ULTRASOUND HYDROPHONE AND ITS CALIBRATION UP TO 100 MHz

超声波水听器及其高达 100 MHz 的校准

• 批准号: 6529948
• 负责人: Peter A. Lewin
• 金额: $ 23.49万
• 依托单位: DREXEL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-30 至 2004-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6529948
• 关键词: bioimaging /biomedical imaging; biomedical equipment development; clinical biomedical equipment; fiber optics; sound frequency; ultrasonography

DESCRIPTION (Provided by Applicant): This work proposes development and implementation of acoustic and optic measurement methods capable of determining absolute sensitivity of miniature ultrasonic hydrophone probes over a wide, 100 M}Iz bandwidth. Absolutely calibrated probes are needed to determine and monitor acoustic output of ultrasound imaging devices, which presently account for about 30 percent of all imaging procedures. Although a majority of clinical imaging is performed at frequencies less than 15 MHz, due to the nonlinear propagation effect in tissue, which constitutes the basis of harmonic imaging, diagnostic pulses can have spectral content from 100 kHz to 100 MHz. Also catheter based systems routinely use frequencies beyond 20 MHz. Moreover, to properly measure mechanical bioeffects exposure index (MI) and to comply with regulatory guidelines, the hydrophone probes should be calibrated in the frequency range extending to 8 times center frequency of the imaging transducer. In addition, dermatological, ophthalmological and pre-clinical applications of ultrasound utilize imaging transducers in the frequency range 20-100 MHz. However, currently used calibration technology is usually limited to approximately 20 MHz and therefore, there is a need for research and development of high frequency calibration techniques capable of determining frequency response of the miniature ultrasound hydrophone probes. In the United States, the national laboratory traceable data are limited to approximately 21 MHz and are available at discrete frequencies only. The outcome of this work will facilitate characterization of high frequency medical ultrasonic fields and assessment of the safety of diagnostic ultrasound devices operating at frequencies beyond 20 MHz or containing harmonics in the signal due to nonlinear propagation phenomena. Globally, no reference laboratory succeeded so far in providing virtually continuous calibration data that are expected to be available as the result of this research. The proposed research will also provide a tool to calculate Mechanical and Thermal Indices in case of conventional 3-12 MHz equipment operating at high pressure amplitudes. The indices are widely accepted as predictors of potential bioeffects. Also, the results of this research are applicable to design and optimization of ultrasound imaging transducers. PIs have succeeded in fabricating fiber optic tips having diameters equal to a fraction of a wavelength at 100 MHz and are hopeful that these fiber optic probes will be suitable to replace piezoelectric hydrophones in measurements where spatial averaging errors are unacceptable.

描述（由申请人提供）：这项工作提出了能够确定的声学和光学测量方法的开发和实施 微型超声水文探针的绝对灵敏度在宽100 m} iz带宽。 需要绝对校准的探针来确定和监视声学 超声成像设备的输出，目前约为30个 所有成像程序的百分比。虽然大多数临床成像是 由于非线性传播，以小于15 MHz的频率进行 在组织中的效果，构成谐波成像，诊断的基础 脉冲可以具有从100 kHz到100 MHz的光谱含量。也基于导管 系统通常使用20 MHz以上的频率。而且，适当测量 机械生物效应暴露指数（MI）并遵守调节 指南，应在频率范围内校准水水探针 延伸到成像传感器的中心频率的8倍。此外， 超声的皮肤病学，眼科和临床前应用 在20-100 MHz的频率范围内利用成像传感器。然而， 目前使用的校准技术通常限制在大约20个 MHz，因此，需要研究和发展高 能够确定的频率校准技术 微型超声水文探针。在美国，国家 实验室可追溯数据仅限于大约21 MHz，可用 仅在离散频率下。 这项工作的结果将有助于高频表征 医疗超声领域和评估诊断超声的安全性 以超过20 MHz的频率运行的设备或在 由于非线性传播现象而引起的信号。全球，没有参考 到目前为止，实验室成功地提供了几乎连续的校准数据 这项研究的结果预计将获得。提议 研究还将提供计算机械和热指标的工具 如果传统的3-12 MHz设备在高压下运行 振幅。这些指数被广泛接受为潜在的预测指标 生物效应。此外，这项研究的结果适用于设计和 优化超声成像传感器。 PIS成功了 制造直径等于一小部分的光纤尖端 波长为100 MHz，希望这些光纤探针将是 适用于在空间的测量中替换压电坦语 平均错误是不可接受的。