Aneurisma de Aorta Abdominal (AAA) é definido como uma dilatação localizada e permanente da parede arterial, geralmente com ocorrência entre as artérias renais e as ilíacas, como conseqüência do enfraquecimento dessa parede ou devido a uma solicitação anormal sobre sua estrutura normal. Essa afecção acomete principalmente a população idosa acima de 65 anos de idade, tendo como principais fatores de risco: tabagismo, hipertensão arterial, histórico familiar e doença obstrutiva crônica pulmonar. A prevalência está aumentando nos últimos anos, havendo uma duplicação dos casos diagnosticados nos Estados Unidos (Bonamigo e Von Ristow, 1999). Hoje o AAA é a 13ª causa de morte nos Estados Unidos, em homens com mais de 65 anos e no caso de aneurisma roto, é a 3ª causa de morte súbita nos Estados Unidos. A mortalidade global do AAA roto está em torno de 80% nos países que têm verificação sistemática e compulsória da causa de óbitos. Isto ocorre devido ao fato de uma hemorragia substancial intra-abdominal geralmente ser acompanhada de atraso no transporte e diagnóstico, e da necessidade de cirurgia de emergência em pacientes idosos que, freqüentemente, tem uma significativa comorbidade renal e cardiopulmonar. Acredita-se que a formação e o crescimento do aneurisma de aorta abdominal são acompanhados do crescimento da tensão na parede da aorta e/ou de uma diminuição da capacidade do tecido de suportar tal tensão. A ruptura ocorre quando a tensão atuante na parede excede a tensão que pode ser suportada pelo tecido. O risco de ruptura aumenta com o crescimento do tamanho do aneurisma, da tensão na parede e é agravado quando associado à hipertensão arterial. No estudo foram obtidos dados morfológicos da região torácica de um paciente com a utilização de tomografia computadorizada multi-fatias. Essas imagens DICOM (Comunicação de Imagens Digitais em Medicina) foram tratadas para selecionar apenas a região de interesse, obtendo-se um modelo tridimensional da aorta infra-renal e artérias ilíacas. A partir daí, foi confeccionado um modelo físico com a utilização de prototipagem rápida. Um simulador cardiovascular controlado por computador foi desenvolvido com o intuito de replicar características fisiológicas e patológicas do sistema cardiovascular humano. Esse modelo de aneurisma foi utilizado para simulação em bancada experimental, onde é possível reproduzir alguns parâmetros como pressão, fluxo, temperatura, resistência e complacência vascular. Também foi gerado um modelo computacional onde os parâmetros obtidos na simulação in vitro foram utilizados como condição de contorno inicial para o estudo computacional. Foram adotados padrões normotenso e hipertenso, e os resultados computacionais e experimentais foram analisados e comparados. O trabalho propõe uma metodologia que possibilite a obtenção de dados anatômicos e hemodinâmicos relativos ao segmento arterial acometido pela afecção, com o objetivo de fornecer informações adicionais no diagnóstico do aneurisma de aorta. / Abdominal Aortic Aneurysm (AAA) is defined as a focal and permanent dilatation of the arterial wall, most often occurring in between the renal and iliac arteries, as consequence of arterial wall weakness or because of an abnormal solicitation of that normal structure. This disease primarily affects elderly population over 65 years of age, and the most important risk factors are smoking, hypertension, family history and chronic obstructive pulmonary disease. In the last years, the prevalence is rising up almost twice the diagnosed cases in the United States (Bonamigo and Von Ristow, 1999). Nowadays, AAA is the thirtieth cause of death in the United States, in the elderly masculine population over 65 years of age, and in case of ruptured aneurysm, it is the third cause of sudden death in the United States. The overall mortality rate is about 80% in countries with systematic and compulsory evaluation of death cause. This is due to the fact that substantial intra-abdominal hemorrhage is often accompanied by delays in transport and diagnoses, and the need for emergency surgery in elderly patients that frequently have significant renal and cardiopulmonary comorbidity. It is suggested that the formation and expansion of the AAA are accompanied by wall stress increasing and / or decreasing in the tissue capacity to withstand this stress. The rupture occurs when the wall stress exceed the stress the tissue can accept. The risk of rupture increases with aneurysm expansion, wall stress increasing and it is exacerbated when associated with arterial hypertension. In the present work, morphological data from thoracic region of the patient was acquired by using multi-slice CT (Computed Tomography). These DICOM images had been treated to select only the interest region, getting a three-dimensional infra-renal aortic and iliac model. Then, it was made a physical model by using rapid prototyping. This model was used for in vitro experimentation in a computer controlled mock system, in which it is possible to replicate physiological and pathological characteristics of human being cardiovascular system. Some parameters such as pressure, flow, temperature, vascular resistance and compliance can be reproduced by the use of a mock circulatory system. These parameters were used as initial boundary conditions in order to calibrate a computational model. It was adopted normotensive and hypertensive patterns and computational and experimental results were analyzed and compared. The paper proposes a methodology which allows the acquisition of anatomical and hemodynamic data on the vessel segment affected by the pathology, with the goal of providing additional information in the diagnosis of aortic aneurysm.

