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IEEE Transactions on Microwave Theory and Techniques
Volume 48 Number 11, November 2000

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On the Feasibility of Detecting Flaws in Artificial Heart Valves

Eugène S. A. M. Lepelaars, Member, IEEE Willem D. R. van Ooijen and Anton G. Tijhuis Member, IEEE

Page 2165.

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.

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