VERY HIGH FREQUENCY (VHF) DIFFRACTIVE TRANSDUCERS FOR BLOOD FLOW MEASUREMENTS

该项目的目标是开发一种准确的方法， 使用小型、扁平、一次性传感器测量血流， 放置在血管上或血管附近。 这种新方法 与角度无关的多普勒速度确定需要衍射 换能器，其平面可以平行于流动定向。 超声多普勒方法现在广泛用于医学， 测量和绘制血流。 所有高端超声波扫描仪 具有多普勒和多普勒成像能力。 的问题 多普勒技术是从多普勒频移中提取速度 是角度相关的，并且角度难以估计。 作为 结果，误差可高达50%。 这种新方法可以提供一个 解决这个长期存在的问题。 衍射传感器具有 在5至25 MHz的频率范围内制造并使用 结合Echocath为动物开发仪器， 患者研究。 传感器性能的有限元模拟也 被执行。

Tho objective of the project is to develop an accurate method for measuring blood flow using small, flat, disposable sensors that can be placed on or near the blood vessel. This new method of angle-independent Doppler velocity determination requires diffractive transducers, whose plane can be oriented parallel to the flow. Ultrasonic Doppler methods are now widely used in medicine for measuring and mapping blood flow. All high end ultrasonic scanners have Doppler and Doppler imaging capabilities. The problem with Doppler techniques is that the velocity extracted from Doppler shift is angle dependent and the angle is difficult to estimate. As a result, the error can be as large as 50%. This new method may offer a solution to this long standing problem. Diffractive transducers have been fabricated in the frequency range form 5 to 25 MHz range and used in conjunction with an instrument developed at Echocath for animal and patient studies. FEA simulation of transducer performance has also been carried out.