Dissertations / Theses on the topic 'CAD reconstruction'

The purpose of this study is to find the design tool to create a soft tissue 3D model able to be used for finite element analysis to simulate the facial soft tissue deformation under g-loading and the helmet and mask/tissue interaction. Such a model will be of value in the design of new helmets and oxygen mask system, to reduce the effects of inertia, to provide improved fit, to minimise oxygen leakage especially when deformed under high g-loading. This work is concerned with the creation of a 3D geometric model. Further work may involve the measurement of mechanical properties of the facial soft tissue, finite element analysis and validation of the model. Using high frequency A-scan ultrasound allows the superficial tissue to be measured on volunteers without risk. The investigation covers 112 points on half of the face, linked to 11 defined morphological zones. The zonal boundaries are based on previous research and are initially identified by inspection and palpation of the face. There is large thickness range difference (30%) over the face in most zones defined in an individual. The iso-thickness zone hypothesis is not valid if the 'constant' thickness criterion is set to be 10% for all zones. Software algorithm for automatically detecting the facial soft tissue thickness is developed and validated to be effective (5% fail rate). Thickness data is acquired from European white males, females and Chinese males. The data collected in this study is also useful in forensic science for facial reconstruction purpose. Laser scanning method has been used to obtain the facial surface profile to create a surface model into which the soft tissue layer thickness distribution around the face can be incorporated. The surface model is exported in IGES format and can be imported in CAD software. Electromagnetic space locating method is used to acquire the ultrasound probe position so as to find the position of the tissue thickness. Point-based registration method is used to integrate the ultrasound thickness data into the laser scanned surface model to create a soft tissue shell solid model. The model is exported in IGES data format so that it can be imported into a finite element analysis package for further processing.

The primary aim of this multidisciplinary project was to develop a new generation of breast implants. Disrupting the currently prevailing paradigm of silicone implants which permanently introduce a foreign body into mastectomy patients, highly porous implants developed as part of this PhD project are biodegradable by the body and augment the growth of natural tissue. Our technology platform leverages computer-assisted-design which allows us to manufacture fully patient-specific implants based on a personalised medicine approach. Multiple animal studies conducted in this project have shown that the polymeric implant slowly degrades within the body harmlessly while the body's own tissue forms concurrently.

De nos jours, la majorité des objets manufacturés sont conçus par des logiciels informatiques de CAO (Conception Assistée par Ordinateur). Cependant, lors de la visualisation, d'échange de données ou des processus de fabrication, le modèle géométrique doit être discrétisé en un maillage 3D composé d'un nombre fini de sommets et d'arêtes. Or, dans certaines situations le modèle initial peut être perdu ou indisponible. La représentation discrète 3D peut aussi être modifiée, par exemple après une simulation numérique, et ne plus correspondre au modèle initial. Une méthode de rétro-ingénierie est alors nécessaire afin de reconstruire une représentation continue 3D à partir de la représentation discrète.Dans ce manuscrit, nous présentons une procédure automatique et complète de rétro-ingénierie pour les maillages 3D issus principalement de la discrétisation d'objets mécaniques. Pour cela, nous proposons des améliorations sur la détection de primitives géométriques simples. Puis, nous introduisons un formalisme clair pour la définition de la topologie de l'objet et la construction des intersections entre les primitives. Enfin, nous décrivons une nouvelle méthode de construction de surfaces paramétriques 3D, fondée sur l'extraction automatique de grilles rectangulaires régulières supports. La méthode a été testée sur des maillages 3D issus d'applications industrielles et permet d'obtenir des modèles B-Rep cohérents<br>Nowadays, most of the manufactured objects are designed using CAD (Computer-Aided Design) software. Nevertheless, for visualization, data exchange or manufacturing applications, the geometric model has to be discretized into a 3D mesh composed of a finite number of vertices and edges. But, in some cases, the initial model may be lost or unavailable. In other cases, the 3D discrete representation may be modified, for example after a numerical simulation, and does not correspond anymore to the initial model. A retro-engineering method is then required to reconstruct a 3D continuous representation from the discrete one.In this Ph.D. Thesis, we present an automatic and comprehensive reverse engineering process mainly dedicated to 3D meshes of mechanical items. We present first several improvements in automatically detecting geometric primitives from a 3D mesh. Then, we introduce a clear formalism to define the topology of the object and to construct the intersections between primitives. At the end, we describe a new method to fit 3D parametric surfaces which is based on extracting regular rectangular grids. The whole process is tested on 3D industrial meshes and results in reconstructing consistent B-Rep models

I detta examensarbete har en undersökning utförts på konsultföretaget ÅF, och deras arbetssätt inom dokumentation och kontrollanläggningar för att utreda om det fanns effektiviseringspotentialer. Undersökningen har i största del innefattat intervjuer med verksamma konsulter inom kontrollanläggningar och elmontage på transformatorstationer. Konsulterna arbetade som konstruktörer och tog fram ritningar främst till kontrollutrustningar. Resultatet från intervjuerna analyserades för att sedan dra slutsatser om effektiviseringsmöjligheter inom verksamheten. Olika kontor i verksamheten undersöktes och arbetssättet varierade på de olika kontoren. En skillnad var det CAD-program som användes och ett förslag var att använda samma program. Effektiviseringspotentialer fanns också genom att återanvända kretsscheman till viss del från föregående projekt. Ett annat förslag var därför att införa databaser där kretsscheman kan samlas in och delas mellan de olika kontoren.<br>In this thesis, a study has been carried out for the consulting company ÅF, and their work method within documentation and control facilities to investigate whether there were any potential for efficiency improvements. The investigation has largely involved interviews with operating consultants within the control facility on substations. The consultants worked as electrical designers and produced drawings mainly for control equipment. The results of the interviews were analyzed to draw conclusions about the efficiency potentials within the business. Different offices in the business were examined and the work approach varied between the offices. One difference was the CAD-software used and a suggestion was to use the same program. Efficiency improvement potentials were also by re-using electrical schematics to some extent from previous projects and another suggestion was to establish databases where electrical schematics can be gathered and shared between the different offices.

