As cirurgias de reconstrução parcial ou total de orelha são um desafio na medicina, exigindo técnicas complexas e qualificadas, sendo as mais utilizadas àquelas que fazem uso de material autógeno (cartilagem da costela do próprio paciente). Trata-se de um processo artesanal em que o cirurgião deve esculpir manualmente a cartilagem para formar o modelo tridimensional da orelha, denominado framework, dessa forma, o resultado final depende, principalmente, da habilidade do cirurgião plástico. Tendo isso em vista, busca-se, neste trabalho, empregar as tecnologias computacionais utilizadas no Design Virtual para auxiliar o planejamento cirúrgico, utilizando digitalização tridimensional e fabricação digital para aprimorar o resultado da técnica de reconstrução auricular. A metodologia proposta sugere a digitalização tridimensional do paciente e, a partir disso, são projetados templates cirúrgicos para auxiliar a modelagem e o posicionamento do framework. A aplicação cirúrgica valida alguns pontos e possibilita o estudo de melhorias em determinados templates, utilizados então em outras duas reconstruções, obtendo-se resultados positivos. Assim, o uso do Design Virtual mostra-se confiável e útil na cirurgia de reconstrução auricular, levando à melhoria no planejamento e, assim, diminuição do tempo cirúrgico, sem riscos ou complicações ao paciente e com melhores resultados anatômicos. / The partial or total reconstruction of ear is a challenge in plastic surgery, requiring complex and skilled techniques. The most successful reconstructions use autogenous material (cartilage from the patient's own rib). It is a handmade process in which the surgeon must manually sculpt the cartilages to form the three-dimensional model of the ear, usually called as framework. Considering this, the final result depends mainly on the plastic surgeon's skill. In this scenario, the aim of this research is employ computer technologies used in Virtual Design to aid surgical planning, using three-dimensional scanning and digital manufacturing to improve the result of ear reconstruction technique. The proposed methodology suggests surgical templates, based on 3D patient scan, designed to assist the modeling and positioning of the framework. The surgical application validates some points and allows the study of improvements in certain templates, then used in other two surgeries, with positive results. Thus, the use of Virtual Design proves to be reliable and useful in ear reconstruction surgery, leading to improved planning and decreasing surgical time, without any risks or complications for the patient and with better anatomical results.

Master of Science / Department of Electrical and Computer Engineering / Punit Prakash / Microwave ablation is clinically used to thermally ablate cancerous tissue in the liver and other organs. When treating large tumor volumes, physicians may use multiple antennas simultaneously. Multiple antennas can ablate a larger tissue volume while using the same total power as a single antenna. Pre-clinical simulation and experimental studies most often presume parallel insertion of antennas. However, due to anatomical constraints, such as the presence of ribs and the diaphragm, it is often challenging to insert antennas in a parallel fashion in practice. Previous studies have attempted to analyze the effect of non-parallel antenna insertion on ablation outcome using computational and experimental approaches; however, they were limited because they did not account for dynamic temperature-dependent changes in tissue electrical properties in simulations and employed limited experimental validation. In this thesis, we have developed improved models of multiple-antenna microwave ablation, including accounting for the effects of temperature-dependent changes in tissue properties. We have also developed a system for experimental assessment of ablation zone profiles in ex vivo tissues. By utilizing 3D printing, we have constructed a device to precisely position antennas within experimental tissue samples and allows for accurate sectioning of the ablation zone relative to the plane of antenna insertion. Furthermore, we implemented image processing techniques for quantifying the size and shape of experimental ablation zones. This enables more accurate and repeatable comparisons of ablation profiles between simulations and experiments. We found that for an inter-antenna spacing in the range of 10 – 20 mm, simulations and experiments indicated that the ablation zone volumes may change by up to 30% due to non-parallel antenna insertion.

