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High Temperature Airflow And Particle Deposition In Human Upper Lung Airway Models With A Focus On The Mucus Layer Dynamics
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Book Synopsis High Temperature Airflow and Particle Deposition in Human Upper Lung-airway Models with a Focus on the Mucus-layer Dynamics by : Nilay Atul Kulkarni
Download or read book High Temperature Airflow and Particle Deposition in Human Upper Lung-airway Models with a Focus on the Mucus-layer Dynamics written by Nilay Atul Kulkarni and published by . This book was released on 2019 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Computational Fluid and Particle Dynamics in the Human Respiratory System by : Jiyuan Tu
Download or read book Computational Fluid and Particle Dynamics in the Human Respiratory System written by Jiyuan Tu and published by Springer Science & Business Media. This book was released on 2012-09-18 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traditional research methodologies in the human respiratory system have always been challenging due to their invasive nature. Recent advances in medical imaging and computational fluid dynamics (CFD) have accelerated this research. This book compiles and details recent advances in the modelling of the respiratory system for researchers, engineers, scientists, and health practitioners. It breaks down the complexities of this field and provides both students and scientists with an introduction and starting point to the physiology of the respiratory system, fluid dynamics and advanced CFD modeling tools. In addition to a brief introduction to the physics of the respiratory system and an overview of computational methods, the book contains best-practice guidelines for establishing high-quality computational models and simulations. Inspiration for new simulations can be gained through innovative case studies as well as hands-on practice using pre-made computational code. Last but not least, students and researchers are presented the latest biomedical research activities, and the computational visualizations will enhance their understanding of physiological functions of the respiratory system.
Book Synopsis Inhaled Particles by : Chiu-sen Wang
Download or read book Inhaled Particles written by Chiu-sen Wang and published by Elsevier. This book was released on 2005-01-20 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inhaled Particles integrates all that is known about inhaled particles in a unified treatment. It aims to provide a scientific framework essential to a reasonable understanding of inhaled particles. The emphasis is placed on demonstrating the key roles of lung morphology on airflow and particle transport as well as identifying physical and biological factors that influence deposition. Special attention is paid to maintaining consistency of treatment and a balance between theoretical modeling and experimental measurements. The book covers all important aspects of inhaled particles including inhalability, aerosol dispersion, particle deposition, and clearance. It reviews concisely the basic background of lung morphology, respiratory physiology, aerodynamics, and aerosol science pertinent to the subject. Essential aspects of health effects and applications are also included. An easy-to-read, self contained introduction to the field An excellent source of updated research information Useful for students and professionals in aerosol science, environmental health science, occupational hygiene, health physics and biomedical engineering
Book Synopsis Airflow and Micro-Particle Transport and Deposition in Realistic Lung Airways Including the Alveolar Region by :
Download or read book Airflow and Micro-Particle Transport and Deposition in Realistic Lung Airways Including the Alveolar Region written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: People may inhale 100 millions of particles each day, including toxic particulate matter as well as drug aerosols. Some of those deposited in the respiratory system can be either harmful or therapeutic to humans depending upon the particle material, deposition site, and local concentration. These transport and deposition phenomena as well as the resulting biomedical processes are greatly determined by the airflow field, particle properties, breathing pattern, and geometric airway characteristics. Realistic models of tracheobronchial and nasal⁄oral- tracheobronchial airways were built. Airflow and particle transport and deposition in these airway models were investigated in detail by mainly using the validated, in-house FORTRAN code CFPD (computational fluid-particle dynamics), which is a cell-centered, finite volume multi-block code. Both laminar and transitional-turbulent-laminar flows were considered for different transient and steady inhalation flow rates and inlet velocity profiles. The resulting effects of transients, upstream conditions and geometric characteristics, i.e., spatial angle and/or cartilaginous rings, are fully discussed. A new code based on the lattice-Boltzmann method (LBM) has been developed and validated to investigate airflow patterns and pressure changes in representative alveolar structures of the human respiratory zone. The new idea of targeted drug aerosol delivery technology was numerically tested for a more realistic human airway configuration and thereby addressing the problem of inter-subject variability. Specifically, controlled air-particle streams were studied using the oral and asymmetric tracheobronchial airway models. The results were compared with data obtained for a symmetric Weibel Type A tracheobronchial airway model.
