A computer aided test stand for medical microvalves

In this paper a computer aided test stand for medical microvalves used in hydrocephalus therapy is presented. Although these microvalves ("shunts") have been used successfully for more than 30 years, some major problems remain unsolved. For example, the implants may be obstructed by blood or proteins or remain open due to ageing and mechanical malfunction. Other problems are malfunctions because of production faults and constructive insufficiencies. Although known, the severity of these problems became visible during the "disaster" with Holter-Hausner valves in the late 80's leading to a recall of a whole years production. Since then, several researchers became interested in developing reliable test methods and equipment. The presented test stand allows to measure the pressure-flow characteristic of shunt systems to determine functional properties of various constructions. Furthermore it may be used for pre- or post-implantation quality control or as a design platform for new systems.