基于鲁棒水听器特征参数反演的HIFU脉冲波形重建研究

High intensity focused ultrasound (HIFU) is among the national strategic emerging industries. The precise measurement of ultrasound field parameters is essential to ensure the accuracy and safety of ultrasound therapy. The HIFU pulse waveform distortion caused by the robust hydrophone used for field characterization is the bottleneck restricting the accurate measurement of the ultrasound field parameters. Therefore, this project proposes a pulse waveform reconstruction method based on the inversion of characteristic parameters of the robust hydrophone. By establishing the complex frequency response characterization model of robust hydrophones based on pulse excitation and laser heterodyne interference, the method explores whether it satisfies the physical mechanism of the minimum phase system, and lays a theoretical foundation for the realization of HIFU pulse waveform reconstruction. By studying the formation mechanism of nonlinear spatial averaging effect of robust hydrophones, a broadband directivity measurement model is established to provide experimental guarantee for characterization and decoupling of complex frequency response. By analyzing the measurement mechanism of robust hydrophones, the decoupling model for the complex frequency response and nonlinear spatial averaging effect is established to achieve accurate reconstruction of the HIFU pulse waveform. The project will provide essential theoretical reserve and technical support for the accurate measurement of HIFU field parameters based on robust hydrophones.

高强度聚焦超声(HIFU)是国家战略性新兴产业，其声场参数的精准计量对保障超声治疗准确性和安全性至关重要。声场定征用鲁棒水听器引起HIFU脉冲波形畸变是制约声场参数精准计量的瓶颈。因此，本项目提出一种基于鲁棒水听器特征参数反演的脉冲波形重建方法。该方法通过研究基于激光外差干涉的鲁棒水听器复频响应定征模型，验证其是否满足最小相位系统的物理机制，为实现HIFU脉冲波形重建奠定理论基础；通过研究鲁棒水听器非线性空间平均效应形成机制，建立宽带指向性解算方法，为实现复频响应定征及解耦提供测量数据；通过分析鲁棒水听器测量机理，建立复频响应和非线性空间平均效应解耦模型，从而实现HIFU脉冲波形精准重建。该项目将为实现基于鲁棒水听器的HIFU声场参数精准计量，提供重要的理论储备与技术支撑。

高强度聚焦超声(HIFU)是国家战略性新兴产业，其声场参数的精准计量对保障治疗超声准确性和安全性至关重要。声场定征用鲁棒水听器引起HIFU脉冲波形畸变是制约声场参数精准计量的瓶颈。本项目针对上述瓶颈问题，开展了基于鲁棒水听器特征参数反演的HIFU波形重建研究，取得的研究成果包括：.(1) 提出了鲁棒水听器复频响应定征方法，建立基于脉冲激励和激光外差干涉的复频响应测量装置，脉冲峰峰值声压高于50 MPa，测量频率覆盖330 kHz ~ 80 MHz；.(2) 提出了鲁棒水听器非线性空间平均效应解算方法，建立激光超声源和指向性测量装置；.(3) 探究了鲁棒水听器特征参数对HIFU脉冲波形的影响规律及作用机理，HIFU脉冲波形畸变受复频响应和非线性空间平均效应耦合影响，两特征参数对脉冲波形的影响可通过分离变量法予以修正，其中峰值正/负声压、机械指数、脉冲声强积分等声场参数测量不确定度优于4% (k=1)。.项目通过研究鲁棒水听器脉冲波形精准重建的方法，可有效保障医疗超声设备输出剂量的准确性和安全性。项目的实施对保障国家声学计量体系的完善、参与治疗声场定征等国际标准的制定具有重要意义；同时，对服务高强度治疗超声、超声碎石仪等战略性新兴产业临床应用，打破相关超声医疗器械国际市场准入门槛具有重要推动作用。