Book Synopsis Simulation of Turbulent Airflow and Particle Deposition in Human and Animal Airways by : Taylor Steven Geisler
Download or read book Simulation of Turbulent Airflow and Particle Deposition in Human and Animal Airways written by Taylor Steven Geisler and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Prolonged exposure to inhaled micron-sized airborne particles is a known public health concern. These particles impact the health of staggering numbers of residents of polluted urban areas, as well as significant portions of the third world where it is still common to burn wood or charcoal indoors for cooking or heating. An understanding of the fate of inhaled particles in the lungs is useful for assessing their associated health risks, as well as improving the effectiveness of respiratory drug delivery techniques. The transport of microparticles is inseparable from behavior of the suspending airflow and this is studied using computational fluid dynamics techniques. The anatomy of the airways seems to have evolved to encourage turbulent airflow for functions such as mixing of flow to promote the warming and humidification of inhaled air, as well as for filtration. Large eddy simulation models are employed to capture turbulent flow in extremely complex patient-specific airway geometries. These collectively comprise the oral and nasal cavities, larynx, trachea, and the bronchial tree. The flow in anatomically-accurate rhesus macaque airways is also studied. Simulations are carried out for inspiratory flow rates corresponding to nominal Reynolds numbers in the hundreds to low-thousands yet somewhat surprisingly yield unsteady flows due to local geometric factors. A computed mean flow field is compared extensively with magnetic resonance velocimetry measurements carried out in the same computed-tomography--based lung geometry, showing good agreement. Microparticle deposition predictions are also verified. Focus is placed on the dynamics of the flow in the nasal airway, trachea, and bronchial tree. After becoming unsteady at constrictions in the upper airways, the flow is found to be chaotic, exhibiting fluctuations with broad-band spectra even at the most distal simulated airways in which the Reynolds numbers are as low as 300. The unsteadiness is attributed to the convection of turbulent structures produced in the upper airways as well as to local kinetic energy production throughout the bronchial tree.
Book Synopsis Extrapolation of Dosimetric Relationships for Inhaled Particles and Gases by : James D. Crapo
Download or read book Extrapolation of Dosimetric Relationships for Inhaled Particles and Gases written by James D. Crapo and published by . This book was released on 1989 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extrapolation Modeling, Advancements and Research Issues in Lung Dosimetry; Lung Structure, Function Relationships; Species Differences in Airway Cell Distribution and Morphology; Alternative Methods to Evaluate Species Differences in Upper Airway Structure, Function; Preparation of Rat Nasal Airway Casts and Their Application to Studies of Nasal Airflow; Age Related Morphometric Analysis of Human Lung Casts; Anatomical Modeling of Microdosimetry of Inhaled Particles and Gases in the Lung; Experimental Dosimetry; Particle Deposition at the Alveolar Duct Bifurcations; Effects of Airway Branch Angle, Branch Point Number, and Gravity on Particle Deposition and Retention; Regional Deposition of Inhaled Particulates in Conducting Airways and Lung Segments; The Physical Properties of Mainstream Cigarette Smoke and Their Relationship to Deposition in the Respiratory Tract; Localization of 14C Dotriacontane Labeled Cigarette Smoke Particulate in the Dog Lung; Human Lung Clearance Following Bolus Inhalation of Radioaerosols; Effects of Ventilatory Patterns and Pre-existing Disease on Deposition of Inhaled Particles in Animals; Nasopharyngeal Uptake of Ozone in Humans and Animals; New Methods; Regional Dosimetry of Inhaled Particles Using SPECT; Dual Laser Doppler System for Real Time, Simultaneous Characterization of Aerosols by Size and Concentration; Dosimetry of Inhaled Particles by Means of Light Scattering; Modeling Approaches; Issues That Must Be Addressed When Constructing Anatomical Models of the Developing Lung; Significances of the Variability of Tracheobronchial Airway Paths and Their Air Flow Rates to Dosimetry Model Predictions of the Absorption of Gases; Predicting Respiratory Tract Clearance in Man; The Role of Particle Hygroscopicity in Aerosol Therapy and Inhalation Toxicology; Age-Dependent Lung Dosimetry of Radon Progeny; Deposition and Retention Modeling of Inhaled Cadmium in Rat and Human Lung, An Example for Extrapolation of Effects and Risk Estimation.
