Systems And Devices For Disabled Use Computer Science Essay


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We use devices everyday to communicate with each other as well as for pleasure and practical reasons. Social network sites such as Facebook and Twitter are popular so much so that you can now update them via the mobile phone wherever you are The mobile phone itself is a much used device. Without it one would find it very difficult to communicate and meet up. If you are disabled these devices may not be easily accessible and therefore assistance or adaptation may be needed to enable their free use. In this essay we examine what being a disabled user in today's society may involve with a look at some of the various devices and aids that are currently in use and available. In this essay we looked at certain scenarios where technology has worked in favour of the disabled. We have also discussed the vast amount of technology available and technology that is in the process of becoming available. We stress the importance of usability of the user and how it has the possibility to change someone's life. The importance of individualisation and it costs is also explored with a glance at the possible future of devices their use, adaptations and developments. By covering specific areas such as education, web, personal case studies and modern technology, designs and future developments we hope to introduce some thought to these systems and devices.


Education and Devices

In an Educational Institute

Positives and Negatives

Individual Cases

Cerebral Palsy

Down Syndrome

Individual Case Studies

Web Applications

3.1.1 Vision Impairments

3.1.2 Hearing Impairments

3.1.3 Severe Disabilities

3.2 General Computing

Web and Devices


Modern Technology, Designs and Future Developments



The Peregrine Glove


Phantom Omni

Bionics and Thought




We use devices everyday to communicate with each other as well as for pleasure and practical reasons. Social network sites such as Facebook and Twitter are popular so much so that you can now update them via the mobile phone wherever you are The mobile phone itself is a much used device. Without it one would find it very difficult to communicate and meet up. If you are disabled these devices may not be easily accessible and therefore assistance or adaptation may be needed to enable their free use. There are many forms of social interaction some of which if you are unable to get out you can interact with on line (online game playing, social sites etc.) and we look at some of the various devices and aids that are available. Also looking at how they are used, developed and generally available together with the need for individualisation. Through the covering of devices used in relation to diverse areas such as education, web, together with individual case studies ending with new and future developments, disability and accessibility is focused upon.

Education and Devices

For the most of us disability isn't something we consider unless we or a friend or family member are directly affected. What we think less of is disability and education. Education is a vital part of growing up and is something that sticks with you all your life but for people who suffer from disability physically or mentally, education is not as straight forward.

The most common form of disability which makes education challenging is learning disability. According to a study carried out by the US Department of Education 51% of students aged 6 to 17 accounted for learning disabilities [1]. But what about the other 49% who suffer from physical disability. Computer technology can already allow for a greater educational activities and learning opportunities but now more adaptive computer technologies can help students with severe disabilities to become active learners in the classroom and become integrated into normal education. There is also a wide variety of computer technologies which cover all aspects of disability from speech difficulties right through to paralysis. [1]

For the students suffering from learning disabilities simple everyday software that we use can improve their education. Word Processor is one such piece of software. Students are more prone to working better on their own work and making corrections if presented to them on word processor. It also benefits students whose writing isn't as legible as neater writers and they are also aware of the errors.

Looking at students with speech and language disorders we know that communication is very important even in the classroom between student and teacher and student and student. Augmentative and Alternative Communication (AAC) devices are employed to communicate or help the disabled understand what is being said to them. The Augmentative part is used to enhance speaking capability where as Alternative is to replace ones speech. The Tobii C12[2] is one such device which allows users to communicate using text or symbols which outputs synthesized or digitalized speech. Students who use it have the opportunity to write and edit word documents and also have internet access which is useful for project work.

