Made available in DSpace on 2014-06-11T19:22:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-29Bitstream added on 2014-06-13T19:08:03Z : No. of bitstreams: 1 cortezledesma_ne_me_ilha.pdf: 1539297 bytes, checksum: df4862f51083b9bb17731d2587b77d15 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O monitoramento de integridade estrutural (SHM) baseado na técnica da impedância eletromecânica (EMI) tem sido desenvolvido como uma ferramenta promissora para identificação de falhas estruturais. As aplicações típicas de SHM baseadas em EMI geralmente utilizam um analisador de impedância comercial de alto custo ou sistemas de medição baseados na função de resposta em frequência (FRF). Além do custo elevado, as exigências de capacidade de armazenamento e/ou processamento de dados desses instrumentos são características proibitivas para muitas aplicações. Trabalhos recentes mostram que não é preciso conhecer o valor exato da impedância eletromecânica da estrutura para monitorar sua integridade. Assim, neste trabalho é apresentado um sistema de SHM que permite detectar falhas em estruturas monitorando apenas as variações da tensão elétrica do transdutor. O sistema proposto é portátil, autônomo, rápido, versátil, de baixo custo e substitui com eficiência os instrumentos comerciais na fase de detecção de falhas. A identificação do dano é feita comparando-se as variações da tensão rms da resposta no tempo que um transdutor piezelétrico de PZT, colado na estrutura, fornece para cada frequência do sinal de excitação. Portanto, o sistema proposto não é limitado pela frequência de amostragem, dispensa algoritmos da transformada de Fourier e não exige um computador para processamento, operando de forma autônoma. Um protótipo de baixo custo usando circuitos integrados, um sintetizador digital e um microcontrolador foi construído e testado através de experimentos em estruturas de alumínio para a faixa de frequências a partir de 3 kHz até 50 kHz com boa precisão e estabilidade / Structural health monitoring (SHM) based on electromechanical impedance (EMI) technique has been developed as a promising tool for identifying structural damage. Typical applications in SHM based on EMI generally use high-cost commercial impedance analyzers or measurement systems based on frequency response function (FRF). Besides the high cost, the requirements for storage and/or data processing of these instruments are prohibitive features for many applications. Recent studies show that the exact value of the electromechanical impedance is not required for damage detection. Thus, this work presents a SHM system that can detect damage in structures only monitoring the changes in the voltage of the transducer. The proposed system is portable, autonomous, fast, versatile, low-cost and replaces efficiently commercial instruments in the damage detection stage. The identification of damage is done by comparing the variations in the rms voltage of time response signals from a piezoelectric transducer, such as PZT, bonded to the structure. Different time response signals are obtained for each frequency of the excitation signal. Therefore, the proposed system is not limited by the sampling frequency, dispenses Fourier transform algorithms and does not require a computer for processing, operating autonomously. A low-cost prototype using integrated circuits, a microcontroller and a digital synthesizer was built and tested through experiments with aluminum structures for frequencies ranging from 3 kHz to 50 kHz with good accuracy and stability

Resumo: Nesta dissertação é apresentada uma aplicação web, dinâmica e interativa, para o controle e monitoramento de transdutores inteligentes conectados em rede de acordo com o padrão IEEE 1451. O ambiente está hospedado em um computador pessoal que desempenha as funções de um servidor web e da parte lógica de um processador com capacidade de operar em rede. O acesso aos transdutores da rede é realizado através de um módulo de interface para transdutores inteligentes, implementado em um dispositivo lógico programável. No desenvolvimento do MATIW 1451 utilizou-se somente plataforma operacional e linguagens de programação de domínio público, abertas e padronizadas como estabelece o comitê gestor do padrão IEEE 1451. O sistema foi testado em uma rede de transdutores contendo um sensor de temperatura e uma ventoinha e em uma rede de distribuição de água, contendo sensores de pressão, vazão e um redutor de pressão. / Abstract: This paper presents an interactive and dynamic web application to control and monitor smart transducers connected in network according to the IEEE 1451 standart, named MATIW 1451. A personal computer acts as a web server and as the logical part of a NCAP (Network Capable Application Process). The transducers are accessed via a STIM (Smart Transducer Interface Module) implemented by a PLD (Programmable Logic Device). The tools used in the implementation of MATIW 1451 are all in public domain, open as defined by the 1451 committee, including the operating system, languages, libraries and API’s. The system was tested in a network of transducers comprised by a temperature sensor and cooler, and also tested in a water distribution kit with pressure and flow sensors, and a pressure reducer. / Orientador: Alexandre César Rodrigues da Silva / Coorientador: Carlos Antônio Alves / Banca: Ailton Akira Shinoda / Banca: Mauro Conti Pereira / Mestre

