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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.
111

Eficácia e segurança do uso da ventilação não invasiva associada à manobra de recrutamento alveolar no pós-operatório de revascularização do miocárdio: ensaio clínico randomizado / Efficacy and safety of using noninvasive ventilation associated with recruitment maneuver in the postoperative period of coronary artery bypass grafting: a randomized clinical trial

Miura, Mieko Claudia 21 November 2017 (has links)
INTRODUÇÃO: Complicações pulmonares são frequentes no pós-operatório da cirurgia de revascularização do miocárdio (RM) e a ventilação não-invasiva (VNI) tem sido utilizada nos cuidados pós-operatórios de forma profilática e terapêutica. A manobra de recrutamento alveolar (MRA) consiste no aumento sustentado de pressão na via aérea utilizando um alto nível de pressão expiratória final positiva (PEEP) em indivíduos hipoxêmicos, garantindo uma ventilação pulmonar homogênea e, com isso melhorando a oxigenação arterial. O objetivo desse estudo foi de avaliar se o uso da VNI associada à MRA pode melhorar a oxigenação e se pode ser aplicada de forma segura nos pacientes pós-operatório de RM. MÉTODOS: Foram incluídos 34 pacientes internados na unidade de terapia intensiva (UTI) ventilados mecanicamente após RM com relação Pa02/Fi02 < 300 e escore radiológico de atelectasia ;:: 2. Os pacientes foram randomizados 16 para o grupo controle (GC) e 18 para o grupo recrutamento (GR), após a extubação a VNI foi aplicada por 30 minutos três vezes ao dia de acordo com a rotina da UTI. No GC a VNI era realizada com PEEP de 8 cm H20 e no GR foi aplicada PEEP de 15 cm H20 e 20 cm H20 durante 2 minutos cada e depois ficava com PEEP de 8 cm H20. Analisamos a Pa02 pela gasometria arterial em ar ambiente e o escore radiológico de atelectasia, estabilidade hemodinâmica e evento adverso até a alta da UTI. RESULTADOS: Aumento de Pa02 12,6 ± 6,8% GC e 23,3 ± 8,5% GR com p < 0,001, o escore radiológico de atelectasia apresentou resolução completa em 94,4% GR, enquanto que no GC, 87,5% apresentou algum grau de atelectasia, p < 0,001. Não houve eventos adversos relacionados. CONCLUSÃO: o uso por 30 minutos da VNI associada à MRA foi seguro, melhorou a oxigenação e reduziu a atelectasia / BACKGROUND: Postoperative pulmonary impairment is common in the early period after coronary artery bypass grafting (CABG) and noninvasive ventilation (NIV) has been used in postoperative care to prevent and treatment. Recruitment maneuver (RM) consists in a sustained raise of airway pressure with high levei of positive end-expiratory pressure (PEEP) in hypoxemic subjects, insuring a homogeneous pulmonary ventilation and enhancing oxygenation. The aims of this study were to evaluate if the use of NIV associated with RM could improve oxygenation and if it could be safely applied in CABG postoperative patients. METHODS: Were included 34 patients admitled to the intensive care unit (ICU) mechanically ventilated after CABG with Pa02/Fi02 ratio < 300 and radiological atelectasis score (RAS) ~ 2. Patients were randomized 16 to the control group (CG) and 18 to the recruitment group (RG), after extubation NIV was applied for 30 minutes three times a day according to ICU routine. In the CG, NIV was performed with PEEP 8 cm H20 and in the RG, was applied PEEP 15 cm H20 and 20 cm H20 for 2 minutes each and then was with PEEP 8 cm H20. We analyzed Pa02 from arterial blood gas at room air and RAS, hemodynamic stability and adverse event until discharged from the ICU. RESUL TS: Increased of Pa02 12.6±6.8% CG and 23.3±8.5% RG p < 0,001, RAS presented complete improvement for 94.4% RG, whereas in the CG, 87.5% presented some degree of atelectasis, p < 0,001. There was no adverse event related. CONCLUSION: The use of 30 minutes of NIV associated with RM was safe, improved oxygenation and reduced atelectasis
112

Analyse, diagnostic et optimisation énergétiques d'un parc de machines électriques sur site industriel. / Analysis, diagnosis and energy optimization of an electrical motor fleet on industrial plant.