When considering students who have hearing impairments, trying to hear and understand what the teacher is saying can be the hardest part. Assistive Listening Devices are anything used to assist students with severe hearing impairments by making use of their other abilities such as sight and touch or anything used to enhance ones hearing. The simple telephone which has been around since the 1800s was mainly invented by Alexander Graham Bell to assist his sister who had a hearing difficulty. The Personal Frequency Modifier System is a device proven in the classroom. The teacher wears a microphone which is linked to the students' hearing aid. Background noise is reduced and student and teacher are allowed move freely around the classroom. This helps particularly in a noisy classroom with students of harder hearing, attention deficit and even for students learning English as a second language.

Now looking at students with severe physical disabilities such as sufferers of autism or brain trauma injuries or paralysis, education and everyday living is always a challenge. However to make this easier simple technologies such as a switch can be used. Switches can be operated using any part of the body from a finger or rib cage using controlled breathing and as result they can communicate with their non-disabled peers and operate computers independently. Touch-sensitive screen technology is another way for users to use a computer easily and is very popular with young computer users.

A more advance technology is Infrared Sensors with Pneumatic Switches. The infrared sensor is worn on the head with the use of a pneumatic switch. It allows the students to freely interact with the computer. With the sensor on the head, the student looks at the computer screen and the cursor follows the students head movement. As a result the student can place the cursor anywhere on the screen by simply moving their head. The second half of the device, the pneumatic switch acts as a mouse click for the student. The switch is activated by inhaling or exhaling through a plastic tube. As the user inhales or exhales, the computer responds in the same way as the mouse button being clicked.

Yet another technology used is voice recognition software whereby the user can simply bypass the keyboard as an input device and just speak to the computer. The computer can be programmed with a set of predefined instructions and then the user can issue commands verbally into a microphone.

2.1 In an Educational Institute

The University of Limerick is a place of education where assistive technologies have been put in place to aid the disabled into normal education. Facilities there include an Assistive Technology Lab, Initial Dyslexia Assessment and Braille printing. They also offer computer access and support, specialized software support and training and training in assistive technology and general IT training.

2.2 Positives and Negatives

Although these technologies are hugely beneficial there are downsides. One of these is cost which is a big consideration for all schools. Often systems and hardware need to be tailor made to suit the student which adds huge cost instantly. Sourcing this money is the main problem as schools have limited funding and other sources such as fundraisers and donations are generally not adequate. Another issue is lack of teacher training as teachers are not always fully prepared to use the technology in line with the school curriculum. This can have a knock on affect on the students because for them technology plays such a vital role in their education.

None the less technology opens many doors for students with disability. It allows them to be integrated into a normal education which, as a child, fitting in is a big part of life. It allows them develop their communication, developmental and functional skills. It allows them to learn and complete their education like their non-disabled peers which gives them opportunity for further education and allows them to reach their full potential. When describing how technology changed his life one student said: "I have never had a voice or way to communicate. Until this year I was on a special education classroom, now I am in a regular school. My computer has been the best thing that has ever happened to me."

2.3 Education

The benefits and issues of assistive technology for educational development and growth in children are shown in numerous case studies carried out on children over long periods of time. The individual case studies of children with different condition also show the variance in the technologies required in separate cases.

2.3.1 Cerebral Palsy

Anne is a child who was born with cerebral palsy and discovered technology at the young age of one. She started gradually at first using switches and toys at home, until her speech therapist encouraged her parents to introduce her to computers when she was two years old, as she knew it could benefit her educational and communication development. Following this suggestion Anne began using a device with was operated using a head-switch "to encourage cognitive skills and beginning scanning skills" (Hutinger et al 2010)

After two years Anne's progress was evaluated and some changes were made to her system. She was uncomfortable using her head-switch at school so her computer was fitted with a hand operated switch instead, she was also supplied with more devices thanks to her health insurance to aid her development such as the Liberator (a wireless keyboard), speech synthesizer and a range of adaptive puzzles. However there have been some barriers to Anne's technological advancement for example "physical fatigue, behaviour problems, occasional lack of interest" (Hutinger et al 2010) but the overall success of her educational development due to these assistive technologies overshadows any problems encountered along the way. Her parents state, "She is happy, communicating, doing well-she is a different child" (Hutinger et al 2010)