Este trabalho teve por objetivo desenvolver e caracterizar um conjunto transdutor piezelétrico de potência e pinça laparoscópica para cortes homeostáticos, o qual constitui parte fundamental do projeto do Bisturi Ultrassônico Nacional. O transdutor, do tipo Langevin, é composto por quatro cerâmicas piezelétricas que convertem energia elétrica em deslocamento mecânico. Um componente importante do transdutor é o amplificador mecânico, cuja finalidade é aumentar a amplitude do deslocamento. O transdutor e o amplificador foram desenvolvidos através de um modelo axissimétrico de elementos finitos implementado no software ANSYS e a lâmina foi desenvolvida através de um modelo tridimensional em elementos finitos. Para cada associação, entre os componentes, os resultados numéricos da resposta em frequência da impedância elétrica e do coeficiente de acoplamento eletromecânico, foram comparados com os resultados experimentais. Também foi desenvolvido um mecanismo inovador de acionamento da pinça laparoscópica. O resultado desta pesquisa proporcionou uma inovação tecnológica na área médica, contribuindo assim para o progresso tecnológico do país. / The aim of this work was to develop and characterize a high power piezoelectric transducer coupled to a laparoscopic forceps for homeostatic cuts, which is a fundamental part of the National Ultrasonic Scalpel Project. The Langevin type transducer consists of four piezoelectric ceramics that convert electrical energy into mechanical displacement. An important component of the transducer is the mechanical amplifier, which increases the amplitude of displacement. The transducer and amplifier have been developed through an axisymmetric finite element model, implemented in ANSYS, and the blade was developed using a three-dimensional finite element model. For each association between the components, the numerical results of the frequency response of the electrical impedance and electromechanical coupling coefficient were compared with the experimental results. An innovative drive mechanism was developed for the laparoscopic forceps. The result of this research provided a technological innovation in the medical field, thus contributing to the technological progress of the country.

Este trabalho apresenta um estudo do processo de corte de pequenas placas de piezocerâmicas usadas na fabricação de materiais piezocompósitos pelo processo de corte e preenchimento. Foi feito o projeto de uma máquina de corte com disco adiamantado de acordo com as necessidades do processo de corte e preenchimento para produzir piezocompósitos que requerem cortes tão finos quanto 30µm. A máquina utiliza um \"spindle\" com mancais aerostáticos com rotação de até 60.000 rpm para cortes com lâminas de 2 polegadas de diâmetro. Os piezocompósitos são os elementos principais na fabricação de transdutores de ultra-som, com freqüências até 10 MHz, para aplicações médicas e industriais. O estudo do corte com discos adiamantados com pequenas espessuras é baseado no modelo cinemático usado para modelar o processo de retífica por abrasão e em verificações experimentais de corte de pequenas placas de piezocerâmicas. Os resultados experimentais do corte de piezocerâmica tipo PZT com disco adiamantado são analisados com o auxílio de um microscópio óptico. São medidas as imperfeições superficiais dos cortes. / This work presents a study of the diamond blade dicing of piezoceramic slabs to fabricate piezocomposites by dicing and fill process. A diamond blade dicing machine is designed according the needs of the dicing and fill process to produce piezocomposites which requires dicing with diamond blades as thin as 30µm. The dicing machine has a high speed (up to 60.000 rpm) spindle with aerostatic bearings for 2 inches diameter dicing blades. The piezocomposites with frequency up to 10 MHz are the main part of ultrasonic transducers for medical and industrial applications. The study of thin diamond blade dicing is based in the kinematic model for grinding and experimental work. The results of diamond blade dicing of PZT piezoceramic slabs are analysed with an optical microscope and the measurements of superficial cracks are presented.

