Page 317 - Handbook of Biomechatronics

Upper and Lower Extremity Exoskeletons 309

The Harvard’s soft exosuit team provided a first proof-of-concept results
showing that its wearable robot could lower energy expenditure in healthy
people walking with a load on their back (Panizzolo et al., 2016). Light-
weight exosuits exoskeleton are a new class of soft robots that combine clas-
sical robotic design and control principles with functional apparel to increase
the wearer’s strength, balance, and endurance (Panizzolo et al., 2016). Soft
Exosuits offer a new way to assist the elderly in maintaining or restoring their
gait, in rehabilitating children and adults with movement disorders due to
stroke, multiple sclerosis, and Parkinson’s disease, or to ease the physical
burden of soldiers, firefighters, paramedics, farmers, and others whose jobs
require them to carry extremely heavy loads (Panizzolo et al., 2016). For
decades, engineers have built exoskeletons that use rigid links in parallel
with the biological anatomy to increase strength and endurance in wearers,
and to protect them from injury and physical stress. A number of systems
have been developed that show strong commercial potential, for example,
in helping spinal-cord injury patients walk, or enabling soldiers carry heavy
loads. However, rigid exoskeletons often fail to allow the wearer to perform
his or her natural joint movements, are generally heavy and can hence cause
fatigue.
Wyss Institute researchers are pursuing a new paradigm (Panizzolo et al.,
2016): the use of soft clothing-like “exosuits.” An exosuit (Fig. 6) does not
contain any rigid elements, so the wearer’s bone structure must sustain all the
compressive forces normally encountered by the body—plus the forces gen-
erated by the exosuit. The soft exosuits translating small amounts of force,
applied by mechanical actuators in the suit at the right time into effective
motions. In addition to soft exosuits that enhance the functionality of lower
extremities, ongoing work at the Wyss is also developing prototypes that
improve mobility of the upper extremities. The Wyss Institute is collaborat-
ing with ReWalk Robotics, Ltd., to accelerate the development of the Insti-
tute’s lightweight, wearable soft exosuit technologies for assisting people
with lower-limb disabilities (Panizzolo et al., 2016). The agreement with
ReWalk will help speed the design of assistive exosuits that could help
patients suffering from stroke and multiple sclerosis to regain mobility.
During its development, the soft exosuit has inspired the innovation of
entirely new forms of functional textiles, flexible power systems, soft sensors,
and control strategies that integrate the suit and its wearer in ways that mimic
the natural biomechanics of the human musculoskeletal system (Majidi,
2014; Panizzolo et al., 2016). Study coauthor and biomechanics expert
Ken Holt, Ph.D., P.T., Associate Professor at Boston University’s Depart-
ment of Physical Therapy and Athletic Training, has worked alongside