1. BY UMAR SHUAIBU (ROLL NO. 140125014) ASSISTIVE TECHNOLOGIES AND DEVICES FOR VISUALLY IMPAIRED 2. 1.0 INTRODUCTION The human eye is like camera that receives and focus light into retina which is then transmitted to the brain. Without retina, eye cannot see thus, render vision impossible, hence the visual impairment. 3. 1.1 VISUAL IMPAIREMENT The decrease in the ability to see to the extent that causes problem which cannot be restore to the normal vision is known as visual impairment. According to international organisation for disease classification, there are for level of visual function which are: 4. Normal vision Moderate visual impairment Severe visual impairment and Blindness. The visually impaired persons face real challenges in moving through dynamically changing environment, in learning, and many other activities for his daily living, thus tend to undermine his independence, as such different assistive technologies and devices were developed 5. ASSISTIVE TECHNOLOGIES AND DEVICES Assistive Technology is a generic term incorporating technology, equipment, devices, appliances, services, systems, processes and environmental change (Environmental Modifications) used by people with disabilities or older people to overcome social, and infrastructural barriers, to actively participate in society and to perform day-to-day activities easily, safely, and efficiently. The visually impaired persons need security, safety, 6. And devices can be grouped into the following Assistive technologies and devices for daily living Assistive technologies and devices for navigation and orientation Assistive technologies and devices for learning. etc 7. 2.0 ASSISTIVE TEHNOLOGIES AND DEVICES FOR DAILY LIVING This can also be grouped into the following Personal care, Timekeeping, alarms and alerting, Food preparation and consumption, Environmental control/ household appliances, Money, finance and shopping 8. The personal care assistive technology refers to two main aspects: labelling and health care monitoring systems. LABELLING SYSTEM Visually impaired people need assistance in identifying different elements of their clothing. Labelling can be grouped in the following types of systems 2.0.1 ASSISTIVE TEHNOLOGIES AND DEVICES FOR PERSONAL CARE 9. Tactile labelling system which is based on different alphabets used for visually impaired like Braille, 10. Barcode labelling system which is using barcode reader and scanner, where a beam of light is send to the barcode to be read, and the reflected ray is then read by the reader. 11. And the radio frequency identification labelling system Where by a tag is given to each items, and then the tag is read by the reader using radio signal whenever the tag is within the field of the reader 12. HEALTH CARE MONITORING SYSTEM to assist visually impaired people in monitoring their general health, among which are: Talking blood pressure meter which measure the blood pressure and give audio output of the result. 13. talking blood glucose meter that measure blood glucose level and give the voice output of the result. 14. 2.0.2 TIME KEEPING, ALARM AND ALARTING One can meet different types of time devices that exist for blind and visually impaired people. Many of these have speech or tactile output, Among which are: Braille watch that give the time in Braille text 15. Talking watch with tactile output that provide both audio as well as the Braille output. 16. And talking carbon monoxide detector which when detect the carbon monoxide inform this through voice output 17. 2.0.3 FOOD PREPARATION AND CONSUMPTION The food preparation and consumption play a significant role in the independent living of a visually impaired. There are different assistive technologies and devices in food preparation and consumption among which are: Talking kitchen thermometer which provide the audio output of the cooking temperature for the visually impaired 18. Talking kitchen scale which provide the audio output of the cooking ingredient and the foodstuff for visually impaired. And many more 19. 2.0.4 ENVIRONMENTAL CONTROL The control of the immediate home environment of the visually impaired people is a condition for their independent life. This means that they have to control a number of home devices and that they have a constant need for feedback from their environment, so that they can accommodate to changes. Light probe and colour probe devices can be used to get information from the environment. talking and tactile thermometers and barometers, washing machine with special functions for 20. 2.0.5 MONEY, FINANCE AND SHOPPING Money is another important aspect of independent life. Accessing it by visually impaired people can be difficult, because of different currency systems. Thus the development of tools that can recognize more, or at least the most commonly used, currencies is an important aspect of assisting visually impaired people in gaining independence. 