1998 Conference Proceedings

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Switch, overlay keyboard and touch screen software for children and adults with profound and multiple disabilities

P. Blenkhorn
Technology for Disabled People Unit (TDPU)
Department of Computation
PO Box 88
M60 1QD
United Kingdom
Email: P.L.Blenkhorn@umist.ac.uk
Tel: +44-161-200-3371
Fax: +44-161-200-3373


For many profoundly disabled children a modern personal computer can provide opportunities for them interact with and control a broad range of both sounds and colourful pictures/visual objects. One of the advantages of current systems is the capability of including sounds and images appropriate to the user.

A range of programs have been developed that are concerned with providing switch, overlay keyboard and/or touch screen access to stimulating environments for (the least able) profoundly disabled children (and adults).

In addition, these programs enable carers to customise the applications and provide appropriate images and sounds for particular clients. Consequently, activities can be produced that are: directed towards a specific curriculum goal; culturally and/or age appropriate; simply stimulating for a particular individual.

Some of these programs will be presented and the feedback from the initial trials will be discussed.

1. Introduction

There are a considerable number of children and adults with profound and multiple disabilities. However, they have many and varied cognitive, motor and sensory difficulties. Many of these clients are in situations where there are educational objectives to be met, and in some cases the computer is seen as a possible vehicle for moving towards those objectives.

Indeed, for some disabled children the computer?s role as a communication aid and as an enabling technology can mean that is the one of the more effective vehicles for providing effective educational activities. Of course, this may be done by simply using an appropriate tool such as a word processor, however, for the client group in question here, i.e. profoundly disabled users, literacy is not yet an issue.

As well as being an enabling device there are additional benefits in using the computer as many children (and adults) find the bright and interactive medium to be stimulating, motivating and engaging.

2. Background

So what is required? Well there are many different areas of educational need, which in some cases will be focussed on and by user?s disability (e.g. visual skills training for clients with a visual disability). What is also required are different and appropriate means of accessing the material, e.g. using Touch Screen, Scanning, Overlay keyboards, etc.

One area that has arisen a number of times in workshops with teachers and therapists working with older children (and adults), who have similar educational objectives as those working with young children, is the need for age appropriate materials.

Further information on the background is this work was covered in a paper given at CSun 97 (Blenkhorn, 1997, Blenkhorn, 1986) and so that is not duplicated here.

3. Means of accessing the computer

So what are some of the different ways in which users can access educational materials on the computer? The traditional ones are the keyboard and mouse, but they are often to complex, confusing and possibly physically inaccessible to this client group. The materials being discussed here generally use one of the following input devices:

Microphone: here the computer simply responds to a noise or more precisely the volume of sound made.

Switches: there are typically used in either single switch mode or with two switches.

Touch Screen: here the interaction happens at the user's fingertips. If a user is capable of using a touch screen then, for many activities, this is a very natural and focused option (Blenkhorn, 1986).

Overlay Keyboard: here a graphics style tablet is attached to the computer that typically has a paper sheet overlaid on the tablet. (A tactile overlay is used in some cases - particularly useful for children with a visual disability.) The computer can detect which area of the overlay has been pressed and responds accordingly.

4. Ongoing work

A number of packages have been produced to initiate work in this area (SEMERC 1998). In this paper, though, the focus is on just three areas.

4.1 Picture building

A difficulty encountered in the UK was that there were a limited number of picture building activities available. As a result Build It was produced. Build It is a simple picture building program with sounds. It uses the keyboard, mouse buttons or switches (one or two). If a Touch Screen or Overlay keyboard is set up to produce keystrokes then they can also be used. Windows metafiles are used and Build It enables them to be ?broken down? into stages that are built every time that a child presses a switch. Tools are provided to enable carers to build their own activities. This has enabled a wide range of picture building activities to be produced.

4.2 Interacting with pictures

A suite of programs (Picture This: Knockout, Reveal, Flip It and Slider) have been produced that enable users to interact with pictures in a number of ways either using switches (with a special version: Picture Switcher), the mouse, a Touch Screen, or with an overlay keyboard set up to emulate a mouse.

4.2.1 Knockout lets the user change areas of an image such as the colour of the windows and the door in a house, or to colour in patterns. Some options enable users to receive a sound reward on completion of a task.

4.2.2 Reveal allows you to uncover areas of an image in steps. It includes a snaking option that only permits a limited area of the picture to be displayed.

4,3,3 Flip It and Slider enable sliding puzzle and jumbled images to be manipulated.

One of the most attractive features of this package is again to enable carers to personalise the materials using their own bitmaps, metafile and/or sound files to have an activity with a picture and sound appropriate to a given client.

4.2 Object manipulation

Draws (and the switch version: Switched on Draws) provide an activity centre where carers can set up different activities that can be controlled by the mouse, Touch Screen, switches or overlay keyboard. Tools provided enable users to colour in objects, move them, resize them, flip them, ? The carer can set up the access method, the tools available, the and materials (i.e. pictures) as appropriate for a given user?s physical need and the educational objective.

5. Discussion

These packages (and others developed in the same range) are being used in a number of schools. Initial feedback is most encouraging and a working group of interested carers has been set up in collaboration with Condover Hall School for the Blind. The area which holds most promise is perhaps also the one which is most difficult ? that of producing appropriate curriculum materials.

There is a lot of interest in developing age appropriate materials, particularly for adults, but carers have limited time and the take up in this area has been less than anticipated. It is intended to address this in meetings of the working group and by a (planned) weekend workshop in the late spring.

As reported last year: ?early comments resulted in the options for controlling the speed to be changed to allow the system to present information much more slowly (for the least able)? (Blenkhorn, 1997), and ?Further feedback has resulted in options to enable carers to set the size of the palettes available to children, and the colours in those palettes? (1).

6. References

Blenkhorn, P. (1997) Computer Assisted Sensory Stimulation for Children with Profound and Multiple Disabilities. In: Proceedings of the Twelfth Annual International Conference on Technology and Persons with Disabilities, Los Angeles, March 1997.

Blenkhorn, P. L. (1986) Microcomputer Software Using a Touch Sensitive Screen. The British Journal of Special Education. December, 4, 161.

Blenkhorn, P. L. (1986a) The RCEVH project on computer assisted learning. The British Journal of Visual Impairment, IV(3), 101-103.

SEMERC catalogue (1998).

See: http://www.promedia-semerc.com/ 

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