Younsi, Mohamed Omar 13 October 2017 (has links)
Les moteurs électriques sont responsables de 67% de la consommation d’électricité dans l’industrie. Remplacer les moteurs installés par des entrainements plus efficients requiert de statuer sur leur adéquation avec les charges qu’ils entrainent. Une contrainte forte est de les analyser « on-line » et sans mesures intrusives ni consignations des installations.Cette thèse répond à un triple objectif. Premièrement, un dispositif de diagnostic « non-invasif » facilement intégrable en milieu industriel a été développé avec quatre méthodes d’évaluation du niveau de charge des moteurs asynchrones directement connectés au réseau. Deux de ces méthodes, existantes et basées sur la mesure du courant et du flux magnétique de dispersion, font l’objet d’améliorations significatives qui les portent à un niveau TRL7. Les deux autres méthodes exploitent la mesure seule du flux de dispersion. Leur applicabilité est vérifiée pour une alimentation par un système de tensions, équilibré ou non, avec des variations permanentes ou aléatoires. Une étude plus exploratoire montre que l’estimation non-invasive du courant absorbé par les machines asynchrones alimentées par convertisseurs électroniques est possible par exploitation du flux rayonné. Deuxièmement, le dispositif de diagnostic énergétique et des algorithmes de recherche de motorisation adaptée à un cycle de fonctionnement défini ont été appliqués à des exemples concrets d’optimisation énergétique sur un site industriel très énergivore, une aluminerie. Troisièmement, cette étude propose une réflexion sur la gestion d’un parc moteurs et, notamment, sur l'analyse des performances des moteurs neufs comparés à ceux ayant subi un rebobinage. / In the industry, electrical motors are responsible for 67% of electricity consumption. Replacing installed motors by more efficient ones requires the knowledge of their suitability with the loads that they drive. Analyzing the load variations without intrusive measurements or installations consignments is a strong constraint.That is why this thesis has a threefold purpose. Firstly, a “noninvasive” diagnostic device has been developed with four methods for evaluating the load of grid-connected induction motors. Two of these methods, based on the measurement of the current and the magnetic stray flux, have been significantly improved up to TRL7. The two other methods exploit only the measurement of the stray flux. Their applicability is checked for balanced and unbalanced supply voltage systems with permanent or random variations. A more exploratory study shows that the noninvasive estimation of the current for inverter-fed induction machines is possible using the radiated external flux. Secondly, the energy diagnosis device and search algorithms adapted to an operating cycle motorization have been applied to practical examples of energy optimization in an electro-intensive industrial plant, an aluminum smelter. Thirdly, a reflection on the management of a motor fleet is proposed, in particular, on the performance analysis between new motors and rewounded ones.
113

Eficácia e segurança do uso da ventilação não invasiva associada à manobra de recrutamento alveolar no pós-operatório de revascularização do miocárdio: ensaio clínico randomizado / Efficacy and safety of using noninvasive ventilation associated with recruitment maneuver in the postoperative period of coronary artery bypass grafting: a randomized clinical trial

