Dental and orthopaedic implants are currently the solutions of choice for teeth and joint replacements with success rates continually improving, but they still have undesirable failure rates in patients who are compromised by disease or age, and who in many cases are the ones most in need. The success of titanium (Ti) implants depends on their ability to osseointegrate with the surrounding bone and this, in turn, is greatly dependent on the surface characteristics of the device. Advancements in surface analysis and surface modification techniques have improved the biological performance of metallic implants by mimicking the hierarchical structure of bone associated with regular bone remodeling. In this process, damaged bone is resorbed by osteoclasts, which produce resorption lacunae containing high microroughness generated after mineral dissolution under the ruffled border, as well as superimposed nanoscale features created by the collagen fibers left at the surface. Indeed, increasing Ti surface roughness at the micro and sub-microscale level has been shown to increase osteoblast differentiation in vitro, increase bone-to-implant contact in vivo, and accelerate healing times clinically. Recently, the clinical application of surface nanomodification of implants has been evaluated. Still, most clinically-available devices remain smooth at the nanoscale and fundamental questions remain to be elucidated about the effect of nanoroughness on the initial response of osteoblast lineage cells. Another property that could be used to control osteoblast development and the process of osseointegration is the electrical surface charge of implants. The presence of endogenous electrical signals in bone has been implicated in the processes of bone remodeling and repair. The existence of these native signals has prompted the use of external electrical stimulation to enhance bone growth in cases of fractures with delayed union or nonunion, with several in vitro and in vivo reports confirming its beneficial effects on bone formation. However, the use of electrical stimulation on Ti implants to enhance osseointegration is less understood, in part because of the lack of in vitro models that truly represent the in vivo environment. In addition, an aspect that has not been thoroughly examined is the electrical implication of implant corrosion and its effect on the surrounding tissue. Implants are exposed to extreme conditions in the body such as high pH during inflammation, and cyclic loads. These circumstances may lead to corrosion events that generate large electrochemical currents and potentials, and may cause abnormal cell and tissue responses that could be partly responsible for complications such as aseptic loosening of implants. Consequently, Ti implants with tailored surface characteristics such as nanotopography and electrical polarization, could promote bone healing and osseointegration to ensure successful outcomes for patients by mimicking the biological environment of bone without the use of systemic drugs. The objective of this thesis is to understand how surface nanostructural and electrical characteristics of Ti and Ti alloy surfaces may affect osteoblast lineage cell response in vitro for normal tissue regeneration and repair. Our central hypothesis is that combined micro/nanostructured surfaces, as well as direct stimulation of Ti surfaces with fixed direct current (DC) potentials, can enhance osteoblast differentiation.

Problem investigated: Chronic wounds are not only a major burden to the patient arising from general pain and discomfort but also generate economic costs to both these individuals and the health care system. Various electrical stimulation regimes have been employed to study the effects of electrical stimulation on wound healing both in vivo and in vitro. In was hypothesised that electrical stimulation using various waveforms can modulate cell function, particularly cell migration. The aim of this thesis was to study the effects of electrical stimulation on cellular migration, in particular endothelial cells and fibroblasts, key cell types involved in wound healing. The impact of collagen matrix on cell migration was also assessed. Methods: Cells were seeded on either glass or collagen I substrate and stimulated with various electrical regimes via platinum electrodes connected to a constant current source. Cell migration was accessed by manual tracking of cell nuclei over a period of 3 hours from digital time-lapse images acquired during stimulation. Data from cell tracking were analysed for directional migration, migration rates and mean square displacement. Results: No directional cell migration for both endothelial cells and fibroblasts were observed when stimulated with either alternating or biphasic currents. However, surface substrate had impacted on cell motility with opposite effects being observed for the two cell types. Endothelial cells tended to migrate at a faster rate on collagen I substrate than on glass, compared with fibroblasts, which displayed a slower rate of migration on collagen I substrate. Significant changes in mean square displacement of biphasic current stimulated cells on collagen I substrate compared to unstimulated cells were also observed. Conclusion: This thesis has illustrated cell migration can be modulated by electrical stimulation, in particular asymmetric biphasic current. It has also been demonstrated surface substrate can impact cell migration.

