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Reconfigurable FSM for Ultra-Low Power Wireless Sensor Network NodesRagavan, Rengarajan January 2013 (has links)
Wireless sensor networks (WSN) play an important role in today’s monitoring and controlsystems like environmental monitoring, military surveillance, industrial sensing and control, smarthome systems and tracking systems. As the application of WSN grows by leaps and bounds, there is anincreasing demand in placing a larger number of sensors and controllers to meet the requirements. Theincreased number of sensors necessitates flexibility in the functioning of nodes. Nodes in wirelesssensor networks should be capable of being dynamically reconfigured to perform various tasks is theneed of the hour.In order to achieve flexibility in node functionality, it is common to adopt reconfigurablearchitecture for WSN nodes. FPGA-based architectures are popular reconfigurable architectures bywhich WSN nodes can be programmed to take up different roles across time. Area and power are themajor overheads in FPGA based architectures, where interconnect consumes more power and area thanlogic cells. The contemporary WSN standard requires longer battery life and micro size nodes for easyplacement and maintenance-free operation for years together.Three solutions have been studied and evaluated to approach this problem: 1) Homogenousembedded FPGA platform, 2) Power gated reconfigurable finite state machines and 3) Pass transistorlogic (PTL) based reconfigurable finite state machines. Embedded FPGA is a CMOS 65nm customdeveloped small homogenous FPGA which holds the functionality of the WSN nodes and it will bedynamically reconfigured from time to time to change the functionality of the node. In Power gatedreconfigurable FSM architecture, the functionality of the node is expressed in the form of finite statemachines, which will be implemented in a LUT based power gated design. In PTL based reconfigurablefinite state machine architecture, the finite state machines are completely realized using PTL basedcustom designed sets of library components. Low power configuration memory is used to dynamicallyreconfigure the design with various FSMs at different times.
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Design of a low power 8-bit A/D converter for wireless neural recorder applicationsYang, Jiao 10 July 2017 (has links)
Human brain and related topics like neuron spikes and their active potentials have become more and more attractive to people these days, as these issues are extremely helpful for curing many neural injuries and cognitive diseases. One method to discover this field is by designing a chip embedded in brains with probes to actual neurons. It is obvious that batteries are not practical for these applications and thereby RF radiation is used as power sources, revealing that chips should operate under a very low power supply. Since neural signals are analog waveforms, analog-to-digital converter (A/D converter, ADC) is the key component in a neural recorder chip.
This thesis proposes the complete design of a low power 8-bit successive approximation register (SAR) A/D converter for use in a wireless neural recorder chip, realizing the function of digitizing a sampled neural signal with a frequency distribution of 10Hz to 10kHz. A modified energy-saving capacitor array in the SAR structure is provided to help save power dissipation. Therefore, the ADC shall operate within a power budget of 20μW maximum from a 1V power source, at a clock frequency of 500kHz corresponding to a conversion rate of 55.5-kS/s. All the circuits are designed and implemented based on the IBM/Global Foundries 8HP 130nm BiCMOS technology. Simulations of schematic and layout versions are done respectively to verify the functionality, linearity and power consumption of the ADC.
