Page 332 - Handbook of Electronic Assistive Technology

Chapter 11 • Robotics 321

Examples of fixed/ stationary systems include:
5
LOKOMAT (HOCOMA, VOLKETSWIL, SWITZERLAND) The Lokomat (Fig. 11-5) is
one of the more well-researched stationary robotic systems developed to support and
automate treadmill training (Riener et al., 2010). It is a modular device consisting of a
powered orthosis/exoskeleton, a suspension system to provide BWS and a treadmill
(Mayr et al., 2007). The hip and knee joints are actuated by linear drives integrated into an
exoskeletal structure. The system offers 2 DOFs in each leg, enabling hip and knee flexion
and extension movements in the sagittal plane (Lunenburger et al., 2004). The patient is
fixed to the orthosis with straps around the waist, thighs and shanks and the system can
be adjusted to the individual’s anthropometry. During training, the Lokomat moves the
patient’s legs through a preprogrammed gait pattern. An augmented feedback module
provides feedback to the patient while walking, by projecting the results of the exercises on
a display panel to enhance their motivation.
LOWER EXTREMITY POWERED EXOSKELETON The Lower Extremity Powered
ExoSkeleton (LOPES) was developed at the University of Twente to assist stroke patients in
walking rehabilitation and to evaluate motor skills (Veneman et al., 2007). The LOPES is a
combination of an exoskeleton robot for the legs and an end-effector robot for the pelvis.
It has a 2D pelvic control system and an exoskeleton leg with 4 actuated DOFs assisting
in hip flexion/extension, adduction/abduction, knee flexion/extension and ankle flexion/
extension (Low, 2011). It allows forward stepping motions while also maintaining the
fundamental instability of standing/walking to allow ‘patient-in-charge’ or ‘robot-in-
charge’ modes (Veneman et al., 2007).
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THE GAITTRAINER (REHA STIM, BERLIN, GERMANY) The GaitTrainer (Fig. 11-6) is
a footplate-based end-effector-based device designed to improve a patient’s ability to
walk by repeated practice. In contrast to a treadmill, it consists of two footplates that are
positioned on two bars, rockers and cranks to provide propulsion (Masiero et al., 2014).
The patient is attached to a harness for BWS and the footplates move the feet along a fixed
trajectory.

OVERGROUND WALKING SYSTEMS/MOBILE EXOSKELETONS
Lower extremity exoskeletons developed for human locomotion assistance are used to
help patients who have completely lost mobility in the lower limbs due to conditions such
as SCI, multiple sclerosis, etc. These systems offer external torque at the location of human
joints to replace the patients’ impaired motor function, enabling them to perform daily
movements such as standing up, sitting down and walking (Chen et al., 2016).
They can function as assistive and rehabilitative devices. Most of these exoskeletons
require the patients to balance themselves and therefore a healthy upper body is required.
Compared to stationary systems such as the Lokomat and LOPES, powered robotic exoskel-
etons are compact, lightweight and portable and can therefore be potentially used at home.

5 http://exoskeletonreport.com/product/lokomat/.
6 http://www.reha-stim.de/cms/index.php?id=76.