Assessment of respiratory mechanical properties with constant-phase models in healthy and COPD lungs

作者：Ionescu Clara^*; Derom Eric; De Keyser Robin

来源：Computer Methods and Programs in Biomedicine, 2010, 97(1): 78-85.

DOI：10.1016/j.cmpb.2009.06.006

• Input respiratory impedance
• Constant-phase model
• Parametric identification
• Respiratory mechanics
• Forced oscillations

This study employs the concept of applying constant-phase models to input respiratory impedance data obtained with the non-invasive Forced Oscillation Technique (FOT) lung function test. Changes in respiratory mechanics from healthy and chronic obstructive pulmonary disease (COPD) diagnosed patients are observed with a four- and a five-parameter constant-phase model. Tissue damping (p << 0.01), tissue elastance (p < 0.02) and tissue hysteresivity (p << 0.01) are calculated from the identified model parameters, providing significant separation between healthy and COPD groups. Limitations of the four-parameter constant-phase model are shown in relation to frequency-dependent impedance values within the range 4-48 Hz. The results clearly show that the five-parameter constant-phase model outperforms the four-parameter constant-phase model in this frequency range. The averaged error is 0.02 and 0.04 for healthy subjects in the five-parameter and four-parameter constant-phase models, respectively. The results show that the identified model values are sensitive to variations between healthy and COPD lungs.

• 出版日期2010-1