Epstein R A, Reznik A M, Epstein M A
Respir Physiol. 1980 Jul;41(1):127-36. doi: 10.1016/0034-5687(80)90028-6.
A mathematical model was developed to predict the distortions in the measured expiratory CO2 concentration time profile caused by catheter sampling systems. Parameters considered included the expiratory flow and concentration profiles, the sample flow rate, the sample tube dimensions and the sample cell volume. Unless care is taken in choosing the parameters of a catheter sampling system, particularly in the presence of low expiratory flow rates and short expiratory times, the CO2 concentration profile may be severely distorted. In worst case situations end tidal CO2 plateaux may not be recognized or alternately artifactual plateaux may be produced. Sample flow rate and sample cell volume are the most important parameters while distortion within the sample tube itself is relatively less important.
开发了一个数学模型，以预测导管采样系统导致的呼气二氧化碳浓度时间曲线测量值中的失真情况。考虑的参数包括呼气流量和浓度曲线、采样流速、采样管尺寸和采样池体积。除非在选择导管采样系统参数时格外小心，尤其是在呼气流量低和呼气时间短的情况下，否则二氧化碳浓度曲线可能会严重失真。在最坏的情况下，呼气末二氧化碳平台期可能无法识别，或者可能会产生人为的平台期。采样流速和采样池体积是最重要的参数，而采样管本身内部的失真相对不太重要。
