聚焦换能器离散发射阵列的辐射力计算

Radiation of dispersed array using focused transducers

为了对医学超声中使用的聚焦换能器离散阵列的辐射力进行估算,文章中应用几何声学的方法,推导了聚焦换能器离散发射阵列超声作用于吸收靶上的辐射力公式,并分别给出了活塞阵元与聚焦阵元的辐射力公式。将该几何声学公式与瑞利积分结果比较显示,当声束倾斜角θi<30°,半孔径角α<15°时,误差不超过4.5%。这种结果说明了这种方法可以用来有效地估算离散阵列聚焦换能器的辐射力。

In order to estimate the radiation power of a dispersed array composed of focused transducers, a ray method is used to derive formulas of the radiated ultrasound acting on an absorbing target that is placed in the focused ultrasonic field. Radiation formulas for arrays with focused transducers and piston elements, respectively, are presented. For an incident beam angle θi <30° and the half-aperture angle α <15° for focused element, difference in the calculated results between a geometrical acoustics method and the Rayleigh integral is less than 4.5%. This indicates that the method can be used effectively to estimate the radiation power of a dispersed array with focused transducers.