Rotger M, Farré R, Peslin R, Navajas D
Laboratori Biofísica i Bioenginyeria, Facultat de Medicina, Universitat de Barcelona, Spain.
J Appl Physiol (1985). 1995 Mar;78(3):938-47. doi: 10.1152/jappl.1995.78.3.938.
The aim of this work was to demonstrate that the three compartments of the lung T network and the chest wall impedance (Zcw) can be identified from input and transfer impedances of the respiratory system if the pleural pressure is recorded during the measurements. The method was tested in six healthy volunteers in the range of 8-32 Hz. The impedances resulting from the decomposition confirm the adequacy of the monoalveolar structure commonly used in healthy subjects. Indeed, the T shunt impedance is well modeled by a purely compliant element, the mean compliance [0.038 +/- 0.081 (SD) l/kPa], which coincides within 9.5 +/- 6.3% of the alveolar gas compressibility derived from thoracic gas volume (0.036 +/- 0.011 l/kPa). The results obtained provide experimental evidence that the alveolar gas compression is predominantly isothermal and that lung tissue impedance is negligible throughout the whole frequency range. The shape of Zcw is consistent with a low compliance-low inertance pathway in parallel with a high compliance-high inertance pathway. We conclude that the proposed method is able to reliably identify the T network featuring the lung and Zcw.
这项工作的目的是证明，如果在测量过程中记录胸膜压力，那么可以从呼吸系统的输入和传递阻抗中识别出肺T网络的三个部分以及胸壁阻抗（Zcw）。该方法在6名健康志愿者身上进行了8至32赫兹范围内的测试。分解得到的阻抗证实了健康受试者常用的单肺泡结构的适用性。实际上，T分流阻抗可以很好地用一个纯顺应性元件来建模，平均顺应性为[0.038±0.081（标准差）升/千帕]，这与从胸气体积得出的肺泡气体可压缩性[0.036±0.011升/千帕]在9.5±6.3%的范围内相符。所获得的结果提供了实验证据，表明肺泡气体压缩主要是等温的，并且在整个频率范围内肺组织阻抗可以忽略不计。Zcw的形状与一个低顺应性 - 低惯性通路和一个高顺应性 - 高惯性通路并联一致。我们得出结论，所提出的方法能够可靠地识别出以肺和Zcw为特征的T网络。