Certaines opérations de maintenance sur sites industriels nécessitent une planification à partir de modèles numériques 3D des scènes où se déroulent les interventions. Pour permettre la simulation de ces opérations, les modèles 3D utilisés doivent représenter fidèlement la réalité du terrain. Ces représentations virtuelles sont habituellement construites à partir de nuages de points relevés sur le site, constituant une description métrologique exacte de l’environnement sans toutefois fournir une description géométrique de haut niveau.Il existe une grande quantité de travaux abordant le problème de la reconstruction de modèles 3D à partir de nuages de points, mais peu sont en mesure de fournir des résultats suffisamment fiables dans un contexte industriel et cette tâche nécessite en pratique l’intervention d’opérateurs humains.Les travaux réalisés dans le cadre de cette thèse visent l’automatisation de la reconstruction,avec comme principal objectif la fiabilité des résultats obtenus à l’issu du processus. Au vu de la complexité de ce problème, nous proposons d’exploiter des connaissances et données a priori pour guider la reconstruction. Le premier a priori concerne la compositiondes modèles 3D : en Conception Assistée par Ordinateur (CAO), les scènes industrielles sont couramment décrites comme des assemblages de primitives géométriques simples telles que les plans, sphères, cylindres, cônes, tores, etc. Nous hiérarchisons l’analyse en traitant dans un premier temps les plans et les cylindres, comme un préalable à la détection de stores. On obtient ainsi une description fiable des principaux composants d’intérêt dans les environnements industriels. Nous proposons en outre d’exploiter un certain nombre de règles régissant la manière dont ces primitives s’assemblent en un modèle CAO, basées surdes connaissances ”métier” caractérisant les scènes industrielles que nous traitons. De plus,nous tirons parti d’un modèle CAO existant d´ecrivant une scène similaire à celle que nous souhaitons reconstruire, provenant typiquement de la reconstruction antérieure d’un site semblable au site d’intérêt. Bien que semblables en théorie, ces scènes peuvent présenterdes différences significatives qui s’accentuent au cours de leur exploitation.La méthode que nous développons se fonde sur une formulation Bayésienne du problème de reconstruction : il s’agit de retrouver le modèle CAO le plus probable vis à visdes différentes attentes portées par les données et les a priori sur le modèle à reconstruire. Les diverses sources d’a priori s’expriment naturellement dans cette formulation. Pour permettre la recherche du modèle CAO optimal, nous proposons une approche basée surdes tentatives d’insertion d’objets générés aléatoirement. L’acceptation ou le rejet de ces objets repose ensuite sur l’am´elioration systématique de la solution en cours de construction. Le modèle CAO se construit ainsi progressivement, par ajout et suppression d’objets, jusqu’à obtention d’une solution localement optimale<br>3D models are often used in order to plan the maintenance of industrial environments.When it comes to the simulation of maintenance interventions, these 3D models have todescribe accurately the actual state of the scenes they stand for. These representationsare usually built from 3D point clouds that are huge set of 3D measurements acquiredin industrial sites, which guarantees the accuracy of the resulting 3D model. Althoughthere exists many works addressing the reconstruction problem, there is no solution toour knowledge which can provide results that are reliable enough to be further used inindustrial applications. Therefore this task is in fact handled by human experts nowadays.This thesis aims at providing a solution automating the reconstruction of industrialsites from 3D point clouds and providing highly reliable results. For that purpose, ourapproach relies on some available a priori knowledge and data about the scene to beprocessed. First, we consider that the 3D models of industrial sites are made of simpleprimitive shapes. Indeed, in the Computer Aided Design (CAD) field, this kind of scenesare described as assemblies of shapes such as planes, spheres, cylinders, cones, tori, . . . Ourown work focuses on planes, cylinders and tori since these three kind of shapes allow thedescription of most of the main components in industrial environment. Furthermore, weset some a priori rules about the way shapes should be assembled in a CAD model standingfor an industrial facility, which are based on expert knowledge about these environments.Eventually, we suppose that a CAD model standing for a scene which is similar to theone to be processed is available. This a priori CAO model typically comes from the priorreconstruction of a scene which looks like the one we are interested in. Despite the factthat they are similar theoretically, there may be significant differences between the sitessince each one has its own life cycle.Our work first states the reconstruction task as a Bayesian problem in which we haveto find the most probable CAD Model with respect to both the point cloud and the a prioriexpectations. In order to reach the CAD model maximizing the target probability, wepropose an iterative approach which improves the solution under construction each time anew randomly generated shape is tried to be inserted in it. Thus, the CAD model is builtstep by step by adding and removing shapes, until the algorithm gets to a local maximumof the target probability

