Switch Access
Encyclopedia
Many people with severe physical or cognitive impairment use one or more switches to access computers. A switch is an assistive technology
device that replaces the need to use a computer keyboard
or a mouse
.
Switches come in a variety of shapes and sizes depending on the action used to activate them (such as sip-puff
, pushing, pulling, pressing, blinking or squeezing). Switches also vary in their colour and aesthetics. For push or press switches, the amount of force required to operate them varies or in some cases can be adjusted. Some switches may only require a touch (not even a press), some may be designed to be kicked.
A switch can be operated by almost any body part that is able to produce consistent and voluntary movement.
, serial
, or PS/2
port.
There are a variety of motivating switch activities that can be used to assess and develop a person's understanding of choice and timing.
Switches can be link to a variety of devices for example: Augmentative and Alternative Communication
devices, switch adapted toys, switch interfaces for computer access, SMART Technology, sensory room equipment and environmental control device
s
device or painful for someone with arthritis.
Some users will prefer to use one switch, others will prefer to use two and sometimes more. For users who are using their switches to access simple activities an additional switch brings about an option of choice. It also allows two users to work collaboratively or to play against each other.
Considering multiple switch access is important for users accessing more advanced activities through switch access scanning
. This is usually determined by their physical capabilities. A single switch requires less physical control and is usually less tiring to access but it reduces scanning options and usually leads to a slower rate of input. Single-switch scanning also requires much greater concentration. Two-switch scanning enables a range of scanning options including row and column, and overscan
. These can greatly increase input rates and can make using a computer or electronic assistive device far more comfortable and efficient.
Assistive technology
Assistive technology or adaptive technology is an umbrella term that includes assistive, adaptive, and rehabilitative devices for people with disabilities and also includes the process used in selecting, locating, and using them...
device that replaces the need to use a computer keyboard
Computer keyboard
In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches...
or a mouse
Mouse (computing)
In computing, a mouse is a pointing device that functions by detecting two-dimensional motion relative to its supporting surface. Physically, a mouse consists of an object held under one of the user's hands, with one or more buttons...
.
Types of switch
Sip-and-puff
Sip-and-Puff or Sip 'n' Puff ' technology is a method used to send signals to a device using air pressure by "sipping" or "puffing" on a straw, tube or "wand." It is primarily used by people who do not have the use of their hands...
, pushing, pulling, pressing, blinking or squeezing). Switches also vary in their colour and aesthetics. For push or press switches, the amount of force required to operate them varies or in some cases can be adjusted. Some switches may only require a touch (not even a press), some may be designed to be kicked.
A switch can be operated by almost any body part that is able to produce consistent and voluntary movement.
Connecting a switch
A switch cannot be plugged directly into a computer. Instead a Switch Interface is required to bridge the gap between the switch and the computer's USBUniversal Serial Bus
USB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....
, serial
Serial port
In computing, a serial port is a serial communication physical interface through which information transfers in or out one bit at a time...
, or PS/2
PS/2 connector
The PS/2 connector is a 6-pin Mini-DIN connector used for connecting some keyboards and mice to a PC compatible computer system. Its name comes from the IBM Personal System/2 series of personal computers, with which it was introduced in 1987...
port.
What can be accomplished with a switch
Switches can be suitable for people with cognitive difficulties, developmental delays and physical limitations. In the simplest use they are a clear and simple way to demonstrate action/reaction often referred to as cause and effect. In the more complex use they could be the means to control mobility or interact with the environnment.There are a variety of motivating switch activities that can be used to assess and develop a person's understanding of choice and timing.
Switches can be link to a variety of devices for example: Augmentative and Alternative Communication
Augmentative and alternative communication
Augmentative and alternative communication is an umbrella term that encompasses the communication methods used to supplement or replace speech or writing for those with impairments in the production or comprehension of spoken or written language...
devices, switch adapted toys, switch interfaces for computer access, SMART Technology, sensory room equipment and environmental control device
Environmental control device
An environmental control system is a form of electronic assistive technology which enables people with significant disabilities to independently access equipment in their environment e.g. home or hospital....
s
Switch types
The smallest amount of interaction that can be provided with a switch is binary switch input as holding down the switch for a certain amount of time may be impossible for a sip and puffSip-and-puff
Sip-and-Puff or Sip 'n' Puff ' technology is a method used to send signals to a device using air pressure by "sipping" or "puffing" on a straw, tube or "wand." It is primarily used by people who do not have the use of their hands...
device or painful for someone with arthritis.
Some users will prefer to use one switch, others will prefer to use two and sometimes more. For users who are using their switches to access simple activities an additional switch brings about an option of choice. It also allows two users to work collaboratively or to play against each other.
Considering multiple switch access is important for users accessing more advanced activities through switch access scanning
Switch access scanning
Switch access scanning is an indirect selection technique , used by an assistive technology user, including those who use augmentative and alternative communication to choose items from the selection set...
. This is usually determined by their physical capabilities. A single switch requires less physical control and is usually less tiring to access but it reduces scanning options and usually leads to a slower rate of input. Single-switch scanning also requires much greater concentration. Two-switch scanning enables a range of scanning options including row and column, and overscan
Overscan
Overscan is extra image area around the four edges of a video image that may not be seen reliably by the viewer. It exists because television sets in the 1930s through 1970s were highly variable in how the video image was framed within the cathode ray tube .-Origins of overscan:Early televisions...
. These can greatly increase input rates and can make using a computer or electronic assistive device far more comfortable and efficient.
External links
- adaptivePlay an organization that adapts toys and has a website full of interactive switch adapted toys for children with special needs.
- HelpKidzLearn a web site full of FREE games for young children and those with learning difficulties.
- Smile Rehab a commercial company who make SMART chairs and platforms
- Inclusive Technology are a commercial company who make many switch accessible products.
- Spectronics is a commercial company where many assistive switches and switch accessible products are available.
- IntelliTools Inc. partnered with Madentec to develop the IntelliSwitch: a wireless switch interface with five switch ports and two built-in switches. IntelliTools is also the creator of the IntelliKeys: a programmable membrane keyboardMembrane keyboardA membrane keyboard is a computer keyboard whose "keys" are not separate, moving parts, as with the majority of other keyboards, but rather are pressure pads that have only outlines and symbols printed on a flat, flexible surface...
with two switch ports. Various switch accessible educational softwareEducational softwareEducational software is computer software, the primary purpose of which is teaching or self-learning.-Early History, 1940s - 1970s:The use of computer hardware and software in education and training dates to the early 1940s, when American researchers developed flight simulators which used analog...
products are also produced by IntelliTools.
- Marblesoft-Simtech is a commercial company whose line of inexpensive software focuses specifically on training single and dual switch use.
- The One Switch Organisation hosts nearly 100 free one switch games for PCs and utilities to play more. It also hosts D.I.Y. switch accessibility adaptation guides and more.
- QED Ltd are a commercial company who make and sell a wide range of switches. The website contains a comprehensive list of the types of currently switches available.