Experimental and Numerical Investigation of Therapeutic Ultrasound Angioplasty
Experimental and Numerical Investigation of Therapeutic Ultrasound Angioplasty
复制标题
治疗性超声血管成形术的实验和数值研究
DOI：
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
G. McGuinness
中科院分区：
文献类型：
--
作者：
G. Gavin;M. Hashmi;G. McGuinness
治疗性超声血管成形术是一种新兴的微创心血管外科手术，它将超声位移输送到小直径线波导的末端。超声末端的位移通过直接接触消融、压力波成分和空化，以及末端周围的声学流动事件影响动脉粥样硬化斑块和血栓。本文采用实验和数值计算相结合的方法，研究了线波导中的超声位移及其对周围流体的影响。
描述了一种实验治疗性超声线波导仪，它向直径为1.0 mm和锥形0.35 mm的镍钛(NiTi)波导的末端输送位移。该装置的工作频率已被实验确定为23.5 kHz，在所测试的功率设置下，向直径为1.0 mm的波导末端提供高达85|im的峰间(p-p)位移。与动脉粥样硬化斑块相比，该设备可以直接消融钙化物质，反应更硬，并产生空化和声流。
建立了一种流固耦合的数值模型，该模型计算了线波导全长方向的位移和应力，并与端部流体相耦合。模型的结构结果与包含4.5%恒定阻尼值的波导位移的实验测量结果进行了验证。该模型的流体结果预测了周围流体中形成的压力幅值，并与文献报道的值进行了密切的比较。该模型预测了引起空化所需的末端位移，这是一种主要的破坏性事件，并与使用超声线波导设备进行的实验观测进行了比较。
波导数值模型将在这一新兴心血管技术的进一步发展和改进中证明是一个有价值的设计工具。
Therapeutic ultrasound angioplasty is an emerging minimally invasive cardiovascular surgical procedure that involves the delivery of ultrasonic displacements to the distal-tip of small diameter wire waveguides. The ultrasonic distal-tip displacements affect atherosclerotic plaque and thrombus by direct contact ablation, pressure wave components and cavitation, in addition to an acoustic streaming event around the distal-tip. This study uses experimental and numerical methods to investigate ultrasonic displacements in wire waveguides and the effect the distal-tip displacements have on the surrounding fluid.
An experimental therapeutic ultrasound wire waveguide apparatus is described that delivers displacements to the distal-tip of 1.0 mm and tapered 0.35 mm diameter nickel-titanium (NiTi) waveguides. The operating frequency of the apparatus has been experimentally determined to be 23.5 kHz and for the power settings tested delivers displacements of up to 85 |im peak-to-peak (p-p) to the distal-tip of 1.0 mm diameter waveguides. The apparatus has been shown to directly ablate calcified materials with a stiffer response when compared with atherosclerotic plaques and to generate cavitation and acoustic streaming.
A coupled fluid-structure numerical model of the waveguide and fluid surrounding the distal-tip has been developed that predicts the waveguide displacements and stresses along the entire length of the wire waveguide. The structural results of the model have been validated against experimental measurements of the displacements of the waveguide with the inclusion of a constant damping value of 4.5%. The fluid results of the model predict the pressure amplitudes developed in the surrounding fluid and compare closely with values reported in literature. The model predicts the distal-tip displacements required to cause cavitation, a major disruptive event, and has been compared with experimental observations made with the ultrasonic wire waveguide apparatus.
The waveguide numerical model will prove a valuable design tool in the further development and improvement of this emerging cardiovascular technology.
DOI：
10.1161/01.atv.12.1.1
发表时间：
1992-01-01
期刊：
ARTERIOSCLEROSIS AND THROMBOSIS
影响因子：
--
作者：
LEE, RT;RICHARDSON, SG;PANDIAN, N
通讯作者：
PANDIAN, N
影响因子：
2.4
作者：
LOREE, HM;GRODZINSKY, AJ;LEE, RT
通讯作者：
LEE, RT