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Hybrid Assistive Limb-3

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 Sankai.

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.

[March 2006]