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  • 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.
91

Expert and local knowledge in decision support for natural resource management : analysis of capture and use

Van Cauwenbergh, Nora 28 January 2008 (has links)
Efficient management of natural resources (NRM) needs to be built on a correct understanding of the objectives of different stakeholders. Therefore, it is required to actively involve experts and stakeholders in the decision making process. However, the introduction of these knowledge claims is controversial. This is due to differences in the quality of the underlying involvement methods. The principle objective of this study was therefore to develop, apply and critically analyse improved (hybrid) methodologies to integrate expert and local knowledge in existing NRM decision making frameworks. Research is performed on 2 case studies. The SAFE case study deals with the development of a framework for evaluating sustainability levels in agricultural systems in Belgium, while the ALERT case study deals with sustainable management of water resources in semi-arid regions, applied to the Andarax catchment in Spain. The analysis of pro's and contra's of both the technocratic and the pure participatory approaches sets the blueprint for a hybrid decision making framework. Experience shows that decision support is improved when an indicator-based assessment structure is embedded in the participatory approach. This is facilitated through the use of soft operational research techniques. A sound methodology for participatory indicator selection is presented and clear-cut answers to problems with reliability of judgments are provided. The design of different typologies of membership functions is an important step to future deliberation of participatory-based norms. A computerized decision support system (DSS) is developed as it proves to be an important means to deal with increased information and complexity in decision support for NRM. In response to calls for greater collaboration with local actors, the DSS contains different functionalities that are designed to be interactive, while optimal default values ensure basic quality standards. Multi-criteria analysis allows an evaluation of alternatives and scenarios in the hybrid decision making framework. We deal with important choices that have to be made when interpreting spatio-temporal variabilities in management performances and the implications thereof on the final projections towards decision makers. The propagation of uncertainty in the hybrid decision making frameworks is critically evaluated. In order to consider uncertainty in an integrated way, a combined uncertainty/sensitivity analysis is presented. This analysis includes uncertainty related to norms, weights and indicators. Finally, guidelines for communication of the findings towards decision makers are drafted. / Pour être efficace, la gestion des ressources naturelles (GRN) doit prendre en compte correctement les objectifs de différents acteurs. Il est dès lors recommandé d’inclure activement les experts et les parties prenantes dans le processus de prise de décision. Cependant, la meilleure manière de prendre en compte différents types de savoir est sujette à controverse. L’objectif principal de cette étude est donc de développer, appliquer et évaluer des méthodes améliorées (hybrides) de prise en compte du savoir des parties prenantes et des experts dans les systèmes actuels de prise de décision pour la GRN. Cette recherche a été appliquée sur deux cas d’étude. Le premier, appelé SAFE, traite du développement d’un cadre pour évaluer la durabilité des systèmes agraires en Belgique. Le second, ALERT, traite de la gestion durable de l’eau dans des régions semi-arides, appliquée ici au bassin de l’Andarax (Espagne). L’analyse comparée des points forts et des points faibles des approches participatives et technocratiques fournit le cadre pour une approche hybride de prise de décision. Les expériences montrent que l’aide à la décision est améliorée lorsqu’une évaluation par des indicateurs est ancrée dans une approche participative. Des techniques de « recherche opérationnelle douce » permettent cette prise en compte. Nous présentons une méthode pour définir les indicateurs d’une façon participative qui permet de donner des réponses claires aux problèmes liés à la fiabilité des jugements. La définition d’une typologie de fonctions d’appartenance spécifique pour les indicateurs est une étape importante pour le choix participatif des normes. Un système informatisé d'aide à la décision (SIAD) a été développé afin de faire face à l’accroissement de la quantité d’information et de la complexité dans l'aide à la décision. En réponse à la demande d'une plus grande collaboration avec les acteurs locaux, le SIAD contient différentes fonctionnalités qui peuvent être configurées interactivement. Par default on propose des valeurs optimalisées pour assurer des standards de qualité. L'analyse multicritère permet une évaluation des alternatives de gestion et des scénarios dans le cadre de la prise de décision hybride. Nous traitons des choix importants à faire lors de l'interprétation des variations spatio-temporelles des performances de gestion et des implications de ceux-ci sur les avis finaux relayés aux décideurs. La propagation des incertitudes dans la prise de décision des cadres hybrides est aussi évaluée. Afin d'examiner l'incertitude d'une manière intégrée, une analyse mixte de sensibilité et d’incertitude est présentée. Celle-ci porte sur l’incertitude liée aux normes, aux poids et aux indicateurs. Afin de mener à une gestion efficace et durable des ressources naturelles, nous proposons des solutions techniques aux décideurs pour mieux valoriser la connaissance intrinsèque des acteurs de terrain et des gestionnaires.
92

