Computational Modeling of Aerosol Deposition Characteristics in Cyclic Bifurcating Tube Flow

2010 ◽  
Author(s):  
Sinjae Hyun ◽  
Sun Jin Moon ◽  
Chong S. Kim
Keyword(s):  
Respiratory System ◽  
The Elderly ◽  
Aerosol Deposition ◽  
Airway Disease ◽  
Patient Treatment ◽  
Toxic Substances ◽  
Industrial Workers ◽  
Dynamics Modeling ◽  
Pharmaceutical Aerosols ◽  
Lung Airways

An accurate model of the human respiratory system allows health scientists to gain insight into the interactions between particulate matter (PM) and the exposed surfaces of the lung airways. Respiratory dose simulations and modeling are frequently used for evaluating health effects of inhaled toxic substances [1–4] and for analyzing the risk potentials of inhaled toxic or harmful PM such as vehicle emissions [4,5]. Pharmaceutical companies and pulmonologists find it useful in evaluating efficacy of inhaled medicinal aerosols and devising new patient treatment regimen [6–8], especially in vulnerable population groups such as children, industrial workers, and the elderly [10]. Recently, the respiratory system has seen increased attention as a possible venue for drug delivery to fight diseases such as AIDS, diabetes, and various cancers, among others. Computational fluid dynamics modeling and simulation continues to be an important tool for understanding of delivery of pharmaceutical aerosols to the lung airways and thereby improving treatment of airway disease, particularly, asthma with bronchodilators and corticosteroids inhalers [11,12].

Aerosol Deposition Study of Subject-Specific Upper Respiratory Model

2012 ◽  
Author(s):  
Anthony L. Fratino ◽  
Sinjae Hyun ◽  
Chong S. Kim
Keyword(s):  
Particulate Matter ◽  
Respiratory System ◽  
Health Professionals ◽  
Aerosol Deposition ◽  
Toxic Substances ◽  
Subject Specific ◽  
Upper Respiratory ◽  
Lung Airways ◽  
Simulations And Modeling ◽  
Insight Into

An accurate model of the human respiratory system allows health professionals to gain insight into the interactions between particulate matter (PM) and the exposed surfaces of the lung airways. Respiratory dose simulations and modeling are frequently used for evaluating health effects of inhaled toxic substances [1–4] and for analyzing the risk potentials of inhaled toxic or harmful PM such as vehicle emissions [4,5].

scholarly journals Letter to the Editor: Microbiota in the Respiratory System—A Possible Explanation to Age and Sex Variability in Susceptibility to SARS-CoV-2

2021 ◽  
Vol 14 ◽  
pp. 117863612098860
Author(s):  
Vishal Shah
Keyword(s):  
Respiratory System ◽  
Elderly Population ◽  
Age Groups ◽  
The Elderly ◽  
Elderly Adult ◽  
Human Respiratory Tract ◽  
System A ◽  
Number Of Patients ◽  
Children And Young Adults ◽  
Age And Sex

The Human respiratory tract is colonized by a variety of microbes and the microbiota change as we age. In this perspective, literature support is presented for the hypothesis that the respiratory system microbiota could explain the differential age and sex breakdown amongst COVID-19 patients. The number of patients in the older and elderly adult group is higher than the other age groups. The perspective presents the possibility that certain genera of bacteria present in the respiratory system microbiota in children and young adults could be directly or through eliciting an immune response from the host, prevent full-fledged infection of SARS-CoV-2. The possibility also exists that the microbiota in older adults and the elderly population have bacteria that make it easier for the virus to cause infection. I call upon the scientific community to investigate the link between human microbiota and SARS-CoV-2 susceptibility to further understand the viral pathogenesis.

scholarly journals Experimental Evaluation of Dry Powder Inhalers During In- and Exhalation Using a Model of the Human Respiratory System (xPULM™)

2021 ◽  
Author(s):  
Richard Pasteka ◽  
Joao Pedro Santos da Costa ◽  
Mathias Forjan
Keyword(s):  
Respiratory Tract ◽  
Respiratory System ◽  
Particle Number ◽  
Particle Diameter ◽  
Upper Airway ◽  
System Model ◽  
Dry Powder Inhalers ◽  
Dry Powder ◽  
Pharmaceutical Aerosols ◽  
Airway Model

