AIDS FOR MOBILITY IMPAIRMENTS

As for accessibility to a personal computer, more problems are encountered with a functional deficit of the arms and concerning the use of the keyboard and the mouse.

• Useful little tips

Examples of problems, could be the need to input characters using a finger only and only one key, or using a stick mounted on a helmet instead of fingers, the greater possibility of making involuntary errors due to tremors or the prolonged pressure on a key, difficulty in using the mouse.

Among the most common changes to make to the keyboard, generally there is the need for a ''mask", a sort of keyboard pad cover in plexi-glass or metal, with holes corresponding to the keys: this way it's possible to lean one's hand on the keyboard and only use the keys chosen by inserting a finger in the hole.

They are very simple aids, they can be made or be purchased in specialised shops.

For less difficult cases, Windows itself can offer some solutions when choosing "Accessibility Options". They allow for avoiding repetitive hitting of a key and they allow for pressing more than one key at the same time and use keyboard arrow keys instead of the mouse, and so on.

• Special Keyboards 

These are specifically built for people with disabilities. There is a vast choice of them and they also allow for extra software programmes aimed at better access. These are the most common of special keyboards:

Smaller keyboards - For those people who cannot articulate movement over a vast area, and fine movements are not a problem, for example when one can use a hand very well but cannot move the arm.

Keyboards that can be re-configured - These are flat surfaces, sensitive to touch where their area is divided according to the position of corresponding keys. This can be worked out by applying a plastic sheet with a drawing of the keyboard. Therefore the keyboard itself can be used in different ways according to the need of the user.

• Tools for alternative input 

If the user cannot manage the keyboard directly, then alternative tools for input must be considedered. At the moment there are two of them, scanning system and voice input.

With Voice Systems, a microphone is applied to an audio and recognition software, able to recognise a number of words spoken by the user to associate them with particular functions of the computer (for example: switch on/off, Open, Save, etc). These systems are good however when the user has good command of his or her voice. At present recognition systems are so evolved that they enable dictation and text trascription using a practically unlimited vocabulary. With a limited vocabulary system a person with a mobility impairment might also be able to control facilities around their home or the wheelchair, etc. etc. With an unlimited vocabulary they will be able to use a wordprocessing programme, connect to the Internet, check their mail and use many Windows applications.

Scanning systems use a limited amount of keys (from a single one to a maximum of five or six). In this case writing is not enabled directly (a key for each character) but through a process of selection and confirmation. This system would have unlimited writing possibilities but as execution times of operation are very long, their use is somewhat still limited. Whenever new faster software has been created, the speed gained involves more complex procedures of use. There are many such programmes distributed in Italy, they differentiate for their graphics, the facility of use and the options selection, as well as some important differences regarding the chosen canning operating systems.

• Sensors 

As to perform the same function of a single key, one could use sensors, alternative machines differentiated by kind of activating mode (pressure, movement, shaking, touching, blowing, etc) as well as their shape and size. There is vast choice of sensors available at aid libraries and specialised shops, adaptable to any residual movement as long as it's voluntary.