Engenharia clínica aplicada à análise da variabilidade de parâmetros de referência para classificação da função pulmonar de adultos brasileiros / Clinical engineering applied to the analysis of the variability of reference parameters for classification of pulmonary function in brazilian adults

Silva, Paulo Roberto da 12 December 2016 (has links)
Uma das aplicações básicas da engenharia biomédica se refere aos testes de equipamentos de uso clínico, a avaliação de sua natureza, acessibilidade e/ou suas características. No âmbito da avaliação do sistema respiratório, estão disponíveis diferentes parâmetros de referência (PR) para o teste de espirometria, um dos principais testes de função pulmonar, que permite medir: volumes, capacidades e fluxos pulmonares. Estes PR baseiam-se principalmente em dados étnicos, idade e gênero de indivíduos saudáveis, mas havendo diferenças entre populações avaliadas, como no Brasil com sua grande diversidade de raças e etnias, pode haver erro diagnóstico. Em razão disto, o objetivo deste estudo foi analisar três dos principais PR utilizados nesta população: PR-P (de Pereira e colaboradores de 2007), PR-K ( de Knudson e colaboradores de 1983) e PR-Q (de Quanjer e colaboradores de 2012). Procedeu-se um estudo exploratório descritivo com 683 indivíduos (180 homens e 503 mulheres) entre 24 e 59 anos, em boas condições de saúde, praticantes de exercícios físicos regulares com frequência mínima de duas vezes por semana. Foi aplicada anamnese, coletados dados de massa, estatura e realizada a espirometria forçada (espirômetro bidirecional - Care Fusion MicroLoop) e as variáveis respiratórias avaliadas foram VEF1, CVF, FEF75 e PFE. Como principais resultados verificou-se que a idade média foi de 42 anos (masculino: 40,6 anos; feminino: 44,4 anos); IMC médio de 26 Kg/m² (masculino: 26,26 Kg/m²; feminino: 26,44 Kg/m²); e tempo da prática de exercícios físicos médio de 52 meses (masculino: 66,9 meses; feminino: 37,9 meses). Ao se analisar a variação dos parâmetros de referência para classificação da função pulmonar entre os três protocolos testados, encontrou-se diferença estatisticamente significativa (p<0,05) entre CVF, VEF1, FEF75 e PFE para os valores previstos e atingidos em todos os PR, além de sinais restritivos e obstrutivos. Para o PR-P, mesmo com indivíduos com características assintomáticas e praticantes de exercícios físicos, 17,2% dos indivíduos foram classificados com algum grau de restrição e 17,3% com obstrução, distanciando-se do PR-K e PR-Q que, respectivamente apresentaram valores para restritivo de 7,0% e 12,8% e para obstrutivos de 7,1% e 4,8%. Conclui-se que os respectivos PR podem induzir a erros, levando a classificações diferentes, podendo um mesmo indivíduo ser considerado em estado de normalidade, restritivo ou obstrutivo, a depender do protocolo escolhido. O estado nutricional interferiu na função respiratória no gênero masculino ao se identificar associação significativa entre o estado nutricional e o teste de função pulmonar, x² = 9,80 (p = 0,04). Desta forma, homens acima do peso tiveram 1,9 vezes mais risco de apresentar o teste de função pulmonar insuficiente, mesmo praticando exercícios físicos regulares. Não houve associação significativa em nenhum dos gêneros entre o teste de função pulmonar e o tempo de prática de exercícios físicos. O teste de correlação de Pearson, confirmou a inexistência de correlação entre as variáveis VEF1, PFE e CVF com o tempo de prática para ambos os gêneros. / One of the basic applications of biomedical engineering refers to the testing of clinical use equipment, the assessment of its nature, accessibility and / or its features. In the evaluation of the respiratory system, are available different parameters of reference (PR) for the spirometry test, one of the main pulmonary function tests, which can measure: volumes, capacities and pulmonary flows. These PR based mainly on ethnic data, age and gender in healthy subjects, but with differences between populations studied, as in Brazil with its great diversity of races and ethnic groups, there may be misdiagnosis. Because of this, the objective of this study was to analyze in this population, three of the most used PR: PR-P (Pereira et al., 2007), PR-K (Knudson et al., 1983) and PR-Q (Quanjer et al., 2012). The procedure was a descriptive exploratory study with 683 subjects (180 men and 503 women) between 24 and 59 years, in good health, regular physical exercises practitioners with minimum frequency of twice a week. Anamnesis was applied, collected data of mass and height, performed forced spirometry (bidirectional spirometer - Care Fusion Microloop) and the following respiratory variables were measured, FEV1, FVC, PEF and FEF75. With the main results it was found that the average age was 42 years (male: 40.6 years; women: 44.4 years); BMI average of 26 kg / m² (male: 26.26 kg / m²; female: 26.44 kg / m²); and time the average physical exercises practice 52 months (male: 66.9 months; female: 37.9 months). When analyzing the variation of the reference parameters for pulmonary function classification between the three protocols tested, we found a statistically significant difference (p <0.05) between FVC, FEV1, PEF and FEF75 to the levels required and achieved in all PR, as well as restrictive and obstructive signs. For the PR-P, even with individuals with asymptomatic characteristics and practitioners of physical exercises, 17.2% of subjects were classified with some degree of restriction and 17.3% with obstruction, away from the PR-K and PR-Q which respectively had values for restrictive of 7.0% and 12.8% and for obstruction of 7.1% and 4.8%. We conclude that these PR may induce to errors, leading to different rating, where one individual can be considered in normal state, restrictive or obstructive, depending on the chosen protocol. It was identified that nutritional status interfere with respiratory function, demonstrating significant association between nutritional status and pulmonary function test for males, x² = 9.80 (p = 0.04). Thus, overweight men had 1.9 times more risk to have the insufficient lung function test, even practicing regular physical exercises. There was no significant association in any of the genres between the pulmonary function test and the time of physical activity. The Pearson correlation test confirmed the lack of correlation between the FEV1, FVC and PEF with practice time for both genders.
93

