KAMI KITT ASSISTIVE TECHNOLOGY Chapter 7 Human/ Assistive Technology Interface

THE HUMAN/TECHNOLOGY INTERFACE  Is a major part of the assistive technology component of the human activity assistive technology model  There are 3 elements of human/technology that contribute to the operation of a device. 1.The control interface 2.The selection set 3.The selection method

CONTROL INTERFACE  Is the hardware by which the human in the assistive technology system operates or controls a device. Also known as an impute device. (e.g. keyboard, joystick)  Selection Set: The items available from which choices are made. These sets are represented by written words, letters, and sentences. The size, modality, and the type are based on the users need.

SELECTION METHODS  There are 2 basic methods 1.Direct Selection: The consumer indicates his choice by using voice, finger, hand, eye, or other body movement 2.Indirect Selection : Uses the method of scanning which uses switches.

 Scanning : requires good visual tracking skills, a high degree of attention, and the ability to sequence. It requires very little motor control to make a selection.  Directed Scanning: Allows user to activate the control interface to select the direction of the scan, vertical or horizontal.  Coded Access is a sequence of movements a individual uses to impute code for each item. (e.g. Morse code)

THE PROCESSOR  This is a set of device functions which is referred to as the Command Domain. Such as a joystick on a powered wheelchair. Pushing it up is transferred as forward movement of the wheelchair, down is transferred as reverse, left moves chair to the left, and pushing it right makes the chair move to the right.

KEYBOARD AND MOUSE EMULATING INTERFACES  Transport Access describes 2 fundamental concepts 1.100% of the functions of the computer must be adapted if the user who has a disability is to have full access. 2.All application software that runs the unmodified computer must also run on the adapted computer.  There must be a bridge between the control interface and the computer to use many of the alternatives to keyboard or mouse, such as an expanded keyboard or a single switch, to access the computer.

GENERAL INPUT DEVICE- EMULATING INTERFACES  Or GIDEI: defines the characteristics of a special processor that translates or decodes the signals from the control interface so they match the command domain requirements of the computer.  A GIDEI set up consists of 3 parts 1.Input Method 2.Overlay 3.Options See page 219 of text Box 7-3 for more details as well as Box 7-1 on same page for the major features of commonly used GIDEI

EMULATORS  Mouse Emulation :Substitutes a set of keys, a scanning array, or Morse code characters for mouse functions.  Emulators use built in synthetic speech feedback to allow the user to receive auditory and visual prompting and feedback. This is useful for young children who may not be able to read, for visually impaired individuals, and for added input for persons with learning disabilities  Coded Access: A sequence of movements a individual uses to impute code for each item. (e.g. Morse code)

GRAPHICAL USER INTERFACE  GUI is characterized by 3 distinguishing features 1.Mouse pointer which is moved across the screen. 2.A graphical menu bar, which appears on the screen. 3.One or more windows, which provides a menu of choices

CHARACTERISTICS OF CONTROL INTERFACES  Spatial Characteristics 1.Overall physical size, shape, and weight 2.The number of available targets contained within the control interface 3.The size of each target 4.The spacing between targets.

 Activation Characteristics: the method of activation, deactivation effort, displacement, flexibility, and durability of a control interface.  Sensory Characteristic: Auditory, somatosensory, and visual feedback produced during the activation of a control interface.

ENHANCEMENTS  Rate Enhancement: Augmentative and alternative communication and computer access approaches that result in the number of characters generated being greater the number of selections the individual makes.  Direct Selection Rate Enhancement: deals with encoding techniques and prediction techniques.  Scanning Rate Enhancement: is based on placement of the most frequently used characters near the beginning so that they are scanned first

 Control Enhancers: Aids and strategies that enhance or extent the physical control a person has available to use a controlled interface.  Control interfaces for Direct Selection includes: Various types of keyboards Pointing interfaces Speech recognition Eye gaze Gesture recognition Cortical signals

CONTROL ENHANCERS  Aids and strategies to enhance or extend the physical control a person has available to use a control interface  Interface positioning, arm supports, mouth sticks head pointers, and hand pointers.  Control interfaces for Direct Selection include: Various types of key boards, pointing interfaces, speech recognition, eye gaze, gesture recognition, and cortical signals

DIFFERENT TABLES TO VIEW  See figure 7-12 page 238 for different types of keyboards.  See Table 7-9 page 248 for Alternative Electronic pointing interfaces  See Table 7-8 page 242 for Speech recognition Interfaces  See Table 7-15 page 269 for types of Text-to-Speech Systems used in assistive Technologies.  See figure 7-9 on page 233 for Selecting a control interface for an individual.

EYE CONTROL SYSTEMS  There are 2 basic types of systems 1.The first type uses IR video camera mounted below the computer screen. (e.g. TOBII. If you ever want to see how one runs, contact me. My little brother uses one at school every day. ) 2.The second one used a head mounted viewer that tracks movement of one eye such as the Vision Key. Both types provide the user with computer access for written or verbal communication, internet access, environmental control, and telephone operation

ALTERNATIVE ELECTRONIC POINTING  Keypad mouse: mouse movement is replaced by keys that move the mouse cursor  Trackball: looks like inverted mouse; a ball is mounted on a stationary base. On the base there are buttons that provide different functions  Continuous input joysticks used for powered mobility and for computer use.

 Head-controlled mouse: the user wears a sensor on the head, which is detected by a unit on the computer.  Light pointers and light sensors emit a light beam that can be used to point to objects.

MOUNTS FOR CONTROL INTERFACE  Keyboards can be placed on stands or easels, some can be mounted to wheelchairs.  The most common mounting locations are attachment to a table, desk, wheelchair, or a persons body.  There are flexible and fixed mounting systems for individuals who require changes in their position because of fluctuating needs or skills.

SPEECH OUTPUTS  There are 2 types of speech used in Assistive Technologies 1.Digital recording: Human speech is stored in electronic memory circuits for later retrieval. 2.Speech Synthesis: which is the generation of human sounding speech by use of electronic circuits and computer software.

QUIZ  quizzes/item quizzes/item3240