Page 188 - Handbook of Electronic Assistive Technology

176 HANDBOOK OF ELECTRONIC ASSISTIVE TECHNOLOGY

of the domains will influence the choices of options for the constituent parts of the EC
provision as follows:
• Means of access or interface to the user to allow selection of control functions.
• Equipment specification to meet the control needs of the individual.
• Operational aspects and management of risk.

Means of access or interface to the user

The means of access is also influenced by the task to be undertaken (e.g., EC vs. computer
access). Simple on/off control or operation of autoscanning EC requires only a single
switch. However, in seeking to access a computer and internet, a direct method of access
is preferable where possible and ideally proportional movement/action with fine motion
control as well. Hence head mouse, eye-gaze or joystick movement may offer greater
accessibility options than switches for some individuals. It should be noted that the inten-
sity and frequency of selections is greater when accessing computer-based functions than
EC functions, which tend to be infrequent and irregular.
Where physical movement is very limited or not consistent, then detection of physi-
ological changes may form a means of access to technology. Examples include electrical
signals of muscle initiation or electrical signals from brain activity. Speech recognition also
provides alternative means of access.
The means of access may allow feedback of its appropriate use in the selection of
function, especially when the user may have impaired sensation and proprioception
of the hand or limb. The feedback may be visual, audible or haptic (i.e., vibration) and the
EC controller can indicate the status of the user input via its display.

Equipment Specification to Meet the Control Needs of the Individual
The choice of particular EC peripheral units will be determined by the user’s own require-
ments/functional goals and the facilities in the environment; for instance, whether a cord-
less or wired landline telephone is necessitated.
The choice of EC controller is also determined by a range of factors; however, it is pri-
marily influenced by the user’s own functional abilities. For instance, the ability to see
items on the display screen, the proximity required to the user, the availability of a remote
means of access or the requirement for audio voice prompts of the menu selections.
The number and type of EC functions required will determine the controller capacity as
well as the types of transmitted control signals.
Many of the configuration options for the EC controller are chosen to suit the user, accord-
ing to assessment aspects such as visual and cognitive abilities and switch access capability.

Operational Aspects and Management of Risk With EC Provision
EC provision often forms part of the risk management for an individual living indepen-
dently. Determining the effectiveness of the EC as well as the management of the additional