abstract: The advent of medical imaging has enabled significant advances in pre-procedural planning, allowing cardiovascular anatomy to be visualized noninvasively before a procedure. However, absolute scale and tactile information are not conveyed in traditional pre-procedural planning based on images alone. This information deficit fails to completely prepare clinicians for complex heart repair, where surgeons must consider the varied presentations of cardiac morphology and malformations. Three-dimensional (3D) visualization and 3D printing provide a mechanism to construct patient-specific, scale models of cardiovascular anatomy that surgeons and interventionalists can examine prior to a procedure. In addition, the same patient-specific models provide a valuable resource for educating future medical professionals. Instead of looking at idealized images on a computer screen or pages from medical textbooks, medical students can review a life-like model of patient anatomy. In cases where surgical repair is insufficient to return the heart to normal function, a patient may proceed to advanced heart failure, and a heart transplant may be required. Unfortunately, a finite number of available donor hearts are available. A mechanical circulatory support (MCS) device can be used to bridge the time between heart failure and reception of a donor heart. These MCS devices are typically constructed for the adult population. Accordingly, the size associated to the device is a limiting factor for small adults or pediatric patients who often have smaller thoracic measurements. While current eligibility criteria are based on correlative measurements, the aforementioned 3D visualization capabilities can be leveraged to accomplish patient-specific fit analysis. The main objectives of the work presented in this dissertation were 1) to develop and evaluate an optimized process for 3D printing cardiovascular anatomy for surgical planning and medical education and 2) to develop and evaluate computational tools to assess MCS device fit in specific patients. The evaluations for objectives 1 and 2 were completed with a collection of qualitative and quantitative validations. These validations include case studies to illustrate meaningful, qualitative results as well as quantitative results from surgical outcomes. The latter results present the first quantitative supporting evidence, beyond anecdotal case studies, regarding the efficacy of 3D printing for pre-procedural planning; this data is suitable as pilot data for clinical trials. The products of this work were used to plan 200 cardiovascular procedures (including 79 cardiothoracic surgeries at Phoenix Children's Hospital), via 3D printed heart models and assess MCS device fit in 29 patients across 6 countries. / Dissertation/Thesis / Doctoral Dissertation Bioengineering 2015

abstract: The microstructure development of Inconel alloy 718 (IN718) during conventional processing has been extensively studied and much has been discovered as to the mechanisms behind the exceptional creep resistance that the alloy exhibits. More recently with the development of large scale 3D printing of alloys such as IN718 a new dimension of complexity has emerged in the understanding of alloy microstructure development, hence, potential alloy development opportunity for IN718. This study is a broad stroke at discovering possible alternate microstructures developing in Direct-Metal-Laser-Sintering (DMLS) processed IN718 compared to those in conventional wrought IN718. The main inspiration for this study came from creep test results from several DMLS IN718 samples at Honeywell that showed a significant improvement in creep capabilities for DMLS718 compared to cast and wrought IN718 (Honeywell). From this data the steady-state creep rates were evaluated and fitted to current creep models in order to identify active creep mechanisms in conventional and DMLS IN718 and illuminate the potential factors responsible for the improved creep behavior in DMSL processed IN718. Because rapid heating and cooling can introduce high internal stress and impact microstructural development, such as gamma double prime formations (Oblak et al.), leading to differences in material behavior, DMLS and conventional IN718 materials are studied using SEM and TEM characterization to investigate sub-micron and/or nano-scale microstructural differences developed in the DMLS samples as a result of their complex thermal history and internal stress. The preliminary analysis presented in this body of work is an attempt to better understand the effect of DMLS processing in quest for development of optimization techniques for DMLS as a whole. A historical sketch of nickel alloys and the development of IN718 is given. A literature review detailing the microstructure of IN718 is presented. Creep data analysis and identification of active creep mechanisms are evaluated. High-resolution microstructural characterization of DMLS and wrought IN718 are discussed in detail throughout various chapters of this thesis. Finally, an initial effort in developing a processing model that would allow for parameter optimization is presented. / Dissertation/Thesis / Masters Thesis Engineering 2017

This document presents the development of a first proposal prototype of a rehabilitation exoskeleton hand. The idea was to create a lighter, less complex and cheaper exoskeleton than the existing models in the market but efficient enough to carry out rehabilitation therapies.The methodology implemented consists of an initial literature review followed by data collection resulting in a pre-design in two dimensions using two different software packages, MUMSA and WinmecC. First, MUMSA provides the parameters data of the movement of the hand to be done accurately. With these parameters, the mechanisms of each finger are designed using WinmecC. Once the errors were solved and the mechanism was achieved, the 3D model was designed.The final result is presented in two printed 3D models with different materials. The models perform a great accurate level on the motion replica of the fingers by using rotary servos. The properties of the model can change depending on the used material. ABS material gives a flexible prototype, and PLA material does not achieve it. The use of distinct methods to print has a high importance on the difficulties of development throughout the entire process of production. Despite found difficulties in the production, the model was printed successfully, obtaining a compact, strong, lightweight and eco-friendly with the environment prototype.

