Pythoud F, Stergiopulos N, Meister J J
Biomedical Engineering Laboratory, Swiss Federal Institute of Technology, Lausanne, Switzerland.
Technol Health Care. 1995 Dec;3(3):201-7.
A nonlinear method has been developed to separate arterial pressure and flow waves into their forward and backward running components. It takes into account nonlinearities arising from the area-pressure relationship as well as convective acceleration. The method is based on the treatment of the Riemann invariants and requires measurements of pressure, flow and diameter at one arterial location. The method has been successfully tested by means of a simulation experiment in which the forward and backward waves were known a priori. It was shown that the new method is significantly more accurate in the predictions of the forward and backward waves when compared to the classical linear method. The new wave separation method was then applied to simulated aortic waves for a) a healthy subject and b) a subject with decreased compliance. Comparison with the classical linear method showed that neglecting nonlinearities leads to an overestimation of the forward and backward pressure wave amplitudes of the order of 5 to 10%.
已开发出一种非线性方法，可将动脉血压和血流波分离为向前和向后传播的分量。该方法考虑了面积 - 压力关系以及对流加速度所产生的非线性。该方法基于对黎曼不变量的处理，并且需要在一个动脉位置测量压力、流量和直径。该方法已通过模拟实验成功测试，在该实验中，向前和向后的波是先验已知的。结果表明，与经典线性方法相比，新方法在预测向前和向后的波时明显更准确。然后将新的波分离方法应用于模拟的主动脉波，分别针对a）健康受试者和b）顺应性降低的受试者。与经典线性方法的比较表明，忽略非线性会导致向前和向后压力波振幅高估5%至10%。
