ULTRASONIC INSTRUMENTATION FOR CARDIOVASCULAR STUDIES

该项目的目标是开发、评估和利用几个 超声波技术在测量血流、心功能、 急性和慢性仪器化动物的心肌血流灌注 心血管疾病的模型，以及患者在期间和之后的情况 心血管外科和器官移植。具体项目 主要有：1)继续发展超声波置换技术 技术，通过优化它来检测心脏的增厚和直径 较小的动物，如老鼠和老鼠。这将补充压力和 多普勒血流测量，现在在有意识的，长期可行的 仪器大鼠，并允许更多类型的心血管研究 在小动物模型中完成。2)研制了一种心外膜传感器，用于 使用回声造影剂和超声心动图测量心肌灌注 指示剂稀释原则。这项技术将直接应用于 动物实验作为放射性微球的替代或补充。 许多必要的验证工作也将适用于量化 人体的血流灌注成像。3)继续申请 人体局部左心室功能测量的位移技术 手术后。心外膜上会加一个多普勒晶体 增稠传感器可同时测量下层的速度 天然冠状动脉。4)继续适用可提取的 用于人体术后血流监测的多普勒血流传感器。这个 应用范围将从冠状动脉旁路移植中的流量测量扩展到 测量成人移植器官的流量和心输出量 孩子们。5)完善了一种多普勒环耦合方法。 消除经皮引线的位移传感器。这将会有 在长期研究中使用慢性仪器的即时应用 动物及其未来在人类中永久使用的潜在应用 植入式流量传感器。6)所有新设备都将集成在一起 在这项资助下开发的模块化超声波测量系统 这样就可以进行心肌血流、功能和血流灌注测量 同时在一个给定的实验中。例如，心内膜VS 心外膜增厚和灌注可在几个月内测量到 使用多用途心外膜传感器进行心肌定位 冠状动脉血流传感器检测回声造影的血流和通过 将是量化绝对和的输入函数所需的度量 相对灌注量。

The goal of this project is to develop, evaluate, and utilize several ultrasonic techniques in the measurement of blood flow, cardiac function, and myocardial perfusion in acute and chronically instrumented animal models of cardiovascular disease, and in patients during and after cardiovascular surgery and organ transplantation. The specific projects are: 1) To continue the development of the ultrasonic displacement technique by optimizing it to sense ventricular thickening and diameter in smaller animals such as rats and mice. This will complement pressure and Doppler flow measurements which are now feasible in conscious, chronically instrumented rats and permit more types of cardiovascular studies to be done in small animal models. 2) To develop an epicardial sensor for myocardial perfusion measurements utilizing echo-contrast agents and indicator dilution principles. This technique will be applied directly to animal studies as a replacement for or adjunct to radioactive microspheres. Much of the necessary validation work will apply as well to quantitative perfusion imaging in man. 3) To continue the application of the displacement technique to the measurement of regional LV function in man postoperatively. A Doppler crystal will be added to the epicardial thickening sensor to measure velocity simultaneously in an underlying native coronary artery. 4) To continue the application of the extractable Doppler flow sensor for postoperative monitoring of blood flow in man. The applications will be expanded from measuring flow in coronary bypass grafts to measuring flow to transplanted organs and cardiac output in adults and children. 5) To perfect a loop coupling method for Doppler and displacement sensors to eliminate percutaneous leads. This will have immediate applications in long-term studies using chronically instrumented animals and potential future applications in man for use with permanently implantable flow sensors. 6) All of the new devices will be integrated into the modular ultrasonic measurement system developed under this grant so that myocardial flow, function, and perfusion measurements can be made simultaneously in a given experiment. For example, endocardial vs epicardial thickening and perfusion will be measurable at several myocardial locations using multipurpose epicardial sensors while the volume flow and passage of echo-contrast sensed by a coronary artery flow sensor will be a measure of the input function needed to quantify absolute and relative perfusion.