Compare the visual, auditory, and tactile systems in terms of their basic function and as substitutes for each other.

8.3 Compare the visual, auditory, and tactile systems in terms of their basic function and as substitutes for each other.

· The two intrinsic enablers of the humans in the Human active assistive technology (HAAT) model are the perception and sense. It is necessary to use sensory aids if there is impairment in any of the two intrinsic enablers. The sensory aids are designed based on the level of impairment. If the primary sensory system that is being aided have sufficient residual function, then the input is improved to make it useful to the user. If the sensory residual capability is insufficient than an alternative sensory pathway is to be used. Visual information is spatially organized in the Central Nervous System by the relationship of objects to each other in space. The features of these objects are preserved based on their location like, up, down, left, right, near and far features. The example of tactile substitution for visual input is the use of braille to reading by blind individuals Auditory and Tactile systems replace the visual system. Visual and tactile systems replace the auditory system. The auditory system functions based on the time relationships in auditory signals that deliver information. This shows that this system is temporarily organized. Tactile system requires both spatial and temporal clues as sensory input and the tactile information is spatially and temporally organized. Even during movement, the images on the retina are stabilized by visual system to input the data. The visual information is substituted by the auditory system in many ways.

8.9 What special problems does the GUI present for persons who are blind?

· The most commonly used interface that is used to communicate by the humans with the computer is the Graphical User Interface (GUI). It is characterized by three distinctive features like, Mouse pointer- To move on the screen Graphical menu bar- It is on the screen One or more windows- It gives a menu of choices. The blind user face several problems with the GUI like: It is not easy to display graphical characters in alternative modes. Text is converted to speech output by text-to-speech programs and speech synthesizers. These are not suitable to the representation of graphics and icons in GUls Locating the screen becomes difficult to the blind user using a GUI As the auditory information is time based and visual information is spatially organized, it is difficult to identify the screen location by speech. Speech alone cannot show the two-dimensional spatial attributes.

8.10 (Optional for bonus credit) What are the features included in the Universal Access and Windows Accessibility options that assist individuals who have low vision or blindness?

8.11 List three limitations of current voice-only screen reading programs developed for visual access.

· Hearcons do not present semantic relationships very effectively and

earcons are merely abstract voice labels that do not have semantic

relationships to the information the represent. . It also lacks in the

area of explaining graphical in tables and charts. The main issues

would consist of, showing size of the table, overloading it with

speech information and ability to inform the user of the location with

in the table the information is stored.

8.13 Describe the relative advantages and disadvantages of software and hardware approaches to obtaining enlarged displays for persons with visual impairments?

· Individuals with visual impairments might not be totally blind. They have vision up to some extent based on their level of impairment. Spacing, size and contrast are the factors that influence the performance of visual system to read. People with low vision use screen magnifying software which helps in enlarging a portion of a screen. Hardware approaches: Some hardware aids are non-optical, optical and electronic aids. These help to provide enlarged display to the visually impaired individuals Advantages The optical aids are light weight, easy to operate, inexpensive and require very less training. Depending on the needs of the individual the optical aids are built in with lenses or combination of lenses and built in with light to enhance the contrast. The electronic devices like the CCTV devices provide enhanced image size when compared to optical aid. The image brightness can be controlled and manipulated. These provide printed material and access to computer screens Disadvantages: The use of field expanders in optical aids limits the visual field. Large printed books in non-optical aids and high intensity lamps help in reading The non-optical aid is specialized to do one to few tasks The CCTV devices share space with the computer and other equipment in the office

8.17 (Optional for bonus credit) What is the primary tactile method used for (displaying) computer output?

· Tactile is the sense of touch. Braille is the most widely used tactile reading substitution for the blind individuals. Six or eight characters in a cell represent each character in braille. Grade 1 braille is the translation of text into braille letter by letter. Some words and word endings are denoted by braille codes which are called as Grade 2 or Grade 3 braille. Raised pin model of braille is called as the Refreshable braille display. It is the substitute for embossed paper model. Set of small pins are present in each braille cell which are arranged in a standard braille cell. Advantages: Electronic circuit in refreshable braille is connected to braille keyboard or computer which helps in electronic storage of data. This can edit text, search text and electronic braille copies can be produced Automatic reading devices use this as output mode

8.29 What are the major barriers to computer use reported by individuals who are blind or have low vision?

· Assistive technology helps to provide input of the information in case of sensory impairments. An initial assessment is done by the assistive technology professional to determine or modify a specific assistive technology suitable for the user. These assistive technologies help the disabled to overcome their disabilities and to improve their performance in their day-today activities. Now-a-days advancement of technology helps the blind to perform all the activities like, using computer, internet and others. But there are also some major limitations that are reported by the visually impaired individual. Some of them are Inadequate training is given before operating the computer with assistive technology. Due to this some people find it better to stop using them. Number of computers available with assistive technology are very few. Technology advancements are not updated to the individuals. Continuous guiding and doubt about operating are not cleared at appropriate time.

