【摘要】：大開(kāi)口半球形相控?fù)Q能器能夠最大化覆蓋顱骨表面,使超聲能量盡可能多地穿越顱骨到達(dá)治療靶區(qū),從而避免顱骨處能量沉積。該文基于人體頭顱結(jié)構(gòu)建立三維高強(qiáng)度聚焦超聲(HIFU)經(jīng)顱傳播模型,利用時(shí)域有限差分法(FDTD)結(jié)合Westervelt聲波非線性傳播方程和Pennes生物熱傳導(dǎo)方程進(jìn)行溫度場(chǎng)數(shù)值仿真,首先研究小開(kāi)口換能器的陣元信號(hào)激勵(lì)頻率、激勵(lì)面積比、陣元半徑和陣元數(shù)對(duì)其形成溫度場(chǎng)的影響及變化規(guī)律,其次將這些規(guī)律應(yīng)用于大開(kāi)口換能器,并對(duì)其形成溫度場(chǎng)特性進(jìn)行研究。小開(kāi)口換能器結(jié)果表明,在一定頻率范圍內(nèi),焦域中心溫度隨激勵(lì)頻率增加而升高,而54℃以上區(qū)域長(zhǎng)軸長(zhǎng)逐漸減小,短軸長(zhǎng)基本無(wú)變化;激勵(lì)總功率一致時(shí),激勵(lì)面積比越大,焦域中心溫度越高,54℃以上區(qū)域長(zhǎng)軸、短軸較長(zhǎng);使用小開(kāi)口直徑換能器模型篩選的陣元激勵(lì)頻率和激勵(lì)面積比可應(yīng)用于設(shè)計(jì)大開(kāi)口換能器,為大開(kāi)口換能器的開(kāi)發(fā)提供結(jié)構(gòu)參數(shù)。
[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，

本文編號(hào)：2395343