Revisão sistemática da literatura sobre quantificação de subclasses de IgG em crianças para detecção de imunodeficiências primárias com defeito na produção de anticorpos

Asch, Karen Helene January 2011 (has links)
Submitted by Luis Guilherme Macena (guilhermelg2004@gmail.com) on 2013-05-07T13:58:14Z No. of bitstreams: 1 DISSERTAÇÃO - Karen Helene Asch.pdf: 1993056 bytes, checksum: 37006a8cb3f8fe11cf9d8147b382b8f8 (MD5) / Made available in DSpace on 2013-05-07T13:58:14Z (GMT). No. of bitstreams: 1 DISSERTAÇÃO - Karen Helene Asch.pdf: 1993056 bytes, checksum: 37006a8cb3f8fe11cf9d8147b382b8f8 (MD5) Previous issue date: 2011 / Fundação Oswaldo Cruz. Instituto Fernandes Figueira. Departamento de Ensino. Programa de Pós-Graduação em Saúde da Criança e da Mulher. Rio de Janeiro, RJ, Brasil
94

Curvas de referência dos parâmetros ósseos obtidos por tomografia computadorizada quantitativa periférica de alta resolução (HR-pQCT) em mulheres saudáveis de 20 a 85 anos de idade / Reference curves of bone parameters obtained by high resolution peripheral quantitative computed tomography (HR-pQCT) in healthy women from 20 to 85 years old

