A computational framework for simulating cardiovascular flows in patient-specific anatomies

Abstract

The goal of the thesis is to develop a computational framework for simulating cardiovascular flows in patient-specific anatomies. The numerical method is based on the curvilinear immersed method approach and is able to simulate pulsatile flow in complex anatomical geometries, incorporates a novel, lumped-parameter kinematic model of the left ventricle wall driven by electrical excitation, and can carry out fluid-structure interaction simulations between the blood flow and implanted bi-leaflet mechanical heart valves (BMHV). The ability of the method to resolve and illuminate the physics of dynamically rich vortex phenomena is demonstrated by carrying out simulations of impulsively driven flow through inclined nozzles and comparing the computed results with experimental measurements. The method is subsequently applied to simulate: 1) vortex formation and wall shear-stress dynamics inside an intracranial aneurysm; 2) the hemodynamics of early diastolic filling in a patient-specific left ventricle (LV); and 3) and fluid-structure interaction of a BMHV implanted in the aortic position of a patient-specific LV/aorta configuration driven by electrical excitation of the LV wall motion. For all cases the computed results yield new, clinically-relevant insights into the underlying flow phenomena and underscore the potential of the numerical method as a powerful tool for carrying out high-resolution simulations in patient-specific anatomic geometries. Future work will focus on extending the fluid-structure interaction scheme to simulate soft tissues and other medical devices, such as stents, bio-prosthetic tri-leaflet and percutaneous heart valves.