• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 109
  • 18
  • 7
  • 6
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 2
  • 1
  • 1
  • Tagged with
  • 160
  • 160
  • 65
  • 16
  • 15
  • 15
  • 13
  • 13
  • 12
  • 12
  • 11
  • 11
  • 11
  • 11
  • 10
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Análise fotogramétrica para predição de volune e comportamento respiratórios em adolescentes

Ripka, Wagner Luis 15 October 2012 (has links)
Introdução: Diversas são as maneiras de se avaliar o sistema respiratório, entre elas destacam-se a pletismografia por indutância e análises cinemáticas tridimensionais, métodos de custo elevado e difícil transportabilidade. O emprego de um método alternativo baseado em imagem fotográfica (fotogrametria) emerge em um contexto como instrumento de baixo custo e de fácil transporte para análises respiratórias. Objetivo: o objetivo geral deste estudo consistiu em correlacionar volumes respiratórios obtidos por equipamento padrão de espirometria com um modelo biomecânico de análise fotogramétrica em jovens sem obstruções ou restrições respiratórias. Metodologia: foram avaliados 40 indivíduos (19 meninos e 21 meninas) com idade entre 14 e 17 anos. Foram excluídos indivíduos que apresentaram algum tipo de obstrução ou restrição respiratória. Realizou-se, com a utilização de marcadores adesivos, um mapeamento de superfície em cinco pontos anatômicos: projeção da cicatriz umbilical ou onfálica (COd), ângulo inferior da 10ª costela (ACd), projeção do manúbrio do esterno (MEd), projeção da apófise xifóide do esterno (AXd) e espinha ilíaca ântero-superior direita (EId). Com cada avaliado na posição decúbito dorsal, solicitou-se o teste de Capacidade Vital Forçada (CVF) em um espirômetro modelo Care Fusion - Microloop. O teste foi repetido e filmado três vezes. Dos filmes foram extraídas imagens referentes ao momento de máxima expiração e inspiração para tratamento fotogramétrico da prova com melhores índices respiratórios. Com o uso de um programa disponível no mercado foram definidas áreas e volumes pulmonares para regiões do tórax superior e inferior e abdômen superior e inferior. Além do teste espirométrico realizaram-se coletas da massa corporal, estatura, gordura corporal e comprimento torácico. Resultados: a idade média do grupo foi de 15,40±0,98 anos. Para massa corporal, estatura, percentual de gordura e comprimento torácico encontraram-se valores médios de 61,29±12,27kg, 1,66±0,09m, 22,70±6,49% e 25,54±1,87 cm, respectivamente. Ao comparar meninos e meninas apenas para a idade, não foi encontrada diferença estatisticamente significativa. A análise fotogramétrica encontrou valores correlacionado, com as medidas espirométricas da CVF, Volume Expiratório Forçado no primeiro segundo (VEF1), Pico de Fluxo Expiratório (PFE) além da Inspiração realizada pós teste (IP). Encontrou-se maior mobilidade ventilatória em meninos quando comparados às meninas para região de Tórax Inferior, Abdômen Superior e Abdômen Inferior. Foi possível chegar a uma regressão com R² = 0,866 para prova de CVF e R² = 0,776 para IP com uso da fotogrametria, apresentando um erro padrão de 0,353 e 0,451, respectivamente. Conclusão: A fotogrametria para estudos de movimentos toracoabdominais por meio da aplicação de análises bidimensionais e tridimensionais em imagens adquiridas com a utilização de câmera filmadora se mostrou uma ferramenta útil, aplicável e reprodutível. Foi possível verificar um tipo de comportamento respiratório em adolescentes e associar as medidas obtidas na imagem com os valores mensurados com o uso do espirômetro. Também foi possível estimar o valor da CVF e do volume de ar inspirado em manobra de inspiração profunda. / Introduction: There are several ways to evaluate the respiratory system, among them inductance plethysmography and three-dimensional kinematic analysis, methods of high cost and difficult transportability. The use of an alternative method based on the photographic image (photogrammetry) emerges as an instrument of low cost and easy transportation for respiratory analysis. Objective: The objective of this study was to correlate respiratory volumes obtained by spirometry standard equipment with a biomechanical model photogrammetric analysis of adolescents. Methods: 40 patients (19 boys and 21 girls) were evaluated, aged between 14 and 17 years. Individuals who showed some sort of respiratory obstruction or restriction were excluded. With the markers stickers, a mapping in five anatomical landmarks: projection of the umbilicus (Cod), inferior angle of 10th rib (ACd), projection of sternum manubriam (MEd), sternal xiphoid projection (AXd) and right spine iliac (EId). With each subject assessed in supine position, tests the Forced Vital Capacity (FVC) were requested, using a spirometer Care Fusion - Microloop. The test was repeated three times and filmed. Images of the films were extracted for the moment of maximum expiration and inspiration for photogrammetric processing of proof with better breathing. With the use a program commercially available, areas and lung volumes were defined for the region of upper and lower chest, as well as top and bottom abdomen. In addition to spirometric test body weight, height, body fat and thoracic length were measure. Results: the mean age was 15.40 ± 0.98 years. For body mass, height, fat percentage and thoracic length, average values of 61.29 ± 12.27 kg, 1.66 ± 0.09 m, 22.70 ± 6.49% and 25.54 ± 1.87 cm were found, respectively. When comparing boys and girls at the age difference was not found statistically significant. The photogrammetric analysis has found values strongly correlated with the spirometric measurements of FVC, forced expiratory volume in one second (FEV1), Peak Expiratory Flow (PEF) in addition to post test performed Inspiration (IP). There was a higher ventilatory mobility for boys than girls for Lower Chest and Lower and Upper Abdomen. It was possible to reach a regression R² = 0.866 for proof of FVC and R² = 0.776 for IP with the use of photogrammetry, presenting a standard error of 0.353 and 0.451, respectively. Conclusion: photogrammetry can be used to study thoracoabdominal movements by applying analytical two-dimensional and three-dimensional images acquired using a video camera being, applicable and reproducible. It was possible to verify respiratory behavior in adolescents including measurements on the image with the values measured using the spirometer. It was also possible to estimate the value of FVC and volume of air breathed in deep inspiration maneuver.
132

