Computer Assistive Devices and Environmental Controls

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Chapter 23 Computer Assistive Devices and Environmental Controls

This chapter provides an overview of assistive technology (AT) devices and services, including definitions, history, and legislation. It also discusses the use of AT by people with communication disorders, impaired mobility, hearing and visual impairments, and cognitive and learning disabilities. It describes the selection of appropriate technology and training in its use, suggests ways to avoid the abandonment of AT by clients and caregivers, and discusses the principles of clinical assessment and physician responsibility. Finally, it briefly discusses the future in terms of research and development, and application of emerging technologies to the needs of people with disabilities.

Defining Assistive Technology

The term assistive technology is fairly new, although history records the use of tools to enable people with disabilities to walk, eat, and see as far back as the sixth or seventh century BC.14,17 Public Law 100-40725 defines AT as “any item, piece of equipment or product system whether acquired commercially off the shelf, modified, or customized that is used to increase or improve functional capabilities of individuals with disabilities.” This definition also includes a second component defining AT services as “any service that directly assists an individual with a disability in the selection, acquisition or use of an AT device.” Public Law 100-407 specifies the following:

Since 1988, this definition has also been used in other federal legislation authorizing services or supports for persons with disabilities. The Individuals with Disabilities Education Act3 (IDEA) and Reauthorization of the Rehabilitation Act24 are both examples of legislation that further codifies Public Law 100-407.

History, Legislation, and Utilization of Assistive Technology

Education: The Individuals with Disabilities Education Act

IDEA originated in 1997 and was reauthorized most recently as Public Law 108-446 by the 108th Congress. IDEA strengthens academic expectations and accountability for the nation’s 5.8 million children with disabilities. One important impact of IDEA legislation is that it specifies that AT devices and services be provided to children from birth to 21 years of age to facilitate education in a regular classroom if such devices and services are required as part of the student’s special education, related services, or supplementary aids and services (Code of Federal Regulations, Title 34, Sections 300.308) (Box 23-1). For students with disabilities, AT supports their acquisition of a free and appropriate public education. All individualized education plans developed for children needing special education services must indicate that AT has been considered as a way “to provide meaningful access to the general curriculum.”27 AT devices and services included as a component of an individualized education plan must also be provided at no cost to the student or parents. The school, however, can use other public and private funding sources that are available to fund the AT (34 CFR).

Part C of IDEA also includes children before they start school. It covers the needs of children as soon as their developmental differences are noted. It intends that infants and toddlers receive services in the home or in other places, such as preschool settings, where possible. The services provided for these children are described in individualized family service plans. Individualized family service plans include parents, extended family, and early childhood interventionists and other related services personnel in planning and identifying goals and necessary services. IDEA also recognizes that coordination is needed to help families and children with the transition from infant and toddler programs to preschool programs. As a result, students with disabilities are being educated in preschool settings along with typically developing children in an effort to help all children reach the same developmental milestones.

The Americans with Disabilities Act and the Reauthorization of the Rehabilitation Act

The American Rehabilitation Act with Disabilities Act (ADA) was originally passed in 1990, and clarified the civil rights of persons with disabilities and specified equal access to public places, employment, transportation, and telecommunications. The ADA built on the foundation of the Rehabilitation Act of 1973 (updated in 2003 as the Reauthorization of the Rehabilitation Act) in recognizing the role of employment in enabling individuals with disabilities to become economically self-sufficient and integrated into communities. The ADA was amended in 2008, and these amendments became effective January 1, 2009. The amended ADA retains the original Act’s basic definition of “disability” as an impairment that substantially limits one or more major life activities, a record of such an impairment, or being regarded as having such an impairment.38,39 However, it changes the way that these statutory terms should be interpreted in several ways. Most significantly, the amended Act does the following:

