Van der Ploeg C P, Dankelman J, Spaan J A
Laboratory for Measurement and Control, University of Technology Delft, The Netherlands.
Adv Exp Med Biol. 1994;345:299-304. doi: 10.1007/978-1-4615-2468-7_40.
By fitting of simulations with an oxygen exchange model to measured responses of the arteriovenous oxygen content difference after a flow step, coronary volumes can be estimated. In this study the dependence of the volume estimates on the choice of the oxygen exchange model for the coronary circulation was investigated. A model consisting of a single well-mixed compartment results in smaller volume estimates than a series array of mixed compartments in which PO2 declines gradually (Krogh-like model). Use of the former model for data analysis resulted in realistic volume estimates. Thus, these results indicate that the oxygen exchange vessels are better represented by a single mixed compartment than by a cylinder having Krogh characteristics. This conclusion agrees with capillary PO2 being equal to or smaller than venous PO2 which cannot be explained by a Krogh model. From these arguments we conclude that though both models are rough representations of the coronary circulation, the coronary O2 exchange vessels of the beating heart can be represented better by a single mixed compartment than by a series array of mixed compartments which has Krogh characteristics.
通过将模拟结果与氧交换模型进行拟合，以匹配流量阶跃后动静脉氧含量差的测量响应，可以估算冠状动脉容积。在本研究中，研究了容积估计值对冠状动脉循环氧交换模型选择的依赖性。由单个充分混合隔室组成的模型所得到的容积估计值，比PO₂逐渐下降的一系列混合隔室（类克罗格模型）所得到的容积估计值要小。使用前一种模型进行数据分析可得到实际的容积估计值。因此，这些结果表明，与具有克罗格特征的圆柱体相比，单个混合隔室能更好地代表氧交换血管。这一结论与毛细血管PO₂等于或小于静脉PO₂相符，而这是克罗格模型无法解释的。基于这些观点，我们得出结论，尽管这两种模型都是对冠状动脉循环的粗略描述，但与具有克罗格特征的一系列混合隔室相比，单个混合隔室能更好地代表跳动心脏的冠状动脉氧交换血管。
