开口凹球面聚焦声场分析

Study of focused ultrasonic field of concave spherical transducer with a hole

高强度聚焦超声(HIFU)治疗局部肿瘤存在聚焦换能器和定位探头同时放置的问题,考虑到实际工程中必须考虑B超探头的放置对聚焦声场的影响,文章就此进行了研究。结果表明:开口的凹球面会降低焦区声压幅度。随着开孔半径的变大,焦区声压呈下降的趋势,焦区越长,越不利于聚焦;随着开孔位置距轴线的距离变大,焦区声压呈下降的趋势,而焦区的位置变化不大。文章同时对相应的温度场也进行了相关的分析。

In local cancer therapy with high intensity focused ultrasound (HIFU), there exists the problem of simultaneous positioning of the focusing transducer and the positioning probe in a Bscanner. The effect of a hole on the surface of the concave focusing transducer on the focal region in ultrasonic fields is studied. The result shows that the hole reduces the amplitude of acoustic pressure in the focal region. The larger the hole radius, the lower the acoustic pressure, and the longer the focal length. This is a disadvantage in focusing. Acoustical pressure decreases in the offaxis region, while the focal region does not change substantially. The effect of the hole on the temperature field is also investigated.