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Rinossinusite é uma causa freqüente de febre em pacientes internados em Unidade de Terapia Intensiva. Seu diagnóstico é muitas vezes tardio por causa da escassez de sinais clínicos e pode levar a complicações como meningite, pneumonia e sépsis. A severidade destas complicações impõe busca ativa do foco infeccioso sinusal, quando existe febre sem foco determinado. A tomografia computadorizada é o exame padrão ouro para esta investigação. Estudos demonstraram, porém, a ocorrência freqüente de rinossinusite detectada em exames radiológicos sem, no entanto, apresentar correlação com infecção sinusal. A endoscopia nasal é um método que permite avaliar as cavidades nasais e, em especial, a região do meato médio e recesso esfenoetmoidal. Esta habilidade tornou a endoscopia nasal um exame fundamental para a avaliação de pacientes com suspeita clinica de rinossinusite. O objetivo deste estudo é avaliar a eficácia da endoscopia nasal como método diagnóstico de rinossinusite em pacientes de terapia intensiva. Trinta pacientes consecutivos, internados em unidades de terapia intensiva, no período de Junho de 2003 a Agosto de 2006, apresentando quadro clínico e tomográfico sugestivo de rinossinusite foram submetidos a endoscopia nasal. Foram incluídos apenas pacientes com indicação de drenagem cirúrgica como modalidade terapêutica, e este é o método de confirmação diagnóstica de rinossinusite adotado. A endoscopia foi realizada antes da drenagem cirúrgica avaliando-se presença de edema e rinorréia em meato médio e recesso esfenoetmoidal. Foi aplicada anestesia e vasoconstrição tópica das fossas nasais, meatos médios e recessos esfenoetmoidais antes da avaliação endoscópica. Os resultados da endoscopia nasal não interferiram na terapêutica adotada para cada paciente, sendo esta determinada pelos intensivistas da Disciplina de Emergências Clinicas, em conjunto com otorrinolaringologistas do Departamento de Otorrinolaringologia do Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo. Dentre os 30 pacientes com suspeita de rinossinusite incluídos neste estudo, 21 apresentaram confirmação diagnóstica por meio de drenagem cirúrgica. No diagnóstico da rinossinusite a tomografia computadorizada mostrou sensibilidade de 97,3% e especificidade de 16,2%. Na endoscopia nasal encontramos sensibilidade de 76,1% e especificidade de 61,2%. Na presença de edema, a endoscopia apresentou sensibilidade de 85% e especificidade de 32%. No diagnóstico da rinorréia a sensibilidade foi de 67,6% com especificidade de 90,4%, e acurácia de 85%. Concluímos que a endoscopia nasal é um método eficaz para o diagnóstico de rinossinusite em pacientes de terapia intensiva, especialmente na presença de rinorréia. / Rhinosinusitis is a frequent cause of fever in Intensive Care Unit (ICU) patients. Diagnosis is sometimes delayed because of lack of clinical signs and it may lead to complications such as meningitis, pneumonia and sepsis. The severity of these complications requires active search for the sinusal infectious focus in the presence of fever of undetermined cause. Computed tomography scan is the gold standard for such investigation. However, studies have demonstrated the frequent occurrence of radiological rhinosinusitis with no correlation with sinusal infection. Nasal endoscopy is a method that enables the assessment of nasal cavities, specially the region of middle meatus and sphenoethmoid recess. This fact has transformed nasal endoscopy into a fundamental exam to assess patients with clinical suspicion of rhinosinusitis. The purpose of the present study was to assess the efficacy of nasal endoscopy as a diagnostic method for rhinosinusitis detection in ICU patients. From June 2003 to August 2006, thirty consecutive patients hospitalized in the ICU who presented clinical picture and tomography results suggestive of rhinosinusitis were submitted to nasal endoscopy. We included only patients with indication of surgical drainage as management option, which was the adopted diagnostic confirmation of rhinosinusitis. Endoscopy was performed before surgical drainage to assess the presence of edema and rhinorrhea in the middle meatus and sphenoethmoid recess. We used anesthesia and topical vasoconstriction of nasal fossa, middle meatus and sphenoethmoid recess before the endoscopic assessment. The results of nasal endoscopy did not interfere in the therapy prescribed to each patient, who was determined by the Intensivists of the Discipline of Clinical Emergency, together with the Otorhinolaryngologists of the Department of Otorhinolaryngology, Hospital das Clinicas, Medical School, University of Sao Paulo. Among the 30 patients with suspicion of rhinosinusitis included in the study, 21 presented diagnostic confirmation through surgical drainage. Computed tomography showed sensitivity of 97.3% and specificity of 16.2% for the diagnosis of rhinosinusitis. In the presence of edema, endoscopy showed sensitivity of 85% and specificity of 32%. In the diagnosis of rhinorrhea, sensitivity was 67.6% and specificity was 90.4%, and accuracy was 85%. We concluded that nasal endoscopy is an effective method for the diagnosis of rhinosinusitis in intensive care unit patients, especially in the presence of rhinorrhea.