Book Synopsis Comparison of Particle Deposition for Realistic Adult and Adolescent Upper Airway Geometries Using Unsteady Computational Fluid Dynamics by : Jonathan Steffens
Download or read book Comparison of Particle Deposition for Realistic Adult and Adolescent Upper Airway Geometries Using Unsteady Computational Fluid Dynamics written by Jonathan Steffens and published by . This book was released on 2010 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Particle deposition in the respiratory tract is studied in order to better understand the negative health effects due to cigarette smoke inhalation. Until recently, idealized models of the respiratory airways based on the original Weibel model have been used to calculate deposition. These models consist of symmetric bifurcating airways and do not take into account variations of airway diameter, and asymmetry in the human respiratory tract. Until recently, little work has been done to accurately recreate the entire upper respiratory tract including the oral cavity, pharynx, and larynx. Technological improvement has changed the way in which researchers approach this problem. With the advent of high resolution scans of the respiratory tract, accurate replica models can be created to better predict cigarette smoke particle (CSP) deposition. These models recreate actual lung geometries found in patients. For this thesis, two realistic geometric models are created. One is based on an adult male and the other on an adolescent male. CSP deposition is determined for both models in order to compare the difference cased by age in smoking. In addition, an unsteady breathing curve, indicative of realistic smoking behavior is utilized to more accurately represent the breathing conditions. Both models consist of the oral cavity, throat, larynx, trachea, and first five to seven generations of the lungs. The adult model is based on a dental cast of the mouth, a CT scan of the throat and larynx, and images based on the National Institute of Health's Visible Human Project for the tracheobronchial tree. The adolescent model is based upon a scaled oral cavity and CT scans of the rest of the reparatory tract. The program 3D Doctor is used to reconstruct the two dimensional CT scan images into a three dimensional model. VPSculpt and SolidWorks are used to combine the different parts of the models and clean up the geometry. The geometry is meshed in Gambit and exported to the Computational Fluid Dynamics (CFD) software package Fluent to perform the fluid flow and particle deposition analysis. The Fluent Discrete Phase Model (DPM) is used to determine particle trajectories and deposition. It is found that deposition increases with the size of the inhaled particles. Particles tend to deposit towards the back of the throat, the area of the trachea just below the glottis, and at bifurcations in the airways. However, when compared to other studies in literature, deposition tended to be higher with smaller particle sizes, but more comparable with larger particle sizes. Adolescent deposition was found to be lower than adult deposition for all particle sizes."--Abstract.
Book Synopsis Computational Flow Modeling of Human Upper Airway Breathing by : Goutham Mylavarapu
Download or read book Computational Flow Modeling of Human Upper Airway Breathing written by Goutham Mylavarapu and published by . This book was released on 2013 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational modeling of biological systems have gained a lot of interest in biomedical research, in the recent past. This thesis focuses on the application of computational simulations to study airflow dynamics in human upper respiratory tract. With advancements in medical imaging, patient specific geometries of anatomically accurate respiratory tracts can now be reconstructed from Magnetic Resonance Images (MRI) or Computed Tomography (CT) scans, with better and accurate details than traditional cadaver cast models. Computational studies using these individualized geometrical models have advantages of non-invasiveness, ease, minimum patient interaction, improved accuracy over experimental and clinical studies. Numerical simulations can provide detailed flow fields including velocities, flow rates, airway wall pressure, shear stresses, turbulence in an airway. Interpretation of these physical quantities will enable to develop efficient treatment procedures, medical devices, targeted drug delivery etc. The hypothesis for this research is that computational modeling can predict the outcomes of a surgical intervention or a treatment plan prior to its application and will guide the physician in providing better treatment to the patients. In the current work, three different computational approaches Computational Fluid Dynamics (CFD), Flow-Structure Interaction (FSI) and Particle Flow simulations were used to investigate flow in airway geometries. CFD approach assumes airway wall as rigid, and relatively easy to simulate, compared to the more challenging FSI approach, where interactions of airway wall deformations with flow are also accounted. The CFD methodology using different turbulence models is validated against experimental measurements in an airway phantom. Two case-studies using CFD, to quantify a pre and post-operative airway and another, to perform virtual surgery to determine the best possible surgery in a constricted airway is demonstrated. The unsteady Large Eddy simulations (LES) and a steady Reynolds Averaged Navier Stokes (RANS) approaches in CFD modeling are discussed. The more challenging FSI approach is modeled first in simple two-dimensional anatomical geometry and then extended to simplified three dimensional geometry and finally in three dimensionally accurate geometries. The concepts of virtual surgery and the differences to CFD are discussed. Finally, the influence of various drug delivery parameters on particle deposition efficiency in airway anatomy are investigated through particle-flow simulations in a nasal airway model.
