包膜微气泡非线性流变特性的建模研究

发布时间：2018-05-13 00:16

本文选题：超声造影剂 + 动力学模型　；参考：《南京大学》2013年硕士论文

【摘要】：超声造影剂(UCA)微气泡的动态响应特性很大程度上受到其包膜外壳特性(如壳的弹性和粘度)的影响。本论文基于Marmottant模型,结合了非线性流变定理,提出一个新的模型来描述复杂的UCA微泡的动态响应。并利用新模型拟合用高速光学成像系统或光散射系统测量到的UCAs动态响应数据,来验证新模型的有效性。测得的半径-时间曲线和数值模拟结果之间的比较结果表明,新模型可以成功模拟UCAs的“只可压缩”行为。其后,基于新模型的模拟结果,对声诺维微泡包膜弹性和粘性系数进行评价的,并从一些现有的UCA模型获得的结果相比。结果证实了新模型因为考虑到包膜的弹性和粘度的非线性变化,减小了微泡包膜参数对初始气泡半径的依赖性(即包膜弹性参数和粘性参数会随半径的增加而增加)。这表明当前的模型更全面的描述了微泡包膜的复杂流变性质(例如“剪切稀化”和“张力减小”)。
[Abstract]:The dynamic response of ultrasonic contrast agent (UCA) microbubbles is greatly affected by the shell properties (such as the elasticity and viscosity of the shell). Based on the Marmottant model and the nonlinear rheological theorem, a new model is proposed to describe the dynamic response of complex UCA microbubbles. The validity of the new model is verified by fitting the UCAs dynamic response data measured by high speed optical imaging system or light scattering system. The comparison between the measured radius-time curves and the numerical simulation results shows that the new model can successfully simulate the "compressible" behavior of UCAs. Then, based on the simulation results of the new model, the elastic and viscosity coefficients of sonovir microbubble were evaluated, and compared with the results obtained from some existing UCA models. The results show that the new model reduces the dependence of the microbubble coating parameters on the initial bubble radius because of the nonlinear variation of the envelope elasticity and viscosity (that is, the envelope elastic parameters and the viscosity parameters increase with the increase of the radius). This suggests that the current model describes more fully the complex rheological properties of the microbubble capsule (such as "shearing thinning" and "tension reduction").
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R445.1;R318

【共引文献】