Key words: Successive approximation register analog-to-digital converter (SAR-ADC), low power design, energy-saving capacitor array, neural recorder applications
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A Low Power Fully Autonomous Wireless Health Monitoring System For Urinary Tract Infection ScreeningWeeseong Seo (5930249) 14 May 2019 (has links)
<div> Recent advancements of health monitoring sensing technologies are enabling plethora of new applications in a variety of biomedical areas. In this work, we present a new sensing technology that enables a fully autonomous monitoring of urinary tract infection (UTI). UTI is the second most common infection in the human body caused by bacterial pathogens, and costs millions of dollars each year to the patients and the health care industry. UTI is easily treatable using antibiotics if identified in early stages. However, when early stage identification is missed, UTI can be a major source of serious complications such as ascending infections, loss of kidney function, bacteremia, and sepsis. Unfortunately, the limitations of existing UTI monitoring technologies such as high cost, time-intensive sample preparation, and relatively high false alarm rate prohibit reliable detection of UTI in early stages. The problem becomes more serious in certain patient groups such as infants and geriatric patients suffering from neurodegenerative diseases, who have difficulties in realizing the symptoms and communicating the symptoms with their caregivers. In addition to the aforementioned difficulties, the fact that UTI is often asymptomatic makes early stage identifications quite challenging, and the reliable monitoring and detection of UTI in early stages remain as a serious problem.</div><div> To address these issues, we propose a diaper-embedded, self-powered, and fully autonomous UTI monitoring sensor module that enables autonomous monitoring and detection of UTI in early stages with minimal effort. The sensor module consists of a paper-based colorimetric nitrite sensor, urine-activated batteries, a boost dc-dc converter, a low-power sensor interface utilizing pulse width modulation, a Bluetooth low energy module for wireless transmission, and a software performing calibration at run-time. </div><div> To further optimize the sensor module, a new fully integrated DC-DC converter with low-profile and low ripple is developed. The proposed DC-DC converter maintains an extremely low level of output voltage ripples in the face of different battery output voltages, which is crucial for realizing low-noise sensor interfaces. Since the DC-DC converter is a part of a module embedded into a diaper, it is highly desirable for the DC-DC converter to have a small physical form factor in both area and height. To address this issue, the proposed DC-DC converter adopts a new charge recycling technique that enables a fully integrated design without utilizing any off-chip components. In addition, the DC-DC converter utilizes sub-module sharing techniques – multiple modules share a voltage buffer and a recycle capacitor to reduce power consumption and save chip area. The DC-DC converter provides a regulated voltage of 1.2V and achieves a maximum efficiency of 80% with a 300ohm load resistance. The output voltage ripple is in the range of 19.6mV to 26.6mV for an input voltage ranging from 0.66 to 0.86V.<br></div>
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Gestion dynamique de la consommation de récepteurs RF : intégration de fronts-end RF ultra faible consommation / Dynamic management of the consumption of RF receivers : integration of ultra low power RF front-endBen Amor, Inès 17 May 2016 (has links)
L’émergence de l’internet des objets (IoT), les applications de types réseaux de capteurs et les nouveaux réseaux pour les objets nécessite le développement d’un nouvel écosystème. De nos jours, elle bouscule plusieurs secteurs de notre société. Cela, sollicite la conception des émetteurs-récepteurs radios fréquence à basse consommation étant donné que la réduction de la consommation d’énergie présente une contrainte importante dans le cas de ces applications afin d’obtenir une autonomie accrue. Dans ce contexte l’objet des travaux de thèse est de proposer des techniques de réduction de la consommation des récepteurs radio fréquence tout en cherchant à minimiser l’impact de ces techniques sur les performances des récepteurs réalisés. Dans l’optique de réaliser un démonstrateur composé d’un émetteur récepteur permettant une transmission vidéo, deux récepteurs UWB impulsionnel non cohérent à gestion dynamique d’énergie ont été réalisés en technologie HCMOS9 0.13µm de STMicroelectronics. Dans un premier temps, une étude des techniques de gestion dynamique d’alimentation sur les circuits analogiques radio fréquences a été proposée. Cette étude a été menée sur différents circuits qui semblent être le plus utilisés en conception de circuits analogiques à hautes fréquences. La technique proposée permet d’allumer et éteindre les circuits entre deux impulsions reçues afin de réduire leur consommation. L’application de cette technique nécessite par ailleurs une réduction du temps de latence causé par l’allumage et les extinctions des fonctions radio fréquence. Dans ce cas, un modèle permettant de minimiser l’impact de l’effet d’encapsulation a été proposé. / The emergence of the Internet of Things (IoT), sensors networks and new networks to objects requires the development of a new ecosystem. Nowadays, it upsets many sectors of our society. It solicits design of low power radio transceivers as reducing energy consumption presents a major constraint in the case of these applications in order to obtain greater autonomy. In this context, the purpose of the thesis is to provide techniques allowing reducing the power consumption of radio frequency receivers while seeking to minimize the impact of these technologies on the performance of the achieved receiver. In order to realize a demonstrator consists of a transmitter and receiver for video transmission, two UWB receivers with dynamic power management have been made in 0.13µm HCMOS9 technology from STMicroelectronics. First, a study of dynamic power management techniques on analog radio frequency circuits was proposed. This study was conducted on different circuits that seem to be the most used in design of analog circuits at high frequencies. The proposed technique allows to turn on and off the circuit between two pulses received to reduce their consumption. The application of this technique also requires a reduction of the latency caused by the ignition and the extinction radio frequency functions. In this case, a model to minimize the impact of the encapsulating effect has been proposed. Secondly, the first receiver was performed for 6-10GHz frequency band and implements dynamic power management using the technique of "Power Gating".
