• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control >Flow imaging with pulsed Doppler ultrasound and flow phantoms
【24h】

Flow imaging with pulsed Doppler ultrasound and flow phantoms

机译：脉冲多普勒超声和流动体模的流动成像

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The use of a multigate profiling system with steady laminar flow in plastic tubes revealed spectral artifacts not previously described. In particular, a double or split profile was often observed. In this paper, these artifacts are related to the dual mode ultrasound propagation in the plastic tube. The propagation speeds and, therefore, refraction angles and propagation paths are different for the longitudinal and the shear wave. The power transmission can be extraordinarily sensitive to small variations in the angle of incidence, and this may combine with the existence of a range of angles of incidence within any focused ultrasound beam to produce spectral distortions. The plastic tube is thus shown equivalent to a selective filter, which diminishes some frequency components in the Doppler spectrum relative to others. The spectral artifacts are explained in terms of the relative power transmitted by each mode, and the degree of beam defocusing experienced by each. Spectral distortions persist even when the beam-to-flow orientation is well away from the critical angle. The results of this study show that it is feasible to understand the acoustic transmission behavior of a flow phantom, based on a knowledge of the material properties, and to demonstrate the usefulness of doing so.
机译：在塑料管中使用具有稳定层流的多门分析系统，可以发现先前未描述的光谱伪影。特别地，经常观察到双重或分裂轮廓。在本文中，这些伪影与双模超声在塑料管中的传播有关。对于纵向波和剪切波，传播速度以及因此的折射角和传播路径是不同的。功率传输可能对入射角的微小变化异常敏感，并且这可能与任何聚焦超声束中一定范围的入射角的存在结合在一起，从而产生频谱失真。因此，示出的塑料管等效于选择性滤波器，其相对于其他滤波器减小了多普勒频谱中的某些频率分量。根据每种模式传输的相对功率以及每种模式经历的光束散焦程度来解释光谱伪影。即使当束流方向远离临界角时，光谱畸变仍然存在。这项研究的结果表明，基于对材料特性的了解，了解流动体模的声传输行为是可行的，并且证明这样做是有用的。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号