Este trabalho apresenta a modelagem da parte dinâmica de dois transdutores de pressão tipo piezorresistivo. Geralmente processos de calibração dinâmica usam bancadas sofisticadas, mas neste trabalho procurou-se um processo simples e de baixo custo. A metodologia baseou-se em aumentar lentamente a pressão, fornecida por um sistema hidráulico básico, até que ocorresse a explosão de um diafragma e, com isso, obteve-se um degrau de pressão, supostamente ideal. Considerado como sistemas lineares, com a resposta obtida verificou-se qual a ordem e o tipo de sistema correspondente à resposta do transdutor. Através dos dados experimentais determinou-se os parâmetros dinâmicos do modelo matemático. Foram obtidos modelos matemáticos lineares de segunda ordem de cada transdutor. As respostas dos modelos mostram ter uma concordância satisfatória quando comparadas aos dados experimentais. / This work presents a dynamic modeling method for two hydraulic piezoresistive pressure transducers. Usually the dynamic calibration processes apply sophisticated devices, but in this work a simple and low cost process was searched. The methodology was based on increasing the pressure slowly, supplied by a basic hydraulic system, up to a diaphragm explosion, assumed as an ideal step pressure variation. Considered as linear systems, the responses obtained were verified and compared with a second order linear system. Using the experimental data, the dynamic parameters of the mathematical model were determined for each of the two transducers. The theoretical responses of the models showed to have a satisfactory agreement when compared with the experimental data.

A modelagem do campo acústico gerado por um transdutor ultra-sônico retangular é importante porque sua geometria é usada freqüentemente por transdutores multielementos (arrays). O conhecimento do campo acústico pode otimizar alguns parâmetros de projeto de transdutores ultra-sônicos, tais como: a sua geometria, a profundidade de foco, a largura do feixe acústico, bem como os parâmetros de focalização de um array (leis de retardos e de apodização). O modelo implementado neste trabalho calcula a pressão acústica e o potencial de velocidade gerados por transdutores de geometria retangular em um conjunto de pontos do espaço. A abordagem usa o método da integral de convolução e da resposta espacial impulsiva, cuja solução computacional do problema é exata e relativamente simples, o que normalmente não ocorre com outros métodos que apresentam um alto custo computacional (tempo de processamento). A resposta em pressão do transdutor em cada ponto do espaço é obtida com o modelo implementado em Matlab e é verificada experimentalmente. São realizadas medidas experimentais do campo de pressão gerado por transdutores retangulares monoelementos na faixa de freqüências de 400 kHz a 2,2 MHz e um array na freqüência de 1 MHz, em um tanque de imersão, utilizando um hidrofone pontual e um sistema computadorizado de varredura de campo. A comparação entre os resultados simulados e experimentais mostra uma boa concordância, bem como as suas limitações. / The simulation of the acoustic field generated by a rectangular ultrasonic transducer is important because its geometry is frequently used in arrays. The knowledge of the acoustic field can optimize some design parameters of ultrasonic transducers, such as: geometry, focus depth, acoustic beam width, as well as the delay laws and the apodization of an array. Such simulation is implemented in this work, using a model that calculates the acoustic pressure in a space point. The approach uses the convolution integral and the spatial impulsive response methods. This computational solution is exact and relatively simple. That does not usually happen to other methods with a higher computational time. The acoustic field simulations obtained with the model implemented in Matlab are verified experimentally. Measurements of the pressure field generated by rectangular transducers in 400 kHz to 2.2 MHz and by an 1 MHz array were made in an immersion tank, using a punctual hidrophone and a computerized system for acoustic field measurements. The comparison between the simulated and experimental results shows good agreement.

