Technical Description: Applying the Generic Control System to a Juvenile Above-Elbow Amputee


In the year since the Generic Control System was described in this forum, several applications have been accomplished. One IS of particular interest since it is the first time an above-elbow prosthesis of "adult" functional complexity has been fitted to a young child. He is a congenital bilateral amputee or small stature for his age (7 + years). A 2-site/4-function controller was constructed using three modules from the Generic Control System family which provides proportional control of a Variety Village Model 62A elbow and constant-speed control of a Steeper 2 1/4-inch Myohand. The completed prosthesis weighs 2.2 lbs, exclusive of the suspension system. Achieving suspension was by far the most difficult aspect of this fitting. Repeated efforts to suspend from the prosthetic side failed because of a lack of bony prominences. Eventually a bivalved vest suspension of Surlyn proved successful. The system is powered by a 6-cell battery pack which is worn on the vest. Special circuitry allows the pack to be charged fully in 5 hours from house current or a car battery. No special training was required even though the child had no prior myoelectric experience.

*Universal Artificial Limb Company, 938 Wayne Avenue, Silver Spring, MD 20910