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Génération de fréquences agiles pour petits objets communicants autonomes / Generation of agile frequencies for autonomous communicating objectsGhorbel, Imen 01 December 2016 (has links)
Le secteur des communications sans fil a connu un essor considérable, soutenu par l’évolution des "smartphones" et par le développement des réseaux de capteurs sans fil et de l’Internet des Objets (connu en anglais sous le nom ‘IoT’ pour Internet of Things). Les applications actuelles visent l’autonomie énergétique des objets communicants et nécessitent la conception de circuits intégrés pouvant assurer à la fois un fonctionnement à hautes performances et à moindre coût. L’une des principales fonctions des systèmes de communications radiofréquences (RF) est la génération de fréquence, assurée par l’oscillateur. De nombreux efforts de conception sont ainsi nécessaires afin d’assurer les performances requises par les nouvelles applications sans fil. Nos travaux de recherche ont pour objectif de proposer une méthode de conception d’oscillateurs agiles à faible consommation au sein des systèmes d’émission-réception RF. Le travail s’est focalisé sur l’étude et l’optimisation des éléments constitutifs d’un oscillateur LC passif en technologie CMOS et sur la proposition d’une méthode de conception. La méthode proposée peut être exploitée pour différentes structures d’oscillateurs afin d’optimiser leurs performances essentiellement en termes de consommation de puissance et de bruit de phase. Cette méthode a été appliquée pour implémenter plusieurs VCOs en technologie CMOS. Une série de mesure sous pointes a permis de valider leur fonctionnement. La suite de ce travail de thèse est consacrée à la proposition d’une nouvelle topologie d’oscillateur LC reconfigurable à base d’inductance active dédiée aux applications multistandards faible coût / The rapid growth of the Internet of Things (IoT) applications and the wireless sensor networks boosts the need for low cost and low power radiofrequency (RF) transceivers. The voltage-controlled oscillator (VCO) is an essential building block of several RF transceivers. Design tradeoffs have been very stringent in terms of power consumption, phase-noise, area and tuning range. In this context, the aim of this work is to propose a design method, aiming to optimize the VCO design and to improve its performances essentially in terms of power consumption and phase noise.The first part of this thesis sets a study of the elements of passive LC oscillators in CMOS technology. The second part presents a complete design method, aiming to optimize the LC-VCO performance regarding the phase noise and power consumption. The evaluation of the proposed method is carried out with some test-cases in full CMOS technology. Many RF LC-VCOs have been implemented and measured. The final part of this thesis presents a new tunable VCO suitable for multi-standards applications. The frequency tuning of the VCO is ensured using an active inductor based on CMOS inverters. The desired bandwidth can be selected while achieving low surface area and low power consumption.
