Page 176 - Handbook of Electronic Assistive Technology

164 HANDBOOK OF ELECTRONIC ASSISTIVE TECHNOLOGY

These provide speech recognition with reasonable accuracy for most users and can
also be linked to home control devices via WiFi and other networks. However, this
speech recognition is entirely dependent on the internet and WiFi connection, with
consequent reliability and security concerns. It is also reliant on the user remember-
ing the command and being able to verbalise in a manner the device will understand.
It therefore tends not to be recommended for high-priority functions such as calling
for help.

Historical Development of EC Equipment

First-Generation Systems: 1960s
Initial systems were developed at the National Spinal Injuries Centre at Stoke Mandeville
Hospital, UK, in response to the needs of patients who would use a whistle suspended
from the ceiling to call for assistance. An electronic device known as a patient-operated
selector mechanism was developed to enable control of a light and television by means of
sip/puff input. This was later extended to control of a typewriter. From this originated the
first generation (Fig. 6-8A and B) of EC systems based on individual switch logic.

FIGURE 6-8 Historical EC Systems: Possum (A) PSU1, (B) PSU3