A Multi-Scale Model Study For Cardiovascular System

Cardio-and cerebrovascular diseases seriously harm human health due to their high morbidity and high risk. These diseases are often accompanied by hemodynamic and vascular abnormalities. Studying the cardiovascular system by mathematical modeling method is helpful for physiological and pathological research of cardiovascular system, as well as the diagnosis and treatment of cardio-and cerebrovascular diseases. OD model can be used to study the lumped parameter property and time property of vascular system, while ID model leads to a simulation of spatial property. The merging of OD and ID model enables a simulating of hemodynamic and wave propagation characteristics of vascular system simultaneously in time and spatial field.This study aims to build a mathematical multi-scale model of the cardiovascular system, and apply it to simulate normal physiological state and common cardio-and cerebrovascular diseases. The main tasks and results are summarized as follows.1. After the intensive analysis of various modeling techniques, appropriate methods for OD, ID modeling and coupling were determined.2. ID models of a single vessel with boundary conditions, a simple bifurcation network, and the circle of Willis (CoW) were established. The models were used to simulate the hemodynamic and blood pressure wave propagation characteristics in vascular network, and the results are consistent with normal physiological conditions.3. A multi-scale model was achieved by coupling ID model of CoW with OD model of the whole cardiovascular system. The validity of the multi-scale model and the coupling method was verified, and the model is able to simulate hemodynamic characteristics of the whole cardiovascular system and blood pressure wave propagation of CoW as well.4. The coupled multi-scale model was applied to simulate common diseases of CoW, investigate the overall hemodynamics, and blood pressure wave propagation characteristics of the CoW under pathological conditions.In conclusion, this study accomplished a multi-scale model of the cardiovascular system and simulated the overall hemodynamics, local hemodynamic and blood pressure wave propagation characteristics of the CoW. And the results agree with clinical physiology and pathology states. After the further improvement of the current modeling method of 0D-1D multi-scale model, it is expected to provide a tool for study in cardio-and cerebrovascular system.