Jackeline Couto Alvarenga 18 June 2015 (has links)
INTRODUÇÃO: O osso é um tecido dinâmico e a formação e reabsorção óssea são processos contínuos que promovem alterações durante toda a vida do organismo. O objetivo deste estudo transversal é estabelecer valores normais relacionadas com a idade, peso e altura, obtidos pela tomografia computadorizada quantitativa periférica de alta resolução (HR-pQCT) quanto à densidade mineral óssea volumétrica, microarquitetura, porosidade cortical e resistência óssea estimada por análise de elemento finito no rádio distal e na tíbia de uma população miscigenada de mulheres com idade entre 20 a 85 anos. MÉTODOS: Curvas de referências da densidade volumétrica (total, trabecular e cortical), estrutura óssea, porosidade cortical e parâmetros de elementos finitos no rádio distal e na tíbia foram calculados em 450 mulheres saudáveis, incluindo mais de 50 indivíduos para cada década. Modelos de regressão linear foram desenvolvidos para prever os valores das curvas normais medidos de acordo com a idade, peso e altura. RESULTADOS: Todos os parâmetros de densidade e estrutura mostraram curvas lineares decrescentes com o envelhecimento em ambos sítios periféricos, exceto para a densidade cortical (Ct.BMD) e espessura cortical (Ct.Th) na tíbia, que apresentaram um padrão de declínio diferente na curva. O parâmetro porosidade cortical (Ct.Po) manteve um platô nas primeiras décadas de vida, seguida de um aumento da porosidade nas décadas seguintes, enquanto que o diâmetro dos poros da cortical (Ct.Po.Dm) mostrou uma curva linear crescente em ambas as regiões analisadas. Os parâmetros de resistência óssea apresentaram curvas lineares, com exceção da rigidez (S) e carga máxima estimada (F.ult) no rádio distal e estresse cortical (C.VM) na tíbia, que apresentavam diferentes curvas de declínio. Foram encontradas correlações significativas da rigidez com todos os parâmetros analisados (p < 0,001), exceto com o parâmetro diâmetro dos poros da cortical (Ct.Po.Dm) na tíbia. CONCLUSÕES: Este trabalho estabeleceu um conjunto de dados de referência para os parâmetros obtidos por HR-pQCT, com base em uma população normal miscigenada, que serão úteis para a interpretação dos dados clínicos de pacientes na prática clínica e em futuros estudos / INTRODUCTION: Bone is a dynamic tissue, and its formation and resorption are continuous processes that promote changes throughout the life of the organism. The aim of this cross-sectional study is to establish normal values related to age, weight and height using high-resolution peripheral quantitative computed tomography (HR-pQCT) regarding volumetric bone mineral density (vBMD), microarchitecture, cortical porosity and estimated bone strength at the distal radius and tibia from a miscegenated population of women aged 20 to 85 years. METHODS: References curves of vBMD (total, trabecular and cortical), bone structure, cortical porosity and finite element parameters at the distal radius and tibia were calculated in 450 healthy women, including more than 50 subjects from each decade within the age range. Linear regression models were developed to predict the values of the normal curves measured according to age, weight and height. RESULTS: All parameters of vBMD and structure showed decreasing linear curves with aging in both peripheral sites, except for compact bone density (Ct.BMD) and cortical thickness (Ct.Th) at the tibia, which had a different declining curve pattern. The cortical porosity parameter (Ct.Po) maintained a plateau in the first decades followed by an increase in porosity, whereas the cortical pore diameter (Ct.Po.Dm) showed an increasing linear curve in both regions analyzed. Parameters of bone strength presented decreasing linear curves, except for stiffness (S) and estimated failure load (F.ult) at the distal radius and cortical stress (C.VM) at the tibia, which presented with different declining curve. Significant correlations of stiffness with the remaining parameters were found (p < 0.001), except with the cortical pore diameter (Ct.Po.Dm) at the tibia. CONCLUSION: This study established a set of reference data for parameters obtained by HR-pQCT, based on a miscegenated normal population, which will be useful for interpreting clinical data from patients in clinical practice and in future studies
95

O papel da escolaridade, do alfabetismo funcional e dos fatores sociodemográficos na avaliação cognitiva do idoso / The role of formal education, functional literacy, and demographic factors on the cognitive assessment of older adults

