| 超声吸收体物理参数对红外热成像测量高强度聚焦超声声场的影响 |
| |
| 引用本文： | 沈国峰,余瑛,张鹤林,汪灿华.超声吸收体物理参数对红外热成像测量高强度聚焦超声声场的影响[J].声学学报,2020,45(5):739-748. |
| |
| 作者姓名： | 沈国峰 余瑛 张鹤林 汪灿华 |
| |
| 作者单位： | 上海交通大学生物医学工程学院 上海200240;江西中医药大学计算机学院 南昌330004 |
| |
| 基金项目： | 国家自然科学基金面上项目(11774231)、国家重大科研仪器研制项目(81727806)、国家科技部2017重点研发计划项目(2017YFC0108900)、2017上海市科技支撑计划项目(17441906400)和江西省自然科学基金项目(20151BAB202014)资助 |
| |
| 摘 要： | 超声吸收体的物理参数对利用水听器和红外热成像技术的高强度聚焦超声(High-Intensity Focused Ultrasound,HIFU)声场测量结果具有重要影响。为了探索超声吸收体的物理参数(密度、声速、衰减系数、热扩散系数、定压比热容)对测量结果的影响规律,本文根据层状模型计算出相同声源功率输出时不同物理参数对应的超声吸收体内部声场和热场,利用有限差分法计算出超声吸收体表面在辐照过程中的温度变化;利用基于水听器和红外热成像技术的聚焦声场测量方法测量出焦域内不同位置上声场特征值(轴线声强和-6 dB声束宽度),与通过理论计算得到的声源在纯水中声场特征值进行比较,分析了不同物理参数对测量结果的影响。超声吸收体的声、热学参数中除了声速外,其它物理参数的变化引起声场特征值的测量造成最大相对差异率小于15%。因为声波传播速度的改变会导致超声吸收体内部热场分布变化,使测量结果与理论计算值有较大偏差,其中-6 dB声束宽度和轴线声强最大相对差异率为95.37%和69.97%。因此在选择超声吸收体的声、热学参数时应重点关注声波在吸收体内声速的影响。超声吸收体的声学参数与水的声学参数相近时,可以在焦域内获得较好的测量结果。
|
| 收稿时间： | 2018-09-27 |
The effect of physical parameters on estimating acoustic intensity in high intensity focused ultrasound field using infrared thermometry |
| |
| Affiliation: | 1 School of Biomedical Engineering, Shanghai Jiao Tong University Shanghai 200240;2 School of Computer Science, Jiangxi University of Traditional Chinese Medicine Nanchang 330004 |
| |
| Abstract: | The physical parameters of acoustic absorber play an important role in the estimating acoustic intensity in High Intensity Focused Ultrasound (HIFU) using infrared thermometry.In order to analyze the rule of the influence of different physical parameters (density,sound speed,attenuation,thermal diffusivity,specific heat capacity) on the measurement results,the theoretical simulation was applied.The sound and thermal field in the acoustic absorber are calculated based on layered model with same output parameters of transducer and different physical parameters.The finite difference method is used to calculate the temperature change at interface during the irradiation.The character value of sound field in the focal region,like intensity on axis and-6 dB beam width,are calculated by the method that based on hydrophone and infrared thermal imaging.The sound distribution in the water which is calculated in theoretical are treated baseline.The sound field characteristics calculated by theoretical calculation and method are compared and analyzed.The acoustic and thermal parameters of absorbers have no significant influence on the measurement results except the sound speed,and the maximum relative difference is less than 15%.Due to the changing of sound speed in the absorber,the distribution thermal field in absorber is changed,which lead to a great deviation,and the maximum relative difference in-6 dB beam width and axis intensity are 95.37% and 69.97%,respectively.Therefore,the appropriated choosing of this parameter play an important role.When the acoustic parameters of absorber are similar to that of water,the measurement results based on hydrophone and infrared thermal imaging have satisfactory accuracy within the focal region. |
| |
| Keywords: | |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
| 点击此处可从《声学学报》浏览原始摘要信息 |
|
点击此处可从《声学学报》下载全文 |
|