Ces travaux de thèse sont le fruit d’un constat : le développement des matériaux organiques dans les MEMS ne cesse de croître. Cela est dû à leurs procédés de fabrication à moindre coût et à leurs propriétés qui diffèrent de celles des matériaux inorganiques. D’un point de vue biologique,les propriétés physiques et chimiques des matériaux organiques sont également plus proches des propriétés de l’environnement extra-cellulaire. Les MEMS sont des systèmes très polyvalents permettant de mesurer de nombreuses grandeurs physiques. Leur utilisation dans le domaine biologique n’est donc pas étonnante et il est intéressant de combiner les MEMS avec des matériaux organique pour l’étude de cellules. L’objectif de ces travaux est de fabriquer et d’utiliser des résonateurs MEMS organiques piézoélectriques dans le but d’étudier la biomécanique et l’adhésion de cellules. En effet,la biomécanique des cellules est un domaine d’étude qui renseigne sur de nombreux processus opérés par les cellules, comme l’adhésion cellulaire, ainsi que sur leur bien être. Dans un premier temps, le procédé de fabrication des résonateurs a été établi et optimisé afin d’obtenir une efficacité d’actionnement piézoélectrique maximale. Dans un deuxième temps, un système d’actionnement et de mesure électrique a été réalisé, comportant une carte électronique ainsi qu’une enceinte étanche. L’influence de la température, de la densité et de la viscosité du milieu sur la résonance des MEMS a également été étudiée. Finalement, les résonateurs créés ont été utilisés dans le suivi en temps réel de l’adhésion de cellules souches mésenchymateuses. D’autres applications ont été réalisées avec les résonateurs piézoélectriques comme l’étude de la position d’une masse sur les résonateurs, la détermination de la rigidité d’un matériau ainsi que de la viscosité d’un liquide. / This PhD thesis is the result of an assessment : the use of organic materials in MEMSis in a constant increase. Organic materials are attractive because of their low-cost fabrication processand their properties that are different from the inorganic ones. From a biological point of view, theirphysical and chemical properties are closer to the properties of extracellular environment. MEMS arevery versatile systems that are able to measure a lot of physical quantities. Therefore, it is not surprisingto use them in biology, and combining MEMS with organic materials is really promising tostudy biological cells behavior. The objective of this work is to fabricate and use piezoelectric organicMEMS resonators to study cell biomechanics and adhesion. In fact, the study of cell biomechanicsgives information on a lot of cellular processes, like the cellular adhesion, as well as on their well-being.Firstly, the resonators fabrication process has been developed and optimized in order to maximize thepiezoelectric actuation. Secondly, an electronic actuation and measurement system has been realized,including an electronic card and a watertight enclosure. The influence of the temperature, mass densityand viscosity of the environment on the dynamic response of the resonators has also been evaluated.Finally, real time measurements of the adhesion of mesenchymal stem cells have been carried out usingthe resonators. The resonators have also been used to study the influence of the position of a mass onthe resonators, to determine the rigidity of a deposited material as well as the viscosity of liquid media.

Abstract This thesis describes the development of pressure sensor arrays and a range of methods suitable for the long-term measurement of heart rate and blood pressure determination using a cuff and a pressure sensor array on the radial artery. This study also reviews the historical background of noninvasive blood pressure measurement methods, summarizes the accuracies achieved and explains the requirements for common national and international standards of accuracy. Two prototype series of pressure transducer arrays based on electro-mechanical film (EMFi) were designed and tested. By offering high (∼TΩ) resistance, EMFi is an excellent material for low-current long-term measurement applications. About 50 transducer arrays were built using different configurations and electrode materials to sense low-frequency pressure pulsations on the radial artery in the wrist. In addition to uniform quality, essential requirements included an adequate linear response in the desired temperature range. Transducer sensitivity was tested as a function of temperature in the range of 25–45 °C at varying static and alternating pressures. The average sensitivity of the EMFi used in the transducers proved adequate (∼2.2 mV/mmHg and ∼7 mV/mmHg for normal and high sensitive films) for the intended purpose. The thesis also evaluates blood pressure measurements by the electronic palpation method (EP) and compares the achieved accuracy to that of the oscillometric method (OSC) using average intra-arterial (IA) blood pressure as a reference. All of these three measurements were made simultaneously for each person. In one test group, measurements were conducted on healthy volunteers in sitting and supine position during increasing and decreasing cuff pressure. Another group, comprising elderly cardiac patients, was measured only in the supine position during cuff inflation. The results showed that the EP method was approximately as accurate as the OSC method with the healthy subjects and slightly more accurate with the cardiac patient group. The advantage of the EP method is that also the wave shape and velocity of arterial pressure pulses is available for further analysis, including the assessment of arterial stiffness.