Mieko Claudia Miura 21 November 2017 (has links)
INTRODUÇÃO: Complicações pulmonares são frequentes no pós-operatório da cirurgia de revascularização do miocárdio (RM) e a ventilação não-invasiva (VNI) tem sido utilizada nos cuidados pós-operatórios de forma profilática e terapêutica. A manobra de recrutamento alveolar (MRA) consiste no aumento sustentado de pressão na via aérea utilizando um alto nível de pressão expiratória final positiva (PEEP) em indivíduos hipoxêmicos, garantindo uma ventilação pulmonar homogênea e, com isso melhorando a oxigenação arterial. O objetivo desse estudo foi de avaliar se o uso da VNI associada à MRA pode melhorar a oxigenação e se pode ser aplicada de forma segura nos pacientes pós-operatório de RM. MÉTODOS: Foram incluídos 34 pacientes internados na unidade de terapia intensiva (UTI) ventilados mecanicamente após RM com relação Pa02/Fi02 < 300 e escore radiológico de atelectasia ;:: 2. Os pacientes foram randomizados 16 para o grupo controle (GC) e 18 para o grupo recrutamento (GR), após a extubação a VNI foi aplicada por 30 minutos três vezes ao dia de acordo com a rotina da UTI. No GC a VNI era realizada com PEEP de 8 cm H20 e no GR foi aplicada PEEP de 15 cm H20 e 20 cm H20 durante 2 minutos cada e depois ficava com PEEP de 8 cm H20. Analisamos a Pa02 pela gasometria arterial em ar ambiente e o escore radiológico de atelectasia, estabilidade hemodinâmica e evento adverso até a alta da UTI. RESULTADOS: Aumento de Pa02 12,6 ± 6,8% GC e 23,3 ± 8,5% GR com p < 0,001, o escore radiológico de atelectasia apresentou resolução completa em 94,4% GR, enquanto que no GC, 87,5% apresentou algum grau de atelectasia, p < 0,001. Não houve eventos adversos relacionados. CONCLUSÃO: o uso por 30 minutos da VNI associada à MRA foi seguro, melhorou a oxigenação e reduziu a atelectasia / BACKGROUND: Postoperative pulmonary impairment is common in the early period after coronary artery bypass grafting (CABG) and noninvasive ventilation (NIV) has been used in postoperative care to prevent and treatment. Recruitment maneuver (RM) consists in a sustained raise of airway pressure with high levei of positive end-expiratory pressure (PEEP) in hypoxemic subjects, insuring a homogeneous pulmonary ventilation and enhancing oxygenation. The aims of this study were to evaluate if the use of NIV associated with RM could improve oxygenation and if it could be safely applied in CABG postoperative patients. METHODS: Were included 34 patients admitled to the intensive care unit (ICU) mechanically ventilated after CABG with Pa02/Fi02 ratio < 300 and radiological atelectasis score (RAS) ~ 2. Patients were randomized 16 to the control group (CG) and 18 to the recruitment group (RG), after extubation NIV was applied for 30 minutes three times a day according to ICU routine. In the CG, NIV was performed with PEEP 8 cm H20 and in the RG, was applied PEEP 15 cm H20 and 20 cm H20 for 2 minutes each and then was with PEEP 8 cm H20. We analyzed Pa02 from arterial blood gas at room air and RAS, hemodynamic stability and adverse event until discharged from the ICU. RESUL TS: Increased of Pa02 12.6±6.8% CG and 23.3±8.5% RG p < 0,001, RAS presented complete improvement for 94.4% RG, whereas in the CG, 87.5% presented some degree of atelectasis, p < 0,001. There was no adverse event related. CONCLUSION: The use of 30 minutes of NIV associated with RM was safe, improved oxygenation and reduced atelectasis
114

Efeitos da ventilação mecânica não-invasiva na variabilidade da freqüência cardíaca e no padrão ventilatório de pacientes submetidos à cirurgia de revascularização do miocárdio

