On the asymmetry of bifurcations in the bronchial tree

Phillips, C. G.; Kaye, S

doi:10.1016/s0034-5687(96)02506-6

Cited by 68 publications

(45 citation statements)

References 15 publications

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“…Weibel's symmetric model geometry is a representative anatomic airway model with averaged dimensions. Although most bronchial bifurcations are somewhat asymmetric [32] and non-planar, some studies [33,34] have shown that inspiratory flow in an asymmetric bifurcation exhibits the main features of the symmetric case.…”

Section: Upper Airway Geometrymentioning

confidence: 99%

Numerical analysis of respiratory flow patterns within human upper airway

et al. 2009

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A computational fluid dynamics (CFD) approach is used to study the respiratory airflow dynamics within a human upper airway. The airway model which consists of the airway from nasal cavity, pharynx, larynx and trachea to triple bifurcation is built based on the CT images of a healthy volunteer and the Weibel model. The flow characteristics of the whole upper airway are quantitatively described at any time level of respiratory cycle. Simulation results of respiratory flow show good agreement with the clinical measures, experimental and computational results in the literature. The air mainly passes through the floor of the nasal cavity in the common, middle and inferior nasal meatus. The higher airway resistance and wall shear stresses are distributed on the posterior nasal valve. Although the airways of pharynx, larynx and bronchi experience low shear stresses, it is notable that relatively high shear stresses are distributed on the wall of epiglottis and bronchial bifurcations. Besides, two-dimensional fluid-structure interaction models of normal and abnormal airways are built to discuss the flow-induced deformation in various anatomy models. TheThe project was supported by the

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Section: Upper Airway Geometrymentioning

confidence: 99%

Numerical analysis of respiratory flow patterns within human upper airway

et al. 2009

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“…The minor effects of cartilaginous rings (Martonen, Yang, & Xue, 1994), which may appear especially in the upper airways, and out-ofplane bifurcations have not been considered in the present analysis. Although most bronchial bifurcations are somewhat asymmetric (Horsfield, Dart, Olson, Filley, & Cumming, 1971;Philips & Kaye, 1997) and non-planar, some studies (Chang, 1989;Liu, So, & Zhang, 2003) have shown that inspiratory flow in an asymmetric bifurcation exhibits the main features of the equivalent symmetric case. Non-planar geometries only influence the flow in downstream bifurcations (Caro, Schroter, Watkins, Sherwin, & Sauret, 2002;Zhang & Kleinstreuer, 2002).…”

Section: Upper Airway Geometrymentioning

confidence: 99%

Comparison of micro- and nano-size particle depositions in a human upper airway model

Zhang¹,

Kleinstreuer²,

Donohue³

et al. 2005

Journal of Aerosol Science

280

167

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“…The actual path of the particle, i.e., through either the major or the minor daughter branch, is randomly selected from the¯ow splitting distribution based on cross-sectional area ratios Phillips and Kaye, 1997). As a consequence of the variability of the selected sequence of airways, all paths of inspired particles are different from each other, and so are the deposition probabilities in the individual airways (Note: by de®-nition, the same path is taken upon exhalation).…”

Section: Stochastic Particle Deposition Calculationsmentioning

confidence: 99%

Stochastic dose estimation for inhaled particulates

Hofmann¹

2000

Stochastic Environmental Research and Risk Assessment

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The inherent variability of morphological and physiological parameters can cause signi®cant statistical variations in the deposition patterns of inhaled particles in the human lungs. From a dosimetric point of view, the two major sources of variability are (i) the statistical distribution of particles deposited among all airways in a given generation, caused by the biological variability of the lung structure, and (ii) the local distribution of particles deposited within a given airway bifurcation resulting from the inhomogeneity of¯ow patterns and associated deposition mechanisms. Due to the stochastic nature of particle transport within the lungs in general, and within airway bifurcations in particular, this variability can be described mathematically by stochastic models. In addition to average values, stochastic models also provide information about the statistical distributions of deposition patterns, re¯ecting intra-and intersubject variability in particle deposition.

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On the asymmetry of bifurcations in the bronchial tree

Cited by 68 publications

References 15 publications

Numerical analysis of respiratory flow patterns within human upper airway

Numerical analysis of respiratory flow patterns within human upper airway

Comparison of micro- and nano-size particle depositions in a human upper airway model

Stochastic dose estimation for inhaled particulates

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