一种非侵入式检测聚焦超声场的方法及装置

A Method and Device of Non-invasive Measuring Focused Ultrasound Field

介绍了一种用激光通过声光折射法对聚焦超声场进行非侵入式测量的方法及装置.该方法采用一束直径小于声波长的平行激光束垂直入射于聚焦焦点,通过建立焦点声压与光线最大偏转距离间的关系模型,即可计算出某点的声压.通过将激光沿声轴线方向进行微小位置调节,利用光束在聚焦超声场中由于介质折射率不同导致的光线折射,即可测得焦域范围的声压分布以及焦斑宽度.所得实验测量结果与理论仿真结果对比相差不大,证明此方法是可行的.

This paper introduces a non-invasive method and device of measuring the focused ultrasound field by laser based on acousto-optical refraction. With a beam of parallel laser whose diameter is shorter than that of the ul- trasound wave irradiating into the focused field, the method builds a simple relational model between the sound pres sure of the focus and the maximal deflection distance, to calculate the sound pressure in a certain point. Then, by slightly moving the laser, the method finds the critical point of focusing with the light refraction caused by different medium refractivity in the focused field, to measure the distribution of sound pressure in the focused field and the fo- cal width. The slight difference between the experimental result and theoretical result shows the viability of this method.