Tsoukias N M, Dabdub D, Wilson A F, George S C
Department of Chemical and Biochemical Engineering and Materials Science, 916 Engineering Tower, University of California, 92697-2575, Irvine, CA, USA.
Respir Physiol. 2000 May;120(3):251-71. doi: 10.1016/s0034-5687(00)00104-3.
The diffusing capacity of the lung, DL, is a critical physiological parameter, yet the currently accepted clinical model (Jones-Meade) assumes a well-mixed alveolar region, and a constant DL independent of alveolar volume, VA, despite experimental evidence to the contrary. We have formulated a new mathematical model [Tsoukias, N.M, Wilson, A.F., George, S.C., 2000. Respir. Physiol. 120, 231-249] that considers variable alveolar mixing through a single parameter, k (0<k<1), and a DL that is a positive function of VA (DL=a+bVA or DL=alphaVA(beta)). The goal of this study is to determine the suitability of this model to determine the unknown parameters a, b, alpha, beta, and k from experimental data in normal subjects. The model predicts that the normal lung fills, in part, sequentially (k=0.51+/-0.35). The following average values in all seven subjects were obtained: DLNO=48.VA(2/3) ml/min/mmHg and DLCO=20+0.7.VA ml/min/mmHg (STPD) where VA is expressed in L (STPD). We conclude that the mathematical model is suitable for identifying the unknown parameters and thus can be used to characterize the degree of alveolar mixing (or sequential filling) as well as the volume dependence of DL.
肺的弥散能力（DL）是一个关键的生理参数，然而目前被广泛接受的临床模型（Jones-Meade模型）假定肺泡区域充分混合，且DL与肺泡容积（VA）无关，为常数，尽管有实验证据表明情况并非如此。我们构建了一个新的数学模型[Tsoukias, N.M, Wilson, A.F., George, S.C., 2000. Respir. Physiol. 120, 231 - 249]，该模型通过一个单一参数k（0<k<1）来考虑肺泡混合的变化，以及一个DL是VA的正函数（DL = a + bVA或DL = alphaVA(beta)）。本研究的目的是确定该模型从正常受试者的实验数据中确定未知参数a、b、alpha、beta和k的适用性。该模型预测正常肺部分地按顺序充盈（k = 0.51±0.35）。在所有七名受试者中获得了以下平均值：DLNO = 48.VA(2/3) ml/min/mmHg和DLCO = 20 + 0.7.VA ml/min/mmHg（标准温度和压力干燥），其中VA以升（标准温度和压力干燥）表示。我们得出结论，该数学模型适用于识别未知参数，因此可用于表征肺泡混合程度（或顺序充盈）以及DL对容积的依赖性。
