Page 302 - Handbook of Biomechatronics

294 Andres F. Ruiz-Olaya et al.

microcomputers. BLEEX was the first load-carrying and energetically
autonomous exoskeleton (Zoss et al., 2006). With an anthropomorphic
design, BLEEX has left and right three-segment legs, being analogous to
the human thigh, shank, and foot. Each leg has seven DOFs: hip flexion/
extension (f/e) and abduction/adduction (a/a), knee f/e, and ankle dorsi/
plantar flexion (d/p). The hip presents intra/extra rotation, and the ankle,
inversion/eversion—a/a. ReWalk Robotics, formerly ARGO Medical
Technologies, offers two products: the ReWalk Rehabilitation, launched
in 2011, and the ReWalk Personal, which became available internationally
in 2012. The ReWalk was developed by Dr. Amit Goffer, an Israeli scientist
who became quadriplegic after an accident in 1997. It consists of a metal
brace that supports the legs and part of the upper body, electric motors that
supply movement of the hips, knees and ankles, a tilt sensor, and a backpack
that contains a computer and a power supply (Esquenazi et al., 2012). An
allied product device is produced by Rex Bionics: the REX Rehab and
REX Personal. The REX was designed specifically for users with high levels
of mobility impairment, including paraplegic and quadriplegic users, and
allows them to navigate stairs and ramps safely. In contrast to the ReWalk,
it does not require crutches or a walking frame to provide stability. The
device is powered by DC motors and it is controlled by a simple keypad
and joystick (Bogue, 2015). The Indego Powered Leg Orthosis prototype
presented at OTWorld (2014), in Leipzig, Germany from research at Van-
derbilt University, is a battery-powered, lower-body exoskeleton that pro-
vides up to 4h of use and weights 26lbs (12kg). The exoskeleton uses
gyroscopes and other inertial sensors that allow it to mirror natural human
movement; LED indicators and a wireless software interface provide control
over parameters such as stride length and step frequency. Cyberdyne, a spin-
off from the University of Tsukuba, developed the HAL (full-body exoskel-
eton) units, mainly used for nonmilitary applications, such as nursing and
assisting the disabled in waking. The system was certified by Underwriters
Laboratories to ISO13485 with the international quality standard for med-
ical devices and by the global safety certificate. HAL uses sensors on the
user’s skin for detecting myoelectric signals for estimating his or her intended
motion (Bogue, 2015). Based on these signals, servo motors try to produce
the same torque as that caused by the contraction of human muscle, synchro-
nizing the movement of the exoskeleton with the intention of the user. The
controller of HAL uses battery-powered small PCs that were equipped with
wireless network cards, and located in the back of the exoskeleton. Fig. 5
presents some of lower-limb exoskeleton developed by research groups.