Användningen och intresset för additiv tillverkning (AM) har ökat markant de senaste åren och det finns en teori kring att tillverkningsmetoden kan vara det nästa steget i den industriella revolutionen. Eftersom AM fortfarande befinner sig i utvecklingsstatidet går det att anta att tekniken ännu inte uppnått sin fulla potential och att det kan komma att finnas möjligheter att implementera tekniken i fler branscher och företag. Detta skulle innebära en bredare marknad för AM. Syftet med examensarbetet var att undersöka vilka möjligheter och hinder som finns för ökad användning av AM i Sverige. Studien genomfördes genom kvalitativa intervjuer med åtta olika verksamheter tillhörande den svenska industrin och en litteraturgenomgång för att presentera nuläget för AM i svensk industriell marknad. Resultatet av datainsamlingen analyserades med modellerna PEST, 4P och slutligen SWOT. De fördelar som har setts med användningen av AM har varit minskade ledtider, minskade kostnader för tillverkning av produkter och verktyg, minskat materialspill och en optimal designprocess med ökad kreativitet. De begränsningar som finns i tekniken i dagsläget är att priset för material och maskiner är dyrt. Vidare anses även kvalitet på slutdetalj, begränsad byggvolym och opålitliga processer vara problematiska. De möjligheter som finns beror huvudsakligen på den forskning som görs. Förutsättningarna för AM i svensk industri kommer att bero på hur tekniken kommer att utvecklas. De hinder som finns är kopplat till kompetensbrist och att det inte finns befintliga standarder för material eller process inom AM. / Within the industrial sector, an increased interest and usage of Additive Manufacturing (AM) throughout the decade has been formed. The layer-upon-layer building technology has been seen and recognized as one of the next industrial revolutionizing methods of production. As the technology is still in the trending and uprising phase it should be considered that its full potential has not yet been achieved, as large opportunities for implementation of AM exist and that new companies and markets have a growing interest in this technology. Through this study a market research was conducted to identify and present what opportunities and obstacles there are for an increased usage of AM in Sweden. A literature study on the Swedish market has been made to present the market as of today. Eight qualitative interviews have also been conducted with companies within the industrial sector to identify the areas of use within AM for production. The concepts and models used to analyze these questions was PEST, Marketing Mix and SWOT. The concluded results for advantages in using AM are shortened lead times, reduced costs of production of components and tools, reduced material waste and optimization of design processes with increased creativity. The concluded challenges are expensive materials and machine, the quality of finished components, limited printing volume due to the 3D-printers and reliability of printing processes. The finalized opportunities that are presented in this work are that AM is dependent on how much research on the subject and factors around it is done. How AM will be applied in the coming future revolves around the advancement in the technology. The obstacles that are found in this study are lack of competence and lack of standard for materials and processes within AM.

abstract: Additive manufacturing (AM) describes an array of methods used to create a 3D object layer by layer. The increasing popularity of AM in the past decade has been due to its demonstrated potential to increase design flexibility, produce rapid prototypes, and decrease material waste. Temporary supports are an inconvenient necessity in many metal AM parts. These sacrificial structures are used to fabricate large overhangs, anchor the part to the build substrate, and provide a heat pathway to avoid warping. Polymers AM has addressed this issue by using support material that is soluble in an electrolyte that the base material is not. In contrast, metals AM has traditionally approached support removal using time consuming, costly methods such as electrical discharge machining or a dremel. This work introduces dissolvable supports to single- and multi-material metals AM. The multi-material approach uses material choice to design a functionally graded material where corrosion is the functionality being varied. The single-material approach is the primary focus of this thesis, leveraging already common post-print heat treatments to locally alter the microstructure near the surface. By including a sensitizing agent in the ageing heat treatment, carbon is diffused into the part decreasing the corrosion resistance to a depth equal to at least half the support thickness. In a properly chosen electrolyte, this layer is easily chemically, or electrochemically removed. Stainless steel 316 (SS316) and Inconel 718 are both investigated to study this process using two popular alloys. The microstructure evolution and corrosion properties are investigated for both. For SS316, the effect of applied electrochemical potential is investigated to describe the varying corrosion phenomena induced, and the effect of potential choice on resultant roughness. In summary, a new approach to remove supports from metal AM parts is introduced to decrease costs and further the field of metals AM by expanding the design space. / Dissertation/Thesis / Doctoral Dissertation Mechanical Engineering 2018

