The Equalizer: assistive technology and people with disabilities

Note: pictures of some of these devices are in the slides, see also the links in text.

What if...?

An ordinary computer user usually considers his/her way to work obvious - it is easy to miss the fact that our typical computer actually demands a lot from the human. But what if

• we cannot see, thus are unable to use the monitor?
• we just have one hand - or have none?
• our fingers would not flex?
• we control our movements so badly that even hitting the keyboard is difficult (not only individual keys)?
• we have insufficient muscle power to press the keys?

Actually, very many people with similar qualities are using computers today.

Ordinary or special?

Many computer users with disabilities are facing a dilemma - whether to go for a specially designed device or try to manage with a generic one? A special solution (e.g. a special keyboard) can be more fitting, but a generic one would typically give greater mobility - the person would not depend on the device. Special technology can also be problematic when the computer is used by several people in turn, some of which are with disabilities and some are not. It is a good idea to send accessibility-related feedback to the manufacturers of different devices - in an ideal case, special technology would not be needed at all, as all solutions are fully accessible. However, this is not the case yet.

Assistive IT solutions are most of all needed by two groups of disabilities - those with visual impairments (especially blind people) and those with mobility and/or motor control impairments. For comparison, people with hearing impairments need only some smaller changes (mostly related to certain content as videos which can be subtitled) as currently most of the vital information is transferred visually. In the cases of mental, developmental and behavioural disabilities, the stress would be on methodology and pedagogy rather than technology (still some hardware and software is also developed for these conditions).

Visual impairments

The technology used for this group of disabilities is relatively expensive and specific. The three main categories are

• screen magnification - used when the person is able to use some of his/her vision
• aural (sound) output - used when the remaining vision is very low (or is missing)
• tactile (touch) output - used typically by blind people who are well-versed in Braille alphabet

These systems can face several challenges, including

• being language-specific - most of the voice synthesis is done in a specific human language. E.g. English speech synthesizer is generally unusable for Polish or Estonian, due to different phonemes (sounds for letters) used.
• dependency on operating system and/or hardware - most systems are created for specific operating systems (e.g. MS Windows) and may demand hardware upgrades.
• dependence standards compliance in other hard- and software - while this should be obvious, many providers use non-standard solutions. Typically, blind users are the first to suffer.

Below, an overview of some assistive IT solutions is provided.

Screen reader

Mostly software (hardware readers exist too) that attempts to recognize screen content. The results are sent either to a speech synthesizer (sound output), a Braille display or a Braille printer.

Most of the systems are commercial, proprietary software (but in developed countries there is usually a compensation mechanism which would result in the user only paying a fraction of the otherwise significant price), one of the most common is JAWS. Of free and open-source solutions there are Emacspeak and Speakup. Microsoft Narrator on Windows systems is relatively simple, but the VoiceOver on OS X (since version 10.4) is a full-fledged screen reader. Therefore, Apple systems are somewhat better 'out of the box' for someone with a profound visual impairment - yet the price difference can also be a deciding factor.

Most newer Linux distributions can install Orca - it is designed for Linux but can also be ported to other systems. Orca is a combined access solution, containing a screen reader, a speech synthesizer, a Braille interface and a screen magnifier. However the support of different languages is still under development (different languages being usable in a different grade).

Speech synthesizer

A software which turns the input text to speech (it is often used in combination with a screen reader). Hardware devices also exist. In addition to people with visual impairments, it is a valuable tool for people with speech impairments (e.g. due to spasticity of throat muscles in some forms of cerebral palsy) - to the point that a guy in Estonia is doing own radio programme using one.

Screen magnification

In case of a more modest visual impairment, a 'virtual magnifying glass' is used - it enlarges a portion of screen under its window (mostly by factor of 2 to 16). Sometimes, it is paired with a screen reader to also dictate the screen content.

Problems that may occur:

• using a bigger factor, the screen can be hard to read due to enlarged pixels (screen elements)
• controlling the 'magnifying glass' can be difficult when some software tries to focus on some element on screen which does not suit the magnifier
• dependence on graphic drivers and other software following standards

Braille display

Used to display Braille text via sets of small tactile nuggets (Braille elements). The number of elements can vary typically from 18 to 80, 40-element displays are perhaps the most common. Compared to speech output, the Braille technology is more expensive and also more difficult to learn to use efficiently, but offers much bigger flexibility (e.g. for programming where maneuvering on the text is needed). Braille is also the only viable technology for computer users with both profound visual and hearing impairment (the deaf-blind people).