2.3.2 Down Syndrome

Dusty had Down syndrome and her use of assistive technology was for education and communication. She started using technology at a very young age using software which, explored numbers and the alphabet. In later life a word processing program with large print, speech output and word prediction gave her the ability to write. "Technology is highly motivating and it can bring out the best in people" (Alliance for Technology Access 1994)

Individual Case Studies

3.1 Web Applications

"The power of the web is in its universality. Access by everyone regardless of disability is an essential aspect"

Tim Berners-Lee, W3C Director and inventor of the World Wide Web

"In the United States, over 8 million people are blind or visually impaired [US Health 1997] (McCracken and Wolfe 2004)

3.1.1 Vision Impairments

The web is so visually orientated that is poses difficulties for many people with a range of different visual impairments. The most severe clearly being total blindness but also less apparent conditions such as low vision, colour blindness and health conditions such as epilepsy in which case seizures can be aggravated by visual stimuli.

The Tate Museum of Modern and Contemporary Art put in place an application on their website for the visually impaired following an email they received from a visitor of the museum who was born blind, The I-map is "an online art resource designed for visually impaired people with a general interest in art, art teachers and their visually impaired students" (

The application does not function by examining an entire piece of art at once, "it introduces detail in a carefully planned sequence gradually building towards an understanding of the work as a whole" ( The device works for the visually impaired as it allows people to take in information at a slow pace giving them time to picture, imagine and think about the piece of art more clearly. Resources include a text only commentary (accessed by a screen reader) and PDF raised drawings to download.

Caro Howell, the curator of the website states "It's a complete vindication of the site. Its not a blind person saying this is very visual so its pointless, but saying its interesting so he'll keep plugging away at it" (

3.1.2 Hearing Impairments

Following an intensive search into access to the web and use of web applications for the deaf an interesting survey emerged, which was carried out by Dr. Tracey Skelton (Loughborough University) and Dr. Takao Maruyama (Leeds University). The survey questioned the deaf and hard of hearing on their interest, usability and what they generally like or dislike about the internet in relation to their disability

*Bar chart taken from power point presentation of the survey (

As illustrated in the bar chart the amount of deaf Internet users is far greater than that of the non-users in the three younger age brackets (0-24 yrs, 25-34 yrs, 35-44 yrs) This shows that the use of the Internet is just as common among deaf users as it is with non-deaf users as in both groups generally the older the person the less familiar/reliant with the internet. This is due to assistive technologies that aid the deaf with obstacles they may run into while surfing the web for example, subtitles and video captions.

The people surveyed gave positive opinions towards their views and personal experiences using the Internet.

Adam, age 36 - "It means they're more equal to hearing people, they get access to the same information access to jobs and sport, things like that. So it's definitely been a big improvement for the Deaf community." (

Derrick, age 34 - "If you think about it the aim of the Internet, email, chat rooms, are based on communication and passing information, and for deaf people they can communicate using web cams - it is so easy to do that with MSN chat as well - it is really important for deaf people and I think that the Internet achieves its aim in that way." (

3.1.3 Severe Disabilities

Specific case studies show that even people with severe disabilities can get the same use out of the web as able people by simply using alternative and assistive input and output methods such as alternate keyboards, voice recognition, joysticks and trackballs, speech output and screen readers.

T.J Parker's abilities and life changed dramatically following an accident that left him paralyzed from the neck down and with permanent breathing difficulties. "He woke up a few days later in hospital with a respirator helping him breath and two vertebrae […] fractured, leaving him paralyzed from the neck down" (McCracken and Wolfe 2004 pp. 210-211)

Since his accident T.J has become a self-taught computer programmer and web developer. He operates his computer using speech recognition and a head mouse. "The head mouse is a device that tracks a dot at the end of his nose" (McCracken, Wolfe 2004 p. 227) Using his computer he can also operated devices in his home such as lighting and heating and most importantly his assistive technology enables him to continue to play games with his daughter.

