Aerosol Deposition in the Human Lung Periphery Is Increased by Reduced-Density Gas Breathing

2008 ◽  
Vol 0 (0) ◽  
pp. 080225123426385-10
Author(s):  
Jonathan B. Peterson ◽  
G. Kim Prisk ◽  
Chantal Darquenne
Keyword(s):  
Human Lung ◽  
Aerosol Deposition ◽  
Lung Periphery ◽  
Reduced Density

scholarly journals Aerosol Deposition in the Human Lung Periphery Is Increased by Reduced-Density Gas Breathing

2008 ◽  
Vol 21 (2) ◽  
pp. 159-168 ◽  
Author(s):  
Jonathan B. Peterson ◽  
G. Kim Prisk ◽  
Chantal Darquenne
Keyword(s):  
Human Lung ◽  
Aerosol Deposition ◽  
Lung Periphery ◽  
Reduced Density

scholarly journals Effect of gravity on aerosol dispersion and deposition in the human lung after periods of breath holding

2000 ◽  
Vol 89 (5) ◽  
pp. 1787-1792 ◽  
Author(s):  
Chantal Darquenne ◽  
Manuel Paiva ◽  
G. Kim Prisk
Keyword(s):  
Flow Rate ◽  
Turbulent Mixing ◽  
Direct Evidence ◽  
Human Lung ◽  
Hold Time ◽  
Aerosol Deposition ◽  
Breath Holding ◽  
Breath Hold ◽  
Constant Flow Rate ◽  
Aerosol Dispersion

To determine the extent of the role that gravity plays in dispersion and deposition during breath holds, we performed aerosol bolus inhalations of 1-μm-diameter particles followed by breath holds of various lengths on four subjects on the ground (1G) and during short periods of microgravity (μG). Boluses of ∼70 ml were inhaled to penetration volumes (Vp) of 150 and 500 ml, at a constant flow rate of ∼0.45 l/s. Aerosol concentration and flow rate were continuously measured at the mouth. Aerosol deposition and dispersion were calculated from these data. Deposition was independent of breath-hold time at both Vp in μG, whereas, in 1G, deposition increased with increasing breath hold time. At Vp = 150 ml, dispersion was similar at both gravity levels and increased with breath hold time. At Vp = 500 ml, dispersion in 1G was always significantly higher than in μG. The data provide direct evidence that gravitational sedimentation is the main mechanism of deposition and dispersion during breath holds. The data also suggest that cardiogenic mixing and turbulent mixing contribute to deposition and dispersion at shallow Vp.

One-dimensional simulation of aerosol transport and deposition in the human lung

1994 ◽  
Vol 77 (6) ◽  
pp. 2889-2898 ◽  
Author(s):  
C. Darquenne ◽  
M. Paiva
Keyword(s):  
Particle Diameter ◽  
Aerosol Deposition ◽  
Aerosol Transport ◽  
One Dimensional ◽  
Acinar Structure ◽  
Dimensional Simulation ◽  
Transport And Mixing ◽  
Lung Periphery ◽  
Aerosol Dispersion ◽  
The One

One-dimensional transport models (trumpet model and multibranch-point model) derived from those developed to study gas transport and mixing in the lung are used to simulate aerosol deposition as a function of particle diameter and aerosol dispersion of inhaled bolus in human lungs. In agreement with previous studies, aerosol deposition is satisfactorily simulated by the different models. However, the differences between simulations and experiments of aerosol bolus dispersion suggest that current models are not realistic. This is probably due to the intrinsic limitations of the one-dimensional models to describe aerosol transport in the lung periphery. We show that future model analyses can probably use a symmetric acinar structure like the classic Weibel model of the lung but that multidimensional particle transport equations are required. Furthermore, a rigorous description of aerosol dispersion in the oral-laryngeal path is also needed.

Lung structure parameters estimated from modeling aerosol deposition in isolated dog lungs

1989 ◽  
Vol 67 (5) ◽  
pp. 2014-2025 ◽  
Author(s):  
F. S. Rosenthal
Keyword(s):  
Experimental Data ◽  
Compartment Model ◽  
Aerosol Deposition ◽  
Mean Value ◽  
Breath Holding ◽  
Alveolar Volume ◽  
Lung Structure ◽  
Alveolar Duct ◽  
Lung Periphery ◽  
Parameter Values

A three-compartment model predicting the recovery of aerosol boli (i.e., the ratio of the number of particles expired to the number inspired) as a function of breath-holding time and bolus penetration was fitted to experimental data measured in nine isolated dog lungs. For each lung, the diameters of alveoli and alveolar ducts, as well as the volume fractions of alveoli, alveolar ducts, and airways, were determined as parameters providing the best fit. Parameter values were alveolar diameter = 0.116 +/- 0.007 (SE) mm, alveolar duct diameter = 0.284 +/- 0.015 mm, total alveolar volume/total lung capacity (TLC) = 0.68 +/- 0.02, total alveolar duct volume/TLC = 0.24 +/- 0.02, and total airway volume/TLC = 0.09 +/- 0.01. These values agreed with published values for linear dimensions and volumetric fractions in the canine lung. The mean alveolar diameter determined by the model in the nine lungs agreed closely with a mean value of 0.115 +/- 0.002 mm determined by morphometric analysis of photographs of the subpleural alveoli in the same lungs. The procedure of fitting the model to experimental data appears to have promise as a noninvasive probe of the lung periphery. However, aerosol-derived dimensions were more variable than morphometric ones, possibly because of interlung differences in aerosol distribution not accounted for in the model.

scholarly journals Cardiogenic mixing increases aerosol deposition in the human lung in the absence of gravity

2013 ◽  
Vol 92 (1) ◽  
pp. 15-20 ◽  
Author(s):  
G. Kim Prisk ◽  
Rui Carlos Sá ◽  
Chantal Darquenne
Keyword(s):  
Human Lung ◽  
Aerosol Deposition

scholarly journals Pressurised aerosol deposition in the human lung with and without an "open" spacer device.

Thorax ◽  
1989 ◽  
Vol 44 (9) ◽  
pp. 706-710 ◽  
Author(s):  
S P Newman ◽  
A R Clark ◽  
N Talaee ◽  
S W Clarke
Keyword(s):  
Human Lung ◽  
Aerosol Deposition
Sign in / Sign up

Export Citation Format

Share Document