MRI: Development and Fabrication of a Novel Defocusing Ultrasonic Imaging Camera

号提案 CTS-0421568主要研究者： M.加里布，加州技术学院该基金将开发一种基于图像散焦概念的超声三维测速系统，该系统将为工程应用提供一种独特的工具，并导致对目前无法访问的许多重要工业和生物系统的更深入的科学理解。 许多环境、工业和生物流动发生在具有显著边界变形的三维、多相、非稳态复杂几何形状中。 一般来说，这些流是不可光学访问的。 为了研究这些流动，超声成像技术作为可以对不透明物体或流动进行成像的非侵入性方式，已经成为光学或潜在危险的X射线技术的首选方法。尽管超声成像提供了非常重要的优点，但它作为二维成像技术是有限的。 解决该缺陷的尝试涉及通过机械步进或旋转由一维或二维换能器产生的超声波束来扫描期望的体积，并且已经取得了有限的成功。 目前，市场上没有研究质量的仪器，可以促进动态体积映射在不透明的媒体。 所提出的超声版本的基本成像原理与其光学版本非常相似，后者已在加州理工学院开发并成功实施。 这种仪器的发展将产生一个实质性的一步，目前国家的最先进的超声动态容积成像。 研究工作的更广泛影响将是在实验流体力学领域提供新的研究和开发工具，为更深入的科学理解提供机会。 这些新发现将有助于开发和评估新型工业、环境和医疗设备。 特别是，该项目将具有临床影响，因为它将为心血管血流动力学研究以及多相流研究提供改进的范例。另一个重要的影响将是在计算流体力学的前沿，在所有雷诺数范围内的时间分辨三维流动信息是迫切需要的代码验证和新的亚网格尺度模型的测试。主要研究者将通过SURF（夏季本科生研究奖学金），MURF（少数民族本科生研究奖学金）和加州理工学院的勤工俭学计划参与本科生的研究活动。

Proposal No. CTS-0421568Principal Investigator: M. Gharib, California Inst. Of TechnologyThis grant is to develop an ultrasound 3-D velocimetry system based on the image-defocusing concept, which will provide a unique tool for engineering applications and lead to deeper scientific understanding of many important industrial and biological systems that are currently inaccessible. Many environmental, industrial and biological flows occur in three-dimensional, multi-phase, unsteady complex geometries with significant boundary deformation. In general these flows are not optically accessible. To study these flows, ultrasound imaging techniques as non-invasive modalities that can image opaque objects or flows have become methods of choice, over optical or potentially dangerous x-ray techniques. Despite the very important advantages that ultrasound imaging offers, it is limited as a two-dimensional imaging technique. Attempts to resolve this deficiency involve scanning of the desired volume by mechanically stepping or rotating the ultrasound beam generated by one or two-dimensional transducers, and have met with limited success. Currently, there is no research-quality instrumentation on the market that can facilitate dynamic volume mapping in opaque media. The basic imaging principles of the proposed ultrasound version are very similar to its optical counterpart, which has been developed and successfully implemented at Caltech. Such instrumentation development will yield a substantial step ahead of present state-of-the-art in ultrasound dynamic volumetric imaging. The broader impact of the research effort will be the availability of new research and development tools in the area of experimental fluid mechanics, providing the opportunity for a deeper scientific understanding. These new discoveries will enable development and evaluation novel industrial, environmental and medical devices. In particular, this project will have clinical impact, as it will provide improved paradigms for cardiovascular hemodynamic studies, as well as for multi-phase flow investigation. Another important impact will be at computational fluid mechanics forefront where time resolved 3-D flow information at all ranges of Reynolds number is badly needed for code validation and testing of new sub-grid scale models. The Principal Investigators will involve undergraduate students in their research activities through SURF (summer undergraduate research fellowship), MURF (minority undergraduate research fellowship) and work-study programs Caltech.