The ventral tegmental area (VTA) and its dopaminergic (DA) mesocorticolimbic projections are thought to be essential in the brain’s reward neurocircuitry. In humans and animal experimental subjects, mild electrical VTA stimulation increases dopamine levels and can induce euphoria. Paradoxically, aversive stimuli activate VTA neurons and forebrain DA activity, and excessive electrical stimulation of the VTA exaggerates fearfulness. Research suggests that experimental manipulation of either the amygdala or the VTA has similar effects on the acquisition and expression of Pavlovian conditioned fear. Recently it was demonstrated that electrical stimulation of the amygdala produced fear extinction deficits in rats. Fear extinction involves the progressive dissipation of conditioned fear responses by repeated non-reinforced exposure to a conditioned stimulus (CS). Maladaptive states of fear in fear-related anxiety disorders, such as post-traumatic stress disorders (PTSD) or specific phobias are thought to reflect fear extinction learning deficits. The primary purpose of the present study was to examine the effects of intra-VTA stimulation on fear extinction learning. Using fear-potentiated startle as a behavioural index of conditioned fear, it was found that 120 VTA stimulations paired or unpaired with non-reinforced CS presentations impaired the extinction of conditioned fear. This effect was not apparent in rats that received electrical stimulation of the substantia nigra (SN), suggesting that not all midbrain regions respond similarly. Electrical stimulation parameters did not have aversive affects because rats failed to show fear conditioning when electrical VTA stimulation was used as the unconditioned stimulus. Also, VTA stimulation did not alter conditioned fear expression in non-extinguished animals. Based on the results it is suggested that VTA activation disinhibited conditioned fear responding. Therefore, VTA neuronal excitation by aversive stimuli may play a role in fear-related anxiety disorders thought to reflect extinction learning deficits.

Neuromuscular electrical stimulation (NMES) has become an increasingly popular rehabilitative treatment approach for swallowing disorders (dysphagia). However, its precise effects on swallowing biomechanics and measures of swallowing neurophysiology are unclear. Clearly defined NMES treatment protocols that have been corroborated by thorough empirical research are lacking. The primary objective of this research programme was therefore to establish optimal NMES treatment parameters for the anterior hyo-mandibular (submental) musculature, a muscle group that is critically involved in the oral and pharyngeal phases of swallowing. Based on previous research, the primary hypothesis was that various NMES treatment protocols would have differential effects of either enhancing or inhibiting the excitability of corticobulbar projections to this muscle group. The research paradigm used to test this hypothesis was an evaluation of MEP amplitude and onset latency, recorded in the functional context of volitional contraction of the submental musculature (VC) and contraction of this muscle group during the pharyngeal phase of volitional swallowing (VPS, volitional pharyngeal swallow). Outcome measures were recorded before and at several time points after each NMES treatment trial. This methodology is similar to, but improved upon, research paradigms previously reported. Changes in corticobulbar excitability in response to various NMES treatment protocols were recorded in a series of experiments. Ten healthy research participants were recruited into a study that evaluated the effects of event-related NMES, whereas 15 healthy research participants were enrolled in a study that investigated the effects of non-event-related NMES. In a third cohort of 35 healthy research participants, task-dependent differences in corticobulbar excitability were evaluated during three conditions of submental muscle contraction: VC, VPS and submental muscle contraction during the pharyngeal phase of reflexive swallowing (RPS, reflexive pharyngeal swallowing). Event-related NMES induced frequency-depended changes in corticobulbar excitability. NMES administered at 80 Hz facilitated MEP amplitude, whereas NMES at 5 Hz and 20 Hz inhibited MEP amplitude. No changes were observed after NMES at 40 Hz. Maximal excitatory or inhibitory changes occurred 60 min post-treatment. Changes in MEP amplitude in response to event-related NMES were only observed when MEPs were recorded during the VC condition, whereas MEPs recorded during the VPS condition remained unaffected. Non-event-related NMES did not affect MEP amplitude in either of the muscle contraction conditions. Similarly, MEP onset latencies remained unchanged across all comparisons. MEPs were detected most consistently during the VC contraction condition. They were less frequently detected and were smaller in amplitude for the VPS condition and they were infrequently detected during pre-activation by RPS. The documented results indicate that event-related NMES has a more substantial impact on MEP amplitude than non-event-related NMES, producing excitatory and inhibitory effects. Comparison of MEPs recorded during VC, VPS and RPS suggests that different neural networks may govern the motor control of submental muscle activation during these tasks. This research programme is the first to investigate the effects of various NMES treatment protocols on the excitability of submental corticobulbar projections. It provides important new information for the use of NMES in clinical rehabilitation practices and our understanding of the neural networks governing swallowing motor control.

<p>This dissertation is about the first substantial restoration of human sense using a medical intervention. In particular, the development of the modern cochlear implant (CI) is described, with a focus on sound processors for CIs. As of October 2015, more than 460 thousand persons had each received a single CI on one side or bilateral CIs for both sides. More than 75 percent of users of the present-day devices use the telephone routinely, including conversations with previously unknown persons and with varying and unpredictable topics. That ability is a long trip indeed from severe or worse losses in hearing. The sound processors, in conjunction with multiple sites of highly-controlled electrical stimulation in the cochlea, made the trip possible.</p><p>Many methods and techniques were used in the described research, including but not limited to those of signal processing, electrical engineering, neuroscience, speech science, and hearing science. In addition, the results were the products of collaborative efforts, beginning in the late 1970s. For example, our teams at the Duke University Medical Center and the Research Triangle Institute worked closely with investigators at 27 other universities worldwide. </p><p>The most important outcome from the research was unprecedented levels of speech reception for users of CIs, which moved a previously experimental treatment into the mainstream of clinical practice.</p> / Dissertation

Lesões na medula espinhal atingem um grande número de pessoas, devido a traumas, doenças congênitas ou adquiridas. Para estes tipos de lesões não há cura e os indivíduos lesados medulares dependem de tratamento através de fisioterapia ou órteses que auxiliem na recuperação de possíveis funções perdidas. A Estimulação Elétrica Neuromuscular (EENM) tem sido pesquisada com essa proposta: reabilitar pessoas portadoras de lesão medular ou disfunções do aparelho locomotor. Muitos estudos já foram desenvolvidos na área de estimulação elétrica neuromuscular, avaliando a marcha, o ato de levantar-se ou outros movimentos. Um ponto em comum entre estes estudos é a preocupação com os efeitos fisiológicos da EENM, como por exemplo o gasto energético. Diante disto, o objetivo deste projeto foi avaliar os efeitos da EENM sobre o gasto energético de lesados medulares. Foi observado o consumo de oxigênio durante o repouso, a marcha e a recuperação. A avaliação proposta foi realizada por método indireto e as análises estatísticas foram realizadas através do teste ANOVA ONE WAY. Os resultados sugerem os voluntários tiveram recuperação fisiológica. Entretanto novas pesquisas são necessárias, com outras variáveis sendo avaliadas. / Lesions in the spinal cord affect a great number of individuals, either due to traumas or to congenital or acquired diseases. Such lesions are incurable, and the injured patients depend on physiotherapy or orthosis to aid in the recovery of lost functions. The Neuromuscular Electrical Stimulation (NMES) has been researched with this purpose: rehabilitating spinal cord injured patients, or those with motor system dysfunction. Several studies have already been developed in the field of neuromuscular electrical stimulation, assessing gait, the act of getting up or other everyday movements. All these studies bear something in common: the concern with the physiologic effects of NMES, such as the energy consumption. Hence, the objective of this project was to evaluate the effects of NMES on the energy cost of spinal injured patients. The consumption of oxygen was assessed during rest, gait and the recovery period. The proposed evaluation was made through indirect method, and the statistical analyses through the ANOVA ONE WAY test. The results to suggest that the volunteers had phisyological recovery. However, news reserchs there are needs, with others variable to be estimated.