Le facteur de transcription STAT1 est un effecteur majeur de la réponse à l’interféron exerçant ainsi un rôle clé dans l’immunité innée. Il est également un suppresseur de tumeur et régule des effets antiprolifératifs et pro-apoptotiques. Afin de mettre en évidence de nouvelles implications anti-tumorales de STAT1, ce projet de doctorat a porté sur son implication fonctionnelle i) dans l’expression des immunoglobulines (Ig), processus essentiel de l’immunité adaptative et ii) dans la réponse cellulaire aux traitements par les agents génotoxiquesNotre étude cinétique, après induction de l’expression de STAT1 dans des cellules initialement totalement déficientes, a montré son implication dans l’expression des IgG membranaires. Le mécanisme régulateur est indirect : il impliquerait une inhibition de l’activation de STAT3 conduisant à l’inhibition de l’expression de BLIMP1, un acteur essentiel de la différenciation plasmocytaire. La capacité de STAT1 à pouvoir se fixer sur le promoteur de BLIMP1, de même que STAT3 n’exclut pas une implication transcriptionnelle.Au cours d’un traitement génotoxique par le MNNG, nous avons décrit la participation de STAT1 à un complexe de réparation de l’ADN. Seule la présence de STAT1 permet l’intégration au complexe MLH1/p53 de la kinase c-Abl. Dans ce contexte, on observe une cytotoxicité sous le contrôle de l’activité kinase de c-Abl, une réparation rapide et efficace de l’ADN, un arrêt seulement transitoire du cycle et une orientation vers la survie cellulaire équivalent à une résistance à ce traitement.Ces résultats mettent en évidence deux nouveaux rôles anti-tumoraux de STAT1 par sa contribution à des complexes régulateurs essentiels et la désigne comme une potentielle cible thérapeutique. / The transcription factor STAT1, as a major effector of interferon, plays a key role in innate immunity. Through its strong anti-proliferative and pro-apoptotic properties STAT1 is also considered as a tumor suppressor. The aim of this project was to delineate new potential tumor suppressor properties for STAT1 in two signaling mechanisms: i) Ig expression in plasmacytoid cells and ii) cellular response to genotoxic stress.Our kinetic experiments, upon “de novo” expression of STAT1 in a rare STAT1-deficient cell line showed its modulation of membrane IgG expression. The underlying mechanism involves a STAT1-dependent inactivation of STAT3 and subsequently a decreased expression of BLIMP1, a major contributor to plasma cell differentiation. Since STAT1, like STAT3, is able to bind to the BLIMP1 promoter elements a transcriptional interference cannot be excluded.During alkylating agent treatment with MNNG we have observed the presence of STAT1 in DNA repair complex. STAT1 expression allows the recruitment into a MLH1/p53 complex of the kinase c-Abl. This complex leads to cytotoxic dependence on c-Abl kinase activity, an efficient DNA repair with a transient cell cycle arrest and to signaling mechanisms toward cell survival. At longer term of exposure STAT1 also lead to cellular resistance to treatment.These results provide evidences for new anti-tumor roles of STAT1 in two major regulatory systems and indicate STAT1 as a potential therapeutic target.

付記する学位プログラム名: 充実した健康長寿社会を築く総合医療開発リーダー育成プログラム / 京都大学 / 新制・課程博士 / 博士(人間健康科学) / 甲第23127号 / 人健博第89号 / 新制||人健||6(附属図書館) / 京都大学大学院医学研究科人間健康科学系専攻 / (主査)教授 杉本 直三, 教授 黒木 裕士, 教授 松田 秀一 / 学位規則第4条第1項該当 / Doctor of Human Health Sciences / Kyoto University / DFAM