La tècnica clàssica per a la reconstrucció mandibular emprant empelt microvascularitzat de peroné implicava en bona mesura la utilització de tècniques de remodelació manual de l’empelt emprant plantilles dissenyades en dues dimensions (2D) amb mesures obtingudes a mà alçada i amb el modelatge manual de les plaques per a la fixació de l’empelt de peroné, que es duia a terme d’una forma artesanal durant el procediment quirúrgic. Al llarg de l’última dècada, i com a conseqüència del desenvolupament de les noves tecnologies, s’ha produït l’aplicació de la cirurgia virtual i del disseny assistit per ordinador (CAD: Computer-Aided Design) a tots els camps de la cirurgia maxil·lofacial, i més específicament en la reconstrucció mandibular. Aquesta tecnologia ha demostrat una millora de l’eficiència, la precisió i la reproduïbilitat en la cirurgia reconstructiva i ha proporcionat els mitjans per generar diferents dispositius i guies quirúrgiques, així com per dur a terme prototips ràpids de models (models de resina estereolitogràfics) sobre els quals poden modelar-se plaques o implants de titani abans de l’operació per al seu posterior ús intraoperatori. Una de les últimes innovacions en el camp de la tecnologia assistida per ordinador en la reconstrucció mandibular ha tingut lloc a través del procés de fabricació assistida per ordinador (CAM: Computer-Aided Manufacturing) amb l’adveniment del titani –imprès en 3D–, que ha permès la impressió de plaques de reconstrucció totalment a mida i personalitzades per al pacient. La impressió de les plaques de titani permet una transició automatitzada i directa del disseny (CAD) a la fabricació assistida per ordinador (CAM), cosa que redueix encara més la introducció d’errors humans en les etapes de fabricació finals, com a conseqüència del modelatge de la placa sobre un model estereolitogràfic. Per aquest motiu, amb aquesta tecnologia es podrien reduir encara més els temps quirúrgics i la freqüència de les complicacions, així com obtenir una reconstrucció més precisa. Amb aquesta tesi es pretén dur a terme una anàlisi exhaustiva d’una sèrie de pacients en els quals es van emprar plaques de titani impreses especifiques per a cada pacient en la reconstrucció mandibular amb empelt microvascularitzat de peroné. La tesi conclou que la reconstrucció mandibular amb tecnologia CAD-CAM emprant plaques de reconstrucció personalitzades és una tècnica que mostra estabilitat dels resultats al llarg del temps, i segura pel que fa a temps quirúrgics i d’isquèmia, complicacions i dies d’hospitalització, i una tècnica que mostra uns bons resultats en termes de qualitat de vida. A més a més, la tesi conclou que és possible descriure un protocol que permeti un flux de treball eficaç i eficient per tal de treballar amb tecnologia CAD-CAM en un hospital terciari.<br>La técnica clásica para la reconstrucción mandibular usando injerto microvascularizado de peroné implicaba en gran medida la utilización de técnicas de remodelado manual del injerto utilizando plantillas diseñadas en dos dimensiones (2D) con medidas obtenidas a mano alzada y con el modelado manual de las placas para la fijación del injerto de peroné, que se realizaba de una forma artesanal durante el procedimiento quirúrgico. En la última década, y debido al desarrollo de las nuevas tecnologías, se ha producido la aplicación de la cirugía virtual y el diseño asistido por ordenador (CAD: Computer-Aided Design) en todos los campos de la cirugía maxilofacial y más específicamente en la reconstrucción mandibular. Esta tecnología ha demostrado mejorar la eficiencia, la precisión y la reproducibilidad en la cirugía reconstructiva y ha proporcionado los medios para generar diferentes dispositivos y guías quirúrgicas así como realizar prototipos rápidos de modelos (modelos de resina estereolitográficos) sobre los cuales pueden modelarse placas o implantes de titanio antes de la operación para su posterior uso intraoperatorio. Una de las últimas innovaciones en el campo de la tecnología asistida por ordenador en la reconstrucción mandibular se ha producido a través del proceso de fabricación asistida por ordenador (CAM: Computer-Aided Manufacturing) con el advenimiento del titanio “impreso en 3D”, que ha permitido la impresión de placas de reconstrucción totalmente a medida y personalizadas para el paciente. La impresión de las placas de titanio permite una transición automatizada y directa del diseño (CAD) a la fabricación asistida por ordenador (CAM), lo que reduce aún más la introducción de errores humanos en las etapas de fabricación finales debido al modelado de la placa sobre un modelo estereolitográfico; por ello, con esta tecnología se podrían reducir aún más los tiempos quirúrgicos y la frecuencia de las complicaciones, así como obtener una reconstrucción más precisa. Con la presente tesis se pretende realizar un análisis exhaustivo de una serie de pacientes en los que se utilizaron placas de titanio impresas específicas para cada paciente en la reconstrucción mandibular con injerto microvascularizado de peroné. La tesis concluye que la reconstrucción mandibular con tecnología CAD-CAM utilizando placas de reconstrucción personalizadas es una técnica que muestra estabilidad de los resultados en el tiempo, y segura en cuanto a tiempos quirúrgicos y de isquemia, complicaciones y días de hospitalización, y una técnica que muestra unos buenos resultados en cuanto a calidad de vida. Además, la tesis concluye que resulta posible describir un protocolo que permita un flujo de trabajo eficaz y eficiente para trabajar con tecnología CAD-CAM en un hospital terciario.<br>The classical technique for mandibular reconstruction using a vascularized fibula flap involved to a great extent using manual modelling techniques on the flap using 2D-designed templates. Dimensions were obtained manually, and plates for locking the fibula flap were also modelled manually in a hand-made process that was performed during the surgical process. Over the last decade, given the development of new technologies, virtual surgery and Computer-Aided Design (CAD) have been applied to all maxillofacial surgery fields, specifically in mandibular reconstruction. This technology has been shown to improve efficiency, accuracy and reproducibility in reconstructive surgery, and has provided the means to generate several devices and surgical guides, and to created model rapid prototypes (stereolithographic resin models) on which to model plates or titanium implants –to be used over the surgical proces– before surgery. One of the latest innovations in computer-assisted technology involved in mandibular reconstruction has been achieved through the Computer-Aided Manufacturing (CAM) process, with the emergence of 3D-printed titanium, which allowed for printing reconstruction plates that are completely customized and tailored to the patient. Printing titanium plates allows for an automated, straightforward transition from design computer-assisted design (CAD) to computer-assisted manufacturing (CAM), which helps further avoid human mistakes in the final manufacturing steps, as the plate is modelled on a stereolithographic model. For this reason, this technology would bring about a further decrease in surgical time and frequency of surgical complications, and would also help increase the accuracy of reconstructions. The aim of this thesis is to perform a comprehensive analysis of a series of patients in which custom-made, patient-specific titanium plates for mandibular reconstruction with microvascularized fibula flap. The thesis concludes that mandibular reconstruction with CAD-CAM technology using custom-made reconstruction plates is a technique that provide stable results over time; it is a safe technique in terms of surgical times, ischemia times, complications and length of hospital stay, and a technique where good quality-of-life results are obtained. Besides, the thesis concludes that it is possible to describe a protocol that allows for an effective and efficient workflow in order to work with CAD-CAM technology in a tertiary hospital.<br>Universitat Autònoma de Barcelona. Programa de Doctorat en Cirurgia i Ciències Morfològiques

Die vorliegende Arbeit befasst sich mit der Entwicklung und Umsetzung von Methoden und Werkzeugen zur Bereitstellung von Modellen und Randbedingungen für die Konstruktion individueller Langzeit-Knochenimplantate (Konstruktionsvorbereitung). Grundlage dabei ist, dass die Planung aus medizinischer Sicht z.B. durch einen Chirurgen und die Konstruktion unter technischen Aspekten z.B. durch einen Konstrukteur getrennt erfolgt. Hierfür wird ein erarbeitetes Planungskonzept vorgestellt, welches sowohl die geplanten geometrischen Merkmale, als auch weiterführende Metadaten beinhaltet (Randbedingungen). Die Übergabe dieser Planungsdaten an die Konstruktion erfolgt über eine dafür entworfene Formatbeschreibung im Kontext der Schnittstelle zwischen Mediziner und Ingenieur. Weiterführend wird die Notwendigkeit von speziellen Funktionen für die Konstruktion von individuellen Implantaten in der Arbeitsumgebung des Konstrukteurs (z.B. Modelliersystem – CAD) am Beispiel der konturlinienbasierten Modellrekonstruktion erörtert. Die gesamtheitliche Basis bildet eine durchgängig digitale Prozesskette zur Datenaufbereitung, Konstruktion und Fertigung. Die Anwendbarkeit der Methoden und zweier umgesetzter Demonstratoren wurde innerhalb eines interdisziplinär angelegten Projektes am realen Patientenfall bestätigt.