nÃo hà / O computador e as novas tecnologias de informaÃÃo e comunicaÃÃo, no sÃculo XXI tÃm representado um marco referencial na atual sociedade do conhecimento em que dados e informaÃÃes, acessados via Web, potencialmente podem gerar novos saberes cientÃficos. Necessita-se entÃo articular pedagogicamente as TDIC à sala de aula integrando-as ao currÃculo, objetivando uma (re)visÃo sobre o fazer ciÃncias da(na) escola. Tomando como aporte teÃrico a aprendizagem significativa e aprendizagem colaborativa procurando ampliar as estratÃgias de aprendizagem, fez-se uso da teoria construcionista de Valente, no intuito de refletir sobre a apreensÃo dos saberes com o emprego do computador enquanto ferramenta de facilitaÃÃo da aprendizagem. Desta forma iniciou-se esta investigaÃÃo ensejando a (re)construÃÃo colaborativa da educaÃÃo cientÃfico-matemÃtica na educaÃÃo bÃsica tendo como base a colaboraÃÃo e o emprego das TDIC para se conceber esta dissertaÃÃo. O campo de anÃlise da pesquisa foi a disciplina de Ensino de CiÃncias e MatemÃtica, ofertada no ano de 2010 para os alunos do Mestrado Profissional em Ensino de CiÃncias e MatemÃtica. A abordagem metodolÃgica empregada na pesquisa foi analise textual qualitativa. Esta anÃlise consistiu na investigaÃÃo de dados que prioriza a apreciaÃÃo de relatos escritos, procura elaborar novos sentidos e entendimentos mais amplos sobre os problemas analisados. A analise textual qualitativa baseou-se (trÃs) aspectos distintos: o processo de unitarizaÃÃo ou desmontagem dos textos estudados, o processo de categorizaÃÃo ou estabelecimento de relaÃÃes entre as informaÃÃes identificadas e a comunicaÃÃo. As ferramentas de apoio empregadas para a pesquisa-aÃÃo foram vinte e nove fÃruns e a ferramenta perfil dentro do AVA TELEDUC procurando compreender imbricaÃÃes entre os relatos-textualizados produzidos em fÃruns, a fim de verificar os aspectos subjacentes relacionados à construÃÃo de saberes e a aprendizagem colaborativa. As opiniÃes, ressignificaÃÃes e relatos experimentais cujos conteÃdos foram assimilados constituÃram-se em um corpus de anÃlise a fim de verificar o processo de aprendizagem e as relaÃÃes envolvidas no processo de cooperaÃÃo entre professores, enquanto circunstÃncias promotoras de mudanÃas conceituais e atitudinais nos professores-alunos em processo de formaÃÃo strictu sensu / The computer and information technologies and communication in the twenty-first century have represented a benchmark, the current knowledge society in which data and information accessed via the Web, can potentially generate new scientific knowledge. Need is then articulate the pedagogical TDIC to the classroom by integrating them into the curriculum, aiming at (re) vision about doing science (in) school. Taking as significant theoretical learning and collaborative learning seeking to broaden the learning strategies, was made use of the constructivist theory of Valens, in order to reflect on the apprehension of knowledge with the use of the computer as a tool for facilitating learning. Thus began this research entailing the (re) building collaborative scientific and mathematical education in basic education based on collaboration and employment of TDIC to develop this thesis. The field of analysis of the research was the discipline of Mathematics and Science Teaching, offered in 2010 for students of the Professional Masters in Teaching Science and Mathematics. The methodological approach employed in the research was qualitative textual analysis. This analysis consisted of the investigation data that prioritizes assessment of written reports, seeks to elaborate new meanings and understandings about the broader problems analyzed. The textual analysis was based on qualitative (three) distinct aspects: the process of unitarization or disassembly of the texts studied, the process of categorization or establishment of relations between the identified information and communication. Support tools were employed to pesquisaÃÃo twenty-nine forums and tool profile within the AVA TELEDUC trying to understand the interplay between-transcribed reports produced in forums, to verify the underlying aspects related to the construction of knowledge and learning telecolaborativa. The opinions, reinterpretation and experimental reports whose contents were assimilated constituted a corpus analysis to verify the learning process and the relationships involved in the process of cooperation between teachers, while the circumstances that promote conceptual and attitudinal changes in teachers Pupils in the process of strictu sensu education