'n Uitkomsgebaseerde leerbegeleidingsbenadering vir die preseptor in intensiewesorg eenhede

Coetzee, Isabella Maria 21 November 2011 (has links)
M.Cur. / From out the researchers experience of the critical care nursing practice, a need for clinical learning outcomes was identified. There are no listed guidelines or outcomes of what the critical care learner should be able to do at the end of the program, to function as a competent critical care-nursing practitioner. From the above mentioned problemstatement the following question were asked namely: Which knowledge's, skills, attitudes and values do the critical care learner need to function as a compatend critical care nursing practitioner? The main aim of this study was to compile a manual with clinical learning outcomes for the following disciplines within the critical care practice + Cardiology and cardio-thorasic surgery + General surgery and Pulmonary + Neuro-surgery and trauma From out the constructivistic learning approach a contextual, qualitative and describing study was done.The first objective namely the formulation of clinical learning outcomes from out the literature was done by means of a extensive literature survey. The second and third objective of the study namely the formulation of clinical learning outcomes for the different disciplines within the critical care practices. And compiling a manual for the preceptor in the critical care practice was done simultaneously. The clinical learning outcomes was written directly into the format of a manual. Eighty questioners was handed out to critical care trained registered nurses. The data gathered from out the questioners was used in identifying learning outcomes. There are generic clinical learning outcomes, these outcomes are universal for al the disciplines within the critical care practice. Specific clinical learning outcomes where identified for • Coronary and thoracic surgery • Neuro-surgery and • Trauma Specific learning outcomes are outcomes that are only applicable within that specific discipline. If effective clinical guidance are facilitated by means of the clinical learning outcomes and the learner has reached al the outcomes, he/she should be able to function as a competend critical nursing practitioner.
133

'n Ondersoek na die moontlike invloed van vervoer en hantering van sekere varswatervis op die respiratoriese funksies van bloed

Van Pletzen, Andre Johannes Jacobus 12 March 2014 (has links)
M.Sc. (Zoology) / Please refer to full text to view abstract
134

The influence of temperature and activity on certain cardiovascular and respiratory parameters in adult sockeye salmon