The identification of deceased individuals is important in society as it not only facilitates the progression of criminal investigations into suspicious deaths, but also enables the resolution of legal matters and brings closure to the families affected by the death. When a corpse is skeletonized, heavily burned, or the soft tissue has degraded to a point that other professionals cannot obtain information about the deceased, a forensic anthropologist or odontologist is often tasked with identification. A variety of methods exist that enable forensic anthropologists to achieve identification. These include: non-imaged records comparisons; craniofacial superimposition and comparative radiography. Facial reconstructions can also be utilized when no ante mortem information about the deceased individual is available or when law enforcement have no suspicions on who the deceased person is. Facial reconstructions are traditionally a manual method however with the recent advancement of photogrammetry and three-dimensional and computer-aided design modeling software, the process can be performed within a virtual space. The purpose of this literature review is to identify an efficient and low-cost method of generating facial reconstructions using photogrammetry and open-source three-dimensional and computer-aided design software.

This thesis deals with the fixation of lower jaw with bone tissue defect using commercially produced fixator. Large defects of bone tissue are mainly caused due to the removal of bone tissue affected by tumor. These topics have been researched on the basis of the literature. Subsequently, stress strain analysis of the lower jaw with the applied fixation plate was performed. This analysis was solved by using computational modeling with variational approach, ie the finite element method. The work also describes in detail the procedure of creating model of geometry, model of material, model of boundary conditions and loads with subsequent solution of several computational models. The stress strain analysis was done for lower jaw with varying size of the removed bone tissue with applied reconstruction plate made of CP-Ti Grade 4 and for the lower jaw with the plate, which is made of -Ti-Mo. Finally, the influence of the mechanical properties of the callus during formation of new bone tissue (callus healing) on the stress and deformation of the solved system was evaluated.

Presentamos un estudio de tesis doctoral enfocado al estudio de la influencia de la planificación preoperatoria en cirugía reconstructiva de cabeza y cuello, concretamente en cirugía reconstructiva mandibular, valorando su influencia en la reducción del tiempo quirúrgico empleado para estos procedimientos y su influencia sobre la calidad de vida del paciente. La hipótesis de trabajo de este estudio piloto es que la planificación preoperatoria en cirugía reconstructiva mandibular supone una mejora en el tiempo quirúrgico de reconstrucción. Este tiempo quirúrgico de reconstrucción, se define como el tiempo transcurrido desde el inicio simultáneo de la disección del colgajo libre y la cirugía exerética mandibular, hasta el posicionamiento del colgajo y su osteosíntesis, previo a la anastomósis microvascular. El objetivo principal del estudio es comparar el parámetro definido como tiempo quirúrgico de reconstrucción. De forma paralela estudiamos la calidad de vida de los pacientes incluidos en el estudio mediante la encuesta UW-QOL v4. University of Washington Quality of life Questionnaire. Se plantea para ello de forma prospectiva un estudio de cohortes piloto, en el cual se estudian un total de 20 casos distribuidos en dos grupos. Un grupo expuesto, en el que se emplea un protocolo de planificación, solicitando un modelo tridimensional mandibular y una placa de reconstrucción mandibular customizada y preformada prequirúrgicamente según la planificación asistida por ordenador (CAD); y un grupo no expuesto, en el cual no se realiza la planificación preoperatoria tridimensional, y se dispone de una placa de reconstrucción estándar, siguiendo un protocolo de planificación convencional. La asignación de pacientes en cada grupo del estudio se realizó bajo criterio facultativo, y según aprobación por el Comité de Nuevas Tecnologías y del presupuesto existente, siendo esta no aleatorizada. En el planteamiento del estudio y según el tamaño muestral, se estima en el momento de su inicio, una reducción del tiempo quirúrgico en torno a 45 minutos para el grupo expuesto. Según el resultado final del análisis, se ha valorado la significación estadística de la variable principal y de las variables secundarias. El objetivo de la estimación del tiempo quirúrgico es dar un valor objetivo y cuantificable a un proceso de planificación preoperatoria. Se pretende valorar su contribución para reducir el tiempo de ocupación de quirófano, y el consecuente ahorro de este recurso hospitalario, que pueda compensar el gasto económico en este tipo de planificación. INTRODUCCIÓN: Los objetivos principales en cirugía reconstructiva mandibular son restaurar los componentes anatómicos, funcionales y estéticos de la mandíbula. El empleo de colgajos libres óseos y osteo­mio-cutáneos que permitan una adecuada conformación de la anatomía ósea para reconstruir la configuración tridimensional de la mandíbula, ofrecen en la actualidad un elevado estándar de calidad. Sin embargo, hasta la aparición del Rapid Prototype Modelling (RPM), la placa de titanio para reconstrucción mandibular (TRP) era moldeada de forma intraoperatoria, al igual que el colgajo libre. Este procedimiento intraoperatorio se ha asociado a un incremento en el tiempo quirúrgico y en ocasiones a una conformación subóptima de la placa de reconstrucción mandibular. La cirugía reconstructiva ha evolucionado gracias a la incorporación de nuevas tecnologías como el diseño asistido por ordenador (CAD) y el RPM en la planificación preoperatoria. La utilización de estas nuevas tecnologías en la planificación quirúrgica podría reducir el tiempo de ocupación de quirófano, reducir el tiempo de isquemia del colgajo y mejorar los resultados globales en cirugía reconstructiva. OBJETIVOS: Estudiar el tiempo quirúrgico de reconstrucción mandibular, el tiempo quirúrgico total y la influencia de la planificación preoperatoria en los resultados de la reconstrucción mandibular. MÉTODOS: En 2008 se planificó un estudio de cohortes prospectivo en el que se plantea la inclusión de 20 pacientes para comparar los resultados, tras un tratamiento de reconstrucción mandibular. Se define y establece un protocolo de planificación preoperatoria asistida por ordenador, sistemas de prototipado rápido y placas de titanio de reconstrucción mandibular preformadas, frente a un protocolo de planificación convencional. Se estudia el tiempo quirúrgico total, el tiempo definido como tiempo de reconstrucción mandibular, las complicaciones postquirúrgicas, estancia hospitalaria y variables de calidad de vida relacionadas con la salud a través del UW-QOL v4. Este tiempo quirúrgico de reconstrucción, se de.ne como el tiempo transcurrido desde el inicio simultáneo de la disección del colgajo libre y la cirugía exerética mandibular, hasta el posicionamiento del colgajo y su osteosíntesis, previo a la anastomósis microvascular. RESULTADOS: Entre 2008 y 2013 un total de 26 pacientes fueros tratados de reconstrucción mandibular durante el estudio. Se incluyeron 20 pacientes y se distribuyeron 10 pacientes en cada grupo de estudio. El análisis del tiempo quirúrgico valorado como media del tiempo de reconstrucción en el grupo de planificación preoperatoria con CAD, RPM y TRP preformadas fue de 134.8 (SD 37.25) minutos, frente a 176.4 (SD 58.19) en el grupo de planificación convencional, con un valor de p de 0.0445. El análisis del tiempo quirúrgico total en el grupo de planificación preoperatoria con CAD, RPM y TRP fue de 357.8(SD 94.61), frente a 421(SD 90.59) en el grupo de planificación convencional, con un valor de p de 0.1403. Se observaron diferencias estadísticamente significativas en las complicaciones referentes a maloclusión dental postquirúrgica (p valor 0.025) y exposición del material de osteosíntesis mandibular ( p valor 0.0098). Globalmente los resultados referentes a la calidad de vida relacionada con la salud obtuvieron una mayor puntuación en el grupo de planificación preoperatoria. Los dominios considerados como problemas más importantes en ambos grupos fueron la apariencia y la afectación en la función masticatoria, con una mejor puntuación en el grupo de planificación preoperatoria con respecto al grupo de planificación convencional. CONCLUSIONES: La planificación preoperatoria con CAD, RPM y TRP preformadas puede mejorar la precisión de la microcirugía reconstructiva mandibular y simplificar el procedimiento quirúrgico reduciendo el tiempo de reconstrucción mandibular. El empleo de nuevas tecnologías como la CAD y RPM, poseen un importante papel en el momento actual y en la futura evolución de la cirugía reconstructiva, particularmente en el área de cabeza y cuello, pudiendo contribuir a una mejora final en la calidad de vida.<br>INTRODUCTION: The objectives for mandibular reconstruction are to restore the aesthetic and functional aspects of the jaw. Free flaps should be of a suitable shape and dimension to restore the three-dimensional (3D) configuration of the mandible. Until the advent of Rapid Prototype Modelling (RPM), titanium reconstruction plates (TRP) were bent, and bone flaps were contoured during the surgical procedure.This procedure has been associated with increased operation times and seldom improvable accuracy in plate contouring. Mandibular reconstruction has evolved to an increased standard of quality since the introduction of computer assisted design (CAD) and rapid prototype modelling (RPM) for surgical planning. By using these techniques for surgical planning, it is possible to reduce operation and ischaemic time to improve global results during the reconstructive procedures. OBJECTIVES: We studied operative reconstruction and total operative time and whether this approach of surgical planning could improve microsurgical mandibular reconstruction results. PATIENTS AND METHODS: In the year 2008, a twenty patients cohort pilot study was planned to prospectively compare the outcomes of patients treated for mandibular reconstruction who were subjected to a surgical planning protocol with CAD and RPM guided surgery, using a pre-contoured titanium plate, to those of patients treated following a conventional surgery protocol. We analysed total surgical time, time defined as reconstruction time, complications, length of hospital stay and quality of life related to health through the UW-QOL v4(1). The operative reconstruction time was studied and defined as the operative time from the beginning of the flap raising and resection surgery in the mandible to the final osteosynthesis of the flap, prior to microvascular suture. To better evaluate and determine whether operative time could be reduced, we designated this protocol of analysis. RESULTS: In this study, a total of 26 patients were treated for mandibular reconstruction using a fibula flap between 2008 and 2013. Twenty patients were included in the study, and a total of 10 patients were included in each group of the study. The mean operative time analysed as reconstruction time in the pre-surgical planning group was 134.8 (37.25) min compared to 176.4 (58.19) min in the conventional group (p value 0.0445).