Esta dissertação apresenta modelagem matemática e um método de solução numérica para problemas de conformação eletromagnética de chapas metálicas finas circulares utilizando uma bobina em espiral plana. O método foca especificamente o cálculo do campo eletromagnético gerado pela bobina e análise do circuito que modela o sistema de estampagem eletromagnética. A bobina plana é aproximada por círculos concêntricos carregando a corrente de descarga dos capacitores. Os cálculos das correntes induzidas e perfil da força eletromagnética na chapa e acoplamentos magnéticos entre a bobina e chapa metálica são realizados para o instante inicial, antes da deformação plástica da chapa. O método utiliza a lei de Biot-Savart, sendo que a solução das integrais obtidas para indução magnética é realizada através de métodos numéricos, considerando as simetrias do problema. Para verificação da modelagem matemática, da solução numérica e comprovação da viabilidade técnica deste processo, um dispositivo de estampagem eletromagnética foi desenvolvido e diversos experimentos foram realizados com chapas de alumínio. Os parâmetros investigados foram a espessura da chapa a ser deformada e a influência da presença de vácuo na cavidade da ferramenta. Os resultados experimentais demonstram concordância com os resultados da modelagem proposta. A presença de vácuo também demonstrou um incremento na deformação da chapa. A rotina desenvolvida no software Matlab fornece informações importantes para o processo e permite que se faça ajustes no dispositivo. / This dissertation presents a mathematical model and numerical method to solve the problems of electromagnetic forming of thin circular metal sheets by using a flat spiral coil. The method focuses specifically on the calculation of the electromagnetic field generated by the coil flat and circuit analysis modeling system electromagnetic forming. The flat coil is approximated by concentric circles carrying a discharge current of capacitors. The calculations of induced currents and profile of the electromagnetic force on the plate and magnetic coupling between the coil and sheet metal are made to the initial time, before the plastic deformation of the plate. The method uses the law of Biot-Savart, and the solution of the integral obtained for magnetic induction is performed by numerical methods, considering the symmetries of the problem. To verify the mathematical model, the numerical solution and proving the technical feasibility of this process, a electromagnetic forming device was developed and several experiments were made with aluminum plates. The parameters investigated were the thickness of the plate to be deformed and the influence of the vacuum in the cavity of the tool. The experimental results show agreement with the results of the proposed model. The presence of vacuum also showed an increase in the deformation of the plate. A routine developed in software Matlab provide important information for the process and allow to make adjustments on the device.

INTRODUÇÃO: Os tomógrafos multidetectores (TCMD) aumentaram a sensibilidade na detecção do tromboembolismo pulmonar (TEP). Observa-se, no entanto, um substancial aumento no número de imagens e, conseqüentemente, no tempo de análise pelo radiologista. Uma possível solução, para este problema, é a realização de reconstruções em projeção de intensidade máxima (MIP) que reduz o número de imagens para análise. Existe ainda uma nova modalidade de imagem utilizando reconstrução MIP em planos rotacionais sobre um eixo horizontal ao nível dos hilos pulmonares (reformatação em pás de roda moinho, PRM), que tem demonstrado melhor a continuidade dos ramos arteriais que irradiam dos hilos. No entanto, estudos são necessários para determinar se o uso de reformatações MIP pode reduzir o número de imagens a serem analisadas, sem perda significativa de informações, e se a adição de reformatação PRM pode melhorar o diagnóstico de TEP. OBJETIVOS: Testar a hipótese de que imagens utilizando reconstruções em projeção de intensidade máxima de 2,0 mm e 4,0 mm de espessura, multiplanares, têm o mesmo valor diagnóstico para detecção de TEP nas grandes e pequenas artérias pulmonares, quando comparadas a imagens multiplanares de 1 mm, realizadas em TCMD de 10 e 16 fileiras de detectores. Avaliar se há influência no valor diagnóstico de TEP o acréscimo de reformatações PRM, nas imagens reconstruídas em MIP de 2 mm. CASUÍSTICA E MÉTODOS: Cinqüenta pacientes com suspeita diagnóstica de TEP (30 com TEP positivo e 20 com TEP negativo, detectados no exame tomográfico), realizaram tomografia computadorizada do tórax para avaliação das artérias pulmonares em TCMD com 16 e 10 fileiras de detectores (120 kV, 200 mAs e 1 mm de colimação). Cada exame foi reconstruído em 4 tipos de séries de imagens multiplanares: imagens multiplanares (MPR) de 1 mm e 3 tipos de reconstrução MIP, com espessuras de 2 mm, 4 mm e 2 mm acrescidas de reformatação PRM. Dois observadores avaliaram, independentemente, em estação de trabalho, a presença ou ausência de êmbolos nas