Dry powder inhalers are used by a large number of patients worldwide to treat respiratory diseases. The objective of this work is to experimentally investigate changes in aerosol particle diameter and particle number concentration of pharmaceutical aerosols generated by five dry powder inhalers under realistic inhalation and exhalation conditions. The active respiratory system model (xPULM™) was used as a model of the human respiratory system and to simulate a patient undergoing inhalation therapy. A mechanical upper airway model was developed, manufactured and introduced as a part of the xPULM™ to represent the human upper respiratory tract with high fidelity. Integration of optical aerosol spectrometry technique into the setup allowed for evaluation of pharmaceutical aerosols. The results show that the upper airway model increases the resistance of the overall system and act as a filter for bigger particles (>3 µm). Furthermore, there is a significant difference (p < 0.05) in mean particle diameter between inhaled and exhaled particles with the majority of the particles depositing in the lung. The minimum deposition is reached for particle size of 0.5 µm. The mean particle number concentrations exhaled are 2.94% (BreezHaler®), 2.66% (Diskus®), 10.24% (Ellipta®) 2.13% (HandiHaler®) and 6.22% (Turbohaler®). In conclusion, the xPULM™ active respiratory system model is a viable option for studying interactions of pharmaceutical aerosols and the respiratory tract in terms of applicable deposition mechanisms. The model can support the reduction of animal experimentation in aerosol research and provide an alternative to experiments with human subjects.

Effect of Inhaling Patterns on Aerosol Drug Delivery: CFD Simulation

2008 ◽  
Author(s):  
Jinho Kim ◽  
Jim S. Chen
Keyword(s):  
Secondary Flow ◽  
Particle Deposition ◽  
Cfd Simulation ◽  
Dry Powder Inhaler ◽  
Upper Airway ◽  
Aerosol Deposition ◽  
Dose Inhaler ◽  
Breath Holding ◽  
Pharmaceutical Aerosols ◽  
Airway Model

Inhaled Pharmaceutical Aerosols (IPAs) delivery has great potential in treatment of a variety of respiratory diseases, including asthma, pulmonary diseases, and allergies. Aerosol delivery has many advantages. It delivers medication directly to where it is needed and it is effective in much lower doses than required for oral administration. Currently, there are several types of IPA delivery systems, including pressurized metered dose inhaler (pMDI), the dry powder inhaler (DPI), and the medical nebulizer. IPAs should be delivered deep into the respiratory system where the drug substance can be absorbed into blood through the capillaries via the alveoli. Researchers have proved that most aerosol particles with aerodynamic diameter of about 1–5 μm, if slowly and deeply inhaled, could be deposited in the peripheral regions that are rich in alveoli [1–3]. The purpose of this study is to investigate the effects of various inhaling rates with breath-holding pause on the aerosol deposition (Dp = 0.5–5 μm) in a human upper airway model extending from mouth to 3rd generation of trachea. The oral airway model is three dimensional and non-planar configurations. The dimensions of the model are adapted from a human cast. The air flow is assumed to be unsteady, laminar, and incompressible. The investigation is carried out by Computational Fluid Dynamics (CFD) using the software Fluent 6.2. The user-defined function (UDF) is employed to simulate the cyclic inspiratory flows for different IPA inhalation patterns. When an aerosol particle enters the mouth respiratory tract, its particles experience abrupt changes in direction. The secondary flow changes its direction as the airflow passes curvature. Intensity of the secondary flow is strong after first bend at pharynx and becomes weaker after larynx. In flow separation, a particle can be trapped and follow the eddy and deposit on the surface. Particle deposition fraction generally increases as particle size and inhaling airflow velocity increase.

Age-related Utilization of Advanced Life Support Services

1991 ◽  
Vol 6 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Steven A. Meador
Keyword(s):  
Life Support ◽  
Age Groups ◽  
Rank Correlation ◽  
Advanced Life Support ◽  
The Elderly ◽  
Population Projections ◽  
Patient Treatment ◽  
Related Case ◽  
Spearman’S Rank Correlation ◽  
Age Related

AbstractPurpose:To investigate the relationship between age and Advanced Life Support (ALS) utilization.Population:All patients from 1 January 1987 to 31 December 1988 transported by ALS ambulances within Lebanon County, a rural/urban county of 112,000.Methods:All runs resulting in patient treatment by ALS personnel were tallied at five-year age intervals and sub-grouped by trauma- and non-trauma-related calls. Utilization rates for each age group were obtained by dividing the calls by the population of each group. Correlation with age was tested by Spearman's rank correlation. Treatment rates for age groups were calculated for the six most frequent medical etiologies. To illustrate the effect of age distributions, age rates were applied to projected state and national population distributions.Results:There was a significant correlation with age for all transports (p < .01; r=.93) and for those not related to trauma (p<.01; r=.98). Correlation was not detected for trauma-related responses (p>.10; r=.19). Non-trauma-related case incidence varied among age groups, ranging from 1.1/1,000 for age five through nine years to 89/1,000 for age 80–84 years. Congestive heart failure, cardiac ischemia, syncope, myocardial infarction, and cardiac arrest evidenced increased incidence with age. Seizure did not. Older populations had a higher projected utilization of ALS services than did the younger age groups.Conclusion:Non-trauma ALS utilization is highly dependent on the age of the patient. Due to projected aging of the population and increased utilization of ALS by the elderly, projected utilization will increase at a rate faster than will the population. Age:rate data can be combined with population projections to estimate future need.