21. DEVICES FOR NAVIGATION AND ORIENTATION Navigation of visually impaired people raises questions about orientation, the appropriate route selection, objects and obstacles detection and avoidance. Electronic systems used in navigation can be grouped into two categories: Electronic travelling aids(ETAs) Electronic orientation aids(EOAs) 22. 3.0.1 ELECTRONIC TRAVELLING AID(ETAs) In recent years the traditional tools used by visually impaired people for ETA systems are complex tools to support navigation and are composed of several basic modules among which are: obstacle detection system trajectory planning module, Monitoring system. 23. Electronic travelling aids is a form of assistive technology having the purpose of enhancing mobility of visually impaired. Perhaps the most widely known electronic travelling aids for improving or enhancing the mobility of a visually impaired can be discuss as follow 24. ULTRACANE Ultra cane mimics the innate echolocation capability of bat and dolphin. Bat and dolphin make high frequency sound that bounce off whatever is in front of them. They received these sound and can sense the size, shape, density, distance and even texture of an object 25. The ultra cane emit ultrasound in two mode, the short range for detecting an object within two meters, and the long range for detecting object within four metres of the handle 26. There are two in the handle of the cane which vibrate at various intensity to indicate an object proximity and position. Object on the ground in front of the visually impaired is detected by the lower tactile button. while the top tactile button is vibrate when the visually impaired approached an object between hip and the head level 27. BIONIC EYE The bionic eye ( also known as argus11) system consisted of pair of glasses with small video camera mounted on it, which capture image. A small prosthesis is surgically implanted on the surface of the retina, and the information from the camera is transmitted wirelessly to electrode on the artificial retina. Where it is converted into electrical pulses, any remaining cells that havent been 28. 3.0.2 ELECTRONIC ORIENTATION AIDS(EOTs) Electronic orientation aids have been designed to give orientation and way finding information to blind and partially sighted people. The information they can provide includes location and direction information as well as information on objects in the users environment. An example of an electronic orientation aid is the RNIB REACT system, this system is in use in a number of places including 29. Leeds bus and train stations. The RNIB REACT sign speaks a message as the blind or partially sighted user walks up to it. The blind and partially sighted person can then follow the spoken instructions to find the help point or their stop. The available GPS devices for blind people are the Way finder system, like the The geotact which basically is a GPS sensor. In this system the direction and distance to the next point are given in form of voice, the visually impaired is then required to utilizes the locomotion skills 30. 4.0 ASSISTIVE TECHNOLOGIES AND DEVICE FOR LEARNING Students with visual impairments face unique challenges in the educational environment. Not only must they be able to access text information across all curricular areas, but they also need to be able to participate fully in instruction that is often rich with visual content. Assistive technology is one way of supporting them in that process. Hence assistive technologies in learning can be categorizes into two Assistive technologies and devices for reading and Assistive technologies and devices for writing 31. Assistive technology tools to support reading should reflect the students level of visual functioning, their literacy development, as well as the environmental and task demands. Some of which are: Braille: which is a system of touch reading and writing for blind persons in which raised dots represent the letters of the alphabet. DEVICE FOR READING 32. Audio book which recorded using human voice, and can be accessed through the use of specialized computer software, devices, or mainstream tools like MP3 players. etc 33. reading pen which provided the audio output of the scanned text. etc 34. The assistive technologies for writing for the visually impaired are also significant for their independent living among which are: Braille note taker which is a portable word processing device that utilizes the eight key Braille input system and has an integrated refreshable Braille display. 4.0.2 ASSISTIVE TECHNOLOGIES AND DEVICE FOR WRITING 35. Close circuit television (cctv) which allow magnification of the writing for the visually impaired, and many others 36. 5.0 CONCLUSION The assistive technologies used by visually impaired people are very complex. A wide range of different electronic assistive technologies exist and are used by visually impaired. Some of these tools are unreachable by most of the visually impaired persons. The integration of different assistive solutions in a single assistive system is a great challenge.