Abstract: Treatment of tumors with High Intensity Focused Ultrasound（HIFU） is an effective treatment method in clinical application，it is important to measure the temperature in tissues during treatment.In this paper，the characteristics of concave spherical transducer are discussed in theory.The finite difference method is performed to solve the Pennes equation，and obtains temperature fields in multi-layer biological tissues in concave spherical acoustic transducer.By simulating acoustic fields and temperature fields in multi-layer tissues at different initial parameters such as initial pressure and sound coefficient and heat conductivity，the results indicate that influence of initial pressure and heat conductivity of tissues on the temperature rise is great in the domain of focusing，this research is combined theory and clinical application.

Key words: concave spherical transducer, multi-layer tissues, acoustic fields, temperature fields

摘要： 高强度聚焦超声（HIFU）治疗肿瘤是目前临床治疗的一种有效方法，治疗过程中组织内的温度测量相当重要。分析了凹球面自聚焦换能器的声场特点，采用差分法求解Pennes方程，得到凹球面换能器的声场在多层生物组织中形成的温度场，通过实验仿真，得出不同初始声压、吸收系数和热传导率等参数在多层组织内的声场和温度场的分布情况，结果表明初始声压和热传导率对焦域内温升的影响较大，该研究便于理论与临床应用相结合。

关键词: 凹球面换能器, 多层组织, 声场, 温度场