Abstract
Recent advances in the field of externally powered prosthetics and orthotics are remarkable. The purpose of this paper is to describe typical prosthetic and orthotic appliances (mainly, artificial arms) which have been developed and fitted to patients, at least for clinical investigation, in North American and European countries. Most of these prosthetics and orthotics are using myoelectric control systems.
Although myoelectric control of externally powered prosthetic and orthotic appliances has significant limitations, such as the problems of electrodes, control sites, size and weight etc., it has still primary advantage for the amputee or paralytic, as no physical motion of the body is required for its operation.
The available choices for powering an artificial arm are electric, pneumatic and hydraulic; in Japan only the electric system is popular. There is still a controversy as to which of these is best, but there might be the possibility that hybrid combination of electrics with pneumatics or electrics with hydraulic system would be successfully available in future.
Although it is possible to demand both force and position at some control sites, further sensory information is still likely to be needed.
Further effort should be exerted to solve many serious technical difficulties and make ideal artificial limbs and substitutes for many handicapped people.
