Page 344 - Handbook of Electronic Assistive Technology

Chapter 11 • Robotics 333

FIGURE 11-13 iARM used for making a phone call�

measures should be incorporated at the software (control), hardware and operator levels
(Beyl et al., 2009; Roderick and Carignan, 2005).
Roderick and Carignan (2005) suggest the following potential hazards in the use of exo-
skeletons (Roderick and Carignan, 2005):

• Moving the patient beyond the safe limit of their range of motion.
• Moving the patient at an excessive velocity – sudden movement from the device may
provide muscle strain leading to further injuries.
• Applying an excessive torque to the patient or having the patient apply an excessive
torque against the robot.

Parameters, such as operational velocities and interactive pressure, should be measured
in real time, and safety constraints and control strategies should be in place to ensure the
user’s stability and safety in an emergency (Huo et al., 2016).
A common approach to ensure safety is to incorporate multiple safety features (Van der
Loos and Reinkensmeyer, 2008). Exoskeletons are designed with passive safety features, such
as having no sharp edges, mechanical end stops to prevent joints from exceeding the anatom-
ical range of motion of the human limb, and emergency switches to turn off the robot (Saba
et al., 2013; Nef et al., 2006). The mechanical stops should be able to withstand the maximum