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相控阵高强度聚焦超声换能器可以通过换能器上不同阵元发射超声波的时间不同来实现变焦、多焦点。该论文应用Westervelt方程的近似式,结合Pennes热传导方程,以人体乳房为例,FDTD(finite difference time domain)仿真对比研究平面阵列相控聚焦换能器与曲面阵列相控聚焦换能器形成温度场的特性,同时数值仿真研究不同占空比的正弦激励函数、不同治疗频率、声强对曲面阵列相控聚焦换能器超声温度场的影响。研究结果表明曲面阵列相控聚焦换能器能有效地减少皮肤处的温升,对皮肤的伤害较小;对于曲面阵列相控聚焦换能器,不同占空比的正弦激励函数形成的可治疗区域(60℃以上)大小差别不大,但最高温度不同;随着频率升高,形成的可治疗区域体积减小;随着输入声强的增大,可治疗区域变大,但焦距不变。
Phased array high-intensity focused ultrasound transducers can achieve zooming and multi-focus by transmitting different ultrasonic waves at different times on the transducer. In this paper, Westervelt equation approximation, combined with Pennes heat conduction equation, the human breast as an example, FDTD (finite difference time domain) simulation study of planar array phase-controlled focusing transducer and surface-array phase-controlled focusing transducer temperature field The numerical simulations are performed to study the effects of sinusoidal excitation functions with different duty cycles, different treatment frequencies and sound intensities on the ultrasonic temperature field of a surface-phased Focused transducer. The results show that the surface array phase-controlled focusing transducer can effectively reduce the skin temperature rise, less damage to the skin; for the curved array phased focusing transducer, the sinusoidal excitation function of different duty cycle formation of treatable The size of the region (above 60 ℃) is not significantly different but the maximum temperature is different. As the frequency increases, the volume of the treatable region decreases; as the input sound intensity increases, the treatable region becomes larger but the focal length remains unchanged .