A non linear dynamic morphometric model of the human lung, based on Weibel’s symmetrical model, was recently proposed for studying expiratory flow limitation (EFL) during mechanical ventilation in normal and obstructive conditions. The model is modified to study what happens when only a certain part of the lungs is affected by an obstructive pulmonary condition. In particular we consider the two main bronchi separately and, starting from each main bronchus, we divide each lung into two distinct regions with different geometrical and mechanical characteristics. In each region we assume that all branches of a certain generation are identical. The obstructive condition is characterized by increasing the respiratory zone resistance and by decreasing the airway section of deeper generations (from 8 to 16). We also changed the transmural pressure–diameter curves of these generations to account for easier collapsibility of these airways. The latter changes are applied to (a) the pathological region/s only or (b) all four regions. In case (a) we observed that EFL is not present until the pathology affects all the regions. In case (b) moderate EFL was evident even when only 25% of the lungs were involved and increased with increasing percentage of involvement. From this preliminary study, therefore, EFL seems to develop only if distinct parts of the conductive zone become significantly collapsible.

C. Brighenti, P. Barbini, G. Cevenini, G. Gnudi (2005). Expiratory flow limitation in mechanical ventilation: a model study of lung non-homogeneities. SOUTHAMPTON : WIT press.

Expiratory flow limitation in mechanical ventilation: a model study of lung non-homogeneities

BRIGHENTI, CHIARA;GNUDI, GIANNI
2005

Abstract

A non linear dynamic morphometric model of the human lung, based on Weibel’s symmetrical model, was recently proposed for studying expiratory flow limitation (EFL) during mechanical ventilation in normal and obstructive conditions. The model is modified to study what happens when only a certain part of the lungs is affected by an obstructive pulmonary condition. In particular we consider the two main bronchi separately and, starting from each main bronchus, we divide each lung into two distinct regions with different geometrical and mechanical characteristics. In each region we assume that all branches of a certain generation are identical. The obstructive condition is characterized by increasing the respiratory zone resistance and by decreasing the airway section of deeper generations (from 8 to 16). We also changed the transmural pressure–diameter curves of these generations to account for easier collapsibility of these airways. The latter changes are applied to (a) the pathological region/s only or (b) all four regions. In case (a) we observed that EFL is not present until the pathology affects all the regions. In case (b) moderate EFL was evident even when only 25% of the lungs were involved and increased with increasing percentage of involvement. From this preliminary study, therefore, EFL seems to develop only if distinct parts of the conductive zone become significantly collapsible.
2005
Modelling in Medicine and Biology VI
27
36
C. Brighenti, P. Barbini, G. Cevenini, G. Gnudi (2005). Expiratory flow limitation in mechanical ventilation: a model study of lung non-homogeneities. SOUTHAMPTON : WIT press.
C. Brighenti; P. Barbini; G. Cevenini; G. Gnudi
File in questo prodotto:
Eventuali allegati, non sono esposti

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/15549
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact