Computational investigation of particle inertia effects on submicron aerosol deposition in the respiratory tract

Longest, P. Worth; Xi, Jinxiang

doi:10.1016/j.jaerosci.2006.09.007

Cited by 96 publications

(64 citation statements)

References 63 publications

(111 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Examples include wetting phenomena [28,29,30], aerosol deposition and cloud formation [31,32,33,34,35], the transport and coagulation of nanoparticles in pulsatile flow, such as in the cardiovascular system and oscillatory flow mixing [36]. In many of these applications HI also play a crucial role, strongly affecting flow patterns and clustering effects.…”

Section: Introductionmentioning

confidence: 99%

Unification of dynamic density functional theory for colloidal fluids to include inertia and hydrodynamic interactions: derivation and numerical experiments

Goddard

Nold

Savva

et al. 2012

J. Phys.: Condens. Matter

143

View full text Add to dashboard Cite

Abstract. Starting from the Kramers equation for the phase-space dynamics of the N -body probability distribution, we derive a dynamical density functional theory (DDFT) for colloidal fluids including the effects of inertia and hydrodynamic interactions (HI). We compare the resulting theory to extensive Langevin dynamics simulations for both hard rod systems and three-dimensional hard sphere systems with radially-symmetric external potentials. As well as demonstrating the accuracy of the new DDFT, by comparing with previous DDFTs which neglect inertia, HI, or both, we also scrutinise the significance of including these effects. Close to local equilibrium we derive a continuum equation from the microscopic dynamics which is a generalized Navier-Stokes-like equation with additional non-local terms governing the effects of HI. In the overdamped limit we recover analogues of existing configuration-space DDFTs but with a novel diffusion tensor.

show abstract

Section: Introductionmentioning

confidence: 99%

Unification of dynamic density functional theory for colloidal fluids to include inertia and hydrodynamic interactions: derivation and numerical experiments

Goddard

Nold

Savva

et al. 2012

J. Phys.: Condens. Matter

143

View full text Add to dashboard Cite

show abstract

“…Although depositional losses in the aerosol generation and delivery lines were not assessed, it is expected that the use of submicrometer aerosols will greatly reduce inertial deposition, gravitational settling, and turbulent dispersion. (40,61,62) As a result, depositional losses in the aerosol generation and delivery systems will be greatly reduced. Submicrometer aerosols are also expected to largely eliminate deposition in the NIV patient interface, which may be a nasal cannula or face mask.…”

Section: Discussionmentioning

confidence: 99%

“…Submicrometer aerosols are expected to significantly reduce depositional losses in the delivery lines and patient interfaces of NIV systems. (40) Moreover, submicrometer aerosols are known to have very low depositional losses in the nasal airways. (28,41,42) One possible approach for applying the ECG concept to improve aerosol delivery during HFT is proposed in the current study in which a submicrometer aerosol is provided to one nostril at slightly subsaturated conditions.…”

mentioning

confidence: 99%

Improving the Lung Delivery of Nasally Administered Aerosols During Noninvasive Ventilation—An Application of Enhanced Condensational Growth (ECG)

