Modeling Deposition of Inhaled Particles - Aerosols: Measurement, Dosimetry, and Health Effects - page 111

1.0
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Model 7,29
Experiment 236

Model 7,29
Experiment 236

1 10 100 1 10 100

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(A) Particle size (µm) (B) Particle size (µm)

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Model 7,29
Experiment 236

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(C) Particle size (µm)

FIGURE 5.14 Model predictions of total deposition determined using the deterministic model of Martonen, 7,31
plotted against experimental data. 281 (A) Breathing frequency = 30 breaths/min, tidal volume = 500 mL, (B)
breathing frequency = 15 breaths/min, tidal volume = 1000 mL, and (C) breathing frequency = 30 breaths/min,
tidal volume = 1500 mL.

analytical models were developed early on for the nose, 285 but as the complexity of the nasal passages
was recognized and more experimental data were published, 286 it became apparent that more complex
models were needed. Experimental deposition data have also been reported for the oral cavity, 26,133,287
and analytical models have been developed. 288 Historically, most of the modeling that has been done
for the nose 286,289,290 and mouth 289 region has been empirical in nature. Recently, CFPD has offered
an alternative approach to the simulation of particle deposition in the extrathoracic passages, while
at the same time advancements have been made in the manufacture of replica models of the tortuous
extrathoracic airways for use in deposition experiments. Kelly et al. described the deposition of both
coarse 291 and ultraine 292 particles in stereolithography-based plastic nasal model. Their experimental
results have been compared (with good agreement) to results obtained in CFPD models by Schroeter
et al. 76 and Tian et al. 74 Similar comparisons have been done in the oral cavity as well. The mouth
deposition eficiencies predicted by Xi et al. 70 in a realistic mouth geometry using CFPD compared
well with the experiment results obtained by Cheng et al. 293 in a cast of the human mouth.

5.5.3.2.2 Tracheobronchial
Hofmann and Koblinger 282 compared their simulated TB deposition values with the experimental data
of Heyder et al. 283 For particle sizes of 0.05-1 μm, their model predicted deposition in the TB region
of 1%-11%, while zero measured deposition was reported by Heyder et al. It was hypothesized that
these differences were due to inherent limitations of the deinition of different regions in the model.
Theoretical predictions of TB deposition fraction for the model of Martonen 7,32 are plotted versus
corresponding experimental data in Figure 5.15. Again, relatively good agreement between theory
and average experimental data was observed over the range of particle sizes investigated, suggesting
that the physics of the inhaled particles is being adequately simulated.
There have been many comparisons of CFPD models of the TB airways (either idealized or
physiologically realistic models) with experimental data collected in physical models of branching
networks. While these comparisons do not consider in vivo experimental data, they can be useful