Crackles and instabilities during lung inflation

Adriano M. Alencar, Arnab Majumdar, Z. Hantos, Sergey V. Buldyrev, H. Eugene Stanley, Béla Suki

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

In a variety of physico-chemical reactions, the actual process takes place in a reactive zone, called the "active surface". We define the active surface of the lung as the set of airway segments that are closed but connected to the trachea through an open pathway, which is the interface between closed and open regions in a collapsed lung. To study the active surface and the time interval between consecutive openings, we measured the sound pressure of crackles, associated with the opening of collapsed airway segments in isolated dog lungs, inflating from the collapsed state in 120 s. We analyzed the sequence of crackle amplitudes, inter-crackle intervals, and low frequency energy from acoustic data. The series of spike amplitudes spans two orders of magnitude and the inter-crackle intervals spans over five orders of magnitude. The distribution of spike amplitudes follows a power law for nearly two decades, while the distribution of time intervals between consecutive crackles shows two regimes of power law behavior, where the first region represents crackles coming from avalanches of openings whereas the second region is due to the time intervals between separate avalanches. Using the time interval between measured crackles, we estimated the time evolution of the active surface during lung inflation. In addition, we show that recruitment and instabilities along the pressure-volume curve are associated with airway opening and recruitment. We find a good agreement between the theory of the dynamics of lung inflation and the experimental data which combined with numerical results may prove useful in the clinical diagnosis of lung diseases.

Original languageEnglish
Pages (from-to)18-26
Number of pages9
JournalPhysica A: Statistical Mechanics and its Applications
Volume357
Issue number1
DOIs
Publication statusPublished - Nov 1 2005

Fingerprint

Lung
Inflation
lungs
intervals
Interval
Avalanche
Spike
spikes
avalanches
Consecutive
Power Law
trachea
inflating
Closed
dogs
sound pressure
Chemical Reaction
Low Frequency
Pathway
chemical reactions

Keywords

  • Active surface
  • Avalanche
  • Cayley
  • Invasion percolation
  • Recruitment
  • Tree

ASJC Scopus subject areas

  • Mathematical Physics
  • Statistical and Nonlinear Physics

Cite this

Alencar, A. M., Majumdar, A., Hantos, Z., Buldyrev, S. V., Eugene Stanley, H., & Suki, B. (2005). Crackles and instabilities during lung inflation. Physica A: Statistical Mechanics and its Applications, 357(1), 18-26. https://doi.org/10.1016/j.physa.2005.05.047

Crackles and instabilities during lung inflation. / Alencar, Adriano M.; Majumdar, Arnab; Hantos, Z.; Buldyrev, Sergey V.; Eugene Stanley, H.; Suki, Béla.

In: Physica A: Statistical Mechanics and its Applications, Vol. 357, No. 1, 01.11.2005, p. 18-26.

Research output: Contribution to journalArticle

Alencar, AM, Majumdar, A, Hantos, Z, Buldyrev, SV, Eugene Stanley, H & Suki, B 2005, 'Crackles and instabilities during lung inflation', Physica A: Statistical Mechanics and its Applications, vol. 357, no. 1, pp. 18-26. https://doi.org/10.1016/j.physa.2005.05.047
Alencar, Adriano M. ; Majumdar, Arnab ; Hantos, Z. ; Buldyrev, Sergey V. ; Eugene Stanley, H. ; Suki, Béla. / Crackles and instabilities during lung inflation. In: Physica A: Statistical Mechanics and its Applications. 2005 ; Vol. 357, No. 1. pp. 18-26.
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