Pantoni, Camila Bianca Falasco 26 June 2009 (has links)
Made available in DSpace on 2016-06-02T20:19:11Z (GMT). No. of bitstreams: 1 2553.pdf: 1596497 bytes, checksum: 1c1b091ddb6a8fb9d0cc5e1b5bfd8201 (MD5) Previous issue date: 2009-06-26 / Universidade Federal de Minas Gerais / Noninvasive positive pressure ventilation (NIPPV) has been commonly applied in several clinical and postoperative conditions, especially after coronary artery bypass grafting (CABG) surgery and it can cause breathing pattern (BP) alterations and mechanical effects on cardiovascular system, with cardiac autonomic adjustments. However, it is not well established in the literature how these alterations occur in patients submitted to the CABG and if they can be related to the application of different positive airway pressure levels. In this context, we considered the development of two studies that could contribute with new information about these topics. The first study is entitled Acute application of bilevel positive airway pressure influence cardiac autonomic nervous system and its objective was to evaluate the changes in heart rate variability (HRV) during bilevel positive airway pressure (Bilevel) application in healthy young men. Twenty men underwent a 10-min register of R-R intervals (R-Ri) during sham ventilation, Bilevel 8-15cmH2O and Bilevel 13-20 cmH2O. HRV was analyzed in time and frequency-domain and with non-linear statistical measures. Physiological variables (blood pressure, breathing rate, end tidal carbon dioxide- ETCO2) were also collected. R-Ri mean, rMSSD, NN50, pNN50 and SD1 reduced during 13-20 cmH2O compared to sham ventilation, with reduction of the R-Ri mean compared to 8-15 cmH2O. R-Ri mean and high frequency band (HF) reduced and low frequency band (LF) increased during 8-15 cmH2O compared to sham ventilation. Delta of ETCO2 correlated positively with LF, HF, LF/HF, SDNN, rMSSD and SD1. In conclusion, acute application of Bilevel was able to alter cardiac autonomic nervous system, with parasympathetic activity reduction and sympathetic increase and higher level of positive airway pressure can cause a greater influence on the cardiovascular and respiratory system. The second study is entitled The effects of different levels of positive airway pressure on respiratory pattern and heart rate variability in patients submitted to coronary artery bypass grafting surgery and its objective was to access the effects of different levels of continuous positive airway pressure (CPAP) in BP and HRV in CABG postoperative (PO), as well as the impact of CABG in these variables. Eighteen patients underwent CABG was evaluated during spontaneous breathing (SB) and four different CPAP levels of CPAP, in a random order: (a) CPAP = sham (3 cmH2O), (b) 5 CPAP = cmH2O, (c) 8 CPAP= cmH2O, (d) 12 CPAP = cmH2O in PO. HRV was analysed in time and frequency domain and by non-linear methods (Poincaré plot e Detrended Fluctuation Analysis) and BP was analysed by inductive respiratory plethysmograph. There were significant alterations of HRV and BP in the PO of CRM, compared to pre-operative and alterations of DFA&#945;1, DFA&#945;2 e SD2 and respiratory variables during NIPPV, with higher influence observed during application of the two higher levels applied. Moreover, there was relationship between DFA&#945;1 and inspiratory time of delta 12 cmH2O and SB, and 8 cmH2O and SB. In conclusion, acute CPAP application was able to alter the control of cardiac autonomic nervous system and BP of patients submitted to CABG and higher levels promoted better performance of pulmonary and cardiac autonomic function. / A ventilação não-invasiva por pressão positiva (VNIPP) tem sido comumente