adults is emphasized. In Jacobson and Kitchin (1997), the geographic information system (GIS) is used by B&VI. A small experimental study that compares the ability of GIS-based and various adaptive technologies to communicate spatial information using non-visual media is presented. The main benefit of GIS usage is an improvement of the quality of life for B&VI by increasing mobility and independence. Here, GIS for B&VI is discussed in general, as well as budget solutions are not proposed. In Goria et al. (2016), different assistive devices (e.g. NavBelt, Vibe, Prizmo 3, K-sonar), apps (e.g. KNFB Reader, SmartSight, EyeMusic), and user-interface technologies (e.g. the tongue display unit, finger-braille interface, sound patterns) are discussed in detail. Here, the soft- and hardware are presented in general too, as well as budget solutions are not proposed.
Nowadays, the budget assistance devices for the B&VI can be efficiently developed using Arduino Uno/Mega (Warren, Adams, & Molle, 2011; Norris, 2015) and/or Arduino-compatible hardware like NodeMcu Lua ESP8266 ESP-12 WiFi board (User Manual for ESP-12E DevKit based on ESP8266, 2016) of the price up to USD 10. Here, the soft- and hardware is based on the technology Internet of Things (Charalampos Doukas, 2012; Norris, 2015; Dirk Slama et al., 2015). Universidad Politécnica de San Luis Potosí and Tecnológico de Monterrey (campus San Luis Potosí) developed two assistive devices – for the golf game (the sound marking of the golf flagsticks) using mobile app connected to the NodeMcu Lua ESP8266 ESP-12 WiFi boards and for the distance measurement using Arduino Uno together with an ultrasonic sensor. These devices are in use at Instituto para Ciegos y Débiles Visuales “Ezequiel Hernández Romo” nowadays.