The influence of breathing patterns on particle deposition in a nasal replicate cast

Häußermann, S.; Bailey, A.G.; Bailey, Michael R.; Etherington, G.; Youngman, M. J.

doi:10.1016/s0021-8502(02)00044-7

Cited by 61 publications

(44 citation statements)

References 14 publications

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“…Other studies have highlighted the physical importance of tidal breathing, 27 effects of physical activities, 27 airway wall motion, 28 and nasal valve collapse. 29 Environmental aerosols are mostly non-spherical, 30 interacting among themselves, 31 and undergo size changes due to hygroscopic effects 32 or coagulation.…”

Section: Limitationsmentioning

confidence: 99%

Growth of Nasal and Laryngeal Airways in Children: Implications in Breathing and Inhaled Aerosol Dynamics

Zhou

et al. 2013

Respir Care

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BACKGROUND:The human respiratory airway undergoes dramatic growth during infancy and childhood, which induces substantial variability in air flow pattern and particle deposition. However, deposition studies have typically focused on adult subjects, the results of which cannot be readily extrapolated to children. We developed models to quantify the growth of human nasallaryngeal airways at early ages, and to evaluate the impact of that growth on breathing resistance and aerosol deposition. METHODS: Four image-based nasal-laryngeal models were developed from 4 children, ages 10 days, 7 months, 3 years, and 5 years, and were compared to a nasallaryngeal model of a 53-year-old adult. The airway dimensions were quantified in terms of different parameters (volume, cross-section area, and hydraulic diameter) and of different anatomies (nose, pharynx, and larynx). Breathing resistance and aerosol deposition were computed using a highfidelity fluid-particle transport model, and were validated against the measurements made with the 3-dimensional models fabricated from the same airway computed tomography images. RESULTS: Significant differences in nasal morphology were observed among the 5 subjects, in both morphology and dimension. The turbinate region appeared to experience the most noticeable growth during the first 5 years of life. The nasal airway volume ratios of the 10-day, 7-month, 3-year, and 5-year-old subjects were 6.4%, 18.8%, 24.2%, and 40.3% that of the adult, respectively. Remarkable inter-group variability was observed in air flow, pressure drop, deposition fraction, and particle accumulation. The computational fluid dynamics predicted pressure drops and deposition fractions were in close agreement with in vitro measurements. CONCLUSIONS: Age effects are significant in both breathing resistance and micrometer particle deposition. The image/computational-fluid-dynamics coupled method provides an efficient and effective approach in understanding patient-specific air flows and particle deposition, which have important implications in pediatric inhalation drug delivery and respiratory disorder diagnosis.

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Section: Limitationsmentioning

confidence: 99%

Growth of Nasal and Laryngeal Airways in Children: Implications in Breathing and Inhaled Aerosol Dynamics

Zhou

et al. 2013

Respir Care

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“…In the studies of replicate cast (Swift 1991;Häußermann et al 2002), particles were drawn online from the generation source through the cast and the inhalation efficiency was assumed to be 100%. Due to the large particle sizes in the current study, the inhalation efficiency of particles in a relatively calm air condition, where gravity plays a more important role, should be considered.…”

Section: Calibration Of Inhalation Efficiencymentioning

confidence: 99%

“…Numerous studies on the removal efficiency of inhaled particles in the nasal region have been performed in the past decades, by using either replicate casts or human volunteers (Hounam et al 1969;Lippman 1977;Stahlhofen et al 1989;Cheng et al 1991;Swift 1991;Zwartz and Guilmette 2001;Häußermann et al 2002;Moskal et al 2006;Storey-Bishoff et al 2008;Garcia et al 2009;Liu et al 2010). Many empirical equations were also developed to characterize the deposition efficiency in this region (Pattle 1961;Cheng 2003;Kelly et al 2004;Kim and Hu 2006).…”

Section: Introductionmentioning

confidence: 99%

In-Vivo Measurements of Micrometer-Sized Particle Deposition in the Nasal Cavities of Taiwanese Adults

