Calvet J H, Louis B, Giry P, Harf A, Isabey D
Centre d'Etudes du Bouchet, Vert Le Petit, France.
Respir Physiol. 1996 Jul;104(2-3):241-50. doi: 10.1016/0034-5687(96)00018-7.
The forced oscillation technique is a widely-used non-invasive method of characterizing the dynamic behaviour of the respiratory system. We used the forced oscillation technique to investigate respiratory mechanics in healthy subjects during simulated dives in dry hyperbaric chambers. We observed frequency dependence of input impedance, which was mainly density-dependent. To explain this result, we propose a model of the respiratory system, based on flow redistribution in a two-pathway circuit. This model, using the electrical analogue, is composed of two Resistance-Self Inductance-Capacitance (R-I-C) pathways set up in parallel. It allowed us to explain the dynamic behaviour of respiratory impedance under hyperbaric conditions in healthy subjects. Changes in respiratory impedance according to frequency vary with the relative importance of the inequalities of the two time constants RC and I/R between the two pathways. With low values of density, RC inequality predominates, whereas I/R inequality tends to predominate with high values of density.
强迫振荡技术是一种广泛应用的用于表征呼吸系统动态行为的非侵入性方法。我们使用强迫振荡技术在干燥高压舱模拟潜水期间研究健康受试者的呼吸力学。我们观察到输入阻抗的频率依赖性，其主要取决于密度。为了解释这一结果，我们基于双通路回路中的流量重新分布提出了一个呼吸系统模型。该模型使用电气类比，由两条并联的电阻-自感-电容（R-I-C）通路组成。它使我们能够解释健康受试者在高压条件下呼吸阻抗的动态行为。呼吸阻抗随频率的变化取决于两条通路之间两个时间常数RC和I/R的不等式的相对重要性。在低密度值时，RC不等式占主导，而在高密度值时，I/R不等式趋于占主导。
