| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 99 === Pulmonary regurgitation (PR) is a common phenomenon in pulmonary arteries in patients after repair of tetralogy of Fallot (TOF). The regurgitation fraction of left pulmonary artery (LPA) is usually greater than right pulmonary artery (RPA) according to clinic data. It may be related to blood flow in pulmonary arteries. Therefore, understanding hemodynamics in pulmonary arteries helps to comprehend the reason. The aim of this study is to use 3-D reconstructed pulmonary artery models from magnetic resonance imaging (MRI) and to use numerical approaches for simulation of flow variations in pulmonary arteries after repair of TOF. The periphery of pulmonary artery is obtained from MRI of one healthy person and three patients after repair of TOF. To explore the effect of PR, one healthy and three pulmonary arteries after repair of TOF are considered.
From the numerical results, the blood flow is influence by the bifurcation anglesand geometry of pulmonary artery. The regurgitation happens first in LPA after repair of TOF due to the small angle between LPA and main pulmonary artery (MPA). The recirculation region which obstructs forward blood flow to the left lung is found in LPA during acceleration of systole. In addition, the dilation ofMPA usually appears after repair of TOF. Strong vortices are found in the dilation area of MPA during diastole of a cardiac cycle. The complex blood flow patterns occur in end of systole and diastole because the directions of blood flow in MPA changes. It is found that the dilation causes abnormal flow distribution in MPA during regurgitation period in a cardiac cycle. The healthy person does not have those flow patterns. We also analysis the pressure distribution, the extreme pressure variations is in dilation area of MPA. Numerical data including regurgitation in MPA, LPA and RPA are compared with phase contrast MR measured data. Good agreements are found between numerical results and measured data.
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