Assistive technology

Assistive technology is a generic term that includes assistive, adaptive, and rehabilitative devices and the process used in selecting, locating, and using them. AT promotes greater independence for people with disabilities by enabling them to perform tasks that they were formerly unable to accomplish, or had great difficulty accomplishing, by providing enhancements to or changed methods of interacting with the technology needed to accomplish such tasks. Although, Cook & Hussey (2001) report this term is usually not used for rehabilitative devices and for devices that able-bodied find useful. According to disability advocates, technology is often created without regard to people with disabilities, creating unnecessary barriers to hundreds of millions of people.

Assistive technology and universal accessibility
Universal (or broadened) accessibility, or universal design means greater usability, particularly for people with disabilities. But universally accessible technology yields great rewards to the typical user as well; good accessible design is universal design. One example is the "curb cuts" (or dropped curbs) in the sidewalk at street crossings. While these curb cuts enable pedestrians with mobility impairments to cross the street, these also aid parents with carriages and strollers, shoppers with carts, and travellers and workers with pull-type bags.

As an example, the modern telephone is inaccessible to people who are deaf or hard of hearing. Combined with a text telephone (also known as a TDD Telecommunications 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, a deaf person is able to communicate immediately at a distance. Together with "relay" services, in which 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. Some have larger keys well-spaced to facilitate accurate dialling.

Also, a person with a mobility impairment can have difficulty using calculators. Speech recognition software could recognize short commands and make use of calculators easier.

Toys which have been adapted to be used by children with disabilities may have advantages for "typical" children as well. The Lekotek movement assists parents by lending assistive technology toys and expertise to families.

Telecare
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. An 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). Notably, 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 centre who can respond appropriately.

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.

Designing for people with dementia is a good example of how the design of the interface of a piece of AT is critical to its usefulness. People with dementia or any other identified user group must be involved in the design process to make sure that the design is accessible and usable. In the example above, a voice message could be used to remind the person with dementia to turn off the gas himself, but whose voice should be used, and what should the message say? Questions like these must be answered through user consultation, involvement and evaluation.

Accessible computer input
Sitting at a desk with a QWERTY keyboard and a mouse remains the dominant way of interacting with a personal computer. Some AT reduces the strain of this way of work through ergonomic accessories with height-adjustable furniture, footrests, wrist rests, and arm supports to ensure correct posture. Keyguards fits over the keyboard to help prevent unintentional keypresses.

Alternatively AT may attempt to improve the ergonomics of the devices themselves:
 * Ergonomic keyboards reduce the discomfort and strain of typing.
 * Chorded keyboards have a handful of keys (one per digit per hand) to type by ‘chords’ which produce different letters and keys.
 * Expanded keyboards with larger, more widely-spaced keys.
 * Compact and miniature keyboards.
 * Dvorak, Chubon and Colemak layouts, which offer more ergonomic layouts of the keys. There are also variants of Dvorak in which the most common keys are located at either the left or right side of the keyboard.

Input devices may be modified to make them easier to see and understand:
 * Keyboards with lowercase keys
 * Keyboards with big keys.
 * Large print keyboard with high contrast colors (such as white on black, black on white, and black on ivory).
 * Large print adhesive keyboard stickers in high contrast colors (such as white on black, black on white, and black on yellow).
 * Embossed locator dots help find the ‘home’ keys, F and J, on the keyboard.
 * Scroll wheels on mice remove the need to locate the scrolling interface on the computer screen.
 * Footmouse - Foot operated mice.

More ambitiously, and quite crucially when keyboard or mouse prove unusable, AT can also replace the keyboard and mouse with alternative devices: trackballs, joysticks, graphics tablets, touchpads, touch screens, foot mice, a microphone with speech recognition software, sip-and-puff input, and switch access.

