微泡的超声特性研究及其与生物组织的作用

发布时间：2018-04-10 05:11

本文选题：超声造影剂　切入点：微泡　出处：《上海交通大学》2007年硕士论文

【摘要】： 超声造影剂微泡是现代医学中十分活跃的领域。在超声诊断领域中利用微泡的散射特性增强超声成像效果,以及利用微泡的空化效应在超声治疗领域的应用都得到了相当广泛的研究。本文从空化气泡的声致发光实验、理论求解和比较带球壳微泡和空化气泡的动力学特性,和微泡在单双频超声换能器下的与生物组织的作用效果出发,研究微泡的超声特性以及微泡对生物组织的作用效果。首先测量单泡声致发光Mie散射信号,研究空化气泡的半径变化,定性了解气泡的动力学特性,并用理论模拟的气泡半径-时间曲线和实验中的Mie散射信号比较。结果表明单泡声致发光的周期与换能器驱动电压的周期一致,在整个发光周期中,气泡在声场辐射作用下吸收能量缓慢增大,在达到一定程度时在短时间内瞬时坍塌减小释放能量,造成发光现象的产生。然后从流体的连续性方程和动量守恒方程出发,推导经典的微泡理论模型,并应用范德瓦耳斯绝热方程对其进行修正,分别对带球壳微泡和空化气泡建立模型,模拟它们的运动过程。并在此基础上,对两种微泡的散射特性进行了分析与比较,研究了不同驱动声场频
[Abstract]:Ultrasound contrast agent microbubble is a very active field in modern medicine.In the field of ultrasonic diagnosis, the scattering characteristics of microbubbles and the cavitation effect of microbubbles have been widely studied.Based on the sonoluminescence experiments of cavitation bubbles, the kinetic characteristics of microbubbles and cavitation bubbles in spherical shell are calculated and compared theoretically, and the effect of microbubbles acting on biological tissue under single and double frequency ultrasonic transducer is discussed.The ultrasonic characteristics of microbubbles and the effect of microbubbles on biological tissue were studied.First, the Mie scattering signal of single bubble was measured, the radius of cavitation bubble was studied, and the dynamic characteristics of bubble were analyzed qualitatively. The radius-time curve of bubble was compared with the experimental Mie scattering signal.The results show that the period of single bubble sonoluminescence is the same as the period of transducer driving voltage. During the whole period, the absorption energy of bubble increases slowly under the action of sound field radiation.To a certain extent, the transient collapse reduces the releasing energy and causes the luminous phenomenon.Then, based on the continuity equation and momentum conservation equation, the classical theory model of microbubble is deduced, and the van der Waals adiabatic equation is used to modify the model.Simulate their motion.On the basis of this, the scattering characteristics of two kinds of microbubbles are analyzed and compared, and the frequency of sound field driven by two kinds of microbubbles is studied.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：R312

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