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

Abstract

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.

Detailed micro-particle deposition patterns in the human nasal cavity influenced by the breathing zone

“…For consistency with the reported experimental and numerical data, particles were released uniformly from the nostrils using the 'nasal-only' model. For inertial parameter less than 10 4 , the numerical result shows good agreement with Kelly et al [50] (SLA,VIPER) and Schroeter et al [51] (Model A, B, C), and lower than Hsu et al [52]. While for inertial parameter larger than 10 4 , the numerical result matches Hsu et al [52] result more.…”

“…For inertial parameter less than 10 4 , the numerical result shows good agreement with Kelly et al [50] (SLA,VIPER) and Schroeter et al [51] (Model A, B, C), and lower than Hsu et al [52]. While for inertial parameter larger than 10 4 , the numerical result matches Hsu et al [52] result more. When comparing with [51] three models of different surface roughness, the deposition efficiency of NC0 3 is higher than that of the smoothest model C, but lower than that of the roughest model A, and fits that of the model B the best.…”

Nasal sprayed particle deposition in a human nasal cavity under different inhalation conditions

“…Particle deposition in the nasal cavity was compared to experimental data reported by [61, 62] and numerical data [47, 49, 63] (see Fig 8) where the flow rate used for the comparison was a constant 20L/min. In order to standardize the results, the inertial parameter (IP) was used, i.e.…”

Deposition of micrometer-sized aerosol particles in neonatal nasal airway replicas

“…Deposition in adult nasal airways has been well investigated through in vivo and in vitro measurements and in silico simulations, e.g., Hsu and Chuang (2012) and Walenga et al (2014) and references therein. Far fewer studies have been carried out to quantify nasal deposition in children and have compared filtration in children to adults (Becquemin et al 1991;Bennett et al 2008;Golshahi et al 2011;Phalen et al 1989) but with varying results.…”