Introduction : L’utilisation des méthodes anatomiques classiques rend difficile la localisationprécise des micro-fibres nerveuses et ne permet pas de déterminer leur nature ni leur fonction.La chirurgie pelvienne est associée à des séquelles urinaires et sexuelles fréquentes causéespar lésion iatrogène des nerfs pelviens. La connaissance de l’anatomie et de la physiologie del’innervation intra-pelvienne est fondamentale pour tenter de réduire le taux de troublesfonctionnels postopératoires.Objectifs : i) étudier l’anatomie topographique et la nature de fibres nerveuses intrapelvienneen utilisant la reconstruction tridimensionnelle des coupes histologiques immunomarquéesii) standardiser la technique de Dissection Anatomique Assistée par Ordinateur(DAAO) et vérifier sa faisabilité sur des sujets adultes et iii) établir grâce à cette technique deDAAO des modèles pédagogiques tridimensionnels afin d’améliorer la compréhension desdysfonctions sphinctériennes et sexuelles survenant après la chirurgie (rectale et prostatique)et d’adapter éventuellement la technique opératoire.Matériel et méthodes : Des coupes histologiques sériées de pelvis ont été réalisées chez septfoetus masculins, sept foetus féminins et six cadavres adultes masculins. Les coupes ont ététraitées par des méthodes histologiques (Hématoxyline-Eosine et trichrome de Masson) etimmuno-histochimiques pour détecter les fibres nerveuses (anti-S100), les fibres somatiques(anti-PMP22), les fibres adrénergiques (anti-TH), cholinergiques (anti-VAChT), sensitives(anti-SP/CGRP) et nitrergiques (anti-nNOS) ainsi que l’actine lisse des sphincters. Les lamesont ensuite été numérisées par un scanner de haute résolution optique et les imagesbidimensionnelles ont été reconstruites en trois dimensions grâce au logiciel WinSurf.Résultats: La reconstruction tri-dimensionnelle des coupes histologiques immuno-marquéesa permis d'identifier l’anatomie topographique et structurelle de l’innervation intra-pelvienne.Les structures nerveuses afférentes du plexus hypogastrique inférieur (PHI) : nerfssplanchniques pelviens (NSP) et nerfs hypogastriques (NH) véhiculent de façon mixte l’influxsympathique et parasympathique pelvien.Les fibres nerveuses issues de la partie distale du PHI sont responsables de la continenceurinaire et de la fonction sexuelle. Elles sont regroupées et associées au pédicule vasculairepour former la bandelette neuro-vasculaire (BNV). Trois efférences principales sont issues decette BNV : i) des fibres antérieures destinées au sphincter urétral, ii) des fibres antérolatérales,par rapport à la prostate et au vagin, constituant le nerf caverneux destiné aux corpscaverneux du pénis/clitoris et iii) des fibres nerveuses postéro-latérales, par rapport à laprostate et au vagin, formant le « nerf spongieux » destiné aux corps spongieux/bulbesvestibulaires.Les communications autonomiques-somatiques entre le PHI supra-lévatorien et le nerfpudendal infra-lévatorien existent à trois niveaux ; proximal, intermédiaire et distal. Lacommunication distale caverno-pudendale est responsable de l’activité érectile segmentaireobservée au sein du nerf dorsal du pénis/clitoris.Conclusion: La DAAO est une méthode originale de recherche anatomique qui a étéprogressivement améliorée au sein de notre unité de recherche. Cette évolution illustre le faitque l'anatomie descriptive est encore une science dynamique. Notre étude a permis dedévelopper des modèles anatomo-physiologiques d’innervation pelvienne contribuant àaméliorer du point de vue morphologique, chirurgical et pédagogique la compréhension derégions anatomiques complexes comme le petit bassin<br>Introduction: Classic anatomical methods have limitations in micro determination of nervefibre location. Furthermore, the precise detection of the nerve fibres nature is not possible bymeans of dissection. Pelvic surgery is associated with urinary and sexual consequence causedby iatrogenic damage of the pelvic nerves. Anatomic and physiologic knowledge of the intrapelvicinnervation is essential to reduce the rate of postoperative functional complication.Objectives: i) to study the topographic anatomy and the nature of intra-pelvic nerve fibersusing three-dimensional reconstruction of histological immuno-labeled sections ii)standardize the technique of Computer-Assisted Anatomic Dissection (CAAD) and check itsfeasibility on adult subjects iii) reconstructe three dimensional teaching models to improveunderstanding of urinary and sexual dysfunction occurring after surgery (of rectal and ofprostate) to ameliorate the operative technique.Materials and methods: serial histological sections of pelvic portion were performed inseven male foetuses, seven female foetuses and six adult male cadavers. The sections weretraited by histological methods (Hematoxylin-Eosin and Masson's trichrome) and immunohistochemicalmarker of the nerve fibers (anti-S100), the somatic fibers (anti-PMP22), theadrenergic (anti-TH), cholinergic (anti-VAChT), sensory (anti-SP/CGRP) and nitrergic (antinNOS)fibers and the actin smooth muscles. The slides were then digitized by a scanner ofhigh optical resolution and two-dimensional images were reconstructed in three dimensionsusing WinSurf software.Results: The three dimensional reconstruction of histological immuno-labelled sectionsidentified structural and topographic anatomy of intra-pelvic innervation. The afferencenerves of the inferior hypogastric plexus (IHP): pelvic splanchnic nerves (PSN) andhypogastric nerves (HN) contain both sympathetic and parasympathetic fibers.The nerve fibers from the distal part of the IHP is responsible for urinary continence andsexual function. They are grouped and associated with the vascular pedicle to form theneurovascular bundles (NVB). Efferences of this NVB are distributed in three maindirections: i) anterior fibers the urethral sphincter, ii) anterolateral fibers, compared withprostate / vagina, which constitute the cavernous nerve for the corpora cavernosa of the penis/ clitoris and iii) " spongious nerve”, which is the continuity of posterior-lateral nerve fibers,compared with prostate / vagina, for the corpus spongiosum / vestibular bulbs.Autonomic-somatic communications between supra-lavator IHP and infra-levator pudendalnerve are present at three levels; proximal, intermediate and distal communications. Cavernopudendaldistal communication provides segmental erectile activity of the dorsal nerve of thepenis / clitoris.Conclusion: The CAAD is an original method in anatomical research which has beenprogressively improved. This illustrates the fact that descriptive anatomy is still a dynamicscience. Our study has developed anatomico-physiological models of intra-pelvic innervationcontributing to a better understanding of complex anatomical

