Construction of high-frequency ultrasonic nonlinear imaging system and its application to measurements and analyses

高频超声非线性成像系统的构建及其测量分析应用

• 批准号: 13650467
• 负责人: SAITO Shigemi
• 金额: $ 0.45万
• 依托单位: Tokai University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650467/
• 关键词: nonlinear acoustics; focused sound; nonlinearity parameter; acoustical microscope; nonlinear propagation; diffraction effect; acoustic imaging; harmonic imaging

The purpose of the present work is to realize an imaging system for the distribution of the acoustic nonlinearity parameter B/A in a small volume sample such as biological media utilizing a high frequency focused sound. The previously presented B/A measurement method was modified to be applicable to high frequencies, and its validity was experimentally demonstrated at relatively low frequencies first. For the modified method, a new focusing transducer was experimentally produced utilizing the partial inversion of polarization by heat treatment of LiNbO_3 plate in addition to the appropriately designed electrode pattern. By adapting a 30-point asteroid electrode twisted according to the radial distance with 36 deg maximum at the outer fringe, a Gaussian beam to facilitate the analysis can be radiated. The sending and receiving sensitivities with a Gaussian distribution with regard to the radial distance were obtained for the second order resonance as well as the first order resonance. B … More onding to the solid acoustic lens, a focused Gaussian beam was produced by this piezoelectric plate. Utilizing the transducer, the imaging system for the fundamental and second harmonic sounds was constructed. The sound wave emanated from the transducer set on an x-y stage was two dimensionally scanned, for instance, by 20x20 steps with an interval of 0.15 mm on the sample, which was closely set by vacuum suction on the optically polished end-surface of a tungsten rod. The sound transmitting through the sample before and after the reflection at the rod end was received. When the 3x3-mm^2 area of biological samples with 1-mm thickness was imaged, the amplitude of nonlinearly generated second harmonic sometimes differed in spite of the same fundamental amplitude. This suggests non-uniform distribution of the B/A value. Since the present system is not complete yet, the imaging of B/A must be realized by the reform. On the other hand, the imaging utilizing nonlinear component of the sound can be quite different from the images of linear component. This difference was discussed by analyzing the propagation of second harmonic sound, taking into consideration the enhanced nonlinearity and diffraction effect of the focused sound. The result showed that the phase shift accompanied by the diffraction could lead to the different images of the second harmonic sound from that of the fundamental. Less

本工作的目的是实现一个成像系统的声学非线性参数B/A的分布在一个小体积的样品，如生物介质利用高频聚焦声。对以前提出的B/A测量方法进行了修改，使其适用于高频，并首先在相对较低的频率下实验证明了其有效性。在改进的方法中，利用LiNbO_3片的热处理使极化部分反转，并设计了适当的电极图形，实验上制作了一种新的聚焦换能器。通过调整一个30点的小行星电极扭曲的径向距离与36度最大的外边缘，高斯光束，以促进分析可以辐射。得到了二阶谐振和一阶谐振时的发送和接收灵敏度随径向距离的高斯分布。B ...更多信息 在固体声透镜的作用下，利用压电片产生聚焦高斯光束。利用该换能器，构建了基波和二次谐波声成像系统。从设置在x-y台上的换能器发出的声波在样品上进行二维扫描，例如，通过20 × 20个步长，间隔为0.15 mm，样品通过真空抽吸紧密地设置在钨棒的光学抛光端面上。接收在杆端反射之前和之后通过样品传输的声音。当对厚度为1 mm的3 × 3 mm^2生物样品进行成像时，尽管基波振幅相同，但非线性产生的二次谐波振幅有时会不同。这表明B/A值的分布不均匀。由于现行的制度还不完善，B/A的形象必须通过改革来实现。另一方面，利用声音的非线性分量的成像可以与线性分量的图像完全不同。通过对二次谐波声传播的分析，考虑到聚焦声的非线性增强和衍射效应，讨论了这种差异。结果表明，衍射引起的相移会导致二次谐波的声象与基波的声象不同。少

项目成果

斎藤繁実, 岡田卓也, 小原孝之, 池上儀晃: "集束超音波を用いるB/A簡易測定法"電子情報通信学会技術研究報告. 102. 45-50 (2002)

Shigemi Saito、Takuy​​a Okada、Takayuki Ohara、Yoshiaki Ikegami：“使用聚焦超声的简单 B/A 测量方法”IEICE 技术研究报告。 102. 45-50 (2002)。

Shigemi Saito: "Detection of edge-diffracting second harmonic beam with a concave receiver"Acoustical Science and Technology. 23, No.1. 50-52 (2002)

Shigemi Saito：“用凹面接收器检测边缘衍射二次谐波光束”声学科学与技术。

斎藤繁実: "集束超音波を用いるB/A簡易測定法"電子情報通信学会技術研究報告. 102・67. 45-50 (2002)

Shigemi Saito：“使用聚焦超声波的简单B/A测量方法”IEICE技术研究报告102・67（2002）。

Shigemi Saito, Yoshinori Kameyama, Kiyoshi Nakamura: "Ultrasonic focusing Gaussian source to receive nonlinearly generated second harmonic sound by itself"Japanese Journal of Applied Physics. 40. 3664-3667 (2001)

Shigemi Saito、Yoshinori Kameyama、Kiyoshi Nakamura：“超声波聚焦高斯源自行接收非线性生成的二次谐波声音”日本应用物理学杂志。

Shigemi Saito, Takuya Okada, Takayuki Ohara and Yoshiaki Ikegami: "Simple B/A measurement using focused ultrasound"Technical Report of IECE. US2002-14. 45-50 (2002)

Shigemi Saito、Takuy​​a Okada、Takayuki Ohara 和 Yoshiaki Ikegami：“使用聚焦超声进行简单 B/A 测量”IECE 技术报告。