Daniel Apolinario 06 August 2013 (has links)
INTRODUÇÃO: A busca pelo diagnóstico cada vez mais precoce das demências traz a necessidade de estratégias mais eficientes na utilização dos testes cognitivos. A definição dos parâmetros de normalidade para esses testes é particularmente desafiadora no contexto brasileiro de baixa escolaridade e grande heterogeneidade sociocultural. OBJETIVO: Avaliar os efeitos de diferentes estratégias de ajuste de normas nas propriedades do Mini-Exame do Estado Mental (MEEM). MÉTODOS: Duzentos e trinta idosos encaminhados a um serviço de Geriatria por suspeita de comprometimento cognitivo foram recrutados sequencialmente e submetidos ao MEEM. Todos os pacientes passaram por uma segunda avaliação cega para o resultado do MEEM, constituída de testagem neuropsicológica e entrevista com um informante para obtenção de diagnóstico padrão-ouro. Para o ajuste de normas, quatro fatores preditores foram testados: (1) características sociodemográficas; (2) uma classificação simples de alfabetismo funcional com quatro níveis; (3) um questionário de habilidades cognitivas pré-morbidas respondido pelo informante; (4) um teste de leitura de palavras aplicado diretamente ao paciente. Três técnicas de predição foram testadas: (1) agrupamento em níveis; (2) regressão linear; (3) regressão não-linear por modelo polinomial fracional. As combinações de fatores preditores e técnicas de predição deram origem a vinte modelos que foram testados individualmente na comparação com o MEEM sem ajuste. Os desfechos avaliados foram a acurácia do modelo na detecção de comprometimento cognitivo e a variação da sensibilidade e da especificidade entre os níveis socioeconômicos. RESULTADOS: Entre os 230 idosos recrutados, 106 (46%) apresentavam envelhecimento cognitivo normal, 56 (24%) comprometimento cognitivo sem demência e 68 (29%) demência. A classificação de alfabetismo funcional, o questionário de habilidades cognitivas pré-mórbidas e o teste de leitura de palavras não apresentaram propriedades adequadas para ajuste de normas, mas as limitações podem estar relacionadas a problemas específicos dos instrumentos utilizados e não devem ser generalizadas. Alguns modelos baseados em fatores sociodemográficos foram capazes de melhorar a acurácia do MEEM, resultado que diverge da literatura atual e que deve ser confirmado em outros estudos com populações de baixa escolaridade. Um modelo polinomial fracional utilizando variáveis sociodemográficas apresentou propriedades ótimas de acurácia e promoveu estabilização da sensibilidade e da especificidade entre os níveis socioeconômicos. A partir das equações geradas por esse modelo podem ser construídas tabelas simples de uso clínico para converter o resultado bruto em escore z ou percentil. CONCLUSÕES: Nossos resultados apontam o modelo polinomial fracional baseado em variáveis sociodemográficas como a melhor opção para ajuste de normas de testes cognitivos em nosso meio / INTRODUCTION: The need for diagnosing dementia early demands effective strategies on the use of cognitive tests. Establishing criteria of normality for these tests is a challenging task in environments of low education and enormous sociocultural heterogeneity such as observed in Brazil. OBJETIVE: To evaluate how different strategies for adjusting norms can change the properties of the Mini-Mental Status Examination (MMSE). METHODS: Two hundred and thirty older adults referred for a geriatric service because of suspected cognitive impairment were recruited sequentially and completed the MMSE. All the patients underwent a second assessment, blind to the result of the MMSE, which was composed of a neuropsychological battery and an interview with a close informant for the establishment a gold-standard diagnosis. For the adjustment of the norms, four predictive factors were evaluated: (1) demographic characteristics; (2) a simple classification of functional literacy with four levels; (3) a premorbid abilities questionnaire; (4) a word-reading test. Three techniques of prediction were evaluated: (1) grouping in demographic or ability levels; (2) simple or multivariate linear regression; (3) nonlinear regression by using a fractional polynomial model. Some possible combinations of predictive factors and prediction techniques originated twenty models that were assessed individually in comparison with the raw MMSE scores. The endpoints assessed were accuracy of the model for detecting cognitive impairment and the variation of the sensibility and specificity across socioeconomic levels. RESULTS: Of the 230 older adults recruited, 106 (46%) had normal cognitive aging, 56 (24%) presented cognitive impairment no dementia (CIND) and 68 (29%) had dementia. The functional literacy classification, the premorbid cognitive abilities questionnaire and the word-reading test did not present adequate properties for the adjustment of norms, but the limitations may be associated to specific problems of the instruments an cannot be generalized. Some models based on the demographic characteristics were able to improve the accuracy of the MMSE. This finding diverges from the currently available literature and should be confirmed in further studies with low-educated populations. A fractional polynomial model employing demographic factors presented very good properties and was able to stabilize the sensibility and the specificity across the socioeconomic levels. The equations generated by this model can be employed to construct practical tables for converting raw scores into z scores and percentiles. CONCLUSIONS: Our results point to the fractional polynomial model based on demographic variables as the best choice to adjust norms for cognitive tests in our context
96