Template-Based reverse engineering approaches represent a relatively poorly explored strategy in the field of CAD reconstruction from polygonal models. Inspired by recent works suggesting the possibility/opportunity of exploiting a parametric description (i.e. CAD Template) of the object to be reconstructed in order to retrieve a meaningful digital representation, a novel reverse engineering approach for the reconstruction of CAD models starting from 3D mesh data is proposed. The reconstruction process is performed relying on a CAD Template, whose feature tree and geometric constraints are defined according to the a priori information on the physical object. The CAD Template is fitted upon the mesh data, optimizing its dimensional parameters and positioning/orientation by means of a particle swarm optimization algorithm. As a result, a parametric CAD model that perfectly fulfils the imposed geometric relations is produced and a feature tree, defining an associative modelling history, is available to the reverse engineer. The proposed implementation exploits a cooperation between a CAD software package (Siemens NX) and a numerical software environment (MATLAB). Reconstruction tests, covering both synthetic and real-scanned mesh data, are presented and discussed in the manuscript; the results are finally compared with models generated by state of the art reverse engineering software. Possible application scenarios and key aspects to be addressed in future work are described in the thesis.

碩士<br>國立成功大學<br>機械工程學系<br>88<br>This thesis discusses processes and tools of reverse engineering primarily. We will introduce each system and measuring tools about reverse engineering and how to reconstruct CAD models and produce NC codes by CAD/CAM software. For reconstructing CAD models, we use Bi-cubic surface to construct free form surface. We also introduce the functions of this surface and what advantage and disadvantage it has. Finally, we input NC codes to NC machine and produce it, and then analysis the reasons of tolerance.

