Beaver W L, Lamarra N, Wasserman K
J Appl Physiol Respir Environ Exerc Physiol. 1981 Dec;51(6):1662-75. doi: 10.1152/jappl.1981.51.6.1662.
A method has been developed for on-line breath-by-breath calculation of alveolar gas exchange by correcting the gas exchange measured at the mouth for changes in lung gas stores. The corrections are applied to the total lung gas exchange, which is found by directly subtracting expired from inspired volume of each gas. Corrections are made for both breath-to-breath changes in lung volumes and changes in alveolar gas concentrations. The lung volume correction term has the effect of reducing the large error sensitivity of O2 exchange that has, in the past, resulted from direct determination by total lung gas exchange. Error each gas. Corrections are made for both breath-to-breath changes in lung volumes and changes in alveolar gas concentrations. The lung volume correction term has the effect of reducing the large error sensitivity of O2 exchange that has, in the past, resulted from direct determination by total lung gas exchange. Error each gas. Corrections are made for both breath-to-breath changes in lung volumes and changes in alveolar gas concentrations. The lung volume correction term has the effect of reducing the large error sensitivity of O2 exchange that has, in the past, resulted from direct determination by total lung gas exchange. Error sensitivity analysis shows that the effect of inaccuracies due to errors in measuring gas flow or gas concentrations are similar in magnitude to those in the open-circuit method that has traditionally been used. The algorithm for alveolar gas exchange has been implemented in a computer program for on-line respiratory analysis alongside the open-circuit calculation of gas exchange at the mouth that has been used in out laboratory. By use of several experimental studies, it is shown that there are very apparent breath-to-breath differences between the gas exchange measured by the two methods. During metabolic and respiratory transients, these differences often have significant influence on interpretation of the underlying physiology.
已开发出一种方法，通过校正口腔测量的气体交换以考虑肺气体储存量的变化，来逐次呼吸在线计算肺泡气体交换。这些校正应用于总肺气体交换，总肺气体交换是通过直接用每种气体的吸气量减去呼气量来确定的。对肺容积的逐次呼吸变化和肺泡气体浓度变化都进行了校正。肺容积校正项具有降低过去因通过总肺气体交换直接测定导致的氧气交换误差敏感性的作用。对每种气体都进行了误差敏感性分析。对肺容积的逐次呼吸变化和肺泡气体浓度变化都进行了校正。肺容积校正项具有降低过去因通过总肺气体交换直接测定导致的氧气交换误差敏感性的作用。误差敏感性分析表明，由于气体流量或气体浓度测量误差导致的不准确效应，在大小上与传统使用的开路方法中的效应相似。肺泡气体交换算法已在一个用于在线呼吸分析的计算机程序中实现，该程序与我们实验室使用的口腔气体交换开路计算一起运行。通过几项实验研究表明，两种方法测量的气体交换在逐次呼吸之间存在非常明显的差异。在代谢和呼吸瞬变期间，这些差异常常对潜在生理学的解释产生重大影响。
