Switches and Control Interfaces

Question 1

Common examples of control interfaces:

Answer 1

• Keyboard
• Joystick
• Light switch

Question 2

SPATIAL Characteristics of Control Interfaces

Answer 2

• Size of target
• Spacing of target
• Target’s overall physical size

Question 3

Proportional Joystick

Answer 3

Requires that client can grade force and distance of movement.

Question 4

Switch Encoding

Answer 4

• The individual who lacks the ROM or fine-motor control necessary to use a physical or graphical keyboard may be able to use a SWITCH ENCODING INPUT METHOD.
• In Switch Encoding, a small set of switches from one to nine is used to directly access the functionality of the device. An example is Morse Code, a highly efficient method of typing for a person with severe motor control limitations.

Question 5

ROM required to use a switch array with multiple switches

Answer 5

Client’s fine motor must be more refined than for a single switch, but less refined than for a keyboard.

Question 6

Pneumatic (respiratory) control

Answer 6

Interface controlled by client’s amount of inhalation/exhalation (ie: sip n’ puff)

Question 7

Parameters to determine control interface’s effectiveness:

Answer 7

• Monitor fatigue levels
• Ensure client and control are properly positioned
• Track speed and accuracy of task completion

Question 8

Examples of Mechanical Switches

Answer 8

Paddle, plate, button, wobble, lever and membrane

Question 9

Considerations for eye-controlled system:

Answer 9

• Ability to maintain steady head position
• Smooth vertical/horizontal eye movements through majority of range
• Ability to focus on target for sufficient time

Question 10

Elements in the Human-Technology interface:

Answer 10

• Feedback from device (control interface) to person
• User’s motor, sensory, and cog abilities that influence control of the interface
• Positioning of control interface