基于激光外差干涉技术的非接触式光声信号检测研究  

Research on Non⁃contact Photoacoustic Signal Detection Based on Laser Heterodyne Interferometry

作　　者：王成[1,2] 梁宸 皇甫胜男 朱俊 张瑶[1,2] 徐锦程 郑刚[1,2] 项华中[1,2] 张大伟[4] Wang Cheng;Liang Chen;Huangfu Shengnan;Zhu Jun;Zhang Yao;Xu Jincheng;Zheng Gang;Xiang Huazhong;Zhang Dawei(School of Health Science and Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Key Lab of Optical Instruments and Equipment for Medical Engineering,Ministry of Education,University of Shanghai for Science and Technology,Shanghai 200093,China;Yangtze Delta Institute of Optoelectronics,Peking University,Nantong 226010,Jiangsu,China;Engineering Research Center of Optical Instrument and System,Ministry of Education,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学健康科学与工程学院,上海200093 [2]上海理工大学医用光学仪器与设备教育部重点实验室,上海200093 [3]北京大学长三角光电科学研究院,江苏南通226010 [4]上海理工大学光学仪器与系统教育部工程中心,上海200093

出　　处：《中国激光》2024年第3期234-243,共10页Chinese Journal of Lasers

基　　金：国家自然基金(62175153);上海科委项目(21S902700)。

摘　　要：光声信号的传统检测方法是基于超声技术,这样接触式的信号探测方式增加了交叉感染的风险,不利于临床应用。采用纯光学技术的光声成像可提升检测精度和临床舒适度,具有较强的临床应用价值。设计了采用调Q Nd∶YAG脉冲激光器作为激励源的光声信号激发系统,选用双频He-Ne激光器作为探测源采集光声信号,搭建的外差干涉系统产生携带光声信号特征的拍频信号,利用I/Q正交法解调出光声信号。首先通过超声换能器模拟振动信号验证系统性能,实验结果表明光声信号探测系统能较好地还原出超声振动信号,且与水浸探头相比,振动频率的相对测量误差只有0.04%,绝对差值为0.2 kHz。然后以碳棒和离体生物组织作为样品,利用短脉冲光激励诱导光声信号,采用本系统和超声探头进行信号探测,对比分析结果显示所搭建的外差系统在检测带宽内可以实现光声表面振动波的非接触、高精度探测。Objective Photoacoustic imaging is a non-invasive,functional optical imaging technique that uses the photoacoustic effect with ultrasound as a mediator.Despite its potential for various medical applications,traditional contact-based signal detection methods have hindered its progress in clinical practice.To overcome these limitations,non-contact detection of photoacoustic signals has emerged as a solution.This approach uses air-coupled or all-optical detection methods and achieves a wide bandwidth and high sensitivity for ultrasound signal reception,aligning with the demands of modern medical technology.Current contact-based photoacoustic imaging still faces challenges,such as signal attenuation,surface scattering,system sensitivity,and environmental interference.Therefore,in this study,a noncontact,noninvasive,and cost-effective photoacoustic signal detection device,based on the optical heterodyne technology,is proposed.We aim to address the challenges in photoacoustic signal detection,reduce system costs and complexity,and promote the practical application of non-contact photoacoustic imaging in clinical settings.Methods The photoacoustic signals are detected using heterodyne interferometry.First,based on the characteristic parameters of tissue surface vibration signals and the propagation properties of ultrasound waves in a medium,the relationship between the vibration displacement and pressure causing the vibrations is established.Subsequently,by employing the dual-frequency optical heterodyne interferometric theory,the relationship between the photoacoustic signal-induced tissue surface vibration displacement and phase changes is established.Furthermore,I/Q quadrature demodulation is applied to process the photoacoustic signals;this ensures system stability and high demodulation accuracy in complex environments.To achieve all-optical detection of photoacoustic signals,an photoacoustic signal detection system is designed using a He-Ne laser as the detection light source.The optical components are configured t

关 键 词：生物光学 外差干涉 光声信号 I/Q正交法 非接触式探测 

分 类 号：TB57[理学—物理]