3D Finite Time Lyapunov Exponents in a left ventricle laboratory model

Abstract

Finite Time Lyapunov Exponents (FTLEs) are a powerful means to infer characteristic features of the flow that cannot be revealed by other Eulerian criteria. Recently FTLEs are becoming popular also in the medical context, for instance in the analysis of vascular flow measured by means of Magnetic Resonance Imaging. However, many of the FTLE experimental works are based only on two-dimensional velocity fields, moreover those computed on in-vivo data cannot be obtained under controlled and repeatable conditions. Here we present the 3D FTLE evolution inside a Left Ventricle (LV) laboratory model mimicking physiological human conditions. The investigation of FTLE fields highlights distinctive features of the cardiac flow and gives an insight on the physiological development of the Lagrangian Coherent Structures (LCS) that optimize the LV refill.