Davis, John Christopher January 1968 (has links)
The influence of temperature and activity on certain cardiovascular and respiratory parameters in adult sockeye salmon was studied. Cannulae were implanted in the dorsal aorta and buccal cavities of fish which were forced to swim in a tunnel-type respirometer until they fatigued. Three groups of fish were acclimated and tested at 5, 15, and 22°C respectively. Pressures recorded from the dorsal aorta and buccal cavity gave information about heart rate, blood pressure, pulse pressure, ventilation rate and pressures in the buccal cavity before, during and after the fish were fatigued by swimming. Hematocrit data revealed the blood oxygen capacity of these fish, to be approximately 9 vols %. Knowledge of the blood oxygen capacity, heart rate and the metabolic rates of adult sockeye at various temperatures and levels of activity allowed calculation of stroke volume and cardiac output by the Fick principle. During successively greater swimming activity heart rate and blood pressure rose in all three test groups while ventilation rate was highly variable. Calculated stroke volume and cardiac output increased markedly and it is suggested that the peripheral resistance of the vascular system diminished during exercise. The increase in heart rate during exercise is thought to be related to a release of vagal tone or possibly, to the presence of circulating catecholamines. Elevated dorsal aortic pressure during activity was undoubtably the result of elevated cardiac output. Since dorsal aortic pressure did not increase in accordance with the increases in oxygen uptake observed during activity it is suggested that peripheral resistance decreases in the face of elevated cardiac output. Post-exercise ventilation rate approached resting levels within one hour after fatigue but heart rate and buccal pressure remained above resting levels. High post-exercise heart rates and buccal pressures were believed to be evidence for the presence of an oxygen debt. Blood pressures fell below resting levels in the 15 and 22°C test groups following fatigue and remained low one hour after fatigue. These low pressures may indicate that vasodilation of peripheral vessels had occurred to facilitate flushing of the muscles with blood and aid in the elimination of oxygen debt. Temperature appeared to directly influence heart rate of both quiescent and active fish. Higher acclimation and test temperatures produced higher heart rates than lower acclimation and test temperatures. Presumably temperature influences heart rate by acting directly on membrane phenomena in the myocardium. No cardiac failure was observed in sockeye, even at 22°C during severe exercise. Routine and active oxygen uptake increased with temperature but the rate of increase of active oxygen uptake decreased with temperature - possibly because of the low availability of oxygen in warm water. Temperature appeared to directly influence the ventilation rate of quiescent fish. Higher temperatures were accompanied by high ventilation rates, undoubtably as a result of increased routine metabolic rate at high temperatures and scarcity of oxygen in warm water. / Science, Faculty of / Zoology, Department of / Graduate
135

CFD Heat Transfer Simulation of the Human Upper Respiratory Tract for Oronasal Breathing Condition

Srinivasan, Raghavan January 2011 (has links)
In this thesis. a three dimensional heat transfer model of heated airflow through the upper human respiratory tract consisting of nasal, oral, trachea, and the first two generations of bronchi is developed using computational fluid dynamics simulation software. Various studies have been carried out in the literature investigating the heat and mass transfer characteristics in the upper human respiratory tract, and the study focuses on assessing the injury taking place in the upper human respiratory tract and identifying acute tissue damage based on level of exposure. The model considered is for the simultaneous oronasal breathing during the inspiration phase with high volumetric flow rate of 90/liters minute and a surrounding air temperature of 100 degrees centigrade. The study of the heat and mass transfer, aerosol deposition and flow characteristics in the upper human respiratory tract using computational fluid mechanics simulation requires access to a two dimensional or three dimensional model for the human respiratory tract. Depicting an exact model is a complex task since it involves the prolonged use of imaging devices on the human body. Hence a three dimensional geometric representation of the human upper respiratory tract is developed consisting of nasal cavity, oral cavity, nasopharynx, pharynx, oropharynx, trachea and first two generations of the bronchi. The respiratory tract is modeled circular in cross-section and varying diameter for various portions as identified in this study. The dimensions are referenced from the literature herein. Based on the dimensions, a simplified model representing the human upper respiratory tract is generated.This model will be useful in studying the flow characteristics and could assist in treatment of injuries to the human respiratory tract as well as help optimize drug delivery mechanism and dosages. Also a methodology is proposed to measure the characteristic dimension of the human nasal and oral cavity at the inlet/outlet points which are classified as internal measurements.
136

