摘要
研究了高强度聚焦超声热疗场的声场模式,并给出了二维相控阵列的声场模式控制算法。单焦点扫描声场模式在治疗中等偏大的肿瘤时容易引起非线性效应;采用基于伪逆矩阵的声场合成算法,直接形成了多焦点的控制模式,为焦域控制提供了新的思路。利用声场快速算法对30×30二维面阵的单焦点扫描声场模式和多焦点直接合成声场模式进行计算机仿真,仿真结果表明多焦点模式大大降低了焦点处的声强;而且基于此模式,采用加权优化算法对激励向量进行优化从而提高了阵列的激励效率,采用改进的特征向量优化算法优化了多焦点热疗模式的声场增益,增加了能量在目标体积的沉积,同时消除不期望的潜在热点,为超声热疗场的模式控制提供了理论依据。
An acoustic field patterns of the High Intensity Focused Ultrasound (HIFU) are studied in this paper, and controlling algorithms of the 2-D HIFU phased array are provided. It is easy to produce certain nonlinear phenomena when a 2-D phased array uses the single-focus scanning pattern to treat large tumors. However, a directly synthesis method of the acoustic field based on the pseudo-inverse matrix can produce the multiple-focus field pattern. It provides a method for controlling acoustic field patterns. The fast algorithm of the acoustic field was used to simulate the single-focus scanning pattern and the multiple-focus field pattern produced by a phased array consisting of 30×30 elements, and simulation results show that the 2-D array using the multiple-focus pattern can produce the foci with lower intensities. Furthermore, the multiple-focus pattern also allows the complex excitation vector to be weighted to increase the array excitation efficiency, and the improved eigenvector algorithm is used to optimize the intensity gain of the multiple-focus field patterns. It is shown to increase the power deposition in the target volume and eliminate the undesired interference. And this study provides a theoretic guide to the control of ultrasonic field patterns.
出处
《声学学报》
EI
CSCD
北大核心
2005年第3期207-214,共8页
Acta Acustica
基金
清华大学"985"基金资助项目(012-081100501)
关键词
聚焦超声热疗场
声场模式
二维相控阵列
肿瘤治疗
非线性效应
Acoustic fields
Acoustic wave propagation
Computer simulation
Heat transfer
Numerical analysis
Optimization
Ultrasonic waves