utilizada em diversas condições clínicas e pós-operatórias, principalmente na cirurgia de revascularização do miocárdio (CRM) e pode causar alterações do padrão ventilatório (PV) e efeitos mecânicos sobre o sistema cardiovascular, com ajustes autonômicos cardíacos. Entretanto, ainda não é claro se estas alterações ocorrem em pacientes submetidos à CRM e se podem estar relacionadas a diferentes níveis pressóricos aplicados. Neste contexto, propusemos o desenvolvimento de dois estudos que poderiam contribuir com novas informações. O primeiro estudo, intitulado Aplicação aguda de pressão positiva por dois níveis pressóricos nas vias aéreas influencia o sistema nervoso autonômico cardíaco teve por objetivo avaliar as mudanças na variabilidade da frequência cardíaca (VFC) durante aplicação de pressão positiva por dois níveis pressóricos (Bilevel) em indivíduos jovens saudáveis. Vinte homens foram submetidos ao registro de 10 minutos dos intervalos R-R (iR-R) durante aplicação de ventilação sham, Bilevel 8- 15cmH2O e Bilevel 13-20 cmH2O. A VFC foi analisada no domínio do tempo e da freqüência e por métodos não-lineares. Variáveis fisiológicas (pressão arterial, frequência respiratória e fração de dióxido de carbono no final da expiração- ETCO2) também foram coletadas. Houve redução da média dos iR-R, e dos índices rMSSD, NN50, pNN50 e SD1 durante aplicação dos níveis 13-20 cmH2O de Bilevel comparado ao modo sham, ainda com redução da média dos iR-R quando comparados aos níveis 8-15cmH2O. Houve diminuição da média dos iR-R e da banda de alta freqüência (AF), com aumento da banda de baixa freqüência (BF) durante a aplicação de 8-15 cmH2O comparada à ventilação sham. O delta de ETCO2 correlacionou-se positivamente com BF, AF, BF/AF, SDNN, rMSSD e SD1. Em conclusão, a aplicação aguda de Bilevel foi capaz de alterar o sistema nervoso autonômico cardíaco, com redução da atividade parassimpática e aumento da atividade simpática e níveis mais elevados de pressão positiva podem causar maior influência nos sistemas cardiovascular e respiratório. O segundo estudo, intitulado Efeitos de diferentes níveis de pressão positiva nas vias aéreas sobre o padrão ventilatório e a variabilidade da freqüência cardíaca de pacientes submetidos à cirurgia de revascularização do miocárdio objetivou avaliar os efeitos da aplicação de diferentes níveis de pressão positiva contínua nas vias aéreas (CPAP) sobre o padrão ventilatório (PV) e a VFC no pós-operatório (PO) de CRM, bem como o impacto da CRM sobre estas variáveis. Foram avaliados 18 pacientes submetidos à CRM, durante RE (respiração espontânea) e aplicação de quatro níveis de CPAP, de forma randomizada: (a) CPAP = sham (3 cmH2O), (b) CPAP = 5 cmH2O, (c) CPAP= 8 cmH2O, (d) CPAP = 12 cmH2O no PO. A VFC foi analisada no domínio do tempo e da freqüência e por métodos não-lineares (Poincaré plot e Flutuações Depuradas de Tendência) e o PV foi analisado em diferentes variáveis, por meio da pletismografia respiratória por indutância. Houve alteração da VFC e do PV no PO de CRM, comparado ao período pré-operatório, bem como alterações dos índices DFA&#945;1, DFA&#945;2 e SD2, e de variáveis ventilatórias durante aplicação de VNIPP, com maior influência exercida pela aplicação dos dois níveis pressóricos mais elevados. Além disso, houve correlação entre o índice DFA&#945;1 e tempo inspiratório para o delta de 12 cmH2O e RE, e 8 cmH2O e RE. Em conclusão, temos que a aplicação aguda de CPAP foi capaz de alterar o controle do sistema nervoso autonômico cardíaco e o PV de pacientes submetidos à CRM e os níveis mais elevados promoveram melhor desempenho da função pulmonar e autonômica cardíaca. Apoio Financeiro: FAPESP (07/53202-9).
115