Dynamic Modeling and System Identification of the Human Respiratory System

Yuan, Jiayao January 2021 (has links)
The lungs are the primary organ of the respiratory system. Their main function is to provide freshly breathed oxygen (O²) to the blood capillaries, while taking carbon dioxide (CO²) from them and expelling it to the atmosphere. Lung conditions such as Acute Respiratory Distress Syndrome (ARDS), Idiopathic Pulmonary Fibrosis (IPF), Coronavirus Disease (COVID-19), etc., cause impaired gas exchange that is life-threatening. In this dissertation, I developed 1) a physiology-based dynamic pulmonary system to study the lung normo- and patho-physiology, and 2) a model-based constrained optimization algorithm to do parameter estimation in order to non-invasively assess lung health. The goals of this work are 1) to accomplish a respiratory personalized medicine example for clinical decision support, and 2) to further the understanding of respiratory physiology, via a mechanistic physiology-based model and system identification techniques. The mechanistic model presented in this thesis comprises six subsystems: 1) a lung mechanics module that computes airflow transport from the mouth and nose to the alveoli (gas exchange units), 2) a respiratory muscles and rib cage mechanics module that simulates the effect of the respiratory muscle contraction on the lungs and the rib cage, 3) a microvascular exchange system that describes fluid (water) and mass (albumin and globulin) transport between the pulmonary capillaries and the alveolar space, 4) an alveolar elasticity module that computes alveolar compliance as a function of the pulmonary surfactant concentration and the elastic properties of the lung tissue fiber, 5) a pulmonary blood circulation that describes blood transport from the heart to the pulmonary system, and 6) a gas exchange system that describes O² and CO² transport between blood in the pulmonary capillaries and gas in the alveoli. Each subsystem was developed based on the latest knowledge of lung physiology and was validated using patient data when available or published and validated physiology-based models. To our knowledge, the combined six-module model would be the most rigorous and expansive lung dynamic model in the literature. This dynamic respiratory system can be used to describe human breathing under healthy and diseased conditions. The model can readily be used to test different what-if scenarios to find the optimal therapy for the patients. Further, I tailor the proposed lung model and adopt system identification techniques for noninvasive assessment of the lung mechanical properties (resistance and compliance) and the patient breathing effort. Pulmonary syndromes or diseases, such as ARDS and COPD (Chronic Obstructive Pulmonary Disease) evoke alterations in lung resistance and compliance. These two parameters reflect, by and large, the state of health and functionality of the respiratory system. Hence tracking these two parameters can lead to better disease diagnosis and easier monitoring of the respiratory disease progression. For spontaneously breathing patients on ventilatory support, the estimation of the lung parameters is challenging due to the added patient’s breathing effort. This dissertation presents a model-based nonlinear constrained optimization algorithm to estimate, breath-by-breath, the lung resistance, the lung compliance, as well as the patient breathing effort due to the respiratory muscle activity, using readily available non-invasive measurements (airway opening pressure and airflow).
137

The role of malnutrition in prolonged respiratory failure : the effect of accelerated nutritional rehabilitation

Hinze, Candace January 1995 (has links)
No description available.
138

Respiratory health of the informal stone crushers in Dar-Es-Salaam.

