大张角聚焦换能器中的张角变化对生物组织温度场的影响

发布时间：2018-07-08 20:13

本文选题：Spheroidal + Beam　；参考：《南京大学学报(自然科学)》2017年01期

【摘要】：高强度聚焦超声(HIFU)是现代医学肿瘤治疗物理疗法的一项重要技术,其原理是通过聚焦方法将大面积超声聚焦换能器辐射出的声能量汇聚于面积极小的聚焦区,使聚焦区获得较强的声能量并利用超声波的热效应在短时间内使病灶部位获得较高的温升,从而使肿瘤组织热凝固坏死.大张角聚焦换能器指的是球面半张角大于16.6°的球壳式聚焦换能器.相对于传统的小张角换能器,大张角聚焦换能器拥有更强的声聚焦效应,聚焦区半径更小,穿透性更好,声能量聚焦效果明显强于小张角换能器,所以可以获得更好的温升.利用Spheroidal Beam Equation(SBE)方程求解大张角聚焦换能器条件下的声场获得空间热源的产热率,然后通过Pennes方程解出大张角聚焦换能器条件下生物组织中的温度场分布.研究不同改变张角方式下大张角聚焦换能器作用下生物组织的温升分布情况,研究结果表明改变换能器的孔径以改变张角时,张角越大温升越大,而改变其焦距以改变张角时,温度变化则相反.实验也验证了换能器孔径变化对生物组织中的温升的影响.
[Abstract]:High intensity focused ultrasound (HIFU) is an important technique in modern medical tumor therapy. The principle of HIFU is that the sound energy emitted from large area ultrasonic focusing transducer is concentrated in a very small focus area by focusing method. The focus region can obtain strong acoustic energy and the thermal effect of ultrasonic wave can increase the temperature of the focus in a short period of time, thus making the tumor tissue thermal coagulation and necrosis. A large angle focusing transducer refers to a spherical shell focusing transducer with a half tensor angle greater than 16.6 掳. Compared with the conventional small-angle transducer, the large-angle focused transducer has stronger acoustic focusing effect, smaller radius of focus area, better penetration, and better focusing effect of acoustic energy than small-angle transducer, so better temperature rise can be obtained. The Spheroidal Beam equation (SBE) equation is used to solve the acoustic field under the condition of large angle focusing transducer to obtain the heat production rate of the space heat source, and then the temperature field distribution in the biological tissue under the condition of the large opening angle focusing transducer condition is solved by Pennes equation. The temperature rise distribution of biological tissue under the action of large angle focusing transducer is studied in different ways. The results show that when the aperture of transducer is changed to change the angle of tension, the larger the temperature of the angle is, the larger the temperature is, and when the focal length is changed to change the angle of tension, The temperature change is the opposite. The effect of the aperture change of the transducer on the temperature rise in biological tissue was also verified.
【作者单位】：近代声学教育部重点实验室南京大学声学研究所;
【基金】：国家自然科学基金(11274166) 声场声信息国家重点实验室开放课题研究基金(SKLOA201609)
【分类号】：R730.5;TB552

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