Author :Sponsored by The Health Effects Institute Publisher :National Academies Press ISBN 13 :0309037263 Total Pages :703 pages Book Rating :4.3/5 (9 download)
Book Synopsis Air Pollution, the Automobile, and Public Health by : Sponsored by The Health Effects Institute
Download or read book Air Pollution, the Automobile, and Public Health written by Sponsored by The Health Effects Institute and published by National Academies Press. This book was released on 1988-01-01 with total page 703 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The combination of scientific and institutional integrity represented by this book is unusual. It should be a model for future endeavors to help quantify environmental risk as a basis for good decisionmaking." â€"William D. Ruckelshaus, from the foreword. This volume, prepared under the auspices of the Health Effects Institute, an independent research organization created and funded jointly by the Environmental Protection Agency and the automobile industry, brings together experts on atmospheric exposure and on the biological effects of toxic substances to examine what is knownâ€"and not knownâ€"about the human health risks of automotive emissions.
Author :National Research Council (U.S.). Subcommittee on Airborne Particles Publisher : ISBN 13 : Total Pages :376 pages Book Rating :4.:/5 (43 download)
Book Synopsis Airborne Particles by : National Research Council (U.S.). Subcommittee on Airborne Particles
Download or read book Airborne Particles written by National Research Council (U.S.). Subcommittee on Airborne Particles and published by . This book was released on 1979 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :United States. Public Health Service. Office of the Surgeon General Publisher : ISBN 13 : Total Pages :728 pages Book Rating :4.:/5 (318 download)
Book Synopsis How Tobacco Smoke Causes Disease by : United States. Public Health Service. Office of the Surgeon General
Download or read book How Tobacco Smoke Causes Disease written by United States. Public Health Service. Office of the Surgeon General and published by . This book was released on 2010 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report considers the biological and behavioral mechanisms that may underlie the pathogenicity of tobacco smoke. Many Surgeon General's reports have considered research findings on mechanisms in assessing the biological plausibility of associations observed in epidemiologic studies. Mechanisms of disease are important because they may provide plausibility, which is one of the guideline criteria for assessing evidence on causation. This report specifically reviews the evidence on the potential mechanisms by which smoking causes diseases and considers whether a mechanism is likely to be operative in the production of human disease by tobacco smoke. This evidence is relevant to understanding how smoking causes disease, to identifying those who may be particularly susceptible, and to assessing the potential risks of tobacco products.