Kessy, Florian Mathias. January 2010 (has links)
Introduction. Stone crushing in Dar-es-Salaam Tanzania is largely an informal occupational activity, with approximately 7000 workers exposed to varying level of respirable dust. A highly marginalized, self employed, informal stonecrusher is prone to multiple work related risks, particularly dust related respiratory diseases. Aim. This study, the first to be done among informal stone crushers in Southern Africa, aimed at determining the prevalence of dust related respiratory outcomes and relationships between these health endpoints and exposure to respirable dust in this sample of stonecrushers. Methods. This was primarly a cross-sectional descriptive study with analytic components. This study analysed a subset of data collected in a health survey of stone crushers in Kigamboni informal stone quarry in Dar-es-Salaam, Tanzania in 2007. All 200 workers working in the quarry were interviewed. A subset of 86 and 59 workers underwent exposure assessment and health assessments (spirometry and chest radiography) respectively. Associations were investigated between exposure measures and respiratory outcomes. Results. The average age of the workers was 36.3 years with 51.5% males participating in the study. Smoking was common with 30.1% male, 8.25% female smokers, with 2% ex-smokers. Personal dust sampling showed varying dust levels ranging from 0.5-2.8mg/m3 with geometric mean of 1.2gm/m3. The exposure duration of workers in the quarry ranged from 1-62 years with mean of 7.8 years. No single worker was found to use personal protective equipment at work. Reported prevalence of doctor diagnosed respiratory diseases was low: pulmonary tuberculosis (2%), chronic bronchitis (2%), asthma (3%), pneumonia (3%). In contrast, there was high prevalence of respiratory symptoms: chronic cough (13.5%), phlegm production (14.5%), productive cough (10%), wheezing (14%), mild breathlessness (9.5% ) and coughing blood (7.5%). Mean forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) adjusted for age, height and sex was 2.6L/min and 3.7 L respectively, among males and 2.1L/min and 3.0L respectively among females. Adjusted exposure odds ratios for symptoms were statistically significant for mild and moderate breathlessness with odds ratios of 3.4 and 3.1 respectively. Linear regression showed statistically significant decline of 2.3mls in FEV1 with years of exposure while controlling for sex, age, height , doctor diagnosed TB and smoking showing that with prolonged exposure in the quarry, workers are at a risk of developing obstructive lung disease. This trend was not evident for FVC. The majority of films were normal (60.9%), with 19.6% read as 1/0 and 19.9% as 0/1. Discussion. This study identified adverse respiratory outcomes among informal stonecrushers, particularly a high prevalence of respiratory symptoms and clinically important lung function deficits. These are in keeping with other environment studies where workers were exposed to respirable dust. Recommendations. Urgent policy initiatives for developing cost effective hazard control, engineering interventions to protect these marginalized self-employed informal sector stonecrushers are needed. / Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2010.
139

Candidate gene approach to investigating airway inflammation and asthma

Laing, Ingrid A. January 2005 (has links)
[Truncated abstract] Asthma genetic studies have identified many genes that contribute to the pathogenesis of asthma and related variables. Members of the secretoglobin family appear to play an important role in controlling airway inflammation but they have received relatively little attention in asthma genetic research. In this thesis, I have investigated the genes of two members of the secretoglobin family (16 kDa Clara cell secretory protein (CC16) and secretoglobin 3A2 (SCGB3A2)) that are expressed at high levels in the airways and are important anti-inflammatory agents. The overall aim of these studies was to investigate the genetic variability of the CC16 and SCGB3A2 genes and their influence on airway inflammatory disease. The main hypothesis was that genetic variability in the genes for CC16 and SCGB3A2 exert an influence on airway inflammatory disease. Three populations were investigated: (1) a paediatric case control population (n=99), (2) an unselected birth cohort followed longitudinally at ages 1 month (n=244), six (n=123) and 11 years (n=195) and (3) an unselected Aboriginal Australian population (n=251). The case-control population was screened for novel DNA sequence variants in the CC16 promoter and the SCGB3A2 5’UTR and exons. No novel sequence variants were identified in the CC16 promoter and two were identified in the SCGB3A2 5’UTR (G- 811A and G-205A). A single nucleotide polymorphism previously identified in the CC16 gene (A38G) and the two polymorphisms identified in the SCGB3A2 gene were genotyped in both unselected populations. Genotype/phenotype associations were identified with adjustment for potential confounders such as age, gender, height and maternal tobacco smoking, where appropriate. This was due to the contribution of these factors to the aetiology of asthma, atopy and related phenotypes. All three polymorphism frequencies were significantly different between these two ethnically diverse populations
140

An application of geographic information systems in the study of spatial epidemiology of respiratory diseases in Hong Kong, 1996-2000

So, Fun-mun., 蘇歡滿. January 2002 (has links)
published_or_final_version / Geography / Master / Master of Philosophy

Page generated in 0.1204 seconds