Fig. 1. A switch-operated scrolling reading machine, shown under the control of a sip-and-puff switch.

Disability and Technology

Disability and Technology

Engineering a More Equitable Ireland:

By Ted Burke, Annraoi de Paor, and Eugene Coyle

Many of the practical difficulties faced by people with disabilities can be addressed through assistive technology. Engineers who are not directly involved in the disability sector should be aware that by designing devices, environments, and amenities so that they are accessible to people with the widest range of abilities, they can promote greater equality of opportunity in education, employment, and citizenship for disabled people.

Engineering academia plays a part in increasing societal equality for people with disabilities. For example, over a period of 20 years the engineering research laboratory in Ireland’s National Rehabilitation Hospital has hosted approximately 150 disability-related research projects at all levels. The primary benefit of disability-related projects in engineering education is often portrayed as technological outcomes. Unfortunately, only a small minority of such projects translate directly into actual innovative assistive technology products that become widely available to the people who can benefit. More frequently, projects contribute to future developments indirectly through academic publication. In the experience of those involved in this laboratory, an important benefit of the majority of these projects has been the lasting impact on the student engineers who undertook them, giving them a better understanding of the humanitarian role of engineering.

Humanitarian Engineering in Action

People with disabilities tend to be marginalized in many societies, frequently being prevented from accessing public services and amenities, or being deprived of the opportunity to work despite the availability of jobs to which they are well suited. Many are even prevented from expressing themselves freely. In some of the world’s most prosperous nations, assistive technology that could facilitate a reasonable level of independence for people with disabilities is simply not available to them. Engineers have the means to create a more level playing field, a society in which people with disabilities can participate fully, as they are entitled to do. By developing and providing appropriate technology and by promoting inclusive designs of devices, environments and services, engineers can help to build a more inclusive society.

Rehabilitation engineering and assistive technology research are good examples of humanitarian engineering in action. These areas provide an ideal opportunity for students in higher education to take on projects that have real importance, not only because of the potential for the technology produced to improve quality of life, but also because of the educational benefit and sense of professional responsibility that it gives to the students. When students involved in these projects recognize that engineering can have a positive impact on the lives of those who are disadvantaged or socially excluded, the students gain a sense of professional responsibility and compassion.

Disability and Design

Disability is often perceived as something “wrong” with a person. This viewpoint sees “disability” as stemming from a medical diagnosis and is often referred to as the medical model, as opposed to the social model of disability. This model proposes that disability is primarily defined not by a person’s medical condition, but by the prejudices and exclusionary practices of society. Encouraging students to appreciate the significance of the social model of disability can be a challenge for engineering academics teaching in disability-related subjects.

National Rehabilitation Hospital Laboratory in Dublin

University College Dublin’s Rehabilitation Engineering Laboratory, situated within Ireland’s National Rehabilitation Hospital (NRH), was established as part of the University’s Department of Electronic and Electrical Engineering in 1986 by Professor Annraoi de Paor, who remained its Director from that time until his retirement in 2005. During Professor de Paor’s tenure, the laboratory hosted numerous research projects – approximately 100 Bachelor’s degree projects, 40 Master’s projects, and 10 Ph.D.s – most of which arose directly through interaction with the patients and therapists in the hospital. The laboratory was also opened to other institutions, and several students registered at Dublin Institute of Technology and at the University of Dublin worked there. A few of the laboratory’s projects are described in this article.

Accessible Reading Machine

One of the early projects undertaken was the development of a reading aid. This project arose through consultation with a quadriplegic patient who identified without hesitation what he most missed due to his disability – the ability to read a book. This patient’s experience of previous reading devices had been very frustrating – they would frequently tear or crease pages or turn two at once and could not refer back to an earlier page. A new design by a final year undergraduate engineer, Linda Hickey, based upon the ancient principle of scrolling, requires that the book be dismantled and its pages pasted onto a roll of acetate, such as those used on many overhead projectors. (See Fig. 1.)

Since its creation, the scrolling reading machine has instigated several more projects to implement alternative user interfaces. Although many books are now available electronically, which facilitates reading through a computer under the control of an accessible interface device, the scrolling reading machine still remains in constant use today.