artérias principais, lobares, segmentares e subsegmentares dos 50 pacientes em cada uma das reconstruções MIP, as quais foram comparadas usando-se a reformatação MPR de 1 mm como padrão de referência. RESULTADOS: As reconstruções MIP de 2 mm tiveram melhor acurácia, estatisticamente significativa, em relação a MIP de 4 mm, com valores de sensibilidade 100,0 e 100.0 para as artérias principais e lobares; 92,6 e 85,5 para as segmentares e 94,3 e 86,8 para as subsegmentares. Utilizando as imagens multiplanares de 1 mm como referência padrão. Todos pacientes com TEP foram detectados com imagens em MIP de 2 mm. Dois pacientes com TEP não foram diagnosticados com imagens em MIP de 4 mm. Não houve diferença estatisticamente significativa entre a reformatação MIP de 2 mm e 2 mm + PRM na detecção de êmbolos. CONCLUSÃO: Com um número de imagens equivalente a metade da reconstrução MPR de 1 mm, a reconstrução em MIP de 2 mm conseguiu detectar todos os pacientes com TEP positivo que foram diagnosticados pelas imagens multiplanares de 1 mm, com sensibilidade de 100,0 e 100,0 nas artérias principais e lobares, de 92,6 e 85,5 para as artérias segmentares e 94,3 e 86,8 para as artérias subsegmentares. O acréscimo de reformatações PRM às imagens em MIP de 2 mm não aumentou a acurácia na detecção de êmbolos, mas melhorou a visualização da continuidade dos êmbolos, principalmente, nas artérias centrais. / INTRODUCTION: Multidetector computed tomography (MDCT) has been making possible the increase of the sensibility in the detection of the pulmonary embolism (PE). It is observed, however, that there is a substantial increase in the number of images and, consequently, in the time of analysis for the radiologist. A possible solution to this problem is accomplishing a maximum intensity projection reconstruction (MIP) that reduces the number of images for analysis. Still, there is a new image modality using MIP reconstructions in rotational plans that pivot on a central horizontal axis between the lung hila (paddlewheel reformations, PDW). It provides a continuous display of branching arteries that radiate from both hila. However, studies are necessary to determine if the use of multiplan MIP reformation can reduce the number of images to be analyzed, without significant loss of information; and, if the addition of PDW reformation can improve the diagnosis of PE. OBJECTIVE: To test the hypothesis that images using maximum intensity projection reconstructions of 2,0 mm and 4,0 mm of thickness, multiplan, have the same diagnosis value for detection of pulmonary embolism in the big and small pulmonary arteries, when compared to multiplan images of 1 mm collimation, accomplished in 16 and 10 slice MDTC; and to evaluate if there is influence on the diagnosis value of PE the increment of PDW reformation, in the images rebuilt in MIP of 2 mm. CASUISTIC AND METHODS: Fifty patients suspected of having an acute PE (30 with positive PE and 20 with negative PE, detected during the tomography exam) accomplished computerized tomography of the thorax for evaluation of the pulmonary arteries by 16 and 10 slice MDTC (120 kV, 200 mAs and 1 mm collimation). Four kind of images series (1 mm thick multiplan images and 3 kinds of reconstructed images using the MIP tecnhnique with slab thicknesses of 2 mm, 4 mm and 2 mm added of PDW reformation) were obtained from each exam. Two observers independently evaluated, in work station, the presence or absence of emboli in the main and lobar, segmental and subsegmental arteries in the 50 patients in each one of the reconstructions in MIP, which they were compared using the reformation of 1 mm of thickness as reference pattern. RESULTS: The reconstructions in MIP of 2 mm had better accuracy than MIP of 4 mm, statistically significant with values of sensibility 100,0 and 100,0 for the main and lobar pulmonary arteries; 92,6 and 85,5 for the segmental and 94,3 and 86,8 for the subsegmental. The images in MPR of 1 mm were used as a reference pattern. All patients with PE were detected with images in MIP of 2 mm; two patients with PE were not diagnosed with images in MIP of 4 mm. There was not difference statisticament significant among reformation in MIP of 2 mm and 2 mm plus PDW in the detection of emboli. CONCLUSION: Reconstruction in MIP of 2 mm reduced the number of images for the half and it detected all patients with positive PE that were diagnosed by the multiplans images of 1 mm, with sensibility of 100,0 and 100,0 in the main and lobar arteries, of 92,6 and 85,5 and 79,2 for the segmental arteries and 94,3 and 86,8 for the subsegmental arteries. The increment of PDW reformation to the images in MIP of 2 mm didn\'t increase the accuracy in the detection of emboli, but it improved the visualization of the continuity of the emboli, mainly, in the central arteries.