Congenital heart defects are the number one cause of birth defect-related deaths. Cardiovascular diseases are the most common cause of death worldwide. Layered cellular sheet constructs offer one very valuable option for cardiac patch implantation during surgical treatment of both pediatric and adult patients with cardiac defects or damage. A very exciting, relatively unexplored, autologous, available cell source for making patches are placenta-derived mesenchymal stem cells (pMSCs). In this study, pMSCs were assessed as a potential cell source for cardiac repair and regeneration by evaluating their differentiation capacity into cardiomyocytes, their effects on cardiac cell migration and proliferation, and their ability to be grown into cell sheets. It was found that pMSC cardiac protein content was enhanced by differentiation media treatment, but no beating cells were produced. Undifferentiated pMSCs improved migration and proliferation of a cardiac cell population and formed intact, aligned cell sheets. However, like many new cell sources for cardiac repair, pMSCs should still be functionally characterized to understand how compatible they will be with resident heart tissue. Implanting non-autologous, potentially pluripotent, non-myocyte (non-beating) cells presents concerns regarding electromechanical mismatch and implant rejection. The characterization of non-traditional cell sources such as pMSCs motivated the design of a bio-MEMS device that assesses contractile force and conduction velocity in response to electrical and mechanical stimulation of a cell source as it is grown and once it forms a cellular sheet. This ideally creates the ability for patient specific cell sheets to be cultured, characterized, and conditioned to be compatible with the patient’s cardiac environment in vitro, prior to implantation. In this work, the device was designed to achieve the following: cellular alignment, electrical stimulation, mechanical stimulation, conduction velocity readout, contraction force readout, and upon characterization, cell sheet release. The platform is based on a set of comb electrical contacts which are three dimensional wall contacts made of polydimethylsiloxane and coated with electrically conductive metals. Device fabrication and initial validation experiments were completed as part of this study; ultimately the device will allow for the complete functional characterization and conditioning of variable cell source cell sheet implants for myocardial implantation. / 2019-07-02T00:00:00Z

Made available in DSpace on 2015-12-06T23:47:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2008 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A estimulação elétrica de baixa intensidade (EE) tem sido utilizada para o reparo ósseo, mas pouco se sabe sobre seus efeitos no tecido ósseo após a menopausa. Os osteócitos provavelmente desempenham um importante papel mediando este estímulo físico, e poderiam agir como transdutores através da liberação de sinais bioquímicos como o óxido nítrico (NO). O objetivo deste trabalho foi investigar os efeitos da EE no metabolismo ósseo de ratas ovarectomizadas, e se o NO poderia ser um mediador destes efeitos. Sessenta ratas (200-220g) foram divididas em 6 grupos: SHAM; SHAM tratado com 6mg/d de L-NAME, um inibidor da NO sintase (SHAM-L-NAME); ovarectomizado (OVX); OVX tratado com L-NAME (OVX-L-NAME) ou submetido a uma estimulação elétrica no corpo todo do animal (OVX-EE) ou ambos (OVX-EE-L-NAME) por 12 semanas. A densidade mineral óssea (DMO) global, de coluna e membro posterior foram medidas através de densitometria óssea antes e ao final do protocolo. Após o sacrifício, as tíbias foram retiradas para análises histomorfométricas e imunohistoquímicas. A apoptose de osteócitos (técnicas de caspase-3 e TUNEL) e expressões da NO sintase endotelial (eNOS) e indutível (iNOS) foram analisadas por imunohistoquímica. As ratas OVX demonstraram significante (p<0.05 vs SHAM) diminuição da DMO final global, de coluna e de membro posterior, medidas por densitometria, redução de volume ósseo (10% vs 25%) e número de trabéculas (1.7 vs 3.9), e aumento das superfícies de reabsorção (4.7% vs 3.2%) e mineralização (15.9% vs 7.7%), medidas por