碩士<br>國立成功大學<br>機械工程學系碩博士班<br>90<br>InPack, a CAE software is developed for IC packaging analysis. InPack provides a convenient interface to generate good 3-D mesh of hexahedron or prism and dramatically reduces the mesh generation time. For mold flow simulations, the geometry of runner has critical influence when the colloids enter package. However, InPack only generates the meshes inside the package, which is insufficient on accuracy and completeness for the simulation. Therefore, this thesis is focusing on generating runner meshes by developing a function in InPack, which specifically performs reconstruction and mesh generation of CAD solid model. This function reconstructs the various shape of runner from standard data exchange file of geometry model, IGES. Also, this function provides a friendly interface to generate appropriate 3-D meshes by ANSYS mesh generator. The runner meshes can be integrated with the package meshes to complete the mold flow simulations. It reduces the difficulties in pre-processor and improves the accuracy of simulation obviously.

碩士<br>國立成功大學<br>機械工程學系碩博士班<br>90<br>Abstract The process of obtaining scanned points from a physical object using a laser scanner and building its CAD model is called as reverse engineering. Reverse engineering is an appropriate method for designing product with free-form shapes, and recently many industries use reverse engineering method to design new products. The main procedure of reverse engineering involves steps of data points acquisition, multiple view data points registration, data points segmentation, curve fitting, surface fitting and error analysis. In this study, a laser scanner is used to capture data points from objects, a commercial software-Polyworks to merge multiple view data points, and a reverse engineering software, i.e. Surfacer, to manipulate other steps. This research is a study of constructing CAD models. Three physical objects, i.e. electric meter, golf head and residual limb, are employed to demonstrate the process of CAD models generation based on their scanned points.

碩士<br>國立中央大學<br>機械工程學系<br>85<br>Reverse engineering is a technology that is used to reconstruct CAD models from 2D or 3D measured data. It is not only used extensively in mechanical industry for designing new products, but is also becoming more important in medical image processing. The objective of this work was to develop a digitized data processing system for reverse engineering applications. It includes a data processing module, a registration module, an edge detection module, and a medical image processing module. Moreover, this system provides an interface to convert CAD data to other CAD/CAM system by IGES files. The proposed method can be applied for many digitizing systems, such as CMM、Laser scanner、CCD image system. It can also be used to computer tomography images. Several examples will be illustrated to demonstrate the feasibility of the proposed method for the above-mentioned applications.

碩士<br>國立成功大學<br>機械工程學系碩博士班<br>94<br>The aim of this research is to recognize the geometrical features of a mold surface via the computer vision and image process techniques. Based on the geometrical reasoning, 3D CAD model of the molds are reconstructed. This study also includes stereo vision depth measurement system. By employing the image encoding skill, we can transform the 3D point cloud into a 2D image format. The point clouds in each individual surface and its corresponding surface edges are separated by using boundary search, image segmentation and loop tracing in the image format. The surface is recognized by curve fitting of two sectional depth data through the major axes of each regional surface. And the surface can then be recognized as plane, surface of revolution, and freeform surface according to the feature of recognized curves. In the process of reconstruction, the boundaries of surfaces can be judged whether there exist a wall surface according to the intersection of the neighboring surface. The completion of surface model is done by geometric reasoning from the boundary of surface. The reconstructed surface is outputted as IGES format for further usages.

Subsea assets need to be regularly inspected, maintained and repaired. These operations are typically performed using a Remotely Operated Vehicle (ROV) controlled by a pilot that sits in a ship. In order to make operations safer and cheaper, it would be interesting to control the ROVs from land, avoiding the need to hire a ship and crew. As part of these operations, ROVs need to perform high precision actions such as turning valves, which may be hard to perform in this remote setting due to latency. A semi-autonomous vehicle capable of performing high precision tasks could potentiate the transition to fully remote operations, where people stay on land. In order to develop such a system, we need a robust perception model capable of segmenting the assets of interest. Additionally, it is important to fuse that information with 3D models of those same assets in order to have a spatial perception of the environment. This fusion may be useful to, in the future, plan the necessary actions to interact with the given asset. The main goal of this work is to implement a model that: 1) segments different subsea assets of interest, such as valves; and 2) fuse the segmentation information with 3D models of those same assets.

Subsea assets need to be regularly inspected, maintained and repaired. These operations are typically performed using a Remotely Operated Vehicle (ROV) controlled by a pilot that sits in a ship. In order to make operations safer and cheaper, it would be interesting to control the ROVs from land, avoiding the need to hire a ship and crew. As part of these operations, ROVs need to perform high precision actions such as turning valves, which may be hard to perform in this remote setting due to latency. A semi-autonomous vehicle capable of performing high precision tasks could potentiate the transition to fully remote operations, where people stay on land. In order to develop such a system, we need a robust perception model capable of segmenting the assets of interest. Additionally, it is important to fuse that information with 3D models of those same assets in order to have a spatial perception of the environment. This fusion may be useful to, in the future, plan the necessary actions to interact with the given asset. The main goal of this work is to implement a model that: 1) segments different subsea assets of interest, such as valves; and 2) fuse the segmentation information with 3D models of those same assets.

碩士<br>國立嘉義大學<br>森林暨自然資源研究所<br>94<br>The fast growing economy, education reform, and diversified education of Taiwan in recent years have stimulated growing percentage of parents who send their children to learn an instrument. The violin will have potential demand in mass market. The violin is a woodwork with high economic value, is a convergent instrument of science, technology, and art; it is the supreme embodiment of workmanship as its production relies on labor-intensive technology. But, nowadays, the wage hikes in Taiwan and loose advanance to competition with the low-cost products of China or southeast Asia. For this reason, this study aims to construct a new model of wood processing by adopting reverse engineering techniques. After the hand-made violin top plate is processed through reconstructing the CAD mold of top plate and editing the process program, the process by the CNC router is proceeding in the course of DNC transmission; moreover, the sound vibration test is made during the process. This new model could be as references for violin makers and the wood processing industry in developing the product of high-technique, high unit price, and automatic process. Results of the research are summarized as follows: i. The process of making the violin top plate by hand is of important reference for the processing by a CNC router. However, the processing time and precision of a hand-made violin depend on the craftsman’s mastery of skill. ii. The reverse engineering combined with the design method of manual mold is applicable to such complicated free style as the products of violin top plate and etc., the CAD mold constructed by the reverse engineering is able to fast produce engineering drawing, and to allow partial modification on the shape design. iii. When the reconstructed CAD mold is used as the core in the course of using AlphaCAM commercial version software to implement its design and process. It is able to construct the top plate itself, and very quickly and precisely constructs the position mold to be used in the top plate process by employing the edit and amendment function; therefore, the reconstructed CAD mold of the top plate possesses the effectiveness of multiple uses. iv. The process simulation on the computer in advance of the actual process, especially the process of the complicated 3D curve, is imperative for obtaining an accurate program for the process. The CAD/CAM possesses the advantage of a quick output and is able to provide timely accurate amendments to the program. v. The wood process model integrated by the CAD/CAM/CNC system is applicable to the process of 3D violin curve top plate, so as to improve the grade and quality of wood process, make the application of CNC router more flexible, and construct the process model of wood 3D curve shape. vi. Compared to the manual process, the CNC router has a minimized processing time, which is 15 percent of the manual processing times and quality is more stable; CNC is an automatic process that rarely relies on the operator’s skill and is able to process multiple tasks. vii. The surface smoothness of 3D curve shape process can be calculated by a formula, and the scallop height worked out from that formula can be used as the standard process; setting up the width for cut and chip according to the requirements so as to increase the process effectiveness. viii. The vibration frequency of the Taiwan Spruce is unique in acuteness, it’s peak is higher and clearer than others and the amplitude calibration dB is kept on the higher point. The specific gravity of the Agathis is approximate to that of the Taiwan Spruce, it’s frequency response appears similar to that of the Taiwan Spruce through comparison. The Douglas Fir is very distinctive in each stage, as to obtain the material from a single piece or compose from the symmetric patterns, there is no distinguish difference between them.

