一种非线性呼吸力学模型及其参数估计

NONLINEAR MODEL OF RESPIRATORY MECHANICSAND ITS PARAMETER ESTIMATION

本文报道了一个非线性呼吸力学模型,该模型可以反映深呼吸过程中呼吸气体流率、跨肺压力及肺容积变化之间的动态关系。模型参数分别反映气道阻力状态及肺弹性特性。敏感度分析表明,该模型肺弹性参数估计值的准确度高于气道阻力。实验测定了10名被试者的呼吸气体流率、食道压力及肺容积。参数估计结果表明,动、静态肺弹性参数之间存在显著差异(P<0.01)。我们认为肺组织及肺泡表面活性物质的应力松驰机制是造成这种差异的主要原因。

<ABSTRACT> This paper reported a nonlinear model of respiratory mechanics in or- der to express dynamic relationship between respiratory flow rate, trans- pulmonary pressure and lung volume during a deep rcspiratory maneuver. Parameters in the model reflected the airway resistive state and the elas- ticity of the lung respectively. Sensitivity analysis showed that the esti- mates of lung clastic parameters by the model were much more precise than those of airway resistance parameter. Respiratory flow rate, (Continued on page 88) (Continued from page 105 ) esophageal pressure and lung volume were measured in 10 subjects for estima- ting the model parameters. The results indicated that significant differe- nce existed (p<0.01 ) between the dynamic and static lung elastic paramet- ers and the difference might be caused by stressrelaxation mechanism of lung tissue and alveolar surfactant.