Abstract
The development of the hydraulic artificial knee joint controller has significantly improved the quality of life for many amputees. Even though the controller unit is very reliable, gradual deterioration inevitably takes place because the unit consists of many moving parts and is subjected to repetitive loads. This paper describes a simple method to test the reliability of hydraulic artificial knee joint controllers. A life cycle testing machine for artificial knee controllers was designed as part of this programme. This study included life cycle testing of 5 knee controllers. Performance measurements representing the different degrees of deterioration were recorded and correlated against the actual deterioration found during refurbishment of the units. The results can be used (with care), together with simple tests, to judge performance of a given unit.