Vocational rehabilitation services are often the key to enabling employment for adults with disabilities. The Rehabilitation Act mandates that AT devices and services should be considered and provided as a means to acquire vocational training, as well as to enter into and maintain employment. It also requires that AT be considered during the development and implementation of the Individualized Written Rehabilitation Plan, the document that guides a person’s vocational rehabilitation process. For example, if an individual has limited sight and needs to fill out paperwork to determine eligibility for vocational rehabilitation services, assistive devices to facilitate reading must be provided at that time. In recent years the Offices of Vocational Rehabilitation have become an important source of funding for AT devices and services to support employment for adults with disabilities.37

Assistive Technology and the International Classification of Functioning

The term disability is not always precise and quantifiable. The concept of disability is not even agreed on by persons who self-identify as having a disability, by professionals who study disability, or by the general public.23 This lack of agreement creates an obstacle to the study of disability and to the fair and effective administration of programs and policies intended for people with disabilities.4818 With this issue in mind, the World Health Organization (WHO) developed a global common health language, one that includes physical, mental, and social well-being. The International Classification of Impairment, Disabilities, and Handicaps was first published by the WHO in 1980 as a tool for classification of the “consequences of disease.” The newest version, International Classification of Functioning, Disability and Health (ICF), moves away from a “consequence of disease” classification (1980 version) to a more positive “components of health” classification. This latest version provides a common framework and language for the description of health and health-related domains and uses the following language:

The ICF and its language help professionals define the need for health care and related services, such as the provision of AT. It recognizes that physical, mental, social, economic, or environmental interventions can improve lives and levels of functioning for persons with diseases. These might include medical, rehabilitation, psychosocial, or other person-based interventions.41 It also characterizes physical, mental, social, economic or environmental interventions that will improve lives and levels of functioning. Because AT has the potential to improve daily activities and participation in social and physical environments and thus improve the quality of life of individuals with disabilities, it clearly fits within the ICF. The WHO common health language is used throughout this chapter to discuss the potential impact of appropriate AT.

Overview of Assistive Technology Devices

AT devices are designed to facilitate functional abilities and to meet the needs of humans throughout their varied life stages and roles. It is important to remember that AT device usage and requirements will change over time as individuals mature and take on different life roles. Consequently there is no “one size fits all” technology available.

Indirect Selection

Scanning is the most common indirect selection method used by persons with significant motor impairments. A selection set is presented on a display (e.g., a series of pictures or letters) and is sequentially scanned by a light or cursor on the device. The user chooses the desired item by pressing a switch when the indicator reaches the desired location or choice on the display.

Switches come in many styles and are selected based on the body part that will be activating them (e.g., elbow or chin) and the task or setting for using them (e.g., watching television in bed or using a communication device while eating). A switch can be as simple as a “wobble” switch that is activated by a gross motor movement such as hitting the switch with the head (Figure 23-1), hand, arm, leg, or knee. Other switches are activated by tongue touch, by sipping and puffing on a straw, or through very fine movements such as an eye blink or a single muscle twitch. Regardless, switch use and timing accuracy can be very difficult for new users and must be taught. One common method to teach switch activation and use is to interface a switch with battery-operated toys and games, or home or work appliances to increase motivation and teach the concepts used in indirect selection.

Fairly recent developments include eye-gaze switches, which calibrate intentional eye movement patterns and select targets such as individual keys on an onscreen keyboard. Other new developments include brain wave technology (Eye and Muscle Operated Switch [EMOS]) that responds to excitation of alpha waves to trigger a selection.

Assistive Technology for Communication Disorders

Vocal communication allows humans to interact, form relationships, and direct the events of their lives to enable choice and participation. Human communication is based on having both receptive and expressive language abilities and the physical capacity to reliably produce intelligible speech sounds. Communication impairment can result from congenital conditions such as mental retardation, cerebral palsy, developmental verbal apraxia, and developmental language disorders. Other impairments can be acquired through traumatic brain injury, stroke, multiple sclerosis, amyotrophic lateral sclerosis, tetraplegia, ventilator dependence, and laryngectomy resulting from cancer.3 AT devices that meet the needs of persons with many types of speech and language impairment are commonly called augmentative and alternative communication (AAC) devices, because they can either support or substitute for expressive language impairments. More recently the term speech-generating device has entered into the medical vocabulary to differentiate AAC devices from basic computer devices, especially when seeking third-party funding such as that from Medicaid and Medicare.8

Some individuals are completely unable to speak or have such severe expressive difficulties that only those very familiar with them are able to communicate effectively with them. Many devices are available for these individuals, ranging from simple, low-tech picture books to high-end, sophisticated electronic devices with digitally recorded or synthetic text-to-speech output capable of producing complex language interactions (Figure 23-2).

