半球形高强度聚焦超声相控换能器的仿真研究
发布时间：2018-12-29 20:25
【摘要】：大开口半球形相控换能器能够最大化覆盖颅骨表面,使超声能量尽可能多地穿越颅骨到达治疗靶区,从而避免颅骨处能量沉积。该文基于人体头颅结构建立三维高强度聚焦超声(HIFU)经颅传播模型,利用时域有限差分法(FDTD)结合Westervelt声波非线性传播方程和Pennes生物热传导方程进行温度场数值仿真,首先研究小开口换能器的阵元信号激励频率、激励面积比、阵元半径和阵元数对其形成温度场的影响及变化规律,其次将这些规律应用于大开口换能器,并对其形成温度场特性进行研究。小开口换能器结果表明,在一定频率范围内,焦域中心温度随激励频率增加而升高,而54℃以上区域长轴长逐渐减小,短轴长基本无变化;激励总功率一致时,激励面积比越大,焦域中心温度越高,54℃以上区域长轴、短轴较长;使用小开口直径换能器模型筛选的阵元激励频率和激励面积比可应用于设计大开口换能器,为大开口换能器的开发提供结构参数。
[Abstract]:The large opening hemispherical phase controlled transducer can maximize the coverage of the skull surface and make the ultrasonic energy travel through the skull to the therapeutic target as much as possible, thus avoiding the energy deposition in the skull. Based on the human skull structure, a three-dimensional high intensity focused ultrasound (HIFU) transcranial propagation model was established. The numerical simulation of temperature field was carried out by using the finite difference time-domain (FDTD) (FDTD) method combined with the Westervelt acoustic nonlinear propagation equation and the Pennes biothermic conduction equation. Firstly, the effects of excitation frequency, excitation area ratio, radius of array elements and number of array elements on the temperature field of small open transducer are studied, and then these laws are applied to large open transducer. The characteristics of the formation temperature field are also studied. The results of the small open transducer show that, in a certain frequency range, the central temperature of the focal region increases with the increase of the excitation frequency, but the long axis length decreases gradually in the region above 54 鈩，
本文编号：2395343
[Abstract]:The large opening hemispherical phase controlled transducer can maximize the coverage of the skull surface and make the ultrasonic energy travel through the skull to the therapeutic target as much as possible, thus avoiding the energy deposition in the skull. Based on the human skull structure, a three-dimensional high intensity focused ultrasound (HIFU) transcranial propagation model was established. The numerical simulation of temperature field was carried out by using the finite difference time-domain (FDTD) (FDTD) method combined with the Westervelt acoustic nonlinear propagation equation and the Pennes biothermic conduction equation. Firstly, the effects of excitation frequency, excitation area ratio, radius of array elements and number of array elements on the temperature field of small open transducer are studied, and then these laws are applied to large open transducer. The characteristics of the formation temperature field are also studied. The results of the small open transducer show that, in a certain frequency range, the central temperature of the focal region increases with the increase of the excitation frequency, but the long axis length decreases gradually in the region above 54 鈩，
本文编号：2395343
本文链接：https://www.wllwen.com/guanlilunwen/gongchengguanli/2395343.html