Book Synopsis ปัจจัยที่มีผลกระทบต่อการสืบสวนจับกุมคดีอุกฉกรรจ์ by :
Download or read book ปัจจัยที่มีผลกระทบต่อการสืบสวนจับกุมคดีอุกฉกรรจ์ written by and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Voltaire en son temps by : René Pomeau
Download or read book Voltaire en son temps written by René Pomeau and published by . This book was released on 1995 with total page 876 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Particle Deposition in Replica Healthy and Emphysematous Alveolar Models Using Computational Fluid Dynamics by : Edward M. Harding
Download or read book Particle Deposition in Replica Healthy and Emphysematous Alveolar Models Using Computational Fluid Dynamics written by Edward M. Harding and published by . This book was released on 2010 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Particle deposition in the pulmonary region of the lung has gained increasing interest in the past years. Of particular interest are nano-sized particles, because they have the potential of crossing the blood-gas barrier and into the capillaries. Many factors contribute to how and where particles deposit, such as lung morphology, breathing conditions, fluid flow characteristics, and alveolar wall movement. These many factors make simulating particle deposition in the alveoli difficult. The experimental in vivo studies have commonly used micron sized particles and there is a lack of data for smaller sized particles. Due to these many factors, deposition in the pulmonary region is not well understood. Furthermore, little attention has been paid to the emphysematous lungs, which have characteristics quite different than the healthy lung. In this work, healthy and emphysematous replica acinus models were created from human lung casts using a 3D reconstruction software package. The models were used for simulating the particle deposition due to diffusion using Fine Particle Model (FPM). The FPM program was validated against an analytical solution using a straight tube, before moving on to predict the deposition in the alveolar models. Two particle sizes, 1 and 3 nm, were used to understand and compare pure diffusion in the lung using concentration contours. Results showed the particle deposition rate (particles/s) to be higher in the emphysemic. However, deposition rate per area (particles/m2s) was found to be higher in the healthy model. The deposition efficiency (% of particles that deposit) of the healthy model was greater than the emphysemic model, consistent with literature. Results were found to be lower than experimental in vivo measurements and whole lung model of local alveolar deposition (particles deposited in alveoli/particles entering alveoli) in comparison to our results in the pulmonary region, showing the importance of including axial diffusion effects. More work must be done experimentally and numerically before an understanding of deposition of particles of this size can be determined."--Abstract.
Book Synopsis Numerical Simulation of Airflow, Particle Deposition and Drug Delivery in a Representative Human Nasal Airway Model by : Huawei Shi
Download or read book Numerical Simulation of Airflow, Particle Deposition and Drug Delivery in a Representative Human Nasal Airway Model written by Huawei Shi and published by . This book was released on 2006 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: CFD, drug delivery, airflow, particle deposition, nasal airway.
Book Synopsis Study of Particle Deposition in Human Airway Models by : Guosen Yue
Download or read book Study of Particle Deposition in Human Airway Models written by Guosen Yue and published by . This book was released on 2001 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis CFD Evaluation of Cluster Specific Image Based Asthma Lung Features on Particle Transport and Hygroscopic Particle Growth Model Validation by : Lawrence Joseph LeBlanc
Download or read book CFD Evaluation of Cluster Specific Image Based Asthma Lung Features on Particle Transport and Hygroscopic Particle Growth Model Validation written by Lawrence Joseph LeBlanc and published by . This book was released on 2017 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosolized drug delivery to the human lungs for asthma treatment has long been studied and yet the relationship between the delivery efficacy and the inter-subject variability due to gender, age, and disease severity remains unclear. A recent imaging-based cluster analysis on a population of asthmatic patients identifies four clusters with distinct structural and functional characteristics. The use of cluster membership to explore inter-subject variability by investigating numerically the air flow and particle transport in representative subjects of the asthmatic clusters on inhalation drug delivery in asthma sub-populations is proposed. Large-eddy simulations using computed tomography (CT)-based airway models were performed with a slow and deep breathing profile corresponding to application of a metered dose inhaler. Physiologically consistent subject specific boundary conditions in peripheral airways were produced using an image registration technique and a resistance network compliance model. Particle simulations and final deposition statistics were calculated for particle sizes ranging from 1-8 μm. The results suggested an emphasis on the importance of airway constriction for regional particle deposition and prominent effects of local features in lobar, segmental, and sub-segmental airways on overall deposition patterns. Asthmatic clusters characterized by airway constriction had an increase in deposition efficiency in lobar, segmental, and sub-segmental airways. Local constrictions produced jet flows that impinged on distal bifurcations and resulted in large inertial depositions. Decreased right main bronchus (RMB) branching angle decreased the fraction of particles ventilated to the right upper lobe (RUL). Cluster-based computational fluid dynamics results demonstrate particle deposition characteristics associated with imaging based variables that could be useful for future drug delivery improvements.
