[Testing the hydrodynamic properties of heart valve prostheses with a new test apparatus]

A new test apparatus for the testing of artificial heart valves makes it possible to realize both physiological flow through the valve during the flow period, and physiological pressure differences across the artificial valve during the closing phase, both for aortic and mitral valve positions, with freely selectable stroke volume and heart frequency. The major hydraulic parameters of the valve are measured directly (pressure drop, closing volume and closing time, leakage volume) or are calculated (e. g. energy loss). In association with the demonstration of the suitability of the HKP+ test apparatus for the measurement of hydraulic parameters in accordance with ISO 5840, the hydraulic properties of various types and sizes of valve with respect to pressure drop (resistance), together with their closing behaviour and leakage flow, are described for different fluids, and the correlations shown.