光纤水听器测量聚焦换能器声压和温度分布

Research of pressure and temperature distributions in high intensity focused ultrasound therapy using a fiber optic hydrophone

为了解决人体中高强度聚焦超声(HIFU)焦点处的温度场分布检测的难题,给出了从声压分布入手探测温度场分布问题的新方法。通过搭建光纤水听器自动扫描系统,利用光纤水听器同时测量仿组织材料(TMM)样本中焦斑区域的声场和温度的分布,探究声压和温度在人体组织中的分布关系。通过实验得出,声压最大处和温度场最高处坐标同为(0 mm,0 mm);-3 d B和-6 d B声束宽度:声压为2.4 mm、3.22 mm,温度为2.44 mm、2.98 mm。实验结果表明,声压和温度的最大值高度重合;仿组织材料样本中超声焦点处的横切面温度分布要比声压分布陡峭,即相比声压分布,温度场的能量分布更加集中,焦点半径更小。

High intensity focused ultrasound（ HIFU） therapy is an effective and noninvasive method for the clinical treatment of tumors,but the measurement of temperature fields in the body is difficult.In order to explore the bioheat field distribution,we have developed a new method based on the pressure field by studying the relationship between pressure and temperature in tissue mimicking material（ TMM）.The method employs an optical fiber hydrophone,which has a high spatial resolution and can simultaneously measure the pressure and temperature.The experimental results show that： The maximum sound pressure and maximum temperature field are obtained at the coincident top coordinates（ 0 mm,0 mm）; for- 3 d B and- 6 d B,the bandwidth of pressure is 2.4 mm and 3.22 mm respectively,and the temperature is 2.44 mm and 2.98 mm respectively.The maximum point of the sound pressure overlaps with the highest temperature and the distribution of the sound pressure and the temperature are essentially coincident.Furthermore,the sound temperature distribution of the TMM sample at the transverse section of the focus area is more convergent than the pressure distribution.