scholarly journals Pneumonia byListeria monocytogenes: A Common Infection by an Uncommon Pathogen

2015 ◽  
Vol 2015 ◽  
pp. 1-3
Author(s):  
Theocharis Koufakis ◽  
Marianneta Chatzopoulou ◽  
Anastasios Margaritis ◽  
Maria Tsiakalou ◽  
Ioannis Gabranis
Keyword(s):  
Listeria Monocytogenes ◽  
Pregnant Women ◽  
Female Patient ◽  
Respiratory System ◽  
Therapeutic Approach ◽  
The Elderly ◽  
Pulmonary Infections ◽  
Immunosuppressed Patients ◽  
Common Infection

Infections byListeria monocytogenestypically occur in infants, the elderly, pregnant women, and immunosuppressed subjects. Pulmonary infections in adults are extremely uncommon and only few reports can be found in the literature. We here report a case ofListeriapneumonia in an 85-year-old female patient and we discuss our diagnostic and therapeutic approach. Despite being rare and in most cases difficult to be identified,Listeriapneumonia should always be considered in immunosuppressed patients, presenting with fever and symptoms from the lower respiratory system.

scholarly journals Alterations of the Murine Gut Microbiome with Age and Allergic Airway Disease

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Marius Vital ◽  
Jack R. Harkema ◽  
Mike Rizzo ◽  
James Tiedje ◽  
Christina Brandenberger
Keyword(s):  
Community Structure ◽  
Gut Microbiota ◽  
Serum Levels ◽  
The Elderly ◽  
Airway Disease ◽  
Allergic Airway Disease ◽  
Intestinal Microbiome ◽  
16S Rrna Analysis ◽  
Cytokine Analysis ◽  
Old Mice

The gut microbiota plays an important role in the development of asthma. With advanced age the microbiome and the immune system are changing and, currently, little is known about how these two factors contribute to the development of allergic asthma in the elderly. In this study we investigated the associations between the intestinal microbiome and allergic airway disease in young and old mice that were sensitized and challenged with house dust mite (HDM). After challenge, the animals were sacrificed, blood serum was collected for cytokine analysis, and the lungs were processed for histopathology. Fecal pellets were excised from the colon and subjected to 16S rRNA analysis. The microbial community structure changed with age and allergy development, where alterations in fecal communities from young to old mice resembled those after HDM challenge. Allergic mice had induced serum levels of IL-17A and old mice developed a greater allergic airway response compared to young mice. This study demonstrates that the intestinal bacterial community structure differs with age, possibly contributing to the exaggerated pulmonary inflammatory response in old mice. Furthermore, our results show that the composition of the gut microbiota changes with pulmonary allergy, indicating bidirectional gut-lung communications.

Industrialization, the Family Economy, and the Economic Status of the American Elderly

1991 ◽  
Vol 15 (3) ◽  
pp. 337-362 ◽  
Author(s):  
Brian Gratton ◽  
Frances M. Rotondo
Keyword(s):  
Social Security ◽  
Urban Areas ◽  
Economic Status ◽  
The Elderly ◽  
Industrial Workers ◽  
Family Economy ◽  
The Social ◽  
The Family ◽  
Social Security Act ◽  
The Cost

In his 1911 film What Shall We Do with Our Old? D.W. Griffith dramatized the belief that urban, industrial America had no place for the elderly. Fired for being too slow at his work, an impoverished old man cannot buy food or medicine for his wife, who languishes in their drab, one-room apartment. Justice Benjamin Cardozo told a similar tale in upholding the constitutionality of the Social Security Act (Helvering v. Davis, 301 U.S. 619 [1937]): “The number of [aged] unable to take care of themselves is growing at a threatening pace. More and more our population is becoming urban and industrial instead of rural and agricultural.” Cardozo relied on studies by the U.S. Social Security Board (1937: 3), which found that “the major part of the industrial population . . . earns scarcely enough to provide for its existence. Savings are small and generally cover little more than the cost of burial insurance.” As a result, “industrial workers in [urban] areas . . . reach old age with few resources” (ibid.: 33).

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