Optimisation des interactions patient-ventilateur en ventilation assistée : intérêt des nouveaux algorithmes de ventilation / Patient-ventilator interactions optimization : new ventilation algorithms contribution

Carteaux, Guillaume 30 November 2015 (has links)
En ventilation assistée, les interactions patient-ventilateur, qui sont associés au pronostic, dépendent pour partie des algorithmes de ventilation. Objectifs : Caractériser l'intérêt potentiel des nouveaux algorithmes de ventilation dans l'optimisation des interactions patient-ventilateur : 1) en ventilation invasive, deux modes et leurs algorithmes nous ont semblé novateurs et nous avons cherché à personnaliser l'assistance du ventilateur en fonction de l'effort respiratoire du patient au cours de ces modes proportionnels : ventilation assistée proportionnelle (PAV+) et ventilation assistée neurale (NAVA) ; 2) en ventilation non-invasive (VNI) nous avons évalué si les algorithmes VNI des ventilateurs de réanimation et des ventilateurs dédiés à la VNI diminuaient l'incidence des asynchronies patient-ventilateur. Méthodes : 1) En PAV+ nous avons décrit un moyen de recalculer le pic de pression musculaire réalisée par le patient à chaque inspiration à partir du gain réglé et de la pression des voies aériennes monitorée par le respirateur. Nous avons alors évalué la faisabilité clinique d'ajuster l'assistance en ciblant un intervalle jugé normal de pression musculaire. 2) Nous avons comparé une titration de l'assistance en NAVA et en aide inspiratoire (AI) en se basant sur les indices d'effort respiratoire. 3 et 4) En VNI, nous avons évalué l'incidence des asynchronies patient-ventilateur avec et sans l'utilisation d'algorithmes VNI : sur banc d'essai au cours de conditions expérimentales reproduisant la présence de fuites autour de l'interface ; en clinique chez des patients de réanimation. Résultats : En PAV+, ajuster le gain dans le but de cibler un effort respiratoire normal était faisable, simple et souvent suffisant pour ventiler les patients depuis le sevrage de la ventilation mécanique jusqu'à l'extubation. En NAVA, l'analyse des indices d'effort respiratoire a permis de préciser les bornes d'utilisation et de comparer les interactions patient-ventilateur avec l'AI dans des intervalles d'assistance semblables. En VNI, nos données pointaient l'hétérogénéité des algorithmes VNI sur les ventilateurs de réanimation et retrouvaient une meilleure synchronisation patient-ventilateur avec l'utilisation de ventilateurs dédiés à la VNI pour des qualités de pressurisation par ailleurs identiques. Conclusions : En ventilation invasive, personnaliser l'assistance des modes proportionnels optimise les interactions patient-ventilateur et il est possible de cibler une zone d'effort respiratoire normale en PAV+. En VNI, les ventilateurs dédiés améliorent la synchronisation patient-ventilateur plus encore que les algorithmes VNI sur les ventilateurs de réanimation, dont l'efficacité varie grandement selon le ventilateur considéré. / During assisted mechanical ventilation, patient-ventilator interactions, which are associated with outcome, partly depend on ventilation algorithms.Objectives: : 1) during invasive mechanical ventilation, two modes offered real innovations and we wanted to assess whether the assistance could be customized depending on the patient's respiratory effort during proportional ventilatory modes: proportional assist ventilation with load-adjustable gain factors (PAV+) and neurally adjusted ventilator assist (NAVA); 2) during noninvasive ventilation (NIV): to assess whether NIV algorithms implemented on ICU and dedicated NIV ventilators decrease the incidence of patient-ventilator asynchrony.Methods: 1) In PAV+ we described a way to calculate the muscle pressure value from the values of both the gain adjusted by the clinician and the airway pressure. We then assessed the clinical feasibility of adjusting the gain with the goal of maintaining the muscle pressure within a normal range. 2) We compared titration of assistance between neurally adjusted ventilator assist (NAVA) and pressure support ventilation (PSV) based on respiratory effort indices. During NIV, we assessed the incidence of patient-ventilator asynchrony with and without the use of NIV algorithms: 1) using a bench model; 2) and in the clinical settings.Results: During PAV+, adjusting the gain with the goal of targeting a normal range of respiratory effort was feasible, simple, and most often sufficient to ventilate patients from the onset of partial ventilatory support until extubation. During NAVA, the analysis of respiratory effort indices allowed us to precise the boundaries within which the NAVA level should be adjusted and to compare patient-ventilator interactions with PSV within similar ranges of assistance. During NIV, our data stressed the heterogeneity of NIV algorithms implemented on ICU ventilators. We therefore reported that dedicated NIV ventilators allowed better patient-ventilator synchronization than ICU ventilators, even with their NIV algorithms engaged.Conclusions: During invasive mechanical ventilation, customizing the assistance during proportional ventilatory modes with the goal of targeting a normal range of respiratory effort optimizes patient-ventilator interactions and is feasible with PAV+. During NIV, dedicated NIV ventilators allow better patient-ventilator synchrony than ICU ventilators, even with their NIV algorithm engaged. ICU ventilators' NIV algorithms efficiency is however highly variable among ventilators.
116