Hsu

Chuang

2012

Aerosol Science and Technology

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It has been observed that Asians and Caucasians possess considerably different craniofacial features, which may affect the anatomical structure of the upper respiratory tract and, consequently, the characteristics of particle deposition. Most deposition studies on the human respiratory tract were primarily based on a limited number of Caucasian subjects. Therefore, data of the particle deposition efficiency in the upper respiratory tract of Asians are needed to supplement the understanding of the deposition characteristics in the human respiratory tract. This study measured the nasal deposition efficiency of particles ranging from 0.5 to 20 µm in five Taiwanese male and four Taiwanese female adults under different inspiratory flow rates. The measured deposition efficiency showed a very large intersubject variability in the inertial parameters, ranging between 10 3 to 5 × 10 4 µm 2 cm 3 /s, and the deposition efficiency of the subjects with similar values of the minimum nasal cross-sectional area approaches to each other. This study showed that Taiwanese adults have lower nasal deposition efficiency than Caucasians, and that the differences in the nostril shape, inclination of nostrils, and nasal hair density between the two ethnic groups are likely the causes. In addition, this study suggested that up to 15% of overestimation in the nasal deposition efficiency for larger particles may occur if the inhalation efficiency is not considered. An empirical equation adopting inspiratory flow rate and the minimum nasal cross-sectional area was developed to predict the nasal particle deposition in the upper airway of Taiwanese adults.

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“…The breathing frequency in infants is much higher than adults and is apparently responsible for the increased importance of unsteadiness in infants. Haussermann et al (2002) found unsteadiness to be important at high breathing frequency in adults for micron-sized particles.…”

Section: Deposition Of Ultrafine Aerosols In Infant Nasal Airwaysmentioning

confidence: 94%

“…A mass flow meter (Model 4140, TSI, Inc., St. Paul, MN, USA) was used for recording tidal breathing patterns. Periodic patterns were used since previous researchers have shown differences in total deposition of particles during tidal and steady flow through airway replicas at an equal average velocity (Haussermann et al 2002;Shi et al 2006). Only the inhalation half of the breathing pattern was used.…”

Section: Methodsmentioning

confidence: 99%

Deposition of Inhaled Ultrafine Aerosols in Replicas of Nasal Airways of Infants

Golshahi

Finlay

Olfert

et al. 2010

Aerosol Science and Technology

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Experimentally measured deposition of ultrafine particles, ranging from 13-100 nm in diameter, in nasal airway replicas of ten infants aged 3-18 months is presented. The replicas included the face, nostrils, and nasal airways including the upper trachea. A differential mobility analyzer (DMA) and a condensation particle counter (CPC) were used to quantify the nasal deposition by comparing the number of polydisperse sodium chloride particles, generated by evaporation from a Collison atomizer, at the inlet and outlet of the replicas. Particles were individually classified in size by DMA and subsequently were counted one size bin at a time by CPC upstream and downstream of each replica. Since in vivo data is not available for infants to compare to, we validated our experimental procedure instead by comparing deposition in nasal airway replicas of six adults with in vivo measurements reported in literature. In the infant replicas, tidal inhalation was simulated at two physiologically compatible flow rates and the effect of flow rate on deposition was found to be small. Deposition obtained at constant flow rates is lower than with tidal breathing, indicating the importance of unsteadiness, in contrast to similar data in adults where unsteadiness is known to be unimportant. An empirical equation, containing geometrical features of the nasal airways in the form of related non-dimensional dynamical parameters (Reynolds, Schmidt, and Womersley numbers), was best fitted to the infant data. This equation may be useful for a priori prediction of nasal deposition and intersubject variability during exposure of infants to ultrafine aerosols.

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The influence of breathing patterns on particle deposition in a nasal replicate cast

Cited by 61 publications

References 14 publications

Growth of Nasal and Laryngeal Airways in Children: Implications in Breathing and Inhaled Aerosol Dynamics

Growth of Nasal and Laryngeal Airways in Children: Implications in Breathing and Inhaled Aerosol Dynamics

In-Vivo Measurements of Micrometer-Sized Particle Deposition in the Nasal Cavities of Taiwanese Adults

Deposition of Inhaled Ultrafine Aerosols in Replicas of Nasal Airways of Infants

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