During slow inflation of lung lobes, we measure a sequence of short explosive transient sound waves called "crackles," each consisting of an initial spike followed by ringing. The crackle time series is irregular and intermittent, with the number of spikes of size s following a power law, n(s)proportional to s(-alpha), with alpha = 2.77 +/- 0.05. We develop a model of crackle wave generation and propagation in a tree structure that combines the avalanchelike opening of airway segments with the wave propagation of crackles in a tree structure. The agreement between experiments and simulations suggests that (i) the irregularities are a consequence of structural heterogeneity in the lung, (ii) the intermittent behavior is due to the avalanchelike opening, and (iii) the scaling is a result of successive attenuations acting on the sound spikes as they propagate through a cascade of bifurcations along the airway tree. [S1063-651X(99)13810-8].

Scaling behavior in crackle sound during lung inflation / A. Alencar, Z. Hantos, F. Petak, J. Tolnai, T. Asztalos, S. Zapperi, J. Andrade, S. Buldyrev, H. Stanley, B. Suki. - In: PHYSICAL REVIEW E. - ISSN 1063-651X. - 60:4B(1999 Oct 01), pp. 4659-4663.

Scaling behavior in crackle sound during lung inflation

S. Zapperi;
1999

Abstract

During slow inflation of lung lobes, we measure a sequence of short explosive transient sound waves called "crackles," each consisting of an initial spike followed by ringing. The crackle time series is irregular and intermittent, with the number of spikes of size s following a power law, n(s)proportional to s(-alpha), with alpha = 2.77 +/- 0.05. We develop a model of crackle wave generation and propagation in a tree structure that combines the avalanchelike opening of airway segments with the wave propagation of crackles in a tree structure. The agreement between experiments and simulations suggests that (i) the irregularities are a consequence of structural heterogeneity in the lung, (ii) the intermittent behavior is due to the avalanchelike opening, and (iii) the scaling is a result of successive attenuations acting on the sound spikes as they propagate through a cascade of bifurcations along the airway tree. [S1063-651X(99)13810-8].
Wave-form analysis; avalanches
Settore FIS/02 - Fisica Teorica, Modelli e Metodi Matematici
Settore FIS/03 - Fisica della Materia
1-ott-1999
Article (author)
File in questo prodotto:
File Dimensione Formato  
PhysRevE.60.4659.pdf

accesso aperto

Tipologia: Publisher's version/PDF
Dimensione 82.04 kB
Formato Adobe PDF
82.04 kB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

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/2434/656549
Citazioni
  • ???jsp.display-item.citation.pmc??? 4
  • Scopus 24
  • ???jsp.display-item.citation.isi??? 23
social impact