histomorfometria. No entanto, após a EE, todos estes parâmetros foram semelhantes aos valores do grupo SHAM e significantemente diferentes de OVX. A EE não foi capaz de prevenir a redução de volume ósseo e número de trabéculas causadas pela OVX na presença de L-NAME (OVX-L-NAME vs OVXEE-L-NAME), como o fez na ausência deste inibidor da NOS. Porém, o L-NAME não bloqueou os efeitos da EE na reabsorção óssea (superfícies de reabsorção e de osteoclastos) em ratas OVX. A eNOS e iNOS foram: expressas de forma semelhante no córtex das tíbias de SHAM, não expressas em OVX, e similarmente expressas em OVX-EE quando comparadas ao SHAM. As expressões de eNOS e iNOS não foram detectadas no tecido ósseo de nenhum grupo tratado com L-NAME. Nas ratas OVX, a porcentagem de osteócitos apoptóticos (24%) foi significantemente maior do que em SHAM (11%) e OVX-EE (8%). Todos os grupos tratados com L-NAME tiveram uma diminuição na porcentagem de osteócitos apoptóticos. Assim, nosso estudo evidenciou que a EE previne alguns efeitos causados pela OVX no tecido ósseo preservando a DMO, estrutura e microarquitetura ósseas, expressão de eNOS e iNOS e viabilidade de osteócitos. Além disso, foi demonstrado que o L-NAME bloqueia parcialmente os efeitos da EE na estrutura óssea (mas não na reabsorção) e na expressão de eNOS e iNOS em ratas OVX, sugerindo que o NO possa ser um mediador dos efeitos positivos da EE no tecido ósseo. No entanto, não foi possível identificar se os efeitos positivos da EE na viabilidade de osteócitos foram mediados pelo NO, pois os efeitos do L-NAME nestas células foram semelhantes àqueles causados pela EE. / Low Intensity Electrical Stimulation (LIES) has been used for bone repair but little is known about its effects on bone after menopause. Osteocytes probably play a role in mediating this physical stimulus and they could act as transducers through the release of biochemical signals, such as nitric oxide (NO). The aim of the present study was to investigate the effects of LIES on bone metabolism in ovariectomized rats, and if NO could be a mediator of these effects. Sixty rats (200-220g) were divided into 6 groups: SHAM; SHAM treated with 6mg/d of LNAME, an inhibitor of NO synthase (SHAM-L-NAME); ovariectomized (OVX); OVX treated with L-NAME (OVX-L-NAME) or subjected to a whole body electrical stimulation (OVX-LIES) or both (OVX-LIES-L-NAME) for 12 weeks. Global, spine and posterior limb bone mineral density (BMD) were measured by bone densitometry before and at the end of protocol. After sacrifice, tibias were collected for histomorphometric and immunohistochemistry analysis. Osteocyte apoptosis (caspase-3 and TUNEL techniques) and expressions of endothelial NO synthase (eNOS) and inducible NOS (iNOS) were assessed by immunostaining. OVX rats showed significant (p<0.05 vs SHAM) decreased final global, spine and limb BMDs, measured by densitometry, decreased bone volume (10% vs 25%) and trabecular number (1.7 vs 3.9), and increased eroded surfaces (4.7% vs 3.2%) and mineralization surfaces (15.9% vs 7.7%), measured by histomorphometry. In contrast, after LIES, all these parameters tended to be similar to SHAM and significantly different from OVX. LIES was not able to prevent the reduction of bone volume and trabecular number caused by OVX in the presence of L-NAME (OVX-L-NAME vs OVX-LIES-L-NAME), as it did in the absence of this NOS inhibitor. However, L-NAME did not block the effects of LIES on bone resorption (eroded surface and osteoclasts surface) in OVX rats. eNOS and iNOS were: similarly expressed in tibiae cortices of SHAM, not expressed in OVX and correspondingly expressed in OVX+LIES when compared to SHAM. eNOS and iNOS expressions were not detected on bone of none of L-NAME treated groups. In OVX, the percentage of apoptotic osteocytes (24%) was significantly increased when compared to SHAM (11%) and OVX-LIES (8%). All LNAME treated groups showed a diminished percentage of apoptotic osteocytes. In conclusion, our study showed that LIES counteracts some effects of OVX on bone tissue preserving BMD, bone structure and microarchitecture, iNOS and eNOS expression and osteocyte viability. Moreover, it was demonstrated that L-NAME partially blocks the effects of LIES on bone structure (but not on bone resorption) and on iNOS and eNOS expressions in OVX rats, suggesting that NO may be a mediator of the positive effects of LIES on bone. However, it was not possible to identify if the known positive effects of LIES on osteocyte viability were mediated by NO, since the effects of L-NAME on these cells were similar to those caused by LIES. / BV UNIFESP: Teses e dissertações