The goal of this dissertation is to develop a model relating LENSâ„¢ process parameters to deposited thickness, incorporating the effect of substrate heating. A design review was carried out, adapting the technique of functional decomposition borrowed from axiomatic design. The review revealed that coupling between the laser path and laser power caused substrate heating. The material delivery mechanism was modeled and verified using experimental data. It was used in the derivation of the average deposition model which predicted deposition based on build parameters, but did not incorporate substrate heating. The average deposition model appeared capable of predicting deposited thickness for single line, 1- layer and 2-layer builds, performing best for the 1- layer builds which were built under essentially isothermal conditions. This model was extended to incorporate the effect of substrate heating, estimated using an energy partition approach. The energy used for substrate heating was modeled as a series of timed heating events from an instantaneous point heat source along the path of the laser. The result was called the spatial deposition model, and was verified using the same set of experimental data. The model appeared capable of predicting deposited thickness for single line, 1- layer and 2- layer builds and was able to predict the characteristic temperature rise near the borders as the laser reversed direction.

O uso do Sistema CAD/CAM já é bastante consagrado na Odontologia, não sendo diferente na reabilitação facial. Traz diversas facilidades, porém poucos trabalhos relatam as reabilitações da região óculo-palpebral. Nesse estudo, a aquisição de imagem tridimensional foi feita com o uso de um escâner de superfície a laser, FARO Edge ScanArm®, protegendo-se o olho contralateral com uso de lente gelatinosa preta; método que demonstrou eficiência na obtenção de imagem de pálpebras abertas para confecção de protótipo reverso. Foram selecionados 10 pacientes com exenteração de órbita, de ambos os gêneros, sendo 5 com mutilação à esquerda e 5 à direita. Todos os pacientes receberam duas próteses óculo-palpebrais, uma confeccionada pelo método convencional e outra pelo sistema CAD/CAM. As reabilitações foram registradas fotograficamente e avaliadas por 30 indivíduos leigos, 3 especialistas em prótese bucomaxilofacial e pelos próprios pacientes, usando-se a Escala VAS. Para avaliar a variação intraexaminador, 15 leigos repetiram a avaliação com intervalo de uma semana, assim como os 3 especialistas. Os resultados demonstraram consistência interna e uma boa reprodutibilidade dos dados em todos os grupos. A percepção estética foi melhor avaliada nas próteses obtidas pelo método convencional; entretanto, a relevância da diferença observada entre os dois métodos foi avaliada como razoável. / The use of CAD/CAM system is already an established method in Dentistry, no different in facial rehabilitation. It brings several facilities, but few studies have already reported the rehabilitations of the orbital area. In this research the acquisition of the three dimensional image was taken using a surface laser scanner, FARO Edge ScanArm®, protecting the contralateral eye with the use of a black gelatinous contact lens; this method has demonstrated effectiveness in getting image with open eyelids for making reverse prototype. 10 patients were select with orbit exenteration, of both genders, 5 with left mutilation and 5 with right. All patients received two oculopalpebral prostheses, one obtained by the conventional method and another by the CAD/CAM system. The rehabilitations were photo registrated and assessed by 30 lay assessors, 3 bucomaxillofacial prosthetic specialists and by the patients themselves using the VAS Scale. To evaluate the intraexaminer variation, 15 lay assessors repeated the evaluation with one week interval, as did the specialists. The results demonstrated good interexaminer variation and reproducibility of data in all groups. The aesthetic perception was better evaluated in prostheses obtained by the conventional method; however, the relevance of difference between the two methods was assessed as a reasonable one.