Software can also make input devices easier to use:


 * Keyboard shortcuts and MouseKeys allow the user to substitute keyboarding for mouse actions. Macro recorders can greatly extend the range and sophistication of keyboard shortcuts.
 * Sticky_keys allows characters or commands to be typed without having to hold down a modifier key (Shift, Ctrl, Alt) while pressing a second key. Similarly, ClickLock is a Microsoft Windows features that remembers a mouse button is down so that items can be highlighted or dragged without holding the mouse button down throughout.
 * Customization of mouse or mouse alternatives' responsiveness to movement, double-clicking, and so forth.
 * 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.
 * Customization of pointer appearance, such as size, color and shape.
 * Predictive text
 * Spell checkers and grammar checkers

Durable Medical Equipment (DME)

 * Seating products that assist people to sit comfortably and safely (seating systems, cushions, therapeutic seats).
 * Standing products to support people with disabilities in the standing position while maintaining/improving their health (standing frame, standing wheelchair, active stander).
 * Walking products to aid people with disabilities who are able to walk or stand with assistance (canes, crutches, walkers, gait trainers).
 * Wheeled mobility products that enable people with mobility disabilities to move freely indoors and outdoors (wheelchairs, scooters)

Learning difficulties

 * Age appropriate software
 * Cause and effect software
 * Hand-eye co-ordination skills software
 * Diagnostic assessment software
 * Mind mapping software
 * Study skills software
 * Symbol-based software
 * Text-to-speech
 * Touch typing software

Visual impairment
Choice of appropriate hardware and software will depend on the user's level of functional vision.

Hardware

 * Large monitors.
 * Adjustable task lamp, using a fluorescent bulb, shines directly onto the paper and can be adjusted to suit.
 * Copyholder holds printed material in near vertical position for easier reading and can adjusted to suit.
 * Closed circuit television (CCTV) or video magnifier. Printed materials and objects are placed under a camera and the magnified image is displayed onto a screen.
 * Modified cassette recorder. To record a lecture, own thoughts, ideas, notes etc.
 * Desktop compact cassette dictation system. To allow audio cassette playback with the aid of a foot pedal.
 * Fusers produce tactile materials, for example diagrams and maps, by applying heat to special swell paper.
 * Scanner. A device used in conjunction with OCR software. The printed document is scanned and converted into electronic text, which can then be displayed on screen as recognisable text.
 * Standalone reading aids are integrate a scanner, optical character recognition (OCR) software and speech software in a single machine, working without a separate PC.
 * Refreshable Braille display. An electronic tactile device which is placed under the computer keyboard. A line of cells, that move up and down to represent a line of text on the computer screen, enables the user to read the contents of the computer screen in Braille.
 * Electronic Notetaker. A portable computer with a Braille or QWERTY keyboard and synthetic speech. Some models have an integrated Braille display.
 * Braille embosser. Embosses Braille output from a computer by punching dots onto paper. It connects to a computer in the same way as a text printer.
 * Perkins Brailler. To manually emboss Grade 1 or 2 Braille.

Software

 * Customization of graphical user interfaces to alter the colors and size of desktops, short-cut icons, menu bars and scroll bars.
 * Screen magnifiers
 * Screen readers
 * Self-voicing applications
 * Optical character recognition. Converts the printed word into text, via a scanner.
 * Braille translation. Converts the printed word into Braille, which can then be embossed via a Braille embosser.

Augmentative and Alternative Communication (AAC)
Augmentative and alternative communication is a well defined specialty within AT. AAC devices vary widely with respect to their technological sophistication:


 * Low-tech systems. Simple paper or object based systems, i.e. do not require a battery.
 * Light-tech systems. typically consisting of a digitized speech recorder with a touch sensitive display pad and sometimes switch access. Lite-tech systems require a battery.
 * High-tech systems. Computerized VOCAs that vary from single purpose appliance-like systems to multipurpose computer-based communication aids. Typically high-tech systems require training and ongoing support to operate the devices.

Deafness and hearing loss

 * Audiometer
 * Fire alarm paging system
 * Loop system (portable and fixed)
 * Radio aids
 * Telecommunications device for the deaf
 * Teletext
 * Video cassette recorders that can read and record subtitles (Closed Captioning).
 * Vibrating fire alarm placed under pillow when asleep.
 * Door bell lighting system

Others

 * Wakamaru provides companionship, reminds users to take medicine and calls for help if something is wrong.
 * CARE (Call Reassurance) community based program that calls seniors at home ensuring their well-being.
 * Cosmobot is part of a play therapy system designed to motivate children to participate in therapy.