On the feasibility of detecting flaws in artificial heart valves

Abstract

Abstract-In this paper, we investigate the feasibility of detecting defects in certain artificial heart valves by determining the electromagnetic behavior of some simple models with the aid of thin-wire integral equations. The idea is to use the stationary current that occurs at late times after the excitation of a closed loop as a discriminator. This current exhibits an exponential decay when a resistive load is included that is representative of fatigue or a partial fracture. The decay rate is indicative of the severity of the defect. For a wire with an opening, which is representative of a complete fracture, the late-time current is completely absent. As a simplified model of remote detection by a small loop antenna that could be introduced via a catheter, we consider the coupling between two parallel circular wires. In all cases, the dispersive environment of the valve is taken to be homogeneous and filled with blood since this medium exhibits a representative dispersion.