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Magnetic shielding topology applied to low power Hall thrusters / Topologie d’écrantage magnétique appliquée aux moteurs de Hall faible puissanceGrimaud, Lou 25 October 2018 (has links)
Les propulseurs de Hall sont l’une des techniques de propulsion fusée par plasma les plus utilisés. Ils possèdent une impulsion spécifique moyenne et un haut rapport poussé sur puissance qui les rend idéal pour une grande partie des applications commerciales et scientifiques. Une de leurs limitations principales est l’érosion des parois du propulseur par le plasma qui réduit leur durée de vie. La topologie dite “d’écrantage magnétique” est une solution proposée pour prolonger cette durée de vie. Elle est ici appliquée à un petit propulseur de Hall de 200W. Dans cette thèse les règles de mise à l’échelle pour les propulseurs de Hall de la gamme de 100 à 200W sont testées expérimentalement. Un propulseur écranté de 200W est comparé avec un propulseur standard similaire. Le comportement des ions dans ces deux moteurs est extrêmement différent. Des mesures de performance ont été réalisées avec des parois en BN-SiO2 et graphite. Le courant de décharge augmente de 25% avec le graphite dans le propulseur non-écranté. Le résultat et un rendement maximum de 38% avec le nitrure de bore mais de seulement 31% pour le graphite. Le propulseur écranté quant à lui n’atteint que 25% de rendement quel que soit le matériau.Cette baisse de performance dans les petits moteurs écrantés peut être attribuée à un mauvais rendement d’utilisation de l’ergol. Analyses des résultats expérimentaux ainsi que la conduite de simulations suggèrent que cela est dû au fait que la zone d’ionisation ne couvre pas l’ensemble du canal de décharge. Un nouveau design pour un petit propulseur de Hall écranté est proposé. / Hall thrusters are one of the most used rocket electric propulsion technology. They combine moderate specific impulse with high thrust to power ratio which makes them ideal for a wide range of practical commercial and scientific applications. One of their limitations is the erosion of the thruster walls which reduces their lifespan.The magnetic shielding topology is a proposed solution to prolong the lifespan. It is implemented on a small200W Hall thruster.In this thesis the scaling of classical unshielded Hall thrusters down to 200 and 100W is discussed. A 200W low power magnetically shielded Hall thruster is compared with an identically sized unshielded one. The ion behavior inside the thruster is measured and significant differences are found across the discharge channel.Both thrusters are tested with classical BN-SiO2 and graphite walls. The magnetically shielded thruster is not sensitive to the material change while the discharge current increase by 25% in the unshielded one. The result is a maximum efficiency of 38% for boron nitride in the unshielded thruster but only 31% with graphite.The shielded thruster achieves a significantly lower efficiency with only 25% efficiency with both materials.Analysis of the experimental results as well as simulations of the thrusters reveal that the performance difference is mostly caused by low propellant utilization. This low propellant utilization comes from the fact that the ionization region doesn’t cover all of the discharge channel. A new magnetically shielded thruster is designed to solve this issue.
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Avaliação in vivo do potencial regenerativo na Degeneração Walleriana de nervos periféricos - com a utilização de laser de baixa potência e composto polivitamínico 3-NERVE® / Evaluation in potential of live in regenerative Walleriana degeneration peripheral nerve - with laser use low power and compound multivitamin 3-NERVE®Pistarini, Luciana Crepaldi Yazawa 24 June 2015 (has links)
Nas áreas médica e odontológica existem situações clínicas e cirúrgicas que podem ter, como consequência, um dano ao tecido conjuntivo nervoso, chamado de neuropatia. O objetivo deste trabalho é avaliar terapias para tratamento das neuropatias causadas por manipulação do feixe nervoso periférico, minimizando ou eliminando sintomas causados pela lesão. O estudo foi feito em 60 ratos machos Wistar, com a avaliação morfológica da degeneração Walleriana e da regeneração do tecido nervoso no 15º e 30º dia após o trauma. A lesão consistiu na exposição e compressão do nervo isquiático da pata direita do animal, através de três nós consecutivos com fio de sutura e distância entre eles de ~ 2mm. Três tratamentos