Braille printer

A device to output Braille to paper or other similar materials (sometimes, thin sheets of plastic are used). Newer printers can also print two-sided output. The printing can be rather noisy and older printer models needed special paper.

Braille keyboard

Braille keyboards are descendants of Perkins typewriters for Braille (see Fig 4). It is a chord keyboard (several keys are pressed simultaneously, like chords on a piano) with 6 or 8 main keys (depending on the type of Braille used) plus some control keys. Due to having less keys than ordinary keyboard, it can be smaller and more portable. Yet many blind people still use ordinary keyboards not to depend on a special solution.

Tactile mouse

These are mouse-like control devices which also give tactile feedback via vibration and/or tactile elements on the 'back' of the mouse. Several prototypes have been released, but the devices are not widespread yet.

Notebooks for blind people

The devices are used as laptops or notebooks. For output, they typically have either a hardware synthesizer or Braille display (or both), input is done via speech or an ordinary or Braille keyboard. Examples include GW Micro VoiceSense and BrailleNote.

Today, the borders between different devices are disappearing, as different devices obtain functions from others (e.g. smartphones vs handhelds vs tablets vs netbooks) and the mainstream products are slowly getting more accessible - thus it is possible that the need for special devices will decrease in the future.

Mobility and control impairments

A huge field

The spectrum of problems is extremely wide here - limited muscle power, limited movements, various control impairments (e.g. due to cerebral palsy), missing or non-functional limbs, grasping difficulties (due to arthritis) etc etc. Functional problems can occur with different media devices (CD/DVD, diskettes, USB sticks), operations demanding fast precise movements, but also with ordinary input devices which need good control (the mouse is the best example, but also key combinations on keyboard can be difficult). In this category, hardware plays a prominent part, but some problems can be alleviated with just in software as well.

The Rule Number One is: If the person controls any function on his/her body, it can be used to control a computer!

The Rule Number Two is: Never assume that something works just because it worked for another person!

The Rule Number Three is: Be a MacGyver!

Adapting ordinary devices

In many cases, when the person cannot use his/her computer at its typical position, the solution can be in changing the position of keyboard/mouse and/or using suitable input devices. A simple example: some muscular disorders and CP can render the person unable to control his/her fingers or to stretch fingers enough to press the keys. The solution is a simple stick (or a pen) held in the fist and used to press the keys. In some cases, ergonomic keyboards like MS Natural Keyboard can help, but sometimes they are even worse.

Likewise, the keyboard does not need to be on the table. Some people can control their feet better than hands - for them, the proper place for a keyboard is on the floor (or on a small stool). Sometimes, a special keyboard is needed (e.g. in spastic conditions when the user can accidentally smash the keyboard with his/her feet). Also, the whole design of the workplace should be reconsidered in this case.

If using feet is not a solution, the keyboard can be placed at any part of the body. Special consoles can be used which are similar to the mountings of tabletop lamps (see http://www.inclusive.co.uk/catalogue/acatalog/universal_switch_mountings.html). But again, sometimes just the environment can be used. A simple but effective solution for someone only controlling his/her head is to place the keyboard vertically near the user's face, who then presses keys with a stick held in his/her mouth (it can also be attached to the head). There are special input sticks available (some can be used e.g. to pick up small items) but a simple pen may do well.

The other end of the spectrum is devices like Tracker Pro that is used to track head movements and use these to control the computer.

The difficult animal

The mouse can be a main obstacle for someone with a motor impairment. To see this, we can do a very simple test - switch the mouse to the other, non-dominant hand (e.g. left for right-handed people). It is surprisingly difficult to control. But sometimes, the solutions are rather simple.

First the choice of right device. There are mouses with different size and shape, with different number of buttons, with or without the wheel, wired or wireless... Sometimes it's better to use wireless, sometimes wired (e.g. to retrieve it by the cable if it falls down!). The mouse surface can be horizontal, slanted or even vertical (in the latter case, the mouse can hang by the cable). Some disabilities demand sturdier mouses, so they should not be the cheapest ones possible.

But the mouse has got relatives - especially the trackball and the joystick. Again, these are available in both ordinary and special models. Trackballs can be turned with an input stick or basically with any part of the body (knee, elbow, chin - but it demands a well-considered location!).

