Improved prediction of intersubject variability in extrathoracic aerosol deposition using algebraic correlations

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

“…Alternatively, these equations have been found to well predict the average deposition of a population (Yang et al 2017). The errors associated with using deposition correlations in a predictive capacity were further analyzed by Ruzycki et al (2017) who proposed a novel approach using the deposition equation to provide an estimate of the variance of deposition expected in a population. Their predictions accurately mirrored the in vivo results of Yang et al (2017) and thus present an approach for a deposition correlation to be used to predict an average and standard deviation of in vivo deposition in a population, as opposed to expected values in individual subjects.…”

“…The details of this analysis are described by Ruzycki et al (2017), so will not be fully described here. In Figure 6.…”

“…The fit of this deposition correlation is shown in Figure 7. Using this simplified equation allows direct application of the method as developed by Ruzycki et al (2017) where variation in deposition, s h , is due to variation in flow rate, s h Q ; characteristic diameter, s h D ; and geometric dissimilarity, s hgd . The exclusion of the Euler number in the deposition parameter can be thought of as returning shape differences to the data, these differences being then accounted for by the variance in deposition due to geometric dissimilarity.…”

“…For example, variation due to inhalation flow rate is found by calculating deposition at a flow rate one standard deviation below the average (Q 1 ) and one standard deviation above the average (Q 2 ) yielding values for h Q1 and h Q2 , respectively. Note that total deposition is calculated by integrating deposition across the aerosol distribution as was done by Ruzycki et al (2017). This requires a specified aerosol distribution; an MMAD of 3.7 mm and GSD of 2 were used for illustrative purposes to define the aerosol here, which are the values used by Ruzycki et al (2017).…”

“…Note that total deposition is calculated by integrating deposition across the aerosol distribution as was done by Ruzycki et al (2017). This requires a specified aerosol distribution; an MMAD of 3.7 mm and GSD of 2 were used for illustrative purposes to define the aerosol here, which are the values used by Ruzycki et al (2017). The magnitude of the difference in calculated deposition is two times the variation due to flow rate (i.e., 2 s h Q D j h Q2 ¡ h Q1 j ) since flow rate has been varied plus and minus one standard deviation from the mean.…”