Chiari L, Avanzolini G, Ursino M
Department of Electronics, Computer Science, and Systems, University of Bologna, Italy.
Ann Biomed Eng. 1997 Nov-Dec;25(6):985-99.
A comprehensive model of oxygen (O2) and carbon dioxide (CO2) exchange, transport, and storage in the adult human is presented, and its ability to provide realistic responses under different physiological conditions is evaluated. The model comprises three compartments (i.e., lung, body tissue, and brain tissue) and incorporates a controller that adjusts alveolar ventilation and cardiac output dynamically integrating stimuli coming from peripheral and central chemoreceptors. A new realistic CO2 dissociation curve based on a two-buffer model of acid-base chemical regulation is included. In addition, the model explicitly considers relevant physiological factors such as buffer base, the nonlinear interaction between the O2 and CO2 chemoreceptor responses, pulmonary shunt, dead space, variable time delays, and Bohr and Haldane effects. Model simulations provide results consistent with both dynamic and steady-state responses measured in subjects undergoing inhalation of high CO2 (hypercapnia) or low O2 (hypoxia) and subsequent recovery. An analysis of the results indicates that the proposed model fits the experimental data of ventilation and gas partial pressures as some meaningful simulators now available and in a very large range of gas intake fractions. Moreover, it also provides values of blood concentrations of CO2, HCO3-, and hydrogen ions in good agreement with more complex simulators characterized by an implicit formulation of the CO2 dissociation curve. In the experimental conditions analyzed, the model seems to represent a single theoretical framework able to appropriately describe the different phenomena involved in the control of respiration.
本文提出了一个关于成年人氧气（O₂）和二氧化碳（CO₂）交换、运输及储存的综合模型，并评估了其在不同生理条件下给出实际响应的能力。该模型包含三个隔室（即肺、身体组织和脑组织），并纳入了一个控制器，该控制器通过动态整合来自外周和中枢化学感受器的刺激来调节肺泡通气和心输出量。其中包含基于酸碱化学调节双缓冲模型的新的实际CO₂解离曲线。此外，该模型明确考虑了相关生理因素，如缓冲碱、O₂和CO₂化学感受器反应之间的非线性相互作用、肺分流、死腔、可变时间延迟以及波尔效应和哈代效应。模型模拟结果与吸入高CO₂（高碳酸血症）或低O₂（低氧血症）及随后恢复的受试者的动态和稳态响应均一致。结果分析表明，所提出的模型在很大的气体吸入分数范围内，与现有的一些有意义的模拟器一样，能够拟合通气和气体分压的实验数据。此外，它还能给出与以隐含CO₂解离曲线形式表示的更复杂模拟器相符的CO₂、HCO₃⁻和氢离子的血浓度值。在所分析的实验条件下，该模型似乎代表了一个单一的理论框架，能够恰当地描述呼吸控制中涉及的不同现象。