Study of a Particle Based Films Cure Process by High-Frequency Eddy Current Spectroscopy

Patsora, Iryna, Tatarchuk, Dmytro, Heuer, Henning, Hillmann, Susanne 28 March 2017 (has links)
Particle-based films are today an important part of various designs and they are implemented in structures as conductive parts, i.e., conductive paste printing in the manufacture of Li-ion batteries, solar cells or resistive paste printing in IC. Recently, particle based films were also implemented in the 3D printing technique, and are particularly important for use in aircraft, wind power, and the automotive industry when incorporated onto the surface of composite structures for protection against damages caused by a lightning strike. A crucial issue for the lightning protection area is to realize films with high homogeneity of electrical resistance where an in-situ noninvasive method has to be elaborated for quality monitoring to avoid undesirable financial and time costs. In this work the drying process of particle based films was investigated by high-frequency eddy current (HFEC) spectroscopy in order to work out an automated in-situ quality monitoring method with a focus on the electrical resistance of the films. Different types of particle based films deposited on dielectric and carbon fiber reinforced plastic substrates were investigated in the present study and results show that the HFEC method offers a good opportunity to monitor the overall drying process of particle based films. Based on that, an algorithm was developed, allowing prediction of the final electrical resistance of the particle based films throughout the drying process, and was successfully implemented in a prototype system based on the EddyCus® HFEC device platform presented in this work. This prototype is the first solution for a portable system allowing HFEC measurement on huge and uneven surfaces.
117

FAT AND SODIUM QUANTIFICATION AND CORRELATION BY MRSI

Ahmad Abdurahman M. Alhulail (8933363) 16 June 2020 (has links)
<p>Lipids and sodium (<sup>23</sup>Na) are two essential components of the human body. They play a role in almost all biological systems. However, an increase in their levels is associated with metabolic diseases. The elevation of their contents can cause similar health disorders. Examples of prevalent disorders that share an increase of musculoskeletal lipids and <sup>23</sup>Na are hypertension and diabetes. However, the relationship between in vivo lipid and sodium levels in pathophysiology has not been studied enough and therefore is still unclear. Additionally, the available quantification methods to facilitate such a study may not be practical. They are either invasive, not sensitive enough, or require an impractical measurement time.</p> <p>Therefore, in this work, our aims were to develop practical in vivo methods to quantify the absolute sodium concentration as well as the concentration of each lipid component individually, and to study the correlation between them within the skeletal muscles.</p> <p>Since lipids and <sup>23</sup>Na have different nuclear magnetic resonance properties, their quantification by magnetic resonance (MR) techniques face different challenges. Thus, we optimized different MR spectroscopic imaging (MRSI) techniques for lipids and <sup>23</sup>Na. </p> <p>Our proposed proton MRSI was able to provide eight lipid fat fraction (FF) maps representing each musculoskeletal lipid component (fatty acid) detected by our MRSI technique, and demonstrated a superior sensitivity compared to the conventional MR imaging methods.</p> <p>For <sup>23</sup>Na, our developed <sup>23</sup>Na-MRSI was able to measure and map the absolute <sup>23</sup>Na concentration with values agreeing with those reported previously in biopsy studies, and with a high repeatability (CV < 6 %) within significantly shorter acquisition time compared to other available techniques.</p> <p> Finally, the <sup>23</sup>Na concentration and the fat fractions of each lipid component within healthy skeletal muscles were measured and correlated using our developed MRSI methods. Our findings suggest a positive regional relationship between <sup>23</sup>Na and lipids and negative correlation between <sup>23</sup>Na and BMI under healthy conditions.</p>
118

