van den Aardweg J G, Kezic S, Bosch J A, Monster A C
Department of Pulmonology, Leiden University Medical Center, University of Amsterdam, The Netherlands.
IEEE Trans Biomed Eng. 2001 Jul;48(7):772-86. doi: 10.1109/10.930902.
In this paper, it was investigated if the ventilation-perfusion distribution can be estimated from the uptake (U) of inert gases with different solubilities during the single-breath maneuver. A model was implemented that describes U as a function of solubility for inhomogeneously distributed alveolar volume (VA) versus blood and tissue volume (Q + VTIS). The VA/(Q + VTIS) distribution describes the relative contribution of gas-exchange units with different VA/(Q + VTIS) ratios to the expiratory volume. U was derived as the sum of uptakes corresponding to different modes in the distribution, weighted with the relative contribution to the expiratory volume. This permits an estimation of the distribution parameters by fitting U as a function of solubility. The n alkanes were used because of their different solubilities. Analysis of the sensitivity of the estimated VA/(Q + VTIS) distribution parameters to measurement errors showed that mostly two modes can be discerned. The influence of fixed model parameters appeared relatively small. The model could well explain U in normal and emphysematous subjects, with a larger contribution of high VA/(Q + VTIS) ratios in the emphysematous subjects. It was concluded that the VA/(Q + VTIS) distribution can be estimated noninvasively from single-breath alkane uptake.
本文研究了在单次呼吸动作期间，是否可以根据不同溶解度的惰性气体摄取量（U）来估计通气-灌注分布。实施了一个模型，该模型将U描述为肺泡体积（VA）与血液和组织体积（Q + VTIS）不均匀分布时溶解度的函数。VA/（Q + VTIS）分布描述了具有不同VA/（Q + VTIS）比率的气体交换单元对呼气量的相对贡献。U被推导为分布中对应于不同模式的摄取量之和，并根据对呼气量的相对贡献进行加权。这允许通过将U拟合为溶解度的函数来估计分布参数。使用正构烷烃是因为它们具有不同的溶解度。对估计的VA/（Q + VTIS）分布参数对测量误差的敏感性分析表明，大多可以辨别出两种模式。固定模型参数的影响相对较小。该模型可以很好地解释正常受试者和肺气肿受试者的U，肺气肿受试者中高VA/（Q + VTIS）比率的贡献更大。得出的结论是，可以从单次呼吸烷烃摄取量无创地估计VA/（Q + VTIS）分布。
