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Hybrid Assistive Limb-3
Robotics pioneer Yoshiyuki Sankai has built a
bridge between the worlds of science fiction and
reality with his creation of an exoskeletal
"robot suit," dubbed HAL-5, for "Hybrid Assistive
Limb." His hope is that such a device will one
day be able to help disabled or elderly people
with weak muscles move around freely on their
own; and will help human beings increase their
physical capabilities so that they are able to
lift heavy loads they wouldn't have been able to
Born in Okayama, Japan in the late 1950s, Sankai
was intrigued with images of robots he read of in
novels like "I, Robot" and the comic book "Cyborg
009" as a child. In his elementary school science
classes he did experiments on frogs where he
observed the effect electric shocks had on the
creaturesí leg muscles, and as an adolescent he
became interested in potential relationships
between man and machine, specifically, possible
ways that mechanical devices could be used to
augment human performance.
When he entered the University of Tsukuba he
became inspired further when he saw many students
stricken with paralysis struggling to move
around. He decided to focus his studies on
medical technologies, later choosing engineering
over medicine in pursuit of a graduate degree.
After careful study of the human nervous system,
Sankai began working on a system which he hoped
would be able to seize upon and communicate
impulses from the nervous system to a machine.
His first prototype, built in 1997, needed some
fine-tuning, but the work lead to the development
of a "robotic suit" of sorts, which a person of
humble build and weight can easily wear, and
which straps easily onto his or her arms, legs
and back. The suit is equipped with sensors that
detect nerve signals in the brain sent when the
person attempts to move his or her limbs. The
suit's motors and computer work together when
cued by the sensors to assist the person's
motions, allowing him to move much more easily
than he could on his own.
Not only could such a suit, if it were to be mass
produced and made widely available, help disabled
people, it could also help elderly people move
around more easily, help caregivers lift or move
those who are ill or infirm, and could even help
laborers to move heavy equipment around in a
construction, cleanup or industrial setting.
Sankai, who is, as of this 2006 writing, a
professor and engineer at the University of
Tsukuba, dubbed the suit "Hybrid Assistive Limb,"
or HAL for short. The suit was demonstrated to
the public in June 2005 at the World Exposition
in Aichi prefecture, central Japan. The system is
an example of a new field known as "cybernics,"
which incorporates technological and mechanical
elements from areas including mechanics, bionics,
electronics and robotics. HAL employs a
"bio-cybernic" system incorporating bioelectric
sensors attached to limbs to monitor signals
transmitted between the brain and muscles, which
the computer senses to signal the system's motors
to move with just fractions of a second of delay.
This communications system was the most
challenging portion of the project, according to
The latest version, HAL 5, was preceded by
prototypes HAL 3 and HAL 4, and with each
iteration the system has become lighter and more
efficient. Newer HALs include a smaller, wireless
connected computer that fits in a pouch attached
to a belt, smaller motor housings and better
comfort for the wearer. In its latest form it
weighs approximately 15 kg or 33 lbs. in the
lower-body-only model, and 24 kg or 55 lbs. in
the all-body model. It is battery-powered.
Commercial suits for purchase are likely to cost
between $14,000 and $19,000.
Sankai has said one of his aims is to create
technologies that are designed for the benefit of
humankind, rather than for destructive purposes.
He refused, for example, an offer from the
Department of Defense in Washington, D.C., to
work on a robot for military use and declined a
similar offer from the government of South Korea.
He followed through with plan to commercialize
his HAL product via a venture firm he established
through the University of Tsukuba called Cyberdyne, Inc. and continues
to plow ahead with his research endeavors.