Bestimmung der Gesamt-Hämoglobinmenge und des Blutvolumens mit einer direkten Kohlenstoffmonoxid-Bolus-Methode - Methodische Umsetzung und Evaluierung -

Falz, Roberto 10 July 2013 (has links)
Kohlenmonoxid (CO) wird nach Einatmung weitgehend an Hämoglobin gebunden, eine minimale Bindung findet auch an Myoglobin statt. Die Kohlenmonoxid-Hämoglobinkonzentration (COHb) im Blut steigt nach Inhalation proportional zur inhalierten CO-Menge und zur Hämoglobinmasse an. Dieser Anstieg wird über die CO-Hämoxymetrie ermittelt und resultierend aus der CO-Verdünnung die Hämoglobinmenge berechnet. Über die Hämoglobinkonzentration und den Hämatokrit kann im Anschluss das Blutvolumen berechnet werden. Grundsätzlich ist dieses Verfahren seit über 100 Jahren bekannt und wird seit ca. 1995 als Routinemethode zur Blutvolumenbestimmung in der Sportmedizin verwendet. Es existieren darüber hinaus methodische Probleme durch die CO-Abatmung und die Evaluierung in großen Kollektiven. Die hier vorgestellte Methodik beinhaltet die Weiterentwicklung der CO-Methode zur Direktmessung im geschlossenen System. Die Probanden atmen dabei ein exakt definiertes Bolus-Volumen in einem geschlossenen Atmungssystem über 15 Minuten ein. Die maximale Arbeitsplatzkonzentration (MAK: COHb 5%), also die resultierende COHb-Konzentration im Blut bei einer CO-Langzeitexposition von 35 ppm, wird in der Regel nur leicht überschritten. Dazu wurden an 104 Probanden zwei Vergleichsmessungen in definiertem Abstand und an 20 Probanden Wiederholungsmessungen nach Blutspende zum Nachweis der Reliabilität und Validität durchgeführt. Zusätzlich ist die Abfallkinetik von COHb an 20 Probanden bestimmt worden. Im Ergebnis stellt sich methodenbedingt ein COHb-Steady-State nach 9 Minuten Rückatmung im geschlossenen System ein. Der Typical-Error der Messwiederholung der Methodik liegt bei 1,9% bzw. nach weiterer Modifizierung der Methodik bei 1,3%. Der Nachweis eines Blutverlustes von 490 ml im Rahmen einer Blutspende zeigt nur eine minimale Abweichung von 10 g Hämoglobinmasse zwischen gemessenem und kalkuliertem Verlust. Die Halbwertszeit von COHb wurde mit 135 min bestimmt. Die verwendete Methodik zeigt aufgrund der induzierten COHb-Steady-State-Kinetik Vorteile bei der Anwendung und Genauigkeit. Der Nachweis der Wiederholbarkeit und Messgenauigkeit konnte an einem hinreichend großen Kollektiv gezeigt werden. Bei Mehrfachanwendung bietet die Sensitivität der Methodik die Möglichkeit der Aufdeckung von Manipulationen des Blutes über Erythropoetin (EPO) oder Eigenbluttransfusion. Dabei bewegt sich die eingesetzte CO-Belastung während der Methode im Bereich des Konsums von wenigen Zigaretten.
97

Measurement and fusion of non-invasive vital signs for routine triage of acute paediatric illness

