目前相控阵多焦点声场设计一般都没有对声传播方向的声场分布进行限制,而声传播方向的声场分布对高强度聚焦超声(HIFU)治疗很重要,为此,该文在分析二焦点、四焦点模式下,针对声传播方向的声场分布特点,提出改进多焦点声场设计的方法。即在四焦点中心设置另一焦点,通过改变其焦点间的距离,观察声传播方向的声场分布变化。结果发现,五焦点在声场分布比二焦点和四焦点的声场分布有很大的改善。合理的改变焦点个数及焦点间的间距,能有效改善多焦点的声场分布。
In generally,the design of the phased-array multi-focus sound field didn′t restrict the sound field distribution in the sound propagation direction,while the sound field distribution is of importance to the high intense focus ultrasonic(HIFU) diagnostics.Based on the analysis of the distribution characteristics of the sound field with two focuses and four focuses modes,a method to improve the design of the multi-focus sound field has been proposed.The difference of the sound field distribution in the sound propagation direction has been observed by setting up another focus in the center of four focuses and changing the distance between the focuses.The result showed that the sound field distribution with five focuses has been improved greatly compared with the two-focus and four-focus sound field distributions.Altering the number of the focuses and the distance between the focuses reasonably can improve the distribution of the multi-focus sound field effectvely.