Page 189 - Handbook of Electronic Assistive Technology

Chapter 6 • Environmental Control 177

risks it introduces forms a vital part of the equipment assessment and provision process.
This continues into the operational use of the equipment, with its ongoing use and the
need for adaptation for progressive conditions.
Although EC may form part of the risk management strategy, EC provision is not
intended as a substitute for necessary personal care or human intervention. The develop-
ment of personal care robotics may well alter this balance and hence also the role for EC
(Chapter 11).
Key functional aspects of EC assessment therefore relate to the social environment of
the individual, their pattern of life and support from others, whether formalised care or
family and friends. Consideration of specific risk aspects is undertaken for particular EC
functions, as follows.
Summoning Assistance
The need to summon assistance when needed is usually a priority goal of most cases
of EC provision, whether that is help from someone within the same room (i.e., alert
sound), from elsewhere in the same building (i.e., pager or nurse call) or externally
(i.e., emergency lifeline or other telephone link). The priority and level of urgency of the
call depend on the individual’s circumstances, which are required to be evaluated.
The reliability of the means of call using ECS is contributed to by the reliability
of the user in operating their means of access, the reliability of the ECS unit and
the reliability of transmission of the alarm signal to the alarm device. The level of
dependence or reliance on the ECS determines the speed or urgency of response
required to any fault or malfunction with the equipment.
This may be addressed by providing an alternative alarm call to ensure adequate
reliability and availability through duplication of function. For instance, in cases
where eye or head tracking may be the preferred and fastest method of access
for most EC and computer-based functions, they are typically more prone to
unavailability than a simple wired switch. Therefore a back-up alarm pager call via a
single switch is often advisable.
EC equipment is accepted as not being designed or suitable for the control of life-
sustaining equipment such as ventilators, feeding machines or suctioning devices.
Profiling Bed or Chair Control Through ECS
The use of ECS to control movement of powered profiling beds and riser/recliner
chairs introduces inherent risk from dealing with a moving piece of machinery.
Despite the possibility of entrapment of limbs, children or animals, there are few such
beds or chairs fitted with sensors to prevent or warn of this, or to provide incremental
control of movement. Similarly, there is rarely any adjustable limitation of the extent
of movement travel, for instance to avoid excessive bed tilt for a person with poor
trunk control.
For this reason, when controlled through EC, movement of a powered profiling
bed or chair is time limited, typically to 3 s, to avoid excess movement at each
selection. Further movement requires reselection from the EC menu. However,
even with this precaution it is necessary to ensure that the user does not lose