Dynamic Response of Constrained Bubbles to Acoustic Excitation

约束气泡对声激励的动态响应

• 批准号: 0652947
• 负责人: Sheryl Gracewski
• 金额: --
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0652947&HistoricalAwards=false
• 关键词: Dynamic; Response; Constrained; Bubbles; Acoustic

AbstractNumerous systems, from biomedical ultrasound to microfluidics, depend on the dynamic response of bubbles whose expansion is constrained by a surrounding tube or channel. For example, potential therapeutic uses of biomedical ultrasound, including localized drug delivery and clot dissolution, may be enhanced by the acoustic excitation of targeted bubbles within the blood stream. The goal of this project is to develop an understanding of the complex dynamic interactions between a gas cavity in a liquid and a surrounding compliant solid tube or channel. The physical system is quite complex because 1) it is a three-phase system, 2) the deformations of the bubble and tube can be large, and 3) the behavior of the system can be highly nonlinear. A major objective is to identify the important physical parameters and response characteristics of a constrained acoustically excited bubble. In particular, the effect of tube/channel parameters on both the resonance frequencies and nonlinear dynamic responses of bubbles (excited by a range of acoustic sources) will be characterized. To model the highly nonlinear interaction of this three-phase system with large deformations and rapidly changing time scales, simulation techniques will be developed using coupled boundary element and finite element methods. The simulation models will be updated based on the additional insight obtained from ultrasonic displacement measurements and high-speed photography observations of the responses of bubbles subject to a range of acoustic sources.A fundamental understanding of the dynamic response of bubbles to ultrasonic waves confined by vessels or channels will aid the development of a wide variety of systems including a) novel microfluidic devices, b) more effective drug delivery and activation techniques, c) new ultrasonic clot dissolution techniques, and d) guidelines for the safe use of echo contrast agents for improved diagnostic ultrasonic imaging. In addition, a Dynamic Measurements Laboratory will be developed to train undergraduate and graduate students in dynamic system response using experimental techniques such as ultrasonic displacement measurements and high-speed photography. These dynamic measurement techniques will be integrated into undergraduate and graduate laboratories and vibration classes to provide hands-on training tools. Instructional demonstrations to introduce girls in middle and high school to science and engineering will be developed using the high-speed camera.

从生物医学超声到微流体，许多系统都依赖于气泡的动态响应，气泡的膨胀受到周围管道或通道的约束。例如，生物医学超声的潜在治疗用途，包括局部药物递送和凝块溶解，可以通过血流内的靶向气泡的声学激发来增强。这个项目的目标是发展一个复杂的动态之间的相互作用的理解，在液体中的气体腔和周围的兼容固体管或通道。物理系统是相当复杂的，因为1）它是三相系统，2）气泡和管的变形可能很大，以及3）系统的行为可能是高度非线性的。一个主要的目标是识别的重要物理参数和响应特性的约束声激励气泡。特别是，将表征管道/通道参数对气泡（由一系列声源激发）的共振频率和非线性动态响应的影响。为了模拟这种具有大变形和快速变化的时间尺度的三相系统的高度非线性相互作用，将使用耦合边界元和有限元法开发模拟技术。基于超声波位移测量和高速摄影观察气泡对一系列声源的响应所获得的额外洞察，将更新模拟模型。对气泡对被容器或通道限制的超声波的动态响应的基本理解将有助于开发各种各样的系统，包括：a）新型微流体装置，B）更有效的药物输送和激活技术，c）新的超声凝块溶解技术，和d）用于改进诊断超声成像的回波造影剂的安全使用指南。此外，还将建立一个动态测量实验室，利用超声波位移测量和高速摄影等实验技术对本科生和研究生进行动态系统响应培训。这些动态测量技术将集成到本科生和研究生实验室以及振动课程中，以提供实践培训工具。将利用高速摄像机制作教学演示，向初中和高中女生介绍科学和工程。