Non-Invasive Monitoring of Central Blood Pressure in Humans

描述（由申请人提供）：中心血压（BP）在生理学和临床上比外周血压更相关，尤其是在老龄化中。然而，外周BP波形可以通过导管插入术甚至非侵入性地更安全地测量。该项目的主要目标是建立一种从外周BP波形数学推导出中心BP波形的技术。虽然过去已经开发了这样的技术，但是它们基于以下假设：存在单个通用传递函数，该传递函数可以在任何生理条件下将任何对象的外周BP波形忠实地与中心BP波形相关联。因此，这些“广义传递函数”（GTF）技术不适应动脉树的受试者间和时间变异性，这是由于例如年龄相关的动脉顺应性差异和外周阻力的神经体液调节，因此容易出现严重的中心BP误差。在这个项目中，一种新的技术，它能够通过利用升主动脉血流量在舒张期可以忽略不计的事实，在测量时将外周BP与中心BP相关的传递函数与受试者的动脉参数相适应，将在人类中进行严格的研究，作为成功的动物试验的后续行动。具体目标是：（1）优化自适应传递函数（ATF）技术以应用于人类;（2）在人类中广泛验证该技术;以及（3）证明该技术上级先前的人类技术。为了实现这些特定目标，将分析现有数据，包括用于分析的无创外周BP波形和来自多种生理条件下大量不同受试者的参考中心BP波形。一部分数据将用于最大限度地提高ATF技术的准确性，并以其他方式增强其计算速度。这些数据同样将用于优化GTF技术和其他以前的相关技术。剩余数据将用于评价该技术的准确性和导出的中心BP的临床价值以及对分析的外周BP波形中的实际噪声的鲁棒性。然后将进行统计比较，以确定ATF技术的相对能力和任何限制。成功完成该项目后，将对ATF技术进行前瞻性患者测试，并最终改善临床实践中的BP监测。

DESCRIPTION (provided by applicant): Central blood pressure (BP) is physiologically and clinically more relevant than peripheral BP, especially in aging. However, peripheral BP waveforms can be measured more safely via catheterization and even non-invasively. The broad objective of this project is to establish a technique for mathematically deriving a central BP waveform from a peripheral BP waveform. While such techniques have been developed in the past, they are based on the assumption that a single, universal transfer function exists that can faithfully relate a peripheral BP waveform to a central BP waveform of any subject over any physiologic condition. These "generalized transfer functions" (GTF) techniques therefore do not adapt to the inter-subject and temporal variability of the arterial tree due to, for example, age-related arterial compliance differences and neuro-humoral modulation of peripheral resistance and are consequently prone to serious central BP error. In this project, a new technique, which is able to adapt the transfer function relating peripheral BP to central BP to the arterial parameters of the subject at the time of measurement by exploiting the fact that ascending aortic blood flow is negligible during diastole, will be rigorously investigated in humans as a follow-up to successful animal testing. The specific aims are: (1) to optimize the adaptive transfer function (ATF) technique for application in humans; (2) to broadly validate the technique in humans; and (3) to demonstrate that the technique is superior to previous techniques in humans. To accomplish these specific aims, existing data comprising non-invasive peripheral BP waveforms for analysis and reference central BP waveforms from a large number of diverse subjects under multiple physiologic conditions will be analyzed. A portion of the data will be used to maximize the accuracy of the ATF technique and enhance it in other ways including augmenting its computational speed. These data will likewise be used to optimize GTF techniques and other previous, related techniques. The remaining data will be used to evaluate the techniques in terms of accuracy and clinical value of the derived central BP as well as robustness to actual noise in the analyzed peripheral BP waveforms. Statistical comparisons will then be performed to establish the relative capabilities and any limitations of the ATF technique. Successful completion of this project will be followed by prospective patient testing of the ATF technique and may ultimately lead to improved BP monitoring in clinical practice.