A possible entry and control device can be a touchscreen - the keys can be displayed in such a form that is the best for the user (e.g. greatly enlarged).

Even a scanner can have an important assistive role - especially when equipped with OCR (Optical Character Recognition) software. For example, texts can be scanned and converted into a word processor - it can make a huge difference for people with difficulties in text entry.

More on keyboards

Most modern operating systems contain utilities which add some special functions to the keyboard. Historically they were separate utilities, but were soon integrated into the main systems. The utilities which exist in various forms in today's MS Windows, Apple OS X as well as in various distributions of Linux are:

• StickyKkeys - allows replacement of key combinations with sequences. It is especially needed for those typing with one hand/finger or a stick. For example, the Ctrl-H becomes a press on Control, then H.
• RepeatKeys - changes the reaction time of the keyboard. People with slow reaction may trigger the key repeating sequence by holding a key down for a long time. RepeatKeys can turn the mechanism off or change the time to e.g. 5 seconds (instead of 1.5-2 seconds that is the typical default).
• SlowKeys - helps people with control difficulties who often hit wrong keys. It delays the key entry time, making it necessary to hold every key down for a period in order to work. It slows the typing down, but accidenta touches cannot produce unwanted symbols.
• MouseKeys - substitutes the mouse with arrow keys (which in turn can be used with e.g. an input stick).

An useful piece of software is a keyboard emulator (virtual keyboard) which allows entering symbols from the screen. It can be combined with other devices (e.g. touchscreen, switches etc).

A simple hardware addition which can help people with motor impairments is the keyguard. It is attached to the keyboard, creating a frame with holes above the keys and making it difficult to accidentally move onto neighbouring keys. Sometimes, keyboards are available with a built-in keyguard.

Special devices

There are also cases where ordinary devices cannot be used. In these cases, some of the solutions might be

• smooth keyboard - similar to the small, thin solar-powered calculators. The keys are located under a smooth surface and need very little physical power to press. This is a possible tool for people with muscular dystrophy, multiple sclerosis and similar conditions. If control is also affected, a keyguard can be added.
• enlarged keyboard - useful when working with feet or having muscular spasticity.
• minikeyboard - the opposite of the former, can help people with very limited movement.
• chord keyboard - like Braille keyboards, they are used by pressing the keys simultaneously. Some models are designed for one-handed use, yet allow a trained user to reach comparable typing speeds with trained two-handed typists.

Some other solutions include

• concept keyboard - in this case, every key will enter not a single character but transfer a whole concept. An examople: http://www.overlaykeyboard.com/ .
• pedal mouse - a stronger brother of ordinary mouse, designed to be used by feet. An example: http://www.youtube.com/watch?v=If-jkWIa1mg .
• speech input - can help people with mobility impairments when the speech apparatus is undamaged. However, it depends on the overall support of

the given language by the operating system.

Switches

For ordinary people, the term means something they use to turn on lights or a TV. Yet similar devices can also be used by computer users with mobility impairments - and with even very serious ones.

Keyboard keys and mouse buttons can be looked at as switches too - they trigger a certain activity. The access switches tend to be very simple on/off type, but can be of very different size, shape and build. Also, they can be used with a very minimal control of the body - they can be put into armpits, under chin, under the sole, between fingers, in mouth...

Switches are often used in combination with the onscreen keyboard. The first press activates a cursor to start moving between rows, the next press would choose a row and start moving along the keys, the last one would choose the key. It is very slow, but can be the only way to work for someone with a very serious disability. Likewise, a mouse can be used through switches.

A special type of switch is the Morse input. While Morse is not much used in mainstream any more, it can be used to enter text by blowing air into a tube (the puff switch), the pulses of air forming dashes and dots. Newer switches are of sip-and-puff, double action type which allow rather fast pace of work (e.g. http://www.axistive.com/what-are--sip-n-puff--mouth-controlled-joysticks-.html. Similar switches also exist for e.g. whistling different tones.

Conclusion

Assistive technology has gone through significant development during the last decades. Yet in some places, the problem can be in an insufficient legal support framework that should make the devices affordable for users.

The main thing to remember is - there is no disability that is too serious for using the computer. This field is actually very suitable for mechatronics specialists who a) want to make the world better and b) want to accomplish impossible things like MacGyver did. :)

Additional reading

• Microsoft Accessibility Guides
• X Universal Access
• Linux Accessibility HOWTO
• GNOME Accessibility Project