基于换能器驱动信号特征的高强度聚焦超声焦域损伤实时监测  

Real-time monitoring of high intensity focused ultrasound focal damage based on transducer driving signal

作　　者：钱骏 谢伟 周小伟 谭坚文[1,2] 王智彪[1] 杜永洪[1] 李雁浩 Qian Jun;Xie Wei;Zhou Xiao-Wei;Tan Jian-Wen;Wang Zhi-Biao;Du Yong-Hong;Li Yan-Hao(State Key Laboratory of Ultrasonic Medical Engineering,School of Biomedical Engineering,Chongqing Medical University,Chongqing Key Laboratory of Biomedical Engineering,Chongqing 400016,China;National Engineering Research Center of Ultrasonic Medicine,Chongqing Medical University,Chongqing 401121,China)

机构地区：[1]超声医学工程国家重点实验室,重庆医科大学生物医学工程学院,重庆市生物医学工程学重点实验室,重庆400016 [2]超声医疗国家工程研究中心,重庆401121

出　　处：《物理学报》2022年第3期275-283,共9页Acta Physica Sinica

基　　金：重庆市基础研究与前沿探索专项博士后科学基金(批准号:cstc2019jcyj-bshX0075)资助的课题.

摘　　要：高强度聚焦超声(high intensity focused ultrasound,HIFU)焦域的实时监测是聚焦超声临床治疗面临的关键问题,目前临床常采用B超图像强回声的变化实现焦域组织损伤的监测,而B超图像出现的强回声大多与焦域处的空化及沸腾气泡相关,无法准确、实时地监测治疗状态.HIFU治疗中焦域组织会伴随温度升高、空化、沸腾和组织特性等变化,换能器表面的声学负载也在不断变化,针对该问题,本文构建了换能器电压电流实时检测平台,通过测量换能器电学参数来感知焦域组织的状态变化.以离体牛肝组织作为HIFU辐照对象,并将相位差变化的结果与离体牛肝组织损伤的结果进行了对照,实验结果表明,在HIFU辐照过程中,换能器电压与电流的相位会出现由相对平稳到大幅波动的过程,此时停止辐照可见焦域出现明显损伤,而此时B超图像灰度无明显变化;此外,当焦域出现空化时,其波动幅度与范围将较之更大.此方法可为HIFU焦域组织损伤监测提供一种新的研究方案和手段.Real-time monitoring of high intensity focused ultrasound(HIFU)focal region is a key problem in clinical treatment of focused ultrasound.At present,the change of strong echo in B-ultrasound image is often used in clinical practice to monitor tissue damage in the focal area.However,the strong echo in B-ultrasound image is mostly related to cavitation and boiling bubbles in the focal area,which cannot monitor the treatment status accurately or in real time.In the HIFU treatment,the focal area tissue will be accompanied by changes in temperature,cavitation,boiling,and tissue characteristics.The acoustic load on the surface of the transducer is also constantly changing.To solve this problem,a real-time detection platform of transducer voltage and current is built in this work,which can sense the change of focal area tissue state by measuring the electrical parameters of the transducer.The experimental results show that the stability of the phase difference of the transducer driving signal will be different(the fluctuation amplitude will be different)when different media are placed on the surface of the transducer to change the acoustic load on the surface of the transducer.The fluctuation amplitude of the phase difference of the driving signal will be larger than that in the water when the iron plate is placed in the focal plane.However,the phase fluctuation amplitude will be much smaller than that in the water where the beef liver is placed.This shows that different acoustic loads can cause the electrical parameters of the transducer to change.The isolated bovine liver tissue is used as the HIFU irradiation object,and the results of the phase difference change are compared with the results of the isolated bovine liver tissue damage.The experimental results show that the phase of the transducer voltage and current will change from relatively stable to large fluctuations during the HIFU irradiation.At this time,obvious damage can be seen in the focal region when the irradiation is stopped,and the grayscale of B-ultras

关 键 词：高强度聚焦超声损伤监测 互相关 换能器电气特性 

分 类 号：R445.1[医药卫生—影像医学与核医学] TB553[医药卫生—诊断学]