Relatively low rates of homicide solvability results in law-abiding citizens being forced to co-exist with known murderers, which is detrimental to a community’s psyche. This condition happens disproportionately in neighborhoods where crime is high, cohesiveness among its members is weak, and the citizen/police relationship is little or non-existent. This research sought to understand this phenomenon by asking,” How can murder solvability rates improve in marginalized communities?” and employing four theoretical lenses. Using the city of New Orleans as a case study and holding Social Disorganization Theory constant, Spiral of Silence, Habitus, and Dramaturgy were utilized in an attempt to understand individuals who witness violent crime but do not come forward. From these theories, nine assumptions were formed, connecting the literature to this specific area of inquiry. Using a mixed methods approach both qualitative and quantitative data was collected within New Orleans from a variety of instruments: a survey (both web-based and in-person), a questionnaire and two deliberative forums. Utilizing the questionnaire and in conjunction with the Kettering Foundation and the National Issues Forum Institute (NIFI), this research was also able to quantitatively compare New Orleans data with data collected nationally by NIFI. While the data collected support all nine assumptions, five of the nine account for 82% of the data. Of these five, none originated from the Spiral of Silence theory, two originated from the Habitus theory, and three originated from the Dramaturgy theory.

La radiothérapie utilise des faisceaux de particules dans le but d'irradier et d'éliminer les tumeurs cancéreuses tout en épargnant au maximum les tissus sains. La perte d'énergie en forme de pic de Bragg des protons dans la matière permet une amélioration balistique du dépôt de la dose par rapport aux rayons X. Le volume irradié peut ainsi être précisément ajusté au volume tumoral. Cette thèse, dans le cadre du projet RACCAM, vise à étudier et à mettre au point le design d'une installation de protonthérapie basée sur un accélérateur de particules à champ fixe et à gradient alterné FFAG dans le but de construire un aimant FFAG à secteur spiral pour validation. Nous présentons tout d'abord la protonthérapie pour définir un cahier des charges médicales définissant les critères techniques d'une installation de protonthérapie. Puis nous introduisons les accélérateurs FFAG par une présentation des projets passés et en cours dans le monde avant de développer la théorie de la dynamique faisceau dans le cas de l'optique à focalisation invariante. Nous décrivons ensuite les outils de modélisation et simulation mis au point pour étudier cette dynamique faisceau dans une optique FFAG à focalisation invariante et à secteur spiral. Nous expliquons par la suite la recherche des paramètres de l'optique ayant abouti à la construction d'un aimant prototype. Enfin, nous décrivons l'installation de protonthérapie du projet RACCAM depuis le cyclotron injecteur jusqu'au système d'extraction.

La forme du noyau est une caractéristique fondamentale de la matière nucléaire. Les isotopes légers pairs-pairs du krypton possèdent la surprenante propriété de présenter deux minimas pour leur énergie potentielle correspondants à deux déformations opposées. Alors que l'état fondamental 0+ peut avoir une déformation allongée ou aplatie, un second minimum aplati ou allongé respectivement, se dessine à une énergie inférieure à 1 MeV. Un tel phénomène est appelé coexistence de formes. Une première indication expérimentale est l'observation du second minimum correspondant à un état 0+ excité. Celui-ci a été observé tout au long de la chaîne du krypton. Un calcul de mélange des configurations allongée et aplatie met en évidence un changement de forme important de l'état fondamental en fonction du nombre de neutrons. Celui-ci serait de déformation allongée pour les 76,74Kr et deviendrait aplati pour le 72Kr. Une mesure directe de la déformation de ces noyaux est l'étape indispensable pour confirmer ces hypothèses. Une série d'expériences d'excitation Coulombienne auprès du dispositif SPIRAL associé au multi-détecteur EXOGAM au GANIL a été réalisée. Lors de ces expériences, la statistique était suffisante pour extraire les moments quadripolaires intrinsèques de ces noyaux grâce au code GOSIA. Ils établissent le caractère allongé de l'état fondamental et un état excité aplati conformément au scénario de coexistence de formes. Une mesure par « plunger » des temps de vie des états excités complète cette étude. Une expérience a été réalisée à haute énergie auprès du spectromètre LISE au GANIL permettant une première estimation de la collectivité du noyau de 68Se qui présenterait les mêmes propriétés. L'ensemble des résultats obtenus est comparé à des calculs théoriques de type HFB+Sly6+GCM.

