Determination of wave speed and wave separation in the arteries using diameter and velocity
Determination of wave speed and wave separation in the arteries using diameter and velocity
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DOI：
10.1016/j.jbiomech.2009.09.046
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发表时间：
2010-02-10
影响因子：
2.4
通讯作者：
Khir, A. W.
中科院分区：
文献类型：
--
作者：
Feng, J.;Khir, A. W.
通过同时测量压力(P)和速度(U)，建立了动脉波速的测定和前向波和后向波的分离。在这项工作中，我们提出了一种新的算法，通过同时测量直径(D)和U来确定局部波速和波的分离。这项工作的理论基础是求解弹性管中流动的I-D方程。导出了D和U之间的关系，由此可以确定局部波速：C=+/-0.5(Du(+/-)/Din D-+/-)。当只存在单向波时，这种关系描述了In D和U之间的线性关系。因此，构建In DU环应该导致在周期的早期部分产生一条直线，此时波最有可能正向移动。利用波速的这种知识，还可以推导出一组方程，以从测量的D和U波形中分离出前向波和后向波。一旦建立了D和U的向前和向后波形，我们就可以用类似于波强分析的方法来计算向前和向后波所携带的能量。在本文中，我们在体外测试了新的算法，并给出了在人的颈动脉和犬的升主动脉上测量的结果。我们的结论是，这项新技术可以在体外复制，也可以在不同物种的不同血管中体内复制。新的算法易于确定波速，并将D和U波形分离为其正向和反向。使用这项技术的优点是利用非侵入性测量，这将在临床环境中有用。(C)2009爱思唯尔有限公司。保留所有权利。
The determination of arterial wave speed and the separation of the forward and backward waves have been established using simultaneous measurements of pressure (P) and velocity (U). In this Work, we present a novel algorithm for the determination of local wave speed and the separation of waves using the simultaneous measurements of diameter (D) and U. The theoretical basis of this work is the solution of the I D equations of flow in elastic tubes. A relationship between D and U is derived, from which, local wave speed can be determined; C= +/- 0.5(dU(+/-)/dIn D-+/-). When only unidirectional waves are present, this relationship describes a linear relationship between In D and U. Therefore, constructing a In DU-loop should result in a straight line in the early part of the cycle when it is most probable that waves are running in the forward direction. Using this knowledge of wave speed, it is also possible to derive a set of equations to separate the forward and backward waves from the measured D and U waveforms. Once the forward and backward waveforms of D and U are established, we can calculate the energy carried by the forward and backward waves, in a similar way to that of wave intensity analysis. In this paper, we test the new algorithm in vitro and present results from data measured in the carotid artery of human and the ascending aorta of canine. We conclude that the new technique can be reproduced in vitro, and in different vessels of different species, in vivo. The new algorithm is easy to use to determine wave speed and separate D and U waveforms into their forward and backward directions. Using this technique has the merits of utilising noninvasive measurements, which would be useful in the clinical setting. (C) 2009 Elsevier Ltd. All rights reserved.