Longest

Tian²,

Hindle³

2011

Journal of Aerosol Medicine and Pulmonary Drug Delivery

Self Cite

View full text Add to dashboard Cite

Background: Aerosol drug delivery during noninvasive ventilation (NIV) is known to be inefficient due to high depositional losses. To improve drug delivery efficiency, the concept of enhanced condensational growth (ECG) was recently proposed in which a submicrometer or nanoaerosol reduces extrathoracic deposition and subsequent droplet size increase promotes lung retention. The objective of this study was to provide proof-of-concept that the ECG approach could improve lung delivery of nasally administered aerosols under conditions consistent with NIV. Methods: Aerosol deposition and size increase were evaluated in an adult nose-mouth-throat (NMT) replica geometry using both in vitro experiments and CFD simulations. For the ECG delivery approach, separate streams of a submicrometer aerosol and warm (398C) saturated air were generated and delivered to the right and left nostril inlets, respectively. A control case was also considered in which an aerosol with a mass median aerodynamic diameter (MMAD) of 4.67 mm was delivered to the model. Results: In vitro experiments showed that the ECG approach significantly reduced the drug deposition fraction in the NMT geometry compared with the control case [14.8 (1.83)%-ECG vs. 72.6 (3.7)%-control]. Aerosol size increased from an initial MMAD of 900 nm to a size of approximately 2 mm at the exit of the NMT geometry.Results of the CFD model were generally in good agreement with the experimental findings. Based on CFD predictions, increasing the delivery temperature of the aerosol stream from 21 to 358C under ECG conditions further reduced the total NMT drug deposition to 5% and maintained aerosol growth by ECG to approximately 2 mm. Conclusions: Application of the ECG approach may significantly improve the delivery of pharmaceutical aerosols during NIV and may open the door for using the nasal route to routinely deliver pulmonary medications.

show abstract

“…However, inertial deposition can be substantially altered in patients with airflow obstruction, due to the velocity field in partially blocked airways, and affect the deposition of particles 200 nm. 49,72 Apart from the distinct particle size, the breathing pattern of ADAM and AiDA is also different. The breathing …”

Section: Breathing Maneuver In Adam and Aidamentioning

confidence: 99%

Do nanoparticles provide a new opportunity for diagnosis of distal airspace disease?

Löndahl¹,

Jakobsson²,

Broday³

et al. 2016

IJN

View full text Add to dashboard Cite

There is a need for efficient techniques to assess abnormalities in the peripheral regions of the lungs, for example, for diagnosis of pulmonary emphysema. Considerable scientific efforts have been directed toward measuring lung morphology by studying recovery of inhaled micron-sized aerosol particles (0.4-1.5 µm). In contrast, it is suggested that the recovery of inhaled airborne nanoparticles may be more useful for diagnosis. The objective of this work is to provide a theoretical background for the use of nanoparticles in measuring lung morphology and to assess their applicability based on a review of the literature. Using nanoparticles for studying distal airspace dimensions is shown to have several advantages over other aerosol-based methods. 1) Nanoparticles deposit almost exclusively by diffusion, which allows a simpler breathing maneuver with minor artifacts from particle losses in the oropharyngeal and upper airways. 2) A higher breathing flow rate can be utilized, making it possible to rapidly inhale from residual volume to total lung capacity (TLC), thereby eliminating the need to determine the TLC before measurement. 3) Recent studies indicate better penetration of nanoparticles than micron-sized particles into poorly ventilated and diseased regions of the lungs; thus, a stronger signal from the abnormal parts is expected. 4) Changes in airspace dimensions have a larger impact on the recovery of nanoparticles. Compared to current diagnostic techniques with high specificity for morphometric changes of the lungs, computed tomography and magnetic resonance imaging with hyperpolarized gases, an aerosol-based method is likely to be less time consuming, considerably cheaper, simpler to use, and easier to interpret (providing a single value rather than an image that has to be analyzed). Compared to diagnosis by carbon monoxide (D L,CO ), the uptake of nanoparticles in the lung is not affected by blood flow, hemoglobin concentration or alterations of the alveolar membranes, but relies only on lung morphology.

show abstract

Computational investigation of particle inertia effects on submicron aerosol deposition in the respiratory tract

Cited by 96 publications

References 63 publications

Unification of dynamic density functional theory for colloidal fluids to include inertia and hydrodynamic interactions: derivation and numerical experiments

Unification of dynamic density functional theory for colloidal fluids to include inertia and hydrodynamic interactions: derivation and numerical experiments

Improving the Lung Delivery of Nasally Administered Aerosols During Noninvasive Ventilation—An Application of Enhanced Condensational Growth (ECG)

Do nanoparticles provide a new opportunity for diagnosis of distal airspace disease?

Contact Info

Product

Resources

About