Continuous Cardiac Output Monitoring with a Central Venous Catheter Ultrasound Sensor

项目总结 这项研究的目标是开发一种创新的设备，以改善重症监护患者的治疗： 中心静脉导管(CVC)将使用独特的 多普勒超声技术。危重病患者连续监测一氧化碳将改变现代 重症监护，允许临床医生根据每个患者的情况随时指导临床护理 个体病理生理学。提议的转型技术不会增加任何额外风险，几乎不会增加任何增量 成本，同时有可能成为700万条中心线中许多线路的标准护理 每年仅在美国。 心输出量是非常理想的测量方法，但目前还没有连续的心输出量测量方法。 已成为重症监护病房公认的护理标准的系统。这是由于存在安全风险 有创方法，如Swan-Ganz导管或非侵入性或间接方法的不准确性。这个 我们提出的系统将直接测量升主动脉的心输出量，使用一种新型的双光束侧向测量系统. 中心静脉外表面涂布的直视衍射光栅多普勒超声换能器 导管。如前所述，这个系统不会增加ICU中已经有CVC的患者的额外风险 插入并定位在上腔静脉(SVC)内。 这项研究的创新方面包括1)使用多普勒换能器测量动脉血流 相邻静脉(在这种情况下，从SVC内两者所在的位置在升主动脉中流动 对位--但在动脉-静脉配对出现的地方可能有用)；2)应用独特的柔性压电聚合物 将薄膜超声多普勒衍射栅换能器安装在中心静脉导管上；3)使用两个这样的 用于消除多普勒血流测量(即导管运动)中导管角度影响的多普勒换能器 在上腔静脉内，由脉动的血流、病人的运动等引起)。多普勒信号将是 用于指示和确定导管在SVC内的正确位置。《公约》的具体目标 建议的研究包括： 目标1：设计并制作可测量的双波束薄膜多普勒换能器阵列 在SVC中自由摆动时主动脉中的血流，这是一种血管对血管的测量 史无前例的配置。现有的多普勒电子设备将进行改造，以适应新的导管。 目标2：验证由AIM I生成的系统至少与肺动脉导管(SWAN-R)一样准确 Ganz导管)在模拟放置中心线的解剖结构的流动模体中测试时。 目的3：在活体猪模型中演示混合中心线/心输出量装置易于定位， 安全，至少与同时使用的PAC、在线通过时间流量计和 经食道监护仪。

PROJECT SUMMARY The goal of this research is to develop an innovative device to improve patient treatment in intensive care: a central venous catheter (CVC) that will provide continuous measurement of cardiac output (CO) using a unique Doppler ultrasound technology. Continuous measurements of CO in critically ill patients will transform modern intensive care, by allowing clinicians to direct clinical care moment-to-moment in each patient based on their individual pathophysiology. The proposed transformational technology adds no added risk and little incremental cost, while having the potential to become the standard of care for many of the seven million central lines placed annually in the USA alone. Cardiac output is a highly desired measurement, yet there are no continuous cardiac output measurement systems that have become accepted standards of care in intensive care units. This is due to safety risks from invasive methods such as the Swan-Ganz catheter or the inaccuracy of non-invasive or indirect methods. The system we propose will directly measure cardiac output in the ascending aorta using a novel, double-beam, side- looking diffraction-grating Doppler ultrasound transducer coated on the external surface of a central venous catheter. As noted earlier, this system will add no additional risk for patients in the ICU who already have a CVC inserted and positioned within the superior vena cava (SVC). Innovative aspects of this research include 1) Measuring arterial flow using a Doppler transducer in an adjacent vein (in this case, flow in the ascending aorta from a position within the SVC where the two are in apposition -- but potentially useful wherever artery-vein pairs occur); 2) Applying unique flexible piezopolymer thin-film ultrasound Doppler diffraction-grating transducers onto a central venous catheter; 3) Using two such Doppler transducers to cancel the effect of catheter angle in Doppler flow measurements (i.e., catheter motion within the superior vena cava caused by pulsatile blood flow, patient motion, etc.). The Doppler signals will be used to indicate and establish the correct position of the catheter within the SVC. The Specific Aims of the proposed research are: Aim 1: Design and fabricate double-beam thin-film Doppler transducer arrays designed to be able to measure blood flow in the aorta while swinging freely in the SVC, a blood vessel-to-blood vessel measurement configuration that is unprecedented. Existing Doppler electronics will be modified for the new catheters. Aim 2: Validate that the system resulting from Aim I is at least as accurate as Pulmonary Artery Catheters (Swan- Ganz catheters) when tested in flow phantoms that mimic the anatomy where central lines are placed. Aim 3: Demonstrate in living porcine models that a hybrid central line/cardiac output device is easily positioned, safe, and at least as accurate and precise as a simultaneously used PAC, in-line transit-time flowmeter and transesophageal monitors.