Електронски систем препознавања врсте течности, применом интердигиталног кондензатора / Elektronski sistem prepoznavanja vrste tečnosti, primenom interdigitalnog kondenzatora / Electronic system for liquid-type recognition, based on interdigital capacitor

Vuković Rukavina Aleksandra 25 March 2016 (has links)
<p>Коришћењем интердигиталног кондензатора и микроконтролера, систем за препознавање течности је имплементиран и испитан. Пермитивност течних узорака је коришћена као физичка особина на основу које се врши препознавање. Инвазивна и неинвазивна конфигурација сензора је израђена и испитана. Резултати указују на могућност развоја компактних, минијатурних уређаја за теренску употребу.</p> / <p>Korišćenjem interdigitalnog kondenzatora i mikrokontrolera, sistem za prepoznavanje tečnosti je implementiran i ispitan. Permitivnost tečnih uzoraka je korišćena kao fizička osobina na osnovu koje se vrši prepoznavanje. Invazivna i neinvazivna konfiguracija senzora je izrađena i ispitana. Rezultati ukazuju na mogućnost razvoja kompaktnih, minijaturnih uređaja za terensku upotrebu.</p> / <p>By using interdigital capacitor and a microcontroller, a system for liquid-type<br />recognition has been developed and examined. Permittivity of liquid samples<br />has been used as a physical property for recognition. Invasive and noninvasive<br />sensor configuration has been implemented and examined. Results<br />imply the possibility to develop compact, miniature, on-field devices.</p>
119

Development and Optimization of an Integrated Faraday Modulator and Compensator Design for Continuous Polarimetric Glucose Monitoring

Clarke, Brandon William 22 August 2013 (has links)
No description available.
120

NONINVASIVE IMAGING OF LUNG PATHOLOGY AND PHYSIOLOGY IN MURINE MODELS OF ASTHMA AND COPD

Jobse, Brian N. 04 1900 (has links)
<p>Obstructive lung diseases limit airflow and gas exchange and have a major impact on a patient’s long-term health. Asthma and chronic obstructive pulmonary disease (COPD) are the most prevalent obstructive lung diseases and represent a major burden on healthcare systems worldwide. It is now accepted that the pathologies associated with these diseases are heterogeneous in nature, and as the function of the lung is determined by its three-dimensional structure, methods to volumetrically evaluate the lung are important tools in furthering the study of these pathologies.</p> <p>Three-dimensional imaging methodologies, such as computed tomography (CT) and single photon emission computed tomography (SPECT), are used clinically in the diagnosis of lung disease, but results are not commonly quantified. In addition, asthma and COPD develop slowly over time and diagnosis normally takes place after the underlying pathologies are well established. Experimental models in small animals, such as rats and mice, allow for the study of disease pathogenesis in a controlled setting and development of quantitative imaging practices for these models provides translational tools for relating results back to the clinic.</p> <p>In this thesis, CT densitometry and ventilation/perfusion (V/Q) SPECT are explored as methods to investigate models of asthma and COPD. CT densitometry is shown to be capable of quantifying allergic inflammation in an asthma model but is of less use in a model of COPD, predominantly due to the relative amounts of inflammation present. However, V/Q imaging is shown to be quite sensitive to the effects of cigarette smoke in a model of COPD and has been used to better understand how pathologies associated with COPD contribute to gas exchange limitation in the lung.</p> <p>The models, imaging techniques, and analysis methods described in this work provide insight into chronic obstructive lung disease and allow for future investigations into how pathologies effect gas exchange. Further, the characterization of the models described in this thesis allows for drug efficacy studies to be performed, both on established and novel treatments. Future research into asthma and COPD will benefit further from the use of threedimensional imaging methodologies because they provide volumetric information on structure and function and can act as a translational bridge between clinical disease and preclinical animal models.</p> / Doctor of Philosophy (Medical Science)

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