sobre a lesão foram comparados: o uso do biomaterial 3-NERVE®, a laserterapia de baixa potência e a associação dos dois. Os resultados histológicos revelaram que o biomaterial aumentou o processo inflamatório, mas modulou a degeneração inicial, através do surgimento de células de neoformação, favorecendo a regeneração nervosa no decorrer dos trinta dias. A laserterapia foi um tratamento favorável para a parestesia porque modulou os danos do processo de degeneração inicial e estimulou o reparo do tecido desde os 15 primeiros dias. Ao atingir os 30 dias o tecido se apresentou organizado e com uma quantidade menor de tecido neoformado quando comparado com o uso do biomaterial. A associação das terapias associou as propriedades das duas terapias, pois modulou a inflamação inicial, propiciou o aumento do número de células de neoformação do tecido nervoso e favoreceu a regeneração dos feixes nervosos nas amostras de 15 e 30 dias. Conclui-se que o não tratamento dificulta ou impede a regeneração nervosa, pois qualquer uma das terapias citadas modula os eventos desencadeados pela lesão. A associação do uso da laserterapia com o 3-NERVE® mostrou melhores resultados. / In medical and dental areas are clinical and surgical situations that may have, as a result, damage to the nervous tissue. This is called a neuropathy. The objective is to support therapies for treatment of neuropathies caused by manipulation of the peripheral nervous bundle, minimizing or eliminating symptoms caused by injury. The study was conducted in 60 male Wistar rats by morphological analysis of Wallerian degeneration and regeneration of nerve tissue in the 15th and 30th day after the trauma. The lesion consisted of exposure and sciatic nerve compression of the right paw of the animal through three consecutive nodes with suture and the distance between them of ~ 2mm. Three treatments on the injury were compared: the use of -NERVE® biomaterial, the low level laser therapy and their association. Histological findings revealed in samples 15 and 30 days the biomaterial increased inflammation and degeneration of the initial modulated through the cell neogenesis emergence favored nerve regeneration in the course of 30 days. Laser therapy was a favorable treatment for paresthesia because modulates the damage of the initial degeneration process and stimulates tissue repair since the first 15 days. When reaching the 30 days the tissue was organized and presented with a smaller amount of neoformed tissue when compared with the use of the biomaterial. The combination therapies of the modulated the initial inflammation, led to an increase in the number of cells neogenesis and promoted nerve tissue regeneration of nerve bundles in the samples 15 and 30 days. We conclude that no treatment hinders or prevents nerve regeneration, for any of the therapies mentioned modulate the events triggered by the injury. The association between the use of laser therapy with Nerve® proved with better results.
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Os efeitos da irradiação com laser de baixa potência na regeneração do nervo fibular comum do rato submetido a lesão por esmagamento / The effects of low power laser irradiation on the regeneration of the common fibular nerve in rat submitted to a crush lesion.Andraus, Rodrigo Antonio Carvalho 10 February 2009 (has links)
A regeneração dos nervos periféricos é um processo natural, que demanda um período longo para se completar, havendo algumas evidências de que agentes físicos, inclusive o laser, podem acelerá-lo. O objetivo primordial deste estudo foi analisar a influência da irradiação com o laser de baixa potência (AsGaAL) sobre a regeneração nervosa, num modelo de lesão por esmagamento do nervo fibular comum de ratos. O objetivo secundário foi avaliar a concordância entre os índices funcionais do nervo fibular (PFI) e o dos nervos ciático (SFI) e tibial (TFI), segundo os métodos propostos por dois autores diferentes. Foram utilizados 35 ratos Wistar (130 dias de idade, massa corporal média de 240 gramas), divididos em quatro grupos no total, sendo três grupos de dez animais cada, conforme o procedimento realizado (1: esmagamento, sem tratamento; 2: esmagamento e tratamento simulado; 3: esmagamento e tratamento efetivo) e num grupo de cinco animais intactos, para controle. A lesão por esmagamento do nervo fibular comum foi obtida pela aplicação de uma carga de 5 Kgf por dez minutos, com uma pinça especialmente confeccionada para esse fim. A irradiação com o laser foi iniciada no primeiro dia