3.2 General Computing

Victor had cerebral palsy and was nonverbal he was unable to operate conventional technology as his only physical control was his eyes and a single switch he could activate with his head. Through developments in assistive technology Victor was able to communicate by scanning a series of choices as the computer cycled through them and making a selection by using a switch. The system then prints out his message on a narrow ticker tape. (Alliance for Technology Access 1994)

Ben who was a journalist never used computing technology until he lost his vision, assistive technology such as vocally activated computers and word processing software that read what was on the screen aided him in doing a job where the abilities to read, write and edit are essential. (Alliance for Technology Access 1994)

Web Applications for disabled

4.1 Background

From my research of web applications for disabled I have found out the difficulties that disabled people have with accessing the internet safely, if at all. I studied three papers in depth, "Designing Universal Access: Web Applications for the elderly and disabled"," Wireless Internet interface for Person with Physical Disability" and "A Framework for a multi-robot assistance system".

I discovered the different disabilities that were affected; visual disabilities, hearing impairments, physical disabilities, cognitive and neurological disabilities and many more.

4.2 Papers researched

I will now discuss the first paper I studied, "Designing Universal Access: Web Applications for the Elderly and Disabled" by Robert Johnson and Simon Kent. This paper discusses how the Internet informs us on how the Internet is becoming an extremely popular medium for companies and organisations to advertise, communicate and deliver information to the public. They also address the issues relating to the usability of web applications for elderly and disabled users and investigate various ways in which it can be improved, and whether doing so will affect usability for younger and more able users.

In "Wireless Internet Interface for Person with Physical Disability" they discuss how technologically assistive devices are increasingly playing more important roles in the lives of people with disabilities. Using a conventional keyboard for Internet access is prohibitive for people whose hand co-ordination and dexterity are impaired by ailments such as amyotrophic lateral sclerosis. To assist people with physical disabilities in using the Internet, they designed and implemented and easy-to-operate wireless input interface using Morse code as an adaptive communication tool. Moreover, an adaptive Morse recognition process is introduced. After two months practice on this system, three participants with physical disabilities could conveniently gain access to the Internet. The Morse code is a single switch input system. For disabled users, it is difficult to maintain a stable typing rate; the automatic recognition of Morse code is difficult. Therefore, a suitable adaptive application method is needed. A least-mean-square algorithm was method was formed to adaptive Morse code recognition or people with impaired hand co-ordination and dexterity. Four processes are involved, space recognition, tone recognition, adaptive processing and character recognition.

The third and final article I studied was "A Framework for a multi-robot assistance system", this work aims at modelling a system which allows the disabled person, to give a mission to a team of robots and to determine the whole process leading to its execution. They separated the actor: active element subjected to the stimulus (the user and its request), the objective form: object designed in the mind of the actor, the object: element satisfying and corresponding to the satisfaction of the stimulus. The system is based on a several levels diagram for a design directed towards a multi-agents system. In this paper, they mainly described the four stages of the mechanism that lead to the trajectory determination of the robots group. These steps use a Veronoi's generalized graph and a wave front algorithm. The computation of the configuration space for a robot group and an adaptation of the group trajectory allow the group to be formed and reach the final position. For disabled people, the user must be able to take part in the control system, its management and in certain cases to take part in its design. Moreover, the user wishes to have permanently information on the evolution leads us to consider the system design as a participative system.

These participative aspects will involve:

The Human-System interface (HSI)

The request input seen as a set of remote services carried out either in individual or collective way by the robots.

User intervention in the construction of the request solution.

A way to act directly on the robots or on the mission scene in the event of modification, breakdown or execution failure.

Always-available information on the system state. The system design will call upon several levels of abstraction [Arkin et al.1999].