Fleming, Susannah January 2010 (has links)
Serious illness in childhood is a rare occurrence, but accounts for 20% of childhood deaths. Early recognition and treatment of serious illness is vital if the child is to recover without long-term disability. It is known that vital signs such as heart rate, respiratory rate, temperature, and oxygen saturation can be used to identify children who are at high risk of serious illness. This thesis presents research into the development of a vital signs monitor, designed for use in the initial assessment of unwell children at their first point of contact with a medical practitioner. Child-friendly monitoring techniques are used to obtain vital signs, which can then be combined using data fusion techniques to assist clinicians in identifying children with serious illness. Existing normal ranges for heart rate and respiratory rate in childhood vary considerably, and do not appear to be based on clinical evidence. This thesis presents a systematic meta-analysis of heart rate and respiratory rate from birth to 18 years of age, providing evidence-based curves which can be used to assess the degree of abnormality in these important vital signs. Respiratory rate is particularly difficult to measure in children, but is known to be predictive of serious illness. Current methods of automated measurement can be distressing, or are time-consuming to apply. This thesis therefore presents a novel method for estimating the respiratory rate from an optical finger sensor, the pulse oximeter, which is routinely used in clinical practice. Information from multiple vital signs can be used to identify children at risk of serious illness. A number of data fusion techniques were tested on data collected from children attending primary and emergency care, and shown to outperform equivalent existing scoring systems when used to identify those with more serious illness.
98

Curvas de referência dos parâmetros ósseos obtidos por tomografia computadorizada quantitativa periférica de alta resolução (HR-pQCT) em homens saudáveis / Reference curves of bone parameters obtained by high resolution peripheral quantitative computed tomography (HR-pQCT) in healthy men

Alvarenga, Jackeline Couto 26 June 2019 (has links)
INTRODUÇÃO: O surgimento da tomografia computadorizada quantitativa periférica de alta resolução (HR-pQCT) tornou possível medir a densidade mineral óssea (DMO) volumétrica e a microarquitetura óssea tridimensional in vivo, bem como avaliar a resistência óssea através da análise de elemento finito (FE). Como não há na literatura um banco de dados para a população masculina brasileira, o objetivo principal deste estudo transversal e estabelecer valores de referência para os parâmetros ósseos obtidos por HR-pQCT em homens, categorizados por décadas e ajustados por peso e altura, na região distal do rádio e da tíbia. Como objetivo secundário, correlacionar o parâmetro de resistência óssea - rigidez do tecido ósseo (S), com os demais parâmetros medidos por HR-pQCT, e com parâmetros obtidos por absorciometria de raios- X de dupla energia (DXA), incluindo escore de osso trabecular (TBS). METODOS: Homens brasileiros saudáveis (n = 340) entre as idades de 20 e 92 anos foram incluídos neste estudo. O antebraço não dominante e a perna esquerda foram imobilizados, e foram realizados métodos de segmentação padrão e avançado para as análises da região distal do rádio e da tíbia por HRpQCT. A partir das imagens HR-pQCT, a DMO volumétrica e microestrutura do osso trabecular e cortical foram avaliadas, e a resistência óssea foi estimada usando analise de FE. Também foi realizada medição da coluna lombar e fêmur por DXA para obtenção dos valores de DMO e TBS. Os dados foram descritos em mediana e quartis (IQR). Modelos de regressão linear múltipla em função da idade, peso e altura foram desenvolvidos e ilustrados por diagramas de dispersão com intervalos de 95% de normalidade. Foram calculadas as correlações de Pearson entre alguns parâmetros de interesse. RESULTADOS: Tanto na região distal do rádio como na tíbia, os parâmetros de DMO volumétrica, estrutura e de resistência óssea apresentaram relação estatisticamente significativa com a idade (p < 0,05). As correlações entre S com os demais parâmetros de DMO volumétrica e microarquitetura, bem como com DMO areal e TBS, foram mais fortes na região da tíbia, exceto com espessura trabecular, que foi melhor na região do rádio. As correlações entre TBS com os parâmetros de densidade (trabecular e cortical), número e espessura trabecular, e espessura cortical nas regiões periféricas, foram significativas (p < 0,05), exceto com espessura cortical na tíbia. Quando o TBS foi avaliado de acordo com a categoria de risco, e correlacionado com a rigidez do tecido na região distal do rádio e da tíbia, e com DMO da coluna lombar, apenas o grupo de baixo risco (TBS ³ 1.310) apresentou correlações significativas (p < 0,05). CONCLUSOES: Este trabalho estabeleceu valores de referência para os parâmetros ósseos obtidos por HR-pQCT, com base em uma população saudável miscigenada do sexo masculino. As correlações entre os parâmetros ajudam a compreender o papel de cada variável em relação ao risco de fratura. Pesquisadores e clínicos poderão utilizar esses dados como uma ferramenta adicional para avaliar a saúde óssea e alterações na qualidade óssea / INTRODUCTION: The availability of high resolution peripheral quantitative computed tomography (HR-pQCT) has made it possible to measure volumetric bone mineral density (BMD) and three-dimensional bone microarchitecture in vivo, as well as to evaluate bone strength through finite element (FE) analysis. As there is no database for Brazilian male population, the main objective of this cross-sectional study was to establish reference values for the bone parameters obtained by HR-pQCT in men, categorized for decades and adjusted for weight and height, of the distal radius and tibia. As a secondary objective, to correlate the bone strength parameter - stiffness (S) and other parameters measured by HR-pQCT and parameters obtained by dual-energy X-ray absorptiometry (DXA), including trabecular bone score (TBS). METHODS: Healthy Brazilian men (n = 340) including ages of 20 to 92 years were included in this study. The non-dominant forearm and left leg were immobilized, and standard and advanced segmentation methods were performed for the distal radius and tibia analyzes by HR-pQCT. From HR-pQCT images, volumetric BMD and bone microstructure of trabecular and cortical were evaluated, and bone strength was estimated using FE analysis. Measurements of the lumbar spine and femur by DXA were also performed to obtain BMD and TBS values. The data were described as median and quartiles (IQR). Multiple linear regression models according to age, weight and height were developed and illustrated by dispersion diagrams with 95% normality intervals. Pearson correlations were calculated between some parameters of interest. RESULTS: Parameters of volumetric BMD, structure and bone strength, at distal radius and tibia, showed a significant association with age (p < 0.05). The correlations between S with the other parameters of volumetric BMD and microarchitecture, as well as with areal BMD and TBS, were stronger in the tibia except for trabecular thickness, which was better in the distal radius. The correlations between TBS and density parameters (trabecular and cortical), number and trabecular thickness, and cortical thickness in the peripheral sites were significant (p < 0.05), except with cortical thickness in the tibia. When TBS was evaluated according to risk category, and correlated with S in the distal radius and tibia, and lumbar spine BMD, only the low risk group (TBS ³ 1.310) had significant correlations (p < 0.05). CONCLUSION: This work developed reference values for the bone parameters obtained by HR-pQCT, based on a healthy population for males. Correlations between the parameters support to understand the role of each variable and the relationship with fracture risk. Researchers and clinicians can use these data as an additional tool to assess male bone health and changes in bone quality
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Cerebral venous outflow resistance and interpretation of cervical plethysmography data with respect to the diagnosis of chronic cerebrospinal venous insufficiency

