Non-Invasive Monitoring of Central Blood Pressure in Humans

描述(申请人提供)：中心血压(BP)在生理和临床上比外周血压更相关，特别是在年龄增长时。然而，通过插管可以更安全地测量周围血压波形，甚至可以无创地测量。该项目的主要目标是建立一种用于从外围BP波形数学推导出中心BP波形的技术。虽然在过去已经开发了这种技术，但它们是基于这样的假设，即存在单一的通用传递函数，该传递函数可以在任何生理条件下将任何对象的外周BP波形与中心BP波形忠实地联系起来。因此，由于与年龄相关的动脉顺应性差异和外周阻力的神经体液调节，这些“广义传递函数”(GTF)技术不适应动脉树的对象间和时间的变异性，因此容易出现严重的中央BP误差。在这个项目中，一种新的技术，通过利用舒张期升主动脉血流可以忽略不计的事实，能够使外周血压和中心血压之间的传递函数适应测量时受试者的动脉参数，作为成功的动物试验的后续行动，将在人类中进行严格的研究。具体目标是：(1)优化自适应传递函数(ATF)技术在人类中的应用；(2)在人类身上广泛验证该技术；以及(3)证明该技术在人类上优于以前的技术。为了实现这些特定的目的，将分析包括用于分析的非侵入性周围血压波形和参考来自多种生理条件下的大量不同受试者的中心血压波形的现有数据。部分数据将用于最大限度地提高ATF技术的准确性，并以其他方式增强它，包括提高其计算速度。这些数据同样将被用于优化GTF技术和其他以前的相关技术。剩余的数据将用于评估所获得的中心血压的准确性和临床价值以及对分析的外周血压波形中的实际噪声的稳健性。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。该项目成功完成后，将对ATF技术进行预期的患者测试，并最终可能在临床实践中改善血压监测。

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.