A modified nonpulsatile flow system for the in vitro study of cardiac valve prostheses

An in vitro system was constructed for measurements of resistance to forward flow by cardiac valve prostheses at a wide spectrum of flow rates. There was a close correlation between the known area of constriction (valvular orifice) and that calculated from the flow/pressure relationship using derivations of the Bernoulli equation. This simple setup appears particularly suited to determine hydrodynamic efficiency of various cardiac valve concepts on a comparative basis.