基于超声医学应用的声传播的研究  

Propagation of Acoustic Wave Based on Ultrasonic Medical Applications

作　　者：姚文苇[1] 

机构地区：[1]陕西学前师范学院,陕西西安710100

出　　处：《中国医学物理学杂志》2014年第4期5077-5080,共4页Chinese Journal of Medical Physics

基　　金：陕西省科技厅科研计划项目(2011JM1018);陕西教育学院科研基金项目(11KJ022)

摘　　要：目的:近年来,含气泡液体的声衰减和色散广泛应用于生物医学领域,利用这一特性可以对某些生物组织进行超声成像,也对血流进行超声多普勒成像,基于含气泡液体的声学特性对生物医学应用的影响,研究了声波在含有气泡粘性液体内的传播。方法:当液体中入射一列声波时,气泡的存在将改变液体内的传声特性,依据球贝塞尔和汉克尔函数,利用分界面处声波传播引起的质点振动速度和应力为边界条件研究其传播。结果:求解了声波在气-液混合介质内传播的声学参数,均与气泡含量、声波频率及粘滞系数等因素有关;并得到不同频率下声波的传播速度及衰减系数随气泡含量的变化曲线。结论:气泡和声波的传播频率都会影响声波在混合介质内的传播;具体表现在相同频率下,气泡含量增加使声波的传播速度不断下降,而其衰减系数却不断增大;气泡含量一定时,随着声波频率的升高,声波的传播速度下降越来越明显,衰减系数不断增大,即声波的传播能量损失越来越大。所得结论将对超声在医学上的研究和广泛应用有重要的指导意义。Objective： The characteristics of high acoustic attenuation and sound dispersion in bubbleliquid, have been widely used in the biomedical field; and these features can be help for ultrasound imaging of biological tissue, and Doppler ultrasonic imaging of blood flow; the properties of sound propagation are studied based on ultrasonic medical applications. Methods： When acoustic wave acts on the liquid with bubble, which will change the characteristic of sound propagation, propagation of sound is researched in the condition of the particle vibration velocity and the stress at the interface of bubble-liquid, according to Beisel and Hankel function, Results： Acoustic parameters are soluted in the gas - liquid mixed media, which associated with bubble content, the acoustic frequency and viscous coefficient ;at last changing curve are got, which include attenuation coefficient and the propagation velocity of sound waves of different frequencies and the bubble content. Conclusions： acoustic wave are influenced by transmission frequency and bubbles in the mixed medium; At the same frequency, increasing of bubble content lead to propagation velocity sank down, on the other hand, attenuation coefficient generally increases ; If the bubble content is certain, With the increasing of sound frequency, the acoustic wave propagation velocity is slowed down, and the attenuation coefficient increase, In other words, the propagation of the acoustic energy loss more and more. It is important to the research in medical ultrasound and widely used.

关 键 词：超声医学 等效弹性系数 应力 粘性液体 

分 类 号：R445.1[医药卫生—影像医学与核医学]