Assistive Technology
Consider an example of assistive technology. The modern telephone is not accessible to people who are deaf or hard of hearing. Combined with a text telephone (also known as a TDD [Telephone Device for the Deaf] and in the USA generally called a TTY[TeleTYpewriter], which converts typed characters into tones that may be sent over the telephone line, the deaf person is able to communicate immediately at a distance.
Together with “relay” services (where an operator reads what the deaf person types and types what a hearing person says) the deaf person is then given access to everyone’s telephone, not just those of people who possess text telephones.
Many telephones now have volume controls, which are primarily intended for the benefit of people who are hard of hearing but can be useful for all users at times and places where there is significant background noise.
Another example: calculators are cheap, but a person with a mobility impairment can have difficulty using them. The speech recognition software could recognize short commands and make use of calculators a little easier.
People with cognitive disabilities would appreciate simplicity; others would as well.
Telecare is a particular sort of assistive technology that uses electronic sensors connected to an alarm system to help caregivers manage risk and help vulnerable people stay independent at home longer.
A good example would be the systems being put in place for senior people such as fall detectors, thermometers (for hypothermia risk), flooding and unlit gas sensors (for people with mild dementia).
The principle being that these alerts can be customized to the particular person’s risks. When the alert is triggered, a message is sent to a carer or contact center who can respond appropriately. The range of sensors is wide and expanding rapidly.
Technology similar to Telecare can also be used to act within a person’s home rather than just to respond to a detected crisis. Using one of the examples above, unlit gas sensors for people with dementia can be used to trigger a device that turns off the gas and tells someone what has happened. This is safer than just telling an external person that there is a problem.
Designing for people with dementia is a good example of where the design of the interface of a piece of assistive technology (AT) is critical to its usefulness. It is important to make sure that people with dementia or any other identified user group are involved in the design process to make sure that the design is accessible and useable.
In the example above, a voice message could be used to remind the person with dementia to turn off the gas himself, but who’s voice should be used, and what should the message say? Questions like these must be answered through user consultation, involvement, and evaluation.
Assistive technology products
- Accessing the keyboard
- Hardware
- Height-adjustable trolley. Allows precise adjustment, via a handle, of a computer to the correct height – even when fully loaded with equipment.
- Adjustable keyboard and monitor arms. Attaches to a table and swings out to the correct height.
- Footrests. If the user’s feet are dangling down from a seat that is too high they can help to maintain sitting balance and achieve good hand control.
- Wristrests. Stabilizes the arm. Arm supports. Take the weight of the arm and let the user move across the keyboard to access the keys.
- Keyguards. It fits over the keyboard to help prevent unintentional keypresses.
- Ergonomic keyboards. Reduce the discomfort from injuries related to excessive keyboard use (wrist rests are often built in as well).
- Chording keyboards. Have a handful of keys (one per digit per hand) to type by ‘chords’ which produce different letters and keys.
- Expanded keyboards. Keys are larger and more widely spaced. Compact and miniature keyboards. A smaller version of the standard keyboard.
- Dvorak alternative keyboard layout. An ergonomic keyboard layout, where the most common keys are located at either the left or right side of the keyboard.
- Height-adjustable computer table
Software
Sticky keys is a feature of Microsoft Windows 95 onwards and Mac OS X operating systems. Allows characters or commands to be typed without having to hold down a modifier key (Shift, Ctrl, Alt) while pressing a second key.
FilterKeys is a feature of Microsoft Windows 95 onwards. Instructs the keyboard to ignore brief or repeated keystrokes. FilterKeys (Ignore quick keystrokes and slow down the repeat rate) is a feature of Microsoft Windows 95 onwards. Adjusts the speed at which a character repeats when you hold down a key.
ToggleKeys is a feature of Microsoft Windows 95 onwards. A high sound is heard when the CAPS LOCK, SCROLL LOCK, or NUM LOCK key is switched on and a low sound is heard when any of those keys are switched off.
Accessing the mouse
- Hardware Wristrests and supports. Wristrests support the hand so that there is less strain on the wrist; arm supports to support the arm yet still permit free movement.
- Keyboard shortcuts. A combination of keys is used for operations commonly done using the mouse.
- Rollerballs. An upside-down mouse where the ball is moved directly with the fingers (or foot, nose, elbow, etc) to control the mouse pointer.
- Joysticks. The stick is moved directly with the fingers (or foot, nose, elbow, etc) to control the mouse pointer.
- Graphics tablets. The stylus pen, linked to the tablet, is moved with the hand to control the mouse pointer.
- Touchpads. Flat touch-sensitive surface operated with the finger to control the mouse pointer.
- Touch screens. The user can touch objects directly on the screen to move them around.
- Head control. Use head movement to control the mouse pointer.
Software
Double-click speed is a feature of Microsoft Windows. ClickLock is a feature of Microsoft Windows. Locks a mouse button down so that items can be dragged around the screen. Mouse speed is a feature of Microsoft Windows. Sets how far and fast the pointer moves on the screen.
Pointer size is a feature of Microsoft Windows. Changes can be made to the size, colour or shape.
MouseKeys is a feature of Microsoft Windows 95 onwards. Configures the numeric keypad at the right-hand side of the keyboard to control the mouse pointer.
Macro is a feature of Microsoft Word. A particular sequence of keyboard operations is ‘recorded’ and then ‘played back’ by pressing a combination of keys.