Simulation Study on the Influence of Multifrequency Ultrasound on Transient Cavitation Threshold in Different Media
Simulation Study on the Influence of Multifrequency Ultrasound on Transient Cavitation Threshold in Different Media
复制标题
多频超声对不同介质中瞬态空化阈值影响的仿真研究
DOI：
10.3390/app10144778
复制
发表时间：
2020-07-01
影响因子：
2.7
通讯作者：
Qian, Shengyou
中科院分区：
文献类型：
--
作者：
Dong, Hu;Zou, Xiao;Qian, Shengyou
通过多频超声技术的引入，在组织消融等方面取得了显著的效果。利用球形气泡的非线性动力学方程，模拟分析了多频超声的组合方式、峰值负压及其持续时间、相位角差和多变指数对水、血液、脑和肝4种不同介质中瞬态空化阈值的影响。仿真结果表明，在相同的频差和初始气泡半径下，高频、三频组合的瞬态空化阈值高于低频、三频组合。当三重频率的最低频率相同时，频率差越大，瞬态空化阈值越高。当初始气泡半径较小时，频率差对三频组合的瞬态空化阈值影响不大。随着初始气泡半径的增大，频率差对三倍频高频组合的瞬态空化阈值的影响比三倍频低频组合的瞬态空化阈值的影响更明显。当多频组合超声的峰值负压或峰值负压持续时间比单频超声长时，多频组合超声的瞬态空化阈值比单频超声低;相反，多频组合超声的瞬态空化阈值比单频超声高。当多频激励相位差为零时，对应的瞬态空化阈值最低，而多变指数的变化对多频组合的瞬态空化阈值几乎没有影响。研究结果可为多频超声降低瞬态空化阈值提供参考，对空化的实际应用具有重要意义。
Through the introduction of multifrequency ultrasound technology, remarkable results have been achieved in tissue ablation and other aspects. By using the nonlinear dynamic equation of spherical bubble, the effects of the combination mode of multifrequency ultrasound, the peak negative pressure and its duration, the phase angle difference, and the polytropic index on the transient cavitation threshold in four different media of water, blood, brain, and liver are simulated and analyzed. The simulation results show that under the same frequency difference and initial bubble radius, the transient cavitation threshold of the high-frequency, triple-frequency combination is higher than that of the low-frequency, triple-frequency combination. When the lowest frequency of triple frequencies is the same, the larger the frequency difference, the higher the transient cavitation threshold. When the initial bubble radius is small, the frequency difference has little effect on the transient cavitation threshold of the triple-frequency combination. With the increase of initial bubble radius, the influence of frequency difference on the transient cavitation threshold of the higher frequency combination of triple frequency is more obvious than that of the lower frequency combination of triple frequency. When the duration of peak negative pressure or peak negative pressure of the multifrequency combined ultrasound is longer than that of the single-frequency ultrasound, the transient cavitation threshold of the multifrequency combined ultrasound is lower than that of the single-frequency ultrasound; on the contrary, the transient cavitation threshold of the multifrequency combined ultrasound is higher than that of the single-frequency ultrasound. When the phase angle difference of multifrequency excitation is zero, the corresponding transient cavitation threshold is the lowest, while the change of the polytropic index has almost no effect on the transient cavitation threshold for the multifrequency combination. The research results can provide a reference for multifrequency ultrasound to reduce the transient cavitation threshold, which is of great significance for the practical application of cavitation.