pós-operatório, empregando um equipamento de laser AsGaAL de baixa potência (potência de 100 mW, comprimento de onda de 830 nm, dose de 140 J/cm2) de emissão contínua, pelo método transcutâneo pontual de contato, e continuada por 21 dias consecutivos. Os resultados foram avaliados pela medida da velocidade de marcha do animal e do índice funcional do fibular (PFI, de peroneal functional index). A massa corporal, a velocidade de marcha e o PFI foram medidos antes da operação e no 21º dia pós-operatório, o PFI foi obtido por meio de um programa de computador específico para esse fim, utilizando duas fórmulas diferentes. Os resultados mostraram que a massa corporal aumentou em todos os grupos, sem diferença estatística entre os períodos. A velocidade de marcha diminuiu, com diferença estatística em todos os grupos. O PFI aumentou em todos os grupos e com as duas fórmulas utilizadas na sua medida, mas no Grupo 3, embora sem diferença estatística nos períodos pré e pós-operatórios, evidenciando que a irradiação com o laser interferiu na regeneração do nervo fibular esmagado. Houve uma concordância moderada entre o PFI e o SFI, maior no período pós-operatório, demonstrando que o SFI pode ser empregado para a avaliação do nervo fibular, o que, entretanto, não é recomendável. Concluímos que a irradiação do laser de baixa potência influenciou na regeneração do nervo fibular comum esmagado de ratos, pela medida do índice funcional do fibular. / Peripheral nerve regeneration is a natural process, which requires a long period to complete, with a few evidences that physical agents including laser, can speed it up. The main objective of this investigation was to analyze the influence of low power laser (AsGaAL) irradiation on nerve regeneration, in a model of crush injury of the common fibular nerve of rats. A secondary objective was to evaluate the concordance between the fibular (PFI) and sciatic (SFI) nerves functional indexes, according to the methods proposed by two different research groups. Thirty-five Wistar rats (130 days of age, 240 g average body mass) were used and divided into four groups in total, be three groups of ten animals each, according to the procedure carried out (1: crush injury, no treatment; 2: crush injury, sham irradiation; 3: crush injury, effective irradiation), and a group of five untouched animals, for normal control. The crush injury was obtained by the application of a 5 kgf load for 10 minutes, using a spring forceps especially built for this purpose. Laser irradiation was started on the first postoperative day and continued for 21 consecutive days, using a commercially available continuous emission equipment (100 mW intensity, 830 nm wave length, 140 J/cm2 dose) and the transcutaneous punctual contact method. The results were appraised for the measure of the speed of the gait of the animal and of the functional index of the fibular (PFI, de peroneal functional index). Body mass, walking speed and the functional indexes were measured before the operation and on the 21st postoperative day, the functional indexes using a specific software especially developed for this purpose and the two different methods mentioned above. The results showed that the body mass increased while speed decreased with time for all groups, but without statistical significance. The PFI increased in all groups according to the two methods of evaluation used and more markedly in Group 3, although without statistical significance, period pre and post-operative. Moderate concordance was showed between PFI and SFI, higher in the post-treatment than in the preoperative evaluation, meaning that, although not recommendable, the SFI can be used to evaluate the fibular nerve. We concludes that low power laser irradiation influence the regeneration of the crush fibular nerve of rats, as measured by the peroneal functional index.
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Filtros RC-Ativo ULV e ULP combinando OTA de único estágio e transcondutância negativa de entrada para receptores RF de baixa energia. / ULV and ULP active-RC filters combining single-stage OTA and negative input transconductance for low energy RF receivers.Severo, Lucas Compassi 04 February 2019 (has links)