Beggs, Clive B., Shepherd, Simon J., Zamboni, P. January 2014 (has links)
No / PURPOSE: To investigate cerebrospinal fluid (CSF) dynamics in the aqueduct of Sylvius (AoS) in chronic cerebrospinal venous insufficiency (CCSVI)-positive and -negative healthy individuals using cine phase contrast imaging. MATERIALS AND METHODS: Fifty-one healthy individuals (32 CCSVI-negative and 19 age-matched CCSVI-positive subjects) were examined using Doppler sonography (DS). Diagnosis of CCSVI was established if subjects fulfilled >/=2 venous hemodynamic criteria on DS. CSF flow and velocity measures were quantified using a semiautomated method and compared with clinical and routine 3T MRI outcomes. RESULTS: CCSVI was associated with increased CSF pulsatility in the AoS. Net positive CSF flow was 32% greater in the CCSVI-positive group compared with the CCSVI-negative group (P = 0.008). This was accompanied by a 28% increase in the mean aqueductal characteristic signal (ie, the AoS cross-sectional area over the cardiac cycle) in the CCSVI-positive group compared with the CCSVI-negative group (P = 0.021). CONCLUSION: CSF dynamics are altered in CCSVI-positive healthy individuals, as demonstrated by increased pulsatility. This is accompanied by enlargement of the AoS, suggesting that structural changes may be occurring in the brain parenchyma of CCSVI-positive healthy individuals.

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