Although AAC devices are extremely useful to nonspeaking individuals, they do not replace natural communication. AAC device use should be encouraged along with all other available communication modalities such as gestures, vocalizations, sign language, and eye gaze.28

There are no firm cognitive, physical, or developmental prerequisites for using an AAC device. Instead, comprehensive evaluation techniques are used to match the individual’s abilities and communication needs with the appropriate AAC technologies. A qualified team of clinicians performs this evaluation, with input from the individual, family members, teachers, employers, and others. Because speaking is considered to be a critical human function, many parents and family members wait to seek out AAC devices in the hope that natural speech will develop. Research shows, however, that using an AAC device can actually support verbal language development, and can, in fact, increase the potential for natural speech to develop.3 Children and adults with severe communication impairments can benefit socially, emotionally, academically, and vocationally from using a device that allows them to communicate their thoughts, learn and share ideas, and participate in life activities.2

Electronic Voice Output Systems: Digital Speech

A variation in low-tech communication systems has developed as a result of the manufacture of low-cost microprocessors capable of storing digitized speech. These low-tech, digital voice output devices work like a tape recorder, allowing recording and storing of simple phrases into memory within the device. When users want to speak, they simply press a button and the device speaks the prerecorded message.

Devices such as One Step, Step by Step, and Big Mac (Figure 23-3) are simple and relatively inexpensive, and are designed to communicate quick, simple messages such as “hi,” “let’s play,” or “leave me alone.” These technologies are often used by very young children who are beginning communicators, or by those who have significant cognitive impairments. They are not appropriate for individuals needing or wanting to communicate complex thoughts and feelings.12

Complex digitized devices store several minutes of recorded voice that is usually associated with representative pictures or icons on a keyboard. These devices are often used by people who are not yet literate, have developmental disabilities, or simply wish to have a simple device to use when going to the store or out to eat. Examples are the SuperTalker, the ChatBox (Figure 23-4), and the Springboard.

Synthesized speech is created by software that uses rules of phonics and pronunciation to translate alphanumeric text into spoken output through speech synthesizer hardware. Voice output systems such as Tango, VMax, and ECO2 are examples of high-tech text-to-speech devices with built-in speech synthesis that speak words and phrases that have been typed or previously stored in the device, or both. The advantage of these systems is that they allow users to speak on any topic and use any words they wish to use. These systems, which can encode several thousand words, phrases, and sentences, are expensive ($6000 to $9000). They form, however, an essential link to the world for people with severe expressive communication disabilities.

All of these voice output systems, whether digital or text-to-speech, can be activated by direct selection (e.g., using a finger or a pointing device such as a mouth stick or head pointer). They can also be activated using indirect selection (e.g., using a scanning strategy or an infrared or wireless switch). In AAC device use, individuals will most commonly use a scanning strategy called row-column scanning, in which they activate a switch to begin the scan. When the row containing the desired key or icon is highlighted, the user hits the switch again to scan by column. The process is repeated until the desired word or phrase is assembled. Although the process can be slow and tedious, indirect selection often provides the only means many people have to communicate with others.

Among the latest developments for persons who are completely locked in are speech-generating devices that can be activated by a simple eye blink, or by visually gazing or “dwelling” on the desired area of the screen. The DynaVox EyeMax System is one example of this new, advanced access method for communicators who use the DynaVox Vmax. It comprises two parts: a DynaVox VMax and a DynaVox EyeMax Accessory.

