Page 167 - Handbook of Electronic Assistive Technology

Chapter 6 • Environmental Control 155

through the EC was made available using radio signals from the EC unit, which could be
activated from either room.

Outline of an EC System

ECS have developed significantly over the years; however, they began from a core struc-
ture, which they continue to follow, as shown in Fig. 6-2.

User Interface
This is the means by which the user of the EC device has interaction with it to select and
activate a particular function or appliance.
Many of the means of access utilise a repeatable voluntary movement by the user.
Physiological or sensory modalities may also be used, and much of the clinical assessment
role outlined in Chapter 4 is associated with the choice and evaluation of a suitable means
of access for an individual.
Although EC controller units are predominantly accessed by external switches, some
controllers incorporate touchscreens. Some users find switches preferable to modern
touchscreens, which they find to be too sensitive and result in multiple or unintended
selections. If using a touchscreen, keyguards can be of benefit for some users (Chapter 5).

EC Controller Unit
The user interface is connected to the main control unit of the system, the EC controller,
either directly by electrical cable or indirectly by remote signal transmissions, i.e., infra
red (IR) or radio frequency (RF), Bluetooth or WiFi. The controller usually has a number

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