Wood is a major construction material that is used in many contexts, and for different purposes. Serious problems may arise, however, when moisture related deformations as twist occur in wood used in different types of building structures, joinery and furniture. Twist can be explained to a great degree by the helical deviation of the grain angle in relation to the longitudinal direction of the log or the sawn board. Wood fibres form a spiral within the tree, and this is a natural occurrence that is named spiral grain. The wood fibres close to the pith in Norway spruce form a left-handed spiral. In most trees the grain angle turns over to be right-handed with time. Sawn timber that exhibits large grain angles lead to problems of shape stability and stiffness in finished constructions. In this thesis the spiral grain in Norway spruce (Picea abies (L.) Karst.) was stated as well as the effect on sawn timber. The material was based on sample trees from Sweden and Finland. Samples were taken in twenty-two stands at different heights in tree. From six stands studs were sawn and dried for measuring twist and other deformations. The spiral grain was measured with the method scribe test on 390 log discs taken at the top-end of the logs. Account was given concerning changes in grain angle from pith to bark, regarding both increasing annual ring numbers and distance from pith. The development of grain angle over tree age was utilized to study whether annual growth, size of tree, height in tree as well as silvicultural treatments affected spiral grain. Moreover, the relation between grain angle and distance to pith (in mm) was used to forecast twist in sawn timber. The left-handed grain angle was at its greatest between the fourth and eighth annual rings. Thereafter for most trees the grain angle turned from left-handed to right-handed in a linear fashion, in a manner that was unique for each individual tree. The pattern of spiral grain differed significantly between different stands, regarding change of inclination with increasing age or distance from pith. The culmination of the grain angle close to the pith occurred at somewhat higher age higher up in the trunk. The grain angle decreased faster in top logs than it did in the butt logs. The largest trees within a stand had a grain angle that turned to right in a slower way than smaller ones. The thinning strength and type of thinning regime also affected the character of spiral grain in the remaining trees in a stand. There was an indication that strong thinnings, where fast growing trees are retained, may lead to more individuals in a stand that exhibit high grain angles under bark. With knowledge of the size and direction of the grain angle under bark, and the diameter of the log, calculations can be made that show how twisted the sawn timber will be after drying. This can be used for deciding whether an individual log can profitably be sawn and processed further or not. The grain angle under bark can be used to remove trees showing the greatest degree of spiral grain already in the first thinning. Silvicultural methods aiming at even and dense Norway spruce stands, which normally is practised in Scandinavia, will probably result in timber with relatively low risk concerning large grain angle and subsequent risk for twist in sawn wood.

This work consists in the development and design of an energy harvesting device to supply power to the new generation pacemakers, miniaturized leadless implants without battery placed directly in heart chambers. After analyzing different mechanical energy sources in the cardiac environment and associated energy harvesting mechanisms, a concept based on regular blood pressure variation stood out: an implant with a flexible packaging that transmits blood forces to an internal transducer. Advantages compared to traditional inertial scavengers are mainly: greater power density, adaptability to heartbeat frequency changes and miniaturization potential. Ultra-flexible 10-µm thin metal bellows have been designed, fabricated and tested. These prototypes acting as implant packaging that deforms under blood pressure actuation have validated the proposed harvesting concept. A new type of electrostatic transducer (3D multi-layer out-of-plane overlap structure with interdigitated combs) has been introduced and fully analyzed. Promising numerical results and associated fabrication processes are presented. Also, large stroke optimized piezoelectric spiral transducers including their complex electrodes patterns have been studied through a design analysis, numerical simulations, prototype fabrication and experimental testing. Apower density of 3 µJ/cm3/cycle has been experimentally achieved. With further addressed developments, the proposed device should provide enough energy to power autonomously and virtually perpetually the next generation of pacemakers.