Este trabalho propõe novas topologias de circuitos e técnicas de projeto para filtros ativos e amplificadores de ganho programável (PGA) com operação em ultra baixa tensão (ULV) e ultra-baixa potência (ULP). Os receptores de RF do tipo Bluetooth de baixa energia (BLE), utilizados nos circuitos de internet das coisas (IoT), são as aplicações alvo dos circuitos propostos neste trabalho. Na faixa de ULV são utilizados filtros do tipo RC-ativo, uma vez que possuem uma maior linearidade em relação aos filtros do tipo gmC. A operação em ULP é alcançada neste trabalho utilizando uma nova topologia de amplificador operacional de transcondutância (OTA), com único estágio, que apresenta uma alta eficiência e reduzida sensibilidade às variações de processo, tensão e temperatura (PVT). O baixo ganho de tensão do amplificador de estágio único e os efeitos das cargas resistivas de realimentação são compensados usando um transcondutor negativo, robusto a variações em PVT, conectado às entradas do OTA. A faixa dinâmica dos circuitos é elevada usando topologias totalmente diferenciais e as taxas de rejeição de modo comum e de fonte de alimentação são melhoradas utilizando circuitos de realimentação de modo-comum. Para possibilitar a operação na faixa de ULV todos os circuitos usam apenas dois transistores empilhados e o nível de inversão do canal é elevado através da polarização direta do substrato. Neste trabalho são propostas também uma ferramenta de análise do ponto de operação do transistor, baseando-se na simulação elétrica, e algumas metodologias de projetos para circuitos operando em ULV. Os circuitos e metodologias desenvolvidos foram utilizados para o projeto de um filtro passa-faixa complexo RC-ativo de terceira ordem, um amplificador de ganho programável e um filtro biquadrático do tipo Tow-Thomas com ganho programável, compatíveis com receptores de RF do padrão BLE. Para a implementação do PGA, uma nova topologia de transconductor negativo programável foi desenvolvida para permitir a compensação ótima do amplificador operacional em todos os modos de ganho. Todos os circuitos foram projetados para operar com uma tensão de alimentação de 0,4 V e foram prototipados em processos de fabricação CMOS e BiCMOS de 180 nm e 130 nm, respectivamente. Os resultados experimentais e de simulação pós-layout demonstram uma operação adequada em 0,4 V, uma ultra-baixa dissipação de potência, atingindo o mínimo de 10.9 ?W/polo, e a melhor figura-de-mérito (FoM) em relação aos outros filtros ativos e amplificadores disponíveis na literatura. / This thesis proposes novel circuit topologies and design techniques of ultra-low voltage (ULV) and ultra-low power (ULP) active-filters and programmable gain amplifiers (PGA) suitable for the Bluetooth low energy (BLE) RF receivers used in the Internet of Things (IoT) applications. The active-RC filters are preferred to the gm-C topologies at the ULV operation due to its improved linearity. However, the closed-loop operation increases the operational amplifier required voltage gain and its capacity to drive the resistive feedback load. In this work, the ULP dissipation is obtained by proposing a very efficient single-stage inverter-based operational transconductance amplifier (OTA) and a proper forward bulk biasing to reduce the sensitivity to process, voltage and temperature (PVT) variations. The low voltage gain and the resistive load effects on the single-stage OTA are completely compensated by using a PVT robust negative transconductor connected at the OTA inputs. The dynamic range is increased by using fully-differential topologies and common-mode feedback to improve the common-mode and power supply rejection rates. The operation at the ULV range is reached by using only two-stacked transistors in all the circuit implementations and bulk forward bias in some transistors to reduce the threshold voltage and to increase the channel inversion level. An operation point simulation-based tool and some design methodologies are also proposed in this work to design the ULV circuits. The proposed circuits were used to design a third-order active-RC complex band-pass filter (CxBPF), a programmable gain amplifier (PGA) and a Tow-Thomas biquad, with integrated programmable gain capability, suitable for BLE RF receivers. The PGA implementation uses a new programmable input negative transconductor to obtain the optimal closed-loop amplifier compensation in all the gain modes. The circuits were designed to operate at the power supply voltage of 0.4 V and are prototyped in 180 nm and 130 nm low-cost CMOS and BiCMOS process, respectively. The experimental and post-layout simulation results have demonstrated the proper ULV operation at 0.4 V, the ultra-low power dissipation down to 10.9 ?W/pole and the best figure-of-merit (FoM) among the state-of-the-art active-filters and amplifiers from the literature.