As cirurgias de reconstrução parcial ou total de orelha são um desafio na medicina, exigindo técnicas complexas e qualificadas, sendo as mais utilizadas àquelas que fazem uso de material autógeno (cartilagem da costela do próprio paciente). Trata-se de um processo artesanal em que o cirurgião deve esculpir manualmente a cartilagem para formar o modelo tridimensional da orelha, denominado framework, dessa forma, o resultado final depende, principalmente, da habilidade do cirurgião plástico. Tendo isso em vista, busca-se, neste trabalho, empregar as tecnologias computacionais utilizadas no Design Virtual para auxiliar o planejamento cirúrgico, utilizando digitalização tridimensional e fabricação digital para aprimorar o resultado da técnica de reconstrução auricular. A metodologia proposta sugere a digitalização tridimensional do paciente e, a partir disso, são projetados templates cirúrgicos para auxiliar a modelagem e o posicionamento do framework. A aplicação cirúrgica valida alguns pontos e possibilita o estudo de melhorias em determinados templates, utilizados então em outras duas reconstruções, obtendo-se resultados positivos. Assim, o uso do Design Virtual mostra-se confiável e útil na cirurgia de reconstrução auricular, levando à melhoria no planejamento e, assim, diminuição do tempo cirúrgico, sem riscos ou complicações ao paciente e com melhores resultados anatômicos. / The partial or total reconstruction of ear is a challenge in plastic surgery, requiring complex and skilled techniques. The most successful reconstructions use autogenous material (cartilage from the patient's own rib). It is a handmade process in which the surgeon must manually sculpt the cartilages to form the three-dimensional model of the ear, usually called as framework. Considering this, the final result depends mainly on the plastic surgeon's skill. In this scenario, the aim of this research is employ computer technologies used in Virtual Design to aid surgical planning, using three-dimensional scanning and digital manufacturing to improve the result of ear reconstruction technique. The proposed methodology suggests surgical templates, based on 3D patient scan, designed to assist the modeling and positioning of the framework. The surgical application validates some points and allows the study of improvements in certain templates, then used in other two surgeries, with positive results. Thus, the use of Virtual Design proves to be reliable and useful in ear reconstruction surgery, leading to improved planning and decreasing surgical time, without any risks or complications for the patient and with better anatomical results.

Este trabalho avaliou a aplicação das tecnologias de prototipagem rápida por Impressão 3D e FDM (Fused Deposition Modeling) na produção de moldes rápidos. Esta avaliação foi feita com base nas qualidades das peças obtidas por vazamento nos moldes produzidos, bem como nas limitações encontradas em suas utilizações. Foram estabelecidas as principais diferenças do ponto de vista de qualidade, custos, tempos gastos e praticidade. Foram construídos moldes para peças que contemplando vários graus de dificuldades. Para cada ferramental foram obtidos lotes de peças, através dos quais foram analisadas e comparadas as qualidades dos protótipos. / This work evaluated the application of the Rapid Prototyping technologies 3D printer and FDM (Fused Deposition Modeling) in the rapid manufacturing of molds. This evaluation is based on the quality of the parts molded, as well as in the limitations found in the molds applications. As result the main differences related to quality, and usability was established. The molds produced parts with different degrees of geometric difficulties. For each mold, a few prototypes were produced and their qualities compared.

Various facets of direct digital manufactured (DDM) microwave packages are studied. The rippled surface inherent in fused deposition modeling (FDM) fabricated geometries is modeled in Ansoft HFSS, and its effect on the performance of microstrip transmission lines is assessed via simulation and measurement. The thermal response of DDM microstrip transmission lines is analyzed over a range of RF input powers, and linearity is confirmed over that range. Two IC packages are embedded into DDM printed circuit boards, and their performance is analyzed. The first is a low power RF switch, and the second is an RF front end device that includes a low noise amplifier (LNA) and a power amplifier (PA). The RF switch is shown to perform well, as compared to a layout designed for a Rogers 4003C microwave laminate substrate. The LNA performs within datasheet specifications. The power amplifier generates substantial heat, so a thermal management attempt is described. Finally, a capacitively loaded 6dB Wilkinson power divider is designed and fabricated using DDM techniques and materials. Its performance is analyzed and compared to simulation. The device is shown to compare favorably to a similar device fabricated on a Rogers 4003C microwave laminate using traditional printed circuit board techniques.