AAC devices differ in the mapping and encoding strategies used to represent language, and in the storing and retrieving methods used for vocabulary. However, all systems use either orthographic or pictographic symbols, which vary in ease of learning. When selecting a set of symbols for an individual as part of the user interface, it is important to consider these factors and compare them with the individual’s cognitive and perceptual abilities.

Assistive Technology for Mobility Impairments

Motor impairments greatly affect the ability of individuals to interact with their environment. Infants are compelled to roll, then crawl and toddle, to explore their surroundings. Any motor impairment can greatly affect overall development. This is often the situation with cerebral palsy, spina bifida, arthogryposis, and other diagnoses that affect motor skills. Early intervention, and having supportive families able to create modifications and incorporate AT devices into activities, can help children achieve developmental milestones.

The loss of acquired motor abilities through trauma or disease is experienced as a severe loss for children and adults and occurs with spinal cord injury, stroke, multiple sclerosis, and amputation. There are many forms of AT that help compensate for impaired motor skills, and they should be introduced as early as possible in rehabilitation to ensure the best outcome possible.

Upper Body Mobility Devices

Given the importance of computer use in education, training, and employment, many AT devices have been developed to provide access to computers for individuals with upper body mobility impairment, such as poor hand control or paralysis. For individuals who are unable to use a standard mouse and keyboard, multiple AT options are available.

Alternate computer keyboards come in many shapes and sizes. Expanded keyboards such as the Intellikeys (Figure 23-5) provide a larger target or key surrounded by inactive space than is found in a standard keyboard. Options such as delayed activation response help individuals who have difficulty with pointing accuracy or removing a finger after activating a key. Individuals unfamiliar with a standard QWERTY keyboard layout have the option for alphabetical layout. This is often helpful for young children who are developing literacy skills, as well as for adults with cognitive or visual impairments.

There are also smaller keyboards (e.g., Tash Mini Keyboard) designed for persons with limited range of motion and endurance. They are also helpful for individuals who type with one hand, or use a head pointer or mouth stick to type. These keyboards use a “frequency of occurrence” layout. The home or middle row in the center of the keyboard holds the space bar and the letters in English words that occur most frequently (e.g., “a” and “e”). All other characters, numbers, and functions (including mouse control) fan out from the center of the keyboard based on how frequently they are used in common computer tasks.

Voice recognition (VR) is a mass-market technology that has become essential for computer access for many persons with motor impairment. Instead of writing via the keyboard, VR users write by speaking words into a microphone. The computer processor uses information from the user’s individual voice file, compares it with digital models of words and phrases, and produces computer text. If the words are accurate, the user proceeds; if not, the user corrects the words to match what was said. As the process continues, the computer updates its voice file and VR accuracy improves. This software is cognitively demanding yet can offer “hands-free” or greatly reduced keyboarding to many individuals with motor impairment.

Another group of computer input methods includes devices that rely on an onscreen keyboard visible on the computer monitor, such as the Head Mouse Extreme and TrackerPro. The user wears a head-mounted signaling device or a reflective dot on the forehead to select keys on the onscreen keyboard, choose commands from pull-down menus, or direct mouse movement. Onscreen keyboards are typically paired with rate enhancement options like word prediction or abbreviation expansion to increase a user’s word-per-minute rate. Because so many tasks can be accomplished through computers, individuals with disabilities—even those with the most severe motor impairments—can fully participate in life. They can perform education- and work-related tasks, and monitor and control an unlimited array of devices and appliances at home, work, and school.

Lower Body Mobility Devices

Individuals with spinal cord injury, spina bifida or cerebral palsy often have lower body mobility impairments. AT solutions can include crutches, a rolling walker, a powered scooter, or a manual or powered wheelchair (see Chapter 17). Simple environmental modifications or adaptations, such as installing a ramp instead of stairs, raising the height of a desk, or widening doorways, can be critical facilitators for these individuals and might be all that is needed. For other activities or to increase participation, adding automobile hand controls, adapting saddles for horseback riding, or using sit-down forms of downhill skiing is possible (Figure 23-6).

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