Kapitan K S, Wagner P D
J Appl Physiol (1985). 1987 Apr;62(4):1356-62. doi: 10.1152/jappl.1987.62.4.1356.
The defining equations of the multiple inert gas elimination technique are underdetermined, and an infinite number of VA/Q ratio distributions exists that fit the same inert gas data. Conventional least-squares analysis with enforced smoothing chooses a single member of this infinite family whose features are assumed to be representative of the family as a whole. To test this assumption, the average of all ventilation-perfusion ratio (VA/Q) distributions that are compatible with given data was calculated using a linear program. The average distribution so obtained was then compared with that recovered using enforced smoothing. Six typical sets of inert gas data were studied. In all sets but one, the distribution recovered with conventional enforced smoothing closely matched the structure of the average distribution. The single exception was associated with the broad log-normal VA/Q distribution, which is rarely observed using the technique. We conclude that the VA/Q distribution conventionally recovered approximates a simple average of all compatible distributions. It therefore displays average features and only that degree of fine structural detail that is typical of the family as a whole.
多惰性气体消除技术的定义方程是欠定的，并且存在无数种通气/血流比值（VA/Q）分布能拟合相同的惰性气体数据。采用强制平滑的传统最小二乘法分析会从这个无穷集合中选择一个单一成员，其特征被假定为代表整个集合。为了检验这个假设，使用线性规划计算了与给定数据兼容的所有通气/血流比值（VA/Q）分布的平均值。然后将如此得到的平均分布与使用强制平滑恢复的分布进行比较。研究了六组典型的惰性气体数据。除了一组数据外，在所有其他组中，通过传统强制平滑恢复的分布与平均分布的结构紧密匹配。唯一的例外与宽对数正态VA/Q分布相关，使用该技术很少观察到这种分布。我们得出结论，传统恢复的VA/Q分布近似于所有兼容分布的简单平均值。因此，它显示出平均特征，并且只显示出整个集合所特有的那种精细结构细节程度。