8.30 What are the primary challenges in obtaining Web access for people with disabilities?

· The reading devices used for the visually impaired are totally different from the mobility aids used by the visually impaired. Individuals with low vision and blind face several problems with mobility. So, to move safely they orient themselves to the surrounding environment. The blind person gets the terrains and the environment alters through sensory inputs like Sound, surface, smell and air. Long canes are the most commonly used mobility aids by the blind individuals. Besides it uses, it also have limitations like, Limited range of sensory information is obtained. Obstacles outside the range cannot be detected. Obstacles that are above waist level cannot be detected. Example: When a table is in the path of the individual the cane passes between the legs of the table. So, the person can only know the presence of the table only when they pass over it.

8.37 What are the major limitations of the long cane for use as a mobility aid by persons who are blind?

· The Long cane is still till this day the most commonly and widely used

mobility aid for people with visual impairments. However the area couple

limitations such as, the cane can only sense obstacles that are below the

waistline, and the range over which sensory information is obtained is

limited.

8.39 List three advantages and three disadvantages of the laser cane.

· The laser can as advantages and disadvantages:

Advantages:

Extends range of standard cane.

Provides better sensing of drop-offs

Adds the capability of detecting over hangs.

Disadvantages:

Auditory and tactile signals can be misleading due to inability of laser to

convey correct info.

Highly reflective surfaces can provide confusing or false reflections to the

cane user.

Inefficient in terms of cost (significant cost/benefit ration).

8.41 What are the major assistive technologies applied to orientation for people who are blind?

· Assistive technology helps to provide input of the information in case of sensory impairments. An initial assessment is done by the assistive technology professional to determine or modify a specific assistive technology suitable for the user. These assistive technologies help the disabled to overcome their disabilities and to improve their performance in their day-to-day activities. Individuals with low vision and blind face several problems with mobility. So, to move safely they orient themselves to the surrounding environment. The blind person gets the terrains and the environment alters through sensory inputs like sound, surface, smell and air, The limitations of the long cane can be overcome with the help of Electronic travel aid (ETA) ETAS give additional surroundings information to the blind pedestrian and it also senses the obstacles which are missed by the long cane. The three main components of the ETAS are: Environmental interface Information processor User display

5-3 (Optional for bonus credit) Write a sample set of performance specifications for a voice-output oscilloscope to be used by a visually impaired electrical engineering student for a laboratory exercise having to do with operational amplifiers. What features would be needed in the proposed oscilloscope?

· While I do believe the end user of the voice- output oscilloscope will still have

some trouble due to the fact that visual information is organized spatially

and auditory is organized temporally, I do believe that it is more helpful then

just a standard oscilloscope. A few of the design specifications would consist

of,

1) Blue tooth compatibility

2) Express the time frame in which the measurements are being

taken

3) Tell you what channel you are on

4) Allow you to choose what type of wave to use (i.e. sine wave,

square wave)

5) Tell you the pea to peak values

6) Calculate the gain from the two waves from channel A & B

7) Express the values of frequency and amplitude.

5-21 An electronic guide dog has been proposed as an electronic travel aid for a blind person. List some of the specific tasks that such a device must be able to do and the information processing steps needed to realize such an assistive device. List as many items and give as much details as possible. Hints: Consider the problems of obstacle detection, information display, propulsion system, inertial guidance, route recall, power supply, etc.

· There are quiet a few tasks that a mobility aid device must fulfill in order to

be even considered a viable option for people who are blind or have visual

impairments. Some the of the tasks the electronic dog guide must be able to

do are, detect obstacles below and above the waistline (preferable 360

degrees), have a long and efficient battery life to prevent from the AD from

going dead on the user in the middle of the road, have a solid method of

displaying the information gathered to the user in a way that is instant and

efficient. The dog will also have to posses some type of inertial guidance

system in order to correct its path as wit is moving based upon the obstacles

it is approaching. The engineer behind this project will face some significant

problems when it comes to the design of he electric dog. Some the problems

will be, getting the dog to walk at correct pace as the user, getting the

propulsion system timed correctly to move and stop with the user, the size

and weight of the dog, getting the system to retain the information and

directions of the users main routes. The electric guide dog will require

serious research and development prior to being put into production and I

am afraid that it will also be very expensive.

