Intelligent Design Optimization System for Additively Manufactured Flow Channels Based on Fluid-Structure Interaction.

Based on expert system theory and fluid-structure interaction (FSI), this paper suggests an intelligent design optimization system to derive the optimal shape of both the fluid and solid domain of flow channels. A parametric modeling scheme of flow channels is developed by design for additive manufacturing (DfAM). By changing design parameters, a series of flow channel models can be obtained.

Effectiveness of cough etiquette maneuvers in disrupting the chain of transmission of infectious respiratory diseases.

Background: The effectiveness of recommended measures, such as "cover your mouth when coughing", in disrupting the chain of transmission of infectious respiratory diseases (IRD) has been questioned. The objective of the current study was to determine the effectiveness of simple primary respiratory hygiene/cough etiquette maneuvers in blocking droplets expelled as aerosol during coughing.

Method: In this study, 31 healthy non-smokers performed cough etiquette maneuvers in an effort to cover their voluntarily elicited best effort coughs in an open bench format.

Cough aerosol in healthy participants: fundamental knowledge to optimize droplet-spread infectious respiratory disease management.

Background: The Influenza A H1N1 virus can be transmitted via direct, indirect, and airborne route to non-infected subjects when an infected patient coughs, which expels a number of different sized droplets to the surrounding environment as an aerosol. The objective of the current study was to characterize the human cough aerosol pattern with the aim of developing a standard human cough bioaerosol model for Influenza Pandemic control.

Method: 45 healthy non-smokers participated in the open bench study by giving their best effort cough.

In vivo-in vitro correlations: predicting pulmonary drug deposition from pharmaceutical aerosols.

In order to answer the question "what research remains to be done?" we review the current state of the art in pharmaceutical aerosol deposition modeling and explore possible in vivo- in vitro correlations (IVIVC) linking drug deposition in the human lung to predictions made using in vitro physical airway models and in silico computer models. The use of physical replicas of portions of the respiratory tract is considered, alongside the advantages and disadvantages of the different imaging methods used to obtain their dimensions. The use of airway replicas to determine drug deposition in vitro is discussed and compared with the predictions from different empirical curve fits to long-standing in vivo deposition data for monodisperse aerosols.

Surface tension effects on instability in viscoelastic respiratory fluids.

This paper establishes the mathematical formalism for the modeling of the mucus layer in the human trachea as a viscoelastic multiphase fluid system with surface tension with a view toward study of instability properties of the air-mucus system aimed at improving the design of new bioaerosol suppressing medication. The effects of surface tension, previously only conjectured and very poorly understood, are clearly established with quantitative relationships. Several very important physiological conclusions are obtained supporting one method of potential treatment and prevention of disease transmission by alteration of the mucus layer properties over other potential methods.

Improving prediction of aerosol deposition in an idealized mouth using large-Eddy simulation.

Monodisperse aerosol deposition in an idealized mouth geometry with a relatively small inlet diameter (D (in) = 3.0 mm) was studied numerically using a standard Large Eddy Simulation (LES). A steady inhalation flow rate of Q = 32.

Liquid atomizing: nebulizing and other methods of producing aerosols.

Liquid atomization (or nebulization) is the most traditional method of drug delivery to the lung. Although other methods seem to often be preferred for the delivery of new drugs, nebulizers are experiencing a revival, with new devices based on different atomization techniques, and the more traditional jet nebulizers evolving to become "smart nebulizers." These smart devices synchronize delivery with the patient's breath, estimate or measure delivered dose, provide feedback and data storage, and in some cases control breathing maneuvers.

Spray-freeze-dried liposomal ciprofloxacin powder for inhaled aerosol drug delivery.

Spray-freeze drying was utilized to manufacture a liposomal powder formulation containing ciprofloxacin as a model active component. The powder forms liposomally encapsulated ciprofloxacin when wetted. Aerosol properties of this formulation were assessed using a new passive inhaler, in which the powder was entrained at a flow rate of 60l/min.

Use of an impinging jet for dispersion of dry powder inhalation aerosols.

The dispersion of Ventodisk (salbutamol sulphate with lactose) from different drug reservoirs by an air jet at normal impingement is examined experimentally. The effect on dispersion efficiency of jet velocity, nozzle location, reservoir size and shape, and the loaded dose is investigated for possible design of new dosing methods or inhalers. Results show that higher jet velocity (as high as feasible), lower drug loading (2 mg or smaller), a cylindrical hole reservoir (6 mm in diameter and 3 mm in depth) and a medium distance (approximately 5 jet diameters) from the nozzle to the reservoir yield optimum dispersion.

Albuterol aerosol delivered via metered-dose inhaler to intubated pediatric models of 3 ages, with 4 spacer designs.

Objective: To determine the amount of albuterol, in various particle size ranges, delivered from a hydrofluoroalkane-propelled metered-dose inhaler (Airomir) in 3 models of pediatric intubation (ages 8 months, 4 years, and 16 years) using 4 types of aerosol reservoir: 3 spacers (ACE, AeroChamber HC MV, metal NebuChamber without 1-way valve) and 1 holding chamber (metal NebuChamber with 1-way valve).

Methods: Five reservoirs of each type were tested with albuterol sulfate delivered via metered-dose inhaler that delivers 100 microg of albuterol per actuation. Each reservoir was connected to an endotracheal tube (ETT) that corresponded to the given patient age (8 months = 4 French; 4 years = 5 French; 16 years = 7.

In vitro effect of a holding chamber on the mouth-throat deposition of QVAR (hydrofluoroalkane-beclomethasone dipropionate).

Experimental work has been conducted on the effect of an add-on holding chamber (Aerochamber) on the characteristics of deposition in a mouth-throat model using 100-microg hydrofluoroalkane-beclomethazone dipropionate (QVAR) metered dose inhalers at inhalation flow rates of 28.3, 60, and 90 L/min. A filter or cascade impactor downstream of the mouth-throat collected aerosol not depositing.