Real Time Multi-Component Blood FLow Velocimetry

描述(由申请人提供)：开发一种实时非侵入性方法来测量血流的多种成分将对许多心血管、神经、肾脏和放射学应用非常有用。目前，获取多个血流速度分量的唯一方法是通过MRI相速度映射技术，该技术繁琐、耗时且时间分辨率有限。此外，MRI相速度图及其各种对应的技术不是实时技术。我们最近开发了一种基于超声的粒子图像测速技术，在测量复杂的血流模式方面显示出了希望。这种方法被称为ECHO-PIV，它利用超声造影剂微泡在射频域分析的非线性后向散射特性来区分单个微泡，然后随着时间的推移跟踪这些微泡以获得局部速度矢量。我们已经开发了软件算法来分析这些信息，并从体外和体内研究中获得了有希望的数据。该方法现在需要优化并在硬件中实现，以形成实时非侵入式测速方法。我们在超声和多普勒成像方面的经验，实验流体动力学，包括开发和使用各种光学PIV系统，以及与超声行业的长期关系，使该项目非常有可能令人满意地完成。本项目的具体目标是：1)利用微气泡后向散射的数值模拟来研究不同的驱动条件(频率、脉冲形状、脉冲长度、功率等)。将最大化气泡的非线性响应，从而提高ECHO PIV算法的精度。2)在最大限度地满足上述两种临床应用的要求的基础上，组装硬件组件以实现实时ECHO PIV成像系统。3)以基于激光的光学粒子图像测速仪为对比标准，采用体外模型对样机成像系统进行测试。

DESCRIPTION (provided by applicant): The development of a real-time non-invasive method to measure the multiple components of blood flow would be enormously useful for a number of cardiovascular, neurological, renal, and radiological applications. Currently, the only means of obtaining multiple blood velocity components is through MRI phase velocity mapping techniques, which are cumbersome, time-consuming, and limited in temporal resolution. Furthermore, MRI phase velocity mapping and its various counterparts are not real-time techniques. We have recently developed an ultrasound-based particle image velocimetry technique that has shown promise in the measurement of complex blood flow patterns. This method, termed echo-PIV, takes advantage of the non-linear backscatter characteristics of ultrasound contrast micro bubbles analyzed in the RF domain to distinguish individual micro bubbles, which are then tracked over time to obtain the local velocity vector. We have developed software algorithms to analyze this information and have obtained promising data from in vitro and in vivo studies. The method now requires optimization and implementation into hardware to form a real-time non-invasive velocimetry method. Our experience with ultrasound and Doppler imaging, experimental fluid dynamics including the development and use of a variety of optical PIV systems, and long-standing relationship with the ultrasound industry, make the satisfactory completion of this project highly probable. The specific aims of this project are: 1) Use numerical modeling of backscatter from micro bubbles to study which driving conditions (frequency, pulse shape, pulse length, power, etc.) will maximize the non-linear response of the bubbles and thereby increase the accuracy of the echo PIV algorithm. 2) Assemble the hardware components to implement the real-time echo PIV imaging system, based on maximizing the specifications for the two clinical applications described above. 3) Test the prototype imaging system using in vitro models with laser-based optical particle image velocimetry as the standard for comparison.