Fig. 1. A switch-operated scrolling reading machine, shown under the control of a sip-and-puff switch.

Fig. 1. A switch-operated scrolling reading machine, shown under the control of a sip-and-puff switch.

Click to enlarge

Switches in Rehabilitation

Many projects undertaken in the NRH lab have been carried out in cooperation with the staff of the hospital, and almost all have originated as requests or suggestions from staff. One of the themes that has arisen repeatedly over the years, particularly in interaction with the hospital’s occupational therapists and speech and language therapists, has been the use of switches in rehabilitation to control assistive technology programs and devices.

One of the switch-related projects carried out in the NRH lab involved the construction of custom-designed electronic switch interface boxes for the hospital’s Occupational Therapy department where they are now used in retraining head-injured people in the operation of associating cause and effect. The interface box allows any electrical appliance such as a radio to be powered on or off using any simple switch. Controls on the box allow it to be configured in one of three action modes:

  • Momentary mode, in which the appliance is powered only as long as the switch is depressed,
  • Latched mode, in which the appliance is toggled on or off each time the switch is pressed, and
  • Timed mode, in which the appliance stays on for a userselectable period of time after each press of the switch.

Facilitating Communication by Profoundly Physically Disabled People

Occasionally, engineers in the laboratory receive requests from therapists in the hospital to design custom devices for patients with profound physical disabilities for whom no suitable commercially available system can be found.

One of the most successful projects to have begun in this way concerned the development of a webcam-based system for the detection of eye blinks in a patient otherwise completely paralyzed. The camera is trained on the user’s face and a continuous analysis of the color distribution is made in real-time.

In some cases, even though a paralyzed person retains a degree of control over some body movement, it proves difficult to identify a mechanical switch that can be operated consistently. To address this, engineers designed an electromechanical switch simulator that could reproduce the feel and action of a variety of mechanical buttons. The prototype was constructed by a final year undergraduate project student, Niamh Connolly, who integrated the device with real-time simulation software running on a PC via an analog input/output card so that different switch profiles could easily be loaded on the simulator [1].

As part of another project, to facilitate creative expression by children with physical disabilities, a system was developed that allows drawings to be created using vocalizations alone [2]

Socially Engaged, Technically Challenging Projects

The technology described in this article can, in fortunate cases, directly benefit people with disabilities in a substantial way. But direct benefit to people with disabilities of the technology developed should be acknowledged as only part of the motivation for undertaking these projects. A more consistent feature of assistive technology research projects is the indirect benefit to people with disabilities and to society in general. In addition to the technical experience gained from any substantial student project, assistive technology research provides students with a better understanding of the social implications of engineering.

Approximately 150 students carried out Bachelor’s, Master’s, or PhD research projects in the NRH laboratory during Professor de Paor’s tenure as Director. Furthermore, the research community built up around it was deeply involved in the foundation of an interdisciplinary Centre for Disabilities Studies in University College Dublin, which has to date produced well over 100 graduates from Master’s and Higher Diploma programs.

Author Information

Eugene Coyle is with the School of Electrical Engineering Systems, Dublin Institute of Technology, Kevin Street, Dublin 8, Ireland.

Annraoi de Paor is Professor Emeritus of Electrical Engineering, School of Electrical, Electronic and Mechanical Engineering, University College Dublin, Belfield, Dublin 4, Ireland.

Ted Burke is with the School of Electrical Engineering Systems, Dublin Institute of Technology, Kevin Street, Dublin 8, Ireland. Email:

Click here to read the entire article, which appeared in the Spring 2010 issue of the IEEE Technology and Society Magazine.

Hide References
  1. N. Connolly, E. Burke, and A. de Paor, “A general purpose electromechanical simulator for switches used in the rehabilitation of communication-impaired people,” Advances in Electrical and Electronic Engineering (Slovakia), vol. 3, no. 2, pp. 201–204, May 2004.
  2. E. Burke, A. de Paor, and G. McDarby, “A vocalisation-based drawing interface for disabled children,” Advances in Electrical and Electronic Engineering (Slovakia), vol. 3, no. 2, pp. 205–208, May 2004.