Nos processos usuais de prototipagem rapida, a transformacao do material para a construcao do prototipo, de maneira geral, e realizada por fusao ou polimerizacao oriunda do aquecimento via laser ou resistencia eletrica. Isso, necessariamente, envolve equipamento especial para o processo de fusao e deposicao do material para a construcao das superficies camada por camada, o controle de temperatura para assegurar a qualidade e o tratamento de gases exalados pela transformacao entre outros. Essa forma de transformacao nos processos de prototipagem rapida tem assim custos relativamente altos do prototipo e do equipamento. Uma alternativa para o processo de transformacao inclui evidentemente outros materiais para construcao do prototipo. Entretanto, no levantamento bibliografico realizado observou-se que nao existem trabalhos que explorem materiais e processos alternativos. Assim varios materiais foram analisados com base nas seguintes propriedades: processamento sob temperatura ambiente, capacidade de aderencia entre as camadas, tempo de consistencia e de cura do material, custo e disponibilidade no mercado nacional. Com base nesse estudo foi selecionado o seguinte material: composito a base de complexo de carboidrato, o qual transforma-se, de estado fisico, sob temperatura ambiente. Inicialmente analisaram-se os aspectos de aderencia e tempo de cura. Posteriormente estudaram-se as caracteristicas dos dispositivos e dos processos Fused Layer Modeling (FLM). Baseado nesse estudo foi fabricado um dispositivo para se extrudar material em forma de filamentos. Em seguida modelou-se o cinematismo da velocidade de deposicao do dispositivo extrusor e assim delinear o projeto de experimentos para se obter, do processo proposto, os aspectos qualitativo (operacao, preparacao, custos, utilizacao dos prototipos, entre outros) e quantitativo (velocidade de deslocamento dos eixos X e Y, alturas entre camadas, rugosidade e forma geometrica). Desse estudo resulta que a proposta demonstra potencial para aplicacao na fabricacao de mostruarios, pecas de brinquedos, utilizacao em cursos de formacao profissional, prototipos para moldagem a temperatura ambiente, moldes para fundicao em areia. / In usual processes of rapid prototyping the transformation of the material into the prototype construction is usually made by fusion or polymerization by means of heating by laser or electrical resistance. It necessarily requires special equipment for the fusion process and deposition of material for the surface construction, layer on top of layer, the temperature control to certify quality, the treatment of exhalation during the transformation process, among others. This kind of transformation in the rapid prototyping process is relatively expensive compared with the conventional process of prototyping. An alternative for the transformation process includes, obviously, other kinds of material for the prototype construction. However, bibliographic research has show, that there are no such works which explore alternative materials and processes especially in the national context. Therefore, several kinds of material have been analyzed based on the following properties: required temperature for the work, adherence capacity between the layers, consistence time or cure time of the prototype, cost and availability on the national market. The following material was chosen, based on this study: a compound, based on a carbohydrate complex, because it transforms itself from the physical form at room temperature. First of all, adherence aspects and curing time were analyzed,. Then characteristics of the apparatuses and devices of the Fused Layer Modeling process (FLM). Based on these characteristics the project of the extrusion device was developed, to extrude the carbohydrate composite in form of filaments and its kinematics was modeled to determine the depositing speed and design of experiments to obtain, out of the proposed process, the qualitative aspects (operation, preparation, costs, utilization of the prototype, among others) and quantitative (speed of the dislocation of the table at x-y axis, height between the layers, roughness and geometric form, among others). At that rate the developed proposal shows potentiality to be used in production of showcases, toy pieces, utilization in course for professional training, prototypes for molding at room temperature, forms for sand castings.

This dissertation presents information gathered and analyzed through an electronic internet-based Delphi Survey process. The purpose of this study is to identify a consensus of factors that might forecast the future effects of Rapid Prototyping (RP) technology on engineering design education when used for the purpose of overcoming the limitations of 2D representation of 3D space. The identification of consensus was developed from the collection of opinions from a panel of experts in RP technology. Early adopters of emerging technologies can reduce risk through careful research, but decisions must often be made before significant quantitative data are available. Expert subjective judgment may be a valuable source of information for making decisions. RP is just one of the tools used in engineering design education for visualization. This research should help to guide faculty members in making decisions regarding the use of RP technology in the curriculum. The one consensus reached by the panel is that 3D CAD will replace 2D CAD as the default modeling tool in most product-design related curricula within 5 years. The general conclusion of the study is that the appropriate use of the technology in the curriculum is largely situational.

Modern Rapid Prototyping (RP) technology has been available for more than a decade and has aided in shortening product development times and costs in the manufacturing sector. Stereolithography (SL), the most mature of RP technology, has primarily been used to build small to medium sized parts although there are largescale applications i.e. the automotive industry that uses “mammoth SLA”. Recent developments in SL have been aimed at increasing the speed of the additive process of most SL apparatus (SLA). Developments include the chemistry of photopolymer resins, integral-curing processes as opposed to vector-by-vector processes, and what is now called microstereolithography. Integral curing has been made possible by the advent of dynamic masking generators such as liquid crystal displays (LCDs) and digital micromirror devices (DMDs). Much of the theory for this new layering process has been applied to the micro-scale and awaits application for medium to large sized parts. The Limaye Model was applied to a microstereolithography apparatus (µSLA) and used as a process planning method for curing dimensionally accurate micro parts. Examination of the results of this mathematical model shows an irradiance map simulating the irradiances on the resin surface. The light is expected to attenuate from the central axis according to a measured irradiance curve. Improvements can be made to the Limaye Model to make it applicable for the process planning of medium to large parts. It is the aim of this research to present an improved mathematical model of the Limaye Model, so that a given irradiance map will produce an evenly distributed irradiance and account for errors in the optical imaging system. It is hoped that the field of exposure of 200mm x 270mm or larger will be achieved.

