Experimental evaluation of local wave speed in the presence of reflected waves
Experimental evaluation of local wave speed in the presence of reflected waves
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DOI：
10.1016/j.jbiomech.2013.10.007
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发表时间：
2014-01-03
影响因子：
2.4
通讯作者：
Khir, Ashraf W.
中科院分区：
文献类型：
--
作者：
Borotti, Alessandra;Li, Ye;Khir, Ashraf W.
波速度（也称为脉搏波速度）是扰动沿介质沿着行进的速度，并且其取决于血管的机械和几何性质以及血液的密度。波速是一个与临床相关的参数，因为它是动脉僵硬度和心血管疾病的指标，这项工作的目的是比较在台架实验中确定局部波速的不同方法，并调查它们在存在反射时的相对准确性。压力（P）沿沿着柔性管在三个正反射位置和三个负反射位置附近测量流量（Q）和直径（D）。使用PU环、（InD）U环、QA环、（DP）-P-2环、平方和特性阻抗法计算波速。结果进行了比较，脚到脚的方法。我们发现，远离反射，几乎所有的方法得到统一的结果。在接近正反射时，依赖P和Q（或U）的方法高估了波速值，而基于D（或A）和Q（或U）的方法低估了波速值。相反，在接近负反射时，依赖P和Q（或U）的方法低估了波速值，而基于D（或A）和Q（或U）的方法高估了它，（DP）-P-2环似乎不受正反射或负反射的影响，目前用于确定局部波速的方法大多受反射的影响，但是（InD）U形环仍然是临床上最容易使用的技术。(C)2013爱思唯尔有限公司保留所有权利。
Wave speed (also called pulse wave velocity) is the speed by which disturbance travels along the medium and it depends on the mechanical and geometrical properties of the vessel and on the density of the blood. Wave speed is a parameter of clinical relevance because it is an indicator of arterial stiffness and cardiovascular diseases.The aim of this work is to compare different methods for the determination of local wave speed in bench experiments and investigate their relative accuracy when reflections are present.Pressure (P), flow (Q) and diameter (D) were measured along a flexible tube far and close to three positive and three negative reflection sites. Wave speed was calculated using PU-loop, (lnD)U-loop, QA-loop, (DP)-P-2-loop, sum of squares and characteristic impedance methods. Results were compared to the foot-to-foot method.We found that far from the reflections almost all methods give uniform results. Close to positive reflections the methods that rely on P and Q (or U) overestimate the wave speed value, while techniques based on D (or A) and Q (or U) underestimate it. On the contrary, close to negative reflections the methods that rely on P and Q (or U) underestimate the wave speed value, while techniques based on D (or A) and Q (or U) overestimate it. The (DP)-P-2-loop does not seem to be affected by positive or negative reflections.Most of the methods currently used to determine local wave speed are affected by reflections, but the (lnD)U-loop remains the easiest technique to use in the clinic. (C) 2013 Elsevier Ltd. All rights reserved.