General fractal-discrete scheme for high-frequency lung sound production.
A general scheme is proposed to explain the observed spectral properties of high-frequency human respiratory sounds in terms of the interaction between the respiratory flux and a bronchial tree of fractal properties. The air flux is treated as composed of discrete decoupled elements while the tree is assumed to have a Cantor-based geometry. According to this model, the affine behavior often observed in the high-frequency (log-log) spectral range is a direct consequence of the fractal geometry of the bronchial tree in both qualitative and quantitative aspects. This strongly indicates that the dynamics underlying the high-frequency sound generation must have at most nondominant couplings between the relevant fluid components.
De Oliveira
L P L
LP
Centro de Ciências Exatas e Tecnológicas, Universidade do Vale do Rio dos Sinos, UNISINOS, São Leopoldo, RS, Brazil.
Bodmann
B E J
BE
Faistauer
D
D
D003198:Computer Simulation; D005583:Fourier Analysis; D017709:Fractals; D008168:Lung / Q000502:physiology*; D008954:Models, Biological; D012135:Respiratory Sounds / Q000502:physiology*; D012212:Rheology / Q000379:methods*