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Estudo clínico, bioquímico e histológico do efeito da terapia fotodinâmica na mucosite oral induzida por 5-Fluorouracil em hamsters / Clinical, biochemical and histolólico study about the effect of photodynamic therapy in oral mucositis induced by 5-fluorouracil in hamstersCruz, Érika de Paula da 17 July 2014 (has links)
A mucosite oral (MO) é uma consequência debilitante do tratamento quimioterápico, que pode ser aliviada com o uso de fototerapias. A terapia fotodinâmica (Photodynamic Therapy - PDT), pode ser usada para o tratamento da MO, quando esta se encontra infectada por microrganismos. No entanto, não há estudos que demonstrem se a PDT, quando aplicada sobre lesões em mucosa oral, pode interferir na reparação tecidual. Assim, este trabalho tem o objetivo de induzir a MO, em hamsters, através da confecção de ranhuras em animais que receberam o quimioterápico 5-Fluorouracil (5-FU), e avaliar, através de análises clínicas, bioquímicas e histológica, o efeito da PDT no reparo destas lesões. Os animais foram divididos em dois grupos, controle e experimental. O grupo controle é formado pelo grupo CN, o qual recebeu o veículo da quimioterapia e anestesia. O grupo experimental é formado pelos grupos CQ, o qual recebeu quimioterapia (QT), anestesia e indução da MO; CQC, o qual recebeu QT, anestesia, indução da MO e aplicação do corante azul de metileno (AM) 0,01%; CQL, o qual recebeu QT, anestesia, indução da MO e irradiação com laser de baixa potência (LBP - 660nm, 120J/cm2, 40mW, 4,4J por ponto); e PDT, o qual recebeu QT, anestesia, indução da MO, aplicação do AM 0,01% e irradiação com LBP (mesmo protocolo do grupo CQL). O 5-FU foi aplicado através de injeções intraperitoneais ao que se seguiu a indução da MO pela confecção de ranhuras com o auxílio de uma agulha de ponta fina. O experimento teve duração total de 10 dias sendo que a avaliação da severidade da MO foi realizada diariamente através da utilização das escalas propostas pela Organização Mundial de Saúde (OMS) e por W-Smith modificadas para animais. Os animais foram sacrificados após 5, 7 e 10 dias de experimento e suas mucosas jugais (direita e esquerda) foram removidas para a realização das análises bioquímicas (através da determinação da concentração total de proteína e da avaliação de parâmetros do sistema antioxidante, como a atividade enzimática da Superóxido Dismutase - SOD e da Catalase) e histológica (por microscopia de luz). Após análises estatísticas, os resultados clínicos, bioquímicos e histológico mostraram que a PDT diminuiu a severidade da MO no décimo dia do experimento (p<0,05) e mostrou maior queratinização do epitélio com deposição de fibras colágenas organizadas na lâmina própria. Com base no protocolo experimental desenvolvido neste estudo e nos resultados obtidos podemos concluir que a PDT pode ser utilizada de maneira segura em lesões infectadas de MO, pois a mesma não interferirá na reparação destas lesões. / Oral mucositis (OM) is a debilitating side effect of chemotherapy, which can be relieved with the use of phototherapy. Photodynamic therapy (PDT) may be used for the treatment of OM, when infection is present. However, there are no studies that demonstrate PDTs interference on tissue repair processes when applied on lesions of the oral mucosa. In this sense, this work aims to induce OM in hamsters, by grooving the oral mucosa of animals receiving 5-fluorouracil (5-FU) chemotherapy, and evaluate through clinical, biochemical and histological parameters the effect of PDT in repairing these lesions. The animals were divided into two groups, experimental and control. The control group is formed by the C group, which received the vehicle of chemotherapy and anesthesia. The experimental group is formed by the Ch group, which received chemotherapy, anesthesia and induction of OM; ChP, which received chemotherapy, anesthesia, induction of OM and application of methylene blue (MB) 0.01%; ChL, which received chemotherapy, anesthesia, induction of OM and irradiation with low-power laser (LPL - 660nm, 120J/cm2, 40 mW, 4.4 J per point); and PDT, which received chemotherapy, anesthesia, induction of OM, application of MB 0.01% and LPL irradiation (same protocol as ChL group). 5-FU was administered by intraperitoneal injection, which was followed by the induction of OM by making mucosal grooves. The experimental period was of 10 days and the assessment of the severity of OM was performed on a daily basis using the scales proposed by the World Health Organization (WHO) and by W-Smith modified for animals. The animals were sacrificed after 5, 7 and 10 days of the experiment and their cheek pouch mucosa (left and right) were removed for carrying out the biochemical (by measuring the total protein concentration and by evaluating the antioxidant system parameters, such as enzymatic activity of Superoxide Dismutase - SOD and catalase) and histological (by light optical microscopy) analyzes. After statistical analysis, the clinical, biochemical and histological results showed that PDT reduced the severity of OM on the tenth day of the experiment, when compared to the initial mucositis score (p<0.05) and showed greater keratinization with organized collagen deposition in the lamina propria. Based on the experimental protocol developed in this study and the results obtained we can conclude that PDT can be used safely in infected OM injuries because it does not interfere with the repair of these lesions.
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