4.3 How to make a website more accessible:

I also did some online research into how websites could make their sites more accessible to those who are disabled:

Use larger fonts

Use colours that are compatible with the disabled, for example, strong, bright colours.

Audio reading on the website,

Easier linking to other parts of the website.

Make blocks of information more readable by breaking them up into smaller chunks.

While I was doing this research I was also confronted with some problems that people with disabilities come across while browsing the Internet:

People who are deaf may not detect sensitive information being said aloud.

People who are hard of hearing may not realise the volume of the audio.

People with physical disabilities are not able to block sensitive information on the screen like an able person would be.

4.4 Assistive Technologies and Adaptive Strategies formed:

The following assistive technologies and adaptive strategies have been formed:

Alternate keyboards: hardware or software devices used by people with physical disabilities, that provide an alternate way of creating keystrokes that appear to come from the standard keyboard.

Braille: a system using 6-8 raised dots in various patterns to represent letters and numbers that can be read by the fingertips. Dynamic Braille involves the use of a mechanical display where dots can be raised and lowered dynamically to allow any Braille characters to be displayed.

Scanning software: is adaptive software used by individuals with some physical or cognitive disabilities that highlight selection choices. A user selects a desired item by hitting a switch when the desired item is highlighted

Screen magnifiers: used primarily by people with low vision that magnifies a portion of the screen for easier viewing. At the same time screen magnifiers make presentations larger, they also reduce the area of the document that may be viewed, removing surrounding context.

Screen readers: Software used by individuals who are blind that interprets what is displayed on a screen and directs it either to speech synthesis for audio output or to dynamic Braille.

Speech recognition: used by people with some physical disabilities to hands and forearms as a method in some voice browsers.

Speech synthesis: can be generated by screen readers or voice browsers, and involves production of digitized speech from text.

Tabbing through structural elements: some accessibility solutions are adaptive strategies rather than specific assistive technologies such as software of hardware.

Text browsers: an alternative to graphical user interface browsers. They can be used with screen readers for people who are blind.

Visual notification: an alternative feature of some operating systems that allows deaf or hard of hearing users to receive a visual alert of a warning or error message that might otherwise be issued by sound.

Voice browsers: Systems that allow voice-driven navigation, some with both voice-input and voice-output. And some allowing telephone-based web access.

Modern Technology Designs and Future Developments


As we are all individuals so too are our needs. It is our individualisation that makes us who we are. The cost of individualisation of devices is prohibitive in most cases but thankfully as we are in modern times we are able to incorporate virtual world with real world to help reduce the individualisation costs.

There are devices which are in everyday use that can be adapted for use by people with disabilities, specialised devices involving muscles and nerves for movement, devices for increasing the likelihood of repetitive exercised being undertaken to help recovery as well as devices under development in relation to thought making them move. Examples of these devices are below.


These examples include a modern gaming device which is adaptable for use by the disabled, a device for use by someone severely constrained in their movement, another devices used especially as a method of getting patients to practise their exercises at home while having fun and lastly a device in true bionic style.

5.2.1 The Peregrine Glove

The Peregrine Glove ( developed for players within gaming competitions. This device is based on the military-specified mitt device and wires you into a keyboard. The glove's layout involves a five point area on each finger which could be mapped to movements and calibrated for size of area. It also contained a bar pad across the palm. This device could be adapted for use by persons with poor motor skills or stiffness in their hands to exercise and play at the same time. It can be programmed to perform certain actions through calibration and key mapping software which could be adapted to make it harder or easier as the users improved. It would also mean that the user would be able to participate with different types of activities that involved a keyboard and computer and hand movement. This is just a small device open to adaptation and further development.

5.2.2 Telethesis

Technology has advanced so that both the virtual world and the real world combine as a tool for individualising devices for assistance. Telethesis is the name given to devices that are multi-linked, articulated, worn and physically controlled by the user. The use of both virtual and real worlds helps to maintain reasonable costs for the customising of a device as a one- of- a- kind (Song, P et al., 1999). The most important aspect of all devices is its individualism as there are so many different abilities within a disability one design will not fit all.

