Page 346 - Handbook of Electronic Assistive Technology

Chapter 11 • Robotics 335

the robot. However, the user has power to determine the level of robotic aid they would
require. The system should be able to goal orientate itself in accordance with the user’s
intention, and be able to modify these goals in parallel with those of the user.
The degree of autonomy of the robot is an important consideration in the design pro-
cess so as not to reduce the user’s independence or dignity, but rather assist and support,
thus giving the user the higest possible level of control over the robot. A study exploring
the effects of different levels of autonomy on the user found that the higher the autonomy
of the robot, the less satisfied the user was with the system (Kim et al., 2012).
Adaptability: It is important that the robotic exoskeleton can be adapted to fit people with
differences in gender, size, limb segment lengths, joint range of motion, etc. Therefore con-
sideration of human anthropomorphic data is key. Exoskeletons usually incorporate adjust-
able frames to account for the different anatomical profiles of users (Baniqued et al., 2015).
Motivation: Evidence suggests that therapy with an emphasis on ADL increases
patient motivation and results in improved therapeutic outcomes compared with single
joint movements (Nef et al., 2006; Langhammer and Stanghelle, 2000; Chan et al., 2006).
Motivational factors also contribute to a patient’s active participation during therapy. An
effective way of increasing motivation is to use games as part of the exercises during ther-
apy. Virtual games are an engaging way to provide feedback to the patient in the form of
visual, haptic, acoustic media.
Flexibility and usability: Though users may have particular disabilities, their require-
ments may vary based on their abilities and preferences. Usability is a highly important
variable within the design of robotic devices. The device should be customisable and user
friendly. This includes the ease with which the system is set up and the time it takes. The
interface with which the user interacts must be as simple as possible while also being intu-
itive (Babaiasl et al., 2015).
Costs: Currently, the costs of robotic devices are quite high and cater to only a small
population of users who are able to afford such devices, unless government funded or
subsidised. High device costs are especially apparent when users have more complex or
specialised requirements which are not met by more generic devices (Garcia et al., 2013).
Some possible cost-cutting strategies while designing assistive robots are:
• Hardware design using readily available components on the market.
• Trade precision for robustness.
• Reduce complexity of the mechanical design of the system, i.e., add on more
functionality to sensors and software design (Meng and Lee, 2006).

Aesthetics and portability: Portability of the device is a major factor that limits the
application of robotic exoskeletons outside of clinical therapy (Dollar and Herr, 2008).
Increasing the aesthetic value of a rehabilitation device makes patients more relaxed and
willing to use the device (Baniqued et al., 2015).
The physical interface to the user: The design of the physical interface to the user
is important as this affects the transfer of mechanical power from the robotic exoskel-
eton to the user. Exoskeletons are generally attached to a user using padding and straps.
The interface should be comfortable and provide good support to the user to prevent