Electrical Engineering homework help. Questions from Course Textbook’s Chapter on “Control Interfaces for Assistive
Technology”
7.4) What are the two basic selection methods used with control interfaces?
7.5) What are the scanning formats that can be used to accelerate scanning? Describe them. (See Cook et
al, pp. 230-233)
7.25) What are the primary considerations that would lead to the choice of speech recognition as an
alternative direct selection method?
7.28) What are the most common alternatives to a computer mouse? List at least one advantage and one
disadvantage of each.
7.34) List three types of modifications to keyboards and pointing devices, and give an example of the problems
that each solves.
7.35) (Optional question for the engineering students) Describe the three different selection techniques used
with scanning and directed scanning. Which one provides the user with more control and why?
7.38) Describe distributed and integrated control. What are their advantages and disadvantages?
Questions from Reader B’s Chapter on “Rehabilitation Engineering & Assistive
Technology”
5.7) A person’s disabilities and abilities often depend on his/her medical condition. a) A person is known to
have spinal cord injury (SCI) at the C5-C6 level. What does this mean in terms of this person’s probable
motoric and sensory abilities and limitations? b) Repeat part (a) for a person with multiple sclerosis. Include
the prognosis of the second individual in contrast to the person with SCI.
5.10) A 21-year-old female who has muscular dystrophy requested assistance with computer access,
particularly for writing, using spreadsheets, and playing computer games. She lacks movement in all four
extremities except for some wrist and finger movements. With her left hand, she is able to reach about 6 in. past
her midline. With her right hand, she is able to reach only 2 in. past her midline. Both her hands can reach out
about 8 in. from the body. If given wrist support, she has good control of both index fingers. Based on this
description, sketch the work area that she appears able to reach with her two hands. Describe the adaptations
to a standard or contracted keyboard that she would need to access her home computer. For additional
information, consult “The Closing the Gap Product Directory,” the “Cooperative Electronic Library on
Disability,” and the suggested reading materials listed at the end of this chapter.
5.19) (Optional) For persons with good head control and little else, the Head Master (by Prentke Romich
Co., Wooster, OH) has been used to emulate the mouse input signals for a computer. The Head Master consists
of a headset connected to the computer by a cable. The headset includes a sensor that detects head movements
and translates such movements into a signal interpreted as movements of the mouse. A puff and sip pneumatic
switch is also attached to headset and substitutes for clicking of the mouse. Based on this brief description of
the Head Master, draw a block diagram of how this device might work and what basic components that might
be needed in the Head Master. Include in your block diagram the ultrasonic signal source, detectors, timers,
and signal processors that would be needed.