Kazerooni, 1990 refers to such a type of device mentioning that though powered by voluntary actions of the user it would still need some sort of stabilisation to take into account involuntary actions such as tremors, spasms and vibrations. These stabilisers would be actuators and would act like human muscles while set to filter out the interferences.

Using virtual reality with robotics and input from multi-disciplinary parties has increased the possibility of individualisation being more economical. Milgram et al, 1994 described virtual reality as a synthetic world where the user appears to be inside and can have interactions within. The designer would work virtually; building a virtual world with a virtual device and virtual user, incorporating information received from the various doctors, carers, therapists and the user, testing in many simulated environments saving money on producing numerous prototypes.

Peng Song et al, 1999, presented such a programme for a head controlled feeding aid and painting tool. These devices relied upon the users head movements to power them. The head was the input subsystem; the device was the effector subsystem and the apparel / robotics the coupling system. Using the virtual world and the real world together enabled the designer to try out many various designs in numerous settings before production of a device, thus reducing costs. As the device could also be viewed from an aesthetic perspective with pulleys, links and cables related to in the real world (combining worlds) it helped with the best possible appearance.

Phantom Omni

Another example of devices being adapted for use is the Phantom Omni which is a hepatic device with six degrees of function and gives force feedback in three dimensions Lovquist, E et al. 2009 Comprising an extending arm with a pointer like tool which lifted and changed the cards or objects within the virtual world.

This device was used with games scenarios in the virtual world which was used in rehabilitation for people who have suffered strokes. In the development of the device it was recorded from participants that the use of the device in a game scenario kept their interest up and they forgot they were doing exercise just got so involved with the game.

It could also be controlled with the degree of difficulty and weight according to needs and preset by the therapist with increasing levels as the patient progressed.

Patients who used it forgot they were doing exercises and enjoyed the goal and fun aspect of it.

Bionics and Thought

The Bionic Age is here and is now being used to develop the merging of human and machine. Bionic limbs are being built controlled by the power of thought alone. This is the future - the development of the next generation of prosthetic limbs. Dirk Ahlstrom, 2010 In America Prof. Richard Weir and his team are pushing this development forward. We will have a bionic man or woman in the future - making the movies a reality (The Six Million Dollar Man, I Robot). This research is taking place in Chicago and has evolved into the building of a mechanical arm with movement through the means of thought. The initial prototype, Proto1 featured in the National Geographic and the second prototype Proto 2, more advanced, has just been finished. The control for movement of these two prototypes is based on both electronics and "targeted muscle re-innervations". Through the use of the remaining nerves that used to control the hand and arm movements and the muscles which act like a biological amplifier for the nerves means the hand / arm can be controlled by thought, the same way that we do it naturally.

The goal in all this work it to provide arms which potentially over time could provide 22 degrees of movement depending on the correct nerve endings being found and wired up to the remaining muscle. Prof. Weir believes that this means offers the possibility of developing permanent limb replacements lasting a lifetime.


Communication is very important as everyone needs to be able to do this with ease so whether one has a physical, mental or both type of disability it is double important as it also helps maintain involvement within the community. As mentioned virtual reality and reality can work together to benefit the individualisation of devices. With the advances of technology, designs and devices individualisation is becoming more of a realistic reality. Technology and some of what we already have today can be easily adapted for disabled users.

It is becoming easier for disabled users to interact with others through the internet and increases the availability and access to a wide education. Through the covering of devices used in relation to diverse areas such as education, web, together with individual case studies ending with new and future developments, disability and accessibility is focused upon.

Having focused upon devices in relation to education, web, individualisation and case studies the understanding of disability issues has been addressed. We hope we have managed to give you an insight to the importance of technology in today's world and how important it is that it is made accessible for all.

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