Made available in DSpace on 2016-06-02T20:18:10Z (GMT). No. of bitstreams: 1 2334.pdf: 2125906 bytes, checksum: c4e6c6beeb6952220467b64ed76dc7d0 (MD5) Previous issue date: 2009-04-16 / Inflammation is the response of protection of the body to an aggression in order to obtain the healing. This process makes part of many diseases attended by physical therapist, however when it is increased, limits the fast recovery of the patient. High voltage pulsed current (HVPC) is one of the modalities used to interview of inflammatory process; the type of stimulation is considered monophasic pulsed that produces a high-driving voltage 150 V, but the total current (average) delivered to the tissue per second does not exceed 1.2 to 1.5mA. There are many studies that evaluate the effect of HVPC in swelling, but the major part was made in animal models and only one in human beings was found in the review of the literature. The results of the studies in animals had showed the effectiveness of HVPC in reduction of edema, but the study in human only showed clinical differences not statistically significant. Additionally, the action mechanism of HVPC is unknown and some hypotheses have been proposed for explaining its effect. The objective of this study was evaluate the effectiveness of HVPC in the inflammation process, both in humans and animals in a submotor level, 100pps of frequency and 45min of treatment. We made a controlled and randomized clinical trial in subjects with lateral sprain of ankle measuring pain, edema, range of mobility and some parameters of the gait comparing three groups: control group (CG) with standard physical therapy, HVPC(-) with standard physical therapy plus HVPC negative polarity and HVPC(+) with standard physical therapy plus HVPC positive polarity. There was not difference between the study groups, but the clinical results suggested that HVPC(-) could contribute to accelerate the recovery of inflammatory process. Second, an experimental study was done in animals evaluating pain, edema, serum histamine and albumin and the cartilage, comparing a control group, a inflammation group with HVPC(-), a inflammation group with HVPC placebo and the last group only with HVPC(-). We did not find differences between the groups in the variables, only observed the lowest cellularity in the cartilage of inflammation group+HVPC(-) and lowest optical density in inflammation group+HVPC placebo. These results are a contribution for the understanding of the biophysical agent used in the physical therapy, however is necessary more clinical studies including higher sample size, in order to demonstrate the effects of HVPC on the inflammation process. / A inflamação é uma resposta de proteção para livrar o organismo da causa da agressão e de suas conseqüências, para poder alcançar a reparação. Este processo apresenta-se em muitas das enfermidades atendidas pelos fisioterapeutas, mas às vezes sua exacerbação pode limitar a recuperação do sujeito. Uma das formas de tratamento do processo inflamatório é a estimulação elétrica de alta voltagem (EEAV). Este tipo de estimulação é caracterizada por um pulso monofásico pico duplo que gera voltagens superiores a 150V, mas com uma corrente total (média) liberada ao tecido que não excede 1,2 a 1,5mA. Vários estudos foram feitos para avaliar o efeito da EEAV no edema, mas a maioria deles foram realizados em modelos animais, sendo encontrado apenas um estudo em humanos na literatura. Os resultados dos trabalhos em animais têm mostrado a efetividade da EEAV na diminuição do edema contrastando com o estudo em humanos, o qual somente mostrou diferenças clinicas, mas não estatísticas. Adicionalmente, ainda não se conhece o mecanismo de ação da EEAV e têm sido propostas varias hipóteses para explicar este efeito. O objetivo do estudo foi determinar a