Delavault E, Saumon G, Georges R
J Appl Physiol Respir Environ Exerc Physiol. 1982 Dec;53(6):1643-9. doi: 10.1152/jappl.1982.53.6.1643.
The usual impedance measurement by Fourier analysis leads to undetectable errors when applied to nonlinear fluid systems where a nonlinear pressure drop p = K X V2 adds to the linear pressure-flow relationship, but processing series of impedance data with various input levels allows the measurement of such systems. This new method has been tested on simulations, nonlinear resistances, and intubation tubings. It gives accurate estimates of the nonlinear coefficient K together with the true linear impedance of the measured system. This way, the usual respiratory impedance measurement may be applied to intubated patients, as the respiratory impedance of the subject can be separated from the nonlinear behavior of the endotracheal tube or cannula.
当应用于非线性流体系统时，通过傅里叶分析进行的常规阻抗测量会产生无法检测到的误差，在该系统中，非线性压降p = K×V²叠加到线性压力-流量关系上，但处理具有不同输入水平的一系列阻抗数据可以测量此类系统。这种新方法已在模拟、非线性电阻和插管上进行了测试。它能准确估计非线性系数K以及被测系统的真实线性阻抗。通过这种方式，常规的呼吸阻抗测量可应用于插管患者，因为受试者的呼吸阻抗可以与气管内导管或套管的非线性行为区分开来。
