Martonen T B, Wilson A F
J Math Biol. 1982;14(2):203-20. doi: 10.1007/BF01832845.
Absorption of gas from alveoli is examined in a simplified model of the respiratory system during a stylized single breath consisting of constant inspiratory flow, constant expiratory flow, and breathholding. The equations describing gas behavior are general since they are based upon conservation of mass. The equations simplify considerably when gases that are not soluble in pulmonary tissue and/or blood are utilized. In a three-compartment model, diffusing capacity of the lung for carbon monoxide (DCO) will be underestimated except when both uneven distribution of lung volume and DCO are present; under most circumstances, the standard clinical 10-s method [9] is at least as accurate as any other. When pulmonary capillary blood flow (Qc) is calculated by the one point method [2] in a one-compartment lung, it is underestimated; in the three-compartment model, it is underestimated except when both uneven distribution of Qc and lung volume are present. The multiple single breath method [2] accurately measures DCO and Qc. Measurement of pulmonary tissue volume is improved by correcting the value of the intercept of acetylene absorption to the time when carbon monoxide apparently began rather than utilizing the beginning of inspiration.
在一个简化的呼吸系统模型中，对一次程式化单呼吸（包括恒定吸气流量、恒定呼气流量和屏气）过程中肺泡气体吸收情况进行了研究。描述气体行为的方程具有通用性，因为它们基于质量守恒。当使用不溶于肺组织和/或血液的气体时，这些方程会大大简化。在三室模型中，除非同时存在肺容积分布不均和一氧化碳弥散能力（DCO）不均的情况，否则肺对一氧化碳的弥散能力会被低估；在大多数情况下，标准临床10秒法[9]至少与其他任何方法一样准确。当在单室肺中通过单点法[2]计算肺毛细血管血流量（Qc）时，会被低估；在三室模型中，除非同时存在Qc分布不均和肺容积分布不均的情况，否则也会被低估。多次单呼吸法[2]能准确测量DCO和Qc。通过将乙炔吸收截距的值校正到一氧化碳明显开始吸收的时间，而不是利用吸气开始时间，可改善肺组织容积的测量。
