ULTRASOUND EXPOSIMETRY USING LIQUID CRYSTAL PLATES

使用液晶板的超声波曝光测量

• 批准号: 3499029
• 负责人: JASWINDER SINGH SANDHU
• 金额: $ 5万
• 依托单位: SANTEC SYSTEMS, INC.
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-08-01 至 1994-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3499029
• 关键词: biomedical equipment development; dosage; imaging /visualization /scanning; liquid crystal; radiation detector; ultrasonography

Liquid crystal-based sonosensitive plates will be investigated for rapid determination of spatial distributions of temporal average intensities for diagnostic ultrasound beams, including real-time imaging and Doppler modes. From such distributions, exposure parameters such as SPTA (spatial peak-temporal average) and SATA (spatial average-temporal average) can be determined. In this approach, ultrasonic field is visualized directly on the plate as the liquid crystal molecules are reoriented by the ultrasonic field from their initial unidirectional orientation. Then, an electric field is applied to restore the orientation of the molecules. The magnitude of the restoring electric field is then used to determine the sonographic exposure parameters. The approach offers several advantages over presently used hydrophone and radiation force balance methods. For example, image of the cross-sectional field distribution is available at once. Moreover, the distribution of temporal average intensity over the plane perpendicular to the propagation axis is available at once from the electric field data. In comparison, the hydrophone method is cumbersome as point-by-point detection of a large number of sample points is needed to determine field distribution. The radiation force balance method, on the other hand, requires an elaborate set-up and provides no information on the spatial distribution of the ultrasonic field.

基于液晶的声敏板将被研究用于快速检测。 时间平均强度的空间分布的测定 诊断超声束，包括实时成像和多普勒 modes. 根据这样的分布，可以确定曝光参数，例如SPTA（空间 峰值-时间平均）和SATA（空间平均-时间平均）可以被 测定 在这种方法中，超声场直接在 当液晶分子被超声波重新定向时， 从最初的单向定向。 然后，一个电动 施加电场以恢复分子的取向。 的 恢复电场的大小然后用于确定 超声暴露参数。 这种方法有几个优点 而不是目前使用的水听器和辐射力平衡方法。 为 例如，横截面场分布的图像可在 一次 此外，时间平均强度的分布在 垂直于传播轴的平面可立即从 电场数据相比之下，水听器方法是繁琐的， 需要大量样本点的逐点检测 确定场分布。 辐射力平衡法， 另一方面，需要一个精心设计的设置，并提供任何信息， 超声场的空间分布。