5-24 Safe and independent mobility by persons with severe visual impairments remains a challenge. To alleviate such persons of their dependence on guide dogs or a sighted human guide, various portable navigational aids using a Global Positioning System (GPS) receiver have been marketed. (a) Conduct an internet investigation of GPS as the basis for a portable navigational aid for the blind. Answer the following questions: How does GPS work? Can GPS signals be reliably received and detected at every location? How accurate are GPS signals in terms of resolution? Is this level of resolution sufficient for finding the entrance to a building? (b) Describe the various operational requirements of an ideal portable navigational aid for the blind. Consider such ergonomic issues as the user interface, input and output requirements, and target retail price. List some of the human factor design issues involved.

1. The GPS (global position system) is a network of 30 satellites orbiting the

earth at roughly about 20,000 km. From most places on earth you gps

machine is able to reach out and transmit to the satellites orbiting. Once

the system is able to get information on how far at least three satellites

are it will be able to pinpoint your exact location.

2. No the system is not able to transmit and receive from everywhere. If the

system is not able to find the location and distance of three of the orbiting

satellites it will not be able to get the information needed to pin point

your location.

3. While it is tough to say the exact accuracy of the GPS, the United States

currently claims to have a 4-meter (horizontally) accuracy rate. White it

has not been able to determine the accuracy in terms of elevation.

4. Unfortunately if you are in a very busy commercial are such as a mall or

shopping center according to the 4- meter long accuracy, you might be

walking into a business or door four meters south, north, east, or west of

your intended destination.

5. Yes other systems such as inertial guidance might be able to help when

the GPS is down specifically when trying to avoid obstacles that are on

your path way. Although if the are guided through the GPS, I would

assume that the entire system all-together would come to a stop.

Problem B:

The ideal GPS for a person that is blind I believe would work in

conjunction with the AT that the person is already using. I do not believe that

it would give the ability to the person operate with out their cane or service

dog. The GPS would work as a tool to inform the user of their exact location

in the city. Ideally it would be Bluetooth compatible so that the user can use

it in the street and can hear it well even with cars driving by. The GPS should

also be very affordable and MSRP should not accede $100. It would not be

able to serve as the primary method of mobility due to its inability to detect

any kind of obstacles on the path. The GPS can only tell you your exact

location; it cannot tell you if it is safe to cross the street.

1. List the advantages and disadvantages of a paperless Braille system versus paper Braille.

There are strengths and weakness of using paper brail verses digital brail. The strengths and weakness of the paper are:

1. You are able to achieve a higher speed in reading because you are able to use both hands, so skipping blank lines and starting the next line are much easier.

2. Spatial representation of the information on paper is much easier to read and the format is easy to under stand

3. The weakness mainly pertains to space; it takes up a lot of space, which makes t hard to read while traveling.

4. Paper brail also over time can fade and lose the letters on the page.

The strengths and weakness of digital brain are:

1.the reader is able to store and travel with much more reading material.

2. Some paperless brail systems allow for a search bar to find the information for you are looking for quickly.

3. A weakness is if the text is not formatted to brail correctly one can waist a tremendous amount of time truing to read.

4. Paperless brail can also end up deleting certain words or punctuation that is essential to understanding the text due to the addition of a simple hyphen to continue the word from the end of line to the next line.

2*. [Optional for Bonus Credit] Describe, contrast, and compare the electrocutaneous and vibrotactile approaches for tactile sensory aids. [Hint: You may need to search for additional background on the internet to answer this question.]

3. Describe the technical processing steps executed by the Kurzweil reading machine to recognize a character. [Hint: You may need to search the internet to answer this question more completely.]

4. List and briefly describe 3-4 major differences between mobility and reading aids for the blind in terms of their design goals, operating milieu, and consequences of errors.

5. List the major approaches used in Electronic Travel Aids (ETA’s) to detect (or interrogate) the environment and feedback environmental information to blind users.

6. What are the major design considerations or goals for ETAs? Describe how these are met (or not met) in the Laser Cane, the Sonicguide, and Mowat Sensor (or its equivalent successor). [Hint: You may need to use the internet to find out more about these assistive devices.]