<p>New Virtual Reality technologies provide the possibility of widening access to information in data. Haptics, the technology of touch, could be an interesting future aid and have large impact on medical applications. The use of haptic devices allows computer users to use their sense of touch, in order to feel virtual objects with a high degree of realism. </p><p>The aim of the thesis is to investigate the potential deployment and the benefits of using haptic force feedback instruments in maxillo-facial surgery. Based on a produced test application, the thesis includes suggested recommendations for future haptic implementations. </p><p>At the Department of Maxillo-Facial Surgery, at the Karolinska Hospital in Stockholm, Virtual Reality technologies are used as an aid to a limited extent during the production of physical medical models. The physical medical models are produced with Rapid Prototyping techniques. This process is examined and described in the thesis. Moreover, the future of the physical medical models is outlined, and a future alternative visualizing patient data in 3D and use haptics as an interaction tool, is described. Furthermore, we have examined the present use of haptic technology in medicine, and the benefits of using the technology as an aid for diagnostic and treatment planning. </p><p>Based on a presented literature study and an international outlook, we found that haptics could improve the management of medical models. The technology could be an aid, both for physical models as well as for virtual models. We found three different ways of implementing haptics in maxillo-facial surgery. A haptic system could be developed in order to only manage virtual medical models and be an alternative solution to the complete Rapid Prototyping process. A haptic system could serve as a software, handling the image processing and interfacing from a medical scanner to an Rapid Prototyping system. A haptic system could be developed as an alternative interaction tool, which could be implemented as an additional function in currently used image processing software, in order to improve the management of virtual medical models before the Rapid Prototyping process. </p><p>An implementation for planning and examination in maxillo-facial surgery, using haptic force feedback interaction, is developed and evaluated. The test implementation is underlying our aim of investigating the potential deployment and the benefits of using haptic force feedback instruments in maxillo-facial surgery. </p><p>After discussing the possible future of our implementation and the future of haptic force feedback in maxillo-facial surgery, a recommendation is given as a conclusion of our total work.</p>

Digital Clay represents a new type of 3-D human-computer interface device that enables tactile and haptic interactions. The Digital Clay kinematics structure is computer controlled and can be commanded to acquire a wide variety of desired shapes (shape display), or be deformed by the user in a manner similar to that of real clay (shape editing). The design of the structure went through various modifications where we finally settled on a crust matrix of spherical joint unit cells. After designing the kinematics structure, the next step is predicting the deformation of the crust matrix based upon a handful of inputs. One possible solution for predicting the shape outcome is considering minimizing the potential energy of the system. In this thesis two methods will be introduced. The first method will be an abstract model of the crust where the energy is calculated from a simplified model with one type of angular springs. The second method is the actual manufacturable crust model with two types of angular springs. From the implementation of these two methods, the output will be center-points of the unit cells. From the center-points, one can also calculate the joint angles within each unit cell.

Rapid prototyping (RP) is a set of fabrication technologies that are used to produce accurate parts directly from computer aided drawing (CAD) data. These technologies are unique in a way that they use an additive fabrication approach in which a three dimensional (3D) object is directly produced. In this thesis study, a RP application with a modular architecture is designed and implemented to satisfy the possible requirements of future rapid prototyping studies. After a functional classification, the developed RP software is divided into View, RP and Slice Modules. In the RP module, the process parameter selection and optimal build orientation determination steps are carried out. In the Slice Module, slicing and tool path generation steps are performed. View Module is used to visualize the inputs and outputs of the RP software. To provide 3D visualization support for View Module, a fully independent, open for development, high level 3D modeling environment and graphics library called Graphics Framework is developed. The resulting RP application is benchmarked with the RP software packages in the market according to their memory usage and process time. As a result of this benchmark, it is observed that the developed RP software has presented an equivalent performance with the other commercial RP applications and has proved its success.

In this study, a two axes linear positioning system for testing and applying different rapid prototyping techniques was designed and manufactured. A cable/ pulley mechanism is utilized in the system for transmitting motion from motors into linear motion. Use of a cable/ pulley mechanism overcomes the problems resulting from the utilization of conventional drive systems like ball screws and decreases the overall cost of the system. The carriage elements of both axes were designed and manufactured by using investment casting. The molds used in casting were also designed and manufactured within this study. The designed system is controlled by a servo motion control system composed of a motion controller, DC servo motors and linear encoders. All elements of the motion control system were selected, integrated and programmed within the scope of the study.