ULTRASONIC INSTRUMENTATION FOR CARDIOVASCULAR STUDIES

该项目的目标是开发、评估和利用几个 超声技术在测量血流，心脏功能， 急性和慢性仪器动物的心肌灌注 心血管疾病模型，以及在患者治疗期间和治疗后 心血管手术和器官移植。 具体项目 主要有：1）继续发展超声位移 技术，通过优化它来感知心室增厚和直径， 更小的动物，如大鼠和小鼠。 这将补充压力， 多普勒血流测量，现在是可行的，在有意识的，慢性 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)开发一种心外膜传感器， 利用回波造影剂的心肌灌注测量， 指示剂稀释原理。 这项技术将直接应用于 作为放射性微球的替代或辅助的动物研究。 许多必要的验证工作也适用于定量分析。 3）继续应用灌注成像技术， 位移法测定人体左室局部功能 手术后。 将在心外膜上添加多普勒晶体 增厚传感器，用于同时测量底层中的速度 自体冠状动脉 4)继续使用可浸提物 多普勒血流传感器用于人体术后血流监测。 应用范围将从测量冠状动脉旁路移植术中的流量 测量成人移植器官的血流和心输出量， 孩子 5)为了完善多普勒和 位移传感器，以消除经皮导线。 这将具有 在长期研究中的直接应用， 动物和潜在的未来应用在人类永久使用 植入式流量传感器 6)所有的新设备都将被集成到 在此资助下开发的模块化超声波测量系统 从而可以进行心肌血流、功能和灌注测量 同时在实验中。 例如， 心外膜增厚和灌注将是可测量的， 使用多用途心外膜传感器进行心肌定位， 由冠状动脉流量传感器感测的回波造影剂的流量和通过 将是量化绝对值所需的输入函数的度量， 相对灌注

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.