efetividade da EEAV na inflamação em animais e em humanos utilizando um nível de amplitude submotor, freqüência de 100pps e 45min de tratamento. Foi feito um ensaio clínico controlado e aleatorizado em sujeitos com entorse lateral de tornozelo mensurando dor, edema, arco de mobilidade e alguns parâmetros da marcha, comparando três grupos: grupo controle (GC) com fisioterapia convencional; grupo com fisioterapia convencional mais EEAV polaridade negativa e o último grupo com fisioterapia convencional mais EEAV polaridade positiva. Não foram encontradas diferenças estatísticas entre os grupos de estudo, somente diferenças em aspectos clínicos sugerindo uma possível contribuição da EEVA com polaridade negativa na resolução do processo inflamatório. Em uma segunda etapa foi feito um estudo experimental em animais avaliando dor, edema, histamina e albumina séricas e a cartilagem. Os grupos foram: um grupo controle, um inflamado e tratado com EEAV(-), um inflamado e que recebeu EEAV placebo e mais um grupo somente tratado com EEAV(-). Não foram encontradas diferenças entre os grupos nas variáveis mensuradas, mas observou-se menor celularidade na cartilagem dos animais inflamados+EEAV(-) e menor densidade óptica no grupo inflamado+EEVA placebo. Estes resultados são uma contribuição para a validação de um agente biofísico utilizado na fisioterapia, mas precisa-se realizar mais estudos clínicos com amostras maiores para conhecer os reais efeitos da EEAV no processo inflamatório.

Orientador: Aparecido Augusto de Carvalho / Banca: Erica Regina Marani Daruichi Machado / Banca: Ernane José Xavier da Costa / Resumo: Por décadas, a aplicação de Estimulação Elétrica Neuromuscular (EENM) em pacientes paraplégicos e hemiplégicos tem melhorado significativamente sua qualidade de vida. Entretanto, comercialmente, essa técnica é aplicada sem o uso de uma lei de controle em malha fechada, o que limita sua eficiência. Assim, neste trabalho, projetou-se e implementouse um controlador PID embarcado para o uso com estimuladores elétricos neuromusculares. O projeto desse controlador se baseou em um modelo matemático linear de segunda ordem, que representa o comportamento da força muscular devido a um estímulo elétrico. Posteriormente, desenvolveram-se algoritmos na linguagem de programação Python que possibilitam o projeto automático de controladores PID com diferentes especificações para diferentes pacientes. Dessa forma, o usuário informa os parâmetros do paciente e as especificações desejadas para obter a configuração do controlador PID adequada. Além disso, desenvolveuse um programa em linguagem C para o microcontrolador PIC18F4520 que implementa este controlador utilizando o seu conversor A/D interno de 10 bits e um conversor D/A externo de 10 bits. Este controlador pode ser configurado via comunicação serial de forma simples e rápida, permitindo alterar os parâmetros do controlador PID e o tempo de amostragem. Por fim, os resultados obtidos a partir da simulação deste sistema no ambiente Proteus provou a viabilidade do controlador PID projetado. / Abstract: For decades the quality of life of hemiplegic and patients with spinal cord injuries has been improving through the research and use of Neuromuscular Electrical Stimulation (NMES) in rehabilitation engineering. However, most of the times it has been used without closed loop techniques, which is the approach used in this project, where an embedded PID controller has been designed and implemented to control the NMES. The plant to be controlled, i.e., the behaviour of the muscle response to an electrical stimulus, was represented using a secondorder linear model. The language Python was then used to develop PID control algorithms allowing the use of different specifications so that the user can supply the patient parameters to properly configure the PID controller for different patients. Later, these algorithms were implement in a PIC18F4520 microcontroller using C language, exploiting its internal 10 bit A/D converter and an external 10 bit D/A. The final circuit can be configured serially via a PC, adjusting the controller parameters and the sampling rate. The whole system was simulated in the Proteus environment, proving its viability. / Mestre