High-speed optical observations and simulation results of SonoVue microbubbles at low-pressure insonation
High-speed optical observations and simulation results of SonoVue microbubbles at low-pressure insonation
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DOI：
10.1109/tuffc.2008.796
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发表时间：
2008-06-01
影响因子：
3.6
通讯作者：
Eckersley, Robert J.
中科院分区：
文献类型：
--
作者：
Chetty, Kevin;Stride, Eleanor;Eckersley, Robert J.
修正的Rayleigh-Plesset模型通常用于表征超声暴露下微泡的声学响应。在大多数情况下，这些模型已被参数化，通过声学测量采取散装悬浮液的微泡。本研究的目的是参数化的霍夫模型的商业造影剂SonoVue使用光学观察到的振荡从单个微泡记录与高速摄像机。调整壳体弹性模型项以使模拟数据与测量的振荡拟合，同时壳体粘度参数保持恒定在1 Pa. s。结果表明，该模型预测微泡行为的能力有限。壳弹性参数被发现与初始微泡直径成比例地在10和80 MPa之间变化，这意味着粘弹性壳项不是壳材料的恒定性质。使用移动窗口优化来探测微泡响应的进一步分析表明，壳体的弹性可以在声波作用的过程中增加高达50%，特别是对于在更接近其共振频率处振荡的微泡。微泡振荡模型更成功地将一个变化的弹性项到模型中。
Modified Rayleigh-Plesset models are commonly used to characterize the acoustic response of microbubbles under ultrasound exposure. In most instances these models have been parameterized through acoustic measurements taken from bulk suspensions of microbubbles. The aim of this study was to parameterize the Hoff model for the commercial contrast agent SonoVue using optically observed oscillations from individual microbubbles recorded with a high-speed camera. The shell elasticity model term was tuned to fit simulation data to the measured oscillations while the shell viscosity parameter was held constant at 1 Pa.s. The results demonstrate a limited ability of the model to predict the microbubble behavior. The shell elasticity parameter was found to vary proportionally between 10 and 80 MPa with the initial microbubble diameter, implying the viscoelastic shell terms are not a constant property of the shell material. Further analysis using a moving window optimization to probe the microbubble responses suggests that the elasticity of the shell can increase by up to 50% over the course of insonation, particularly for microbubbles oscillating nearer to their resonant frequency. Microbubble oscillations were modeled more successfully by incorporating a varying elasticity term into the model.