碩士<br>國立中央大學<br>機械工程研究所<br>88<br>Applying reverse engineering techniques to reconstruct the CAD models is an important part of product development. By that we can get some experiences about the techniques of product design and manufacturing. The development of propeller inspection techniques can not only provide the data points of the same radius of blade section, but also increase the efficiency of propeller inspection. This work focused on the development of an integrated approach, by combining three-dimensional digitization, reverse engineering and CAD/CAM technology, for the reconstruction of complete CAD models. Besides, applying propeller inspection techniques to get the blade data. With the blade data we can calculate the parameters of the propeller blade and evaluate the shape error of each blade.This work describes the approaches of 3-D coordinate measurement and CAD model reconstruction. Applying the equal radius inspection approach to get digitalized propeller blade information, and performing mathematical calculations to evaluate the blade section parameters.

碩士<br>國立雲林科技大學<br>機械工程系碩士班<br>90<br>The object of this thesis is optimal design l for CAD model reconstruction and machining of reverse engineering by Taguchi method . Choosing design parameters for both CAD model and machining , the experimental design of Taguchi method is conducted to optimal parameter design . Also , the orthogonal array , the analysis of variance（ANOVA）, and the response table are utilized to choose optimal levels of design parameters for both CAD model and machining . The percent contribution of each parameter is evaluated to compare the importance of design parameters for both CAD model and machining . Furthermore , the regression analysis is applied to corre- late design parameters into a mathematical equation . The application of Taguchi method and the regression analysis can help the de- signers to minimize the shape error in CAD model reconstruction and machining of reverse engineering using laser scanning , also to obtain the more accurate geometry shape by adjust proper parameter levels . Besides , the equation by the regression analysis can be used to estimate the shape error to shorten the design cycles and im- prove the quality of products .

The advent and the consolidation of Reverse Engineering (RE) and Additive Manufacturing (AM) techniques in the medical field changed significantly the common therapeutic and surgical approach, pushing towards a new perspective of treatment in which each patient is considered unique. The integration of RE e AM techniques enables the modeling and realization of customized medical devices: RE techniques allow to acquire and reconstruct the patient-specific anatomy, AM processes make possible to create any geometric shape, that could not be realized with traditional production techniques. In the field of plastic surgery, is observed a wide use of such techniques for the production of patient-specific implants and patient-specific surgical guides. Reconstructive surgery is, in fact, a challenge even for the most experienced surgeons due to the complex anatomy involved and the uniqueness of defects and malformations; the use of medical devices which accurately fit the anatomy of the defect, has demonstrated to improve surgical outcomes in terms of aesthetic results, of surgical time and safety for the patients. In this context, the present thesis focuses on the development and design of tools able to support the surgeon in the reconstruction of the external ear. Such reconstructive intervention is performed in patients affected by deformation or absence of the external ear due to congenital reasons (microtia), as a result of trauma, burns or tumor resections. The intervention is considered among the surgeons particularly complex and the surgical outcomes are highly dependent on the experience of clinicians. For such reasons, my research thesis initially focused on the study of methods and tools for the simulation, planning and execution of the intervention with the aim to improve the performance of experienced surgeons and to make this intervention accessible to a wider range of physicians. From a close collaboration with the plastic surgeons of the Meyer Children's Hospital (Florence, Italy), arose the idea of new surgical guides for preoperative simulation and surgery. Technical and clinical requirements of surgical guides were identified by physicians and through a trial phase, that foresaw CAD modeling by engineers and testing by surgeons, the final design of the devices was defined. Secondly, with the idea of making physicians independent of experienced CAD modelers in the manufacturing process of such instruments, a systematic procedure was defined that starts from the patient's anatomy data and leads to 3D modeling of the devices. The procedure was semi-automated and made easily accessible to surgeons through an intuitive graphical user interface that allows them to be independent in the creation of each new device. The aim is to introduce a new tool in the common clinical practice, suitable for use in a hospital environment, which pushes towards a new concept of personalized assistance.

碩士<br>國立中央大學<br>機械工程研究所<br>88<br>For those objects without original CAD models, the application of reverse engineering technology to reconstruct the CAD model is essentially important for product development. The reconstruction of industrial products usually has two problems, (1) The reconstruction method can’t guarantee the accuracy of CAD model. (2) The function of error evaluation in commerce software is incomplete. This work focused on the development of an integrated approach, combining three—dimensional digitization, and reverse engineering technology, for the construction of complete CAD models.Multi-axes machining is typically used to deal with the problems that involve complex sculptured surfaces which cannot be handled by three-axes machining. However, due to the complexity in path planning for multi-axes machining, the problems related to gouging, interfering, engaging and retracting still exist in current CAD/CAM systems. The objective of the this project is that a reverse manufacturing technology is developed. Such a technology combines three-dimensional measurement, reverse engineering, CAD/CAM and 5-axes NC machining for the reproduction of complex sculptured surfaces. The function of error evaluation in commerce software is incomplete. When the coordinate system of two different component isn’t the same, the error evaluation doesn’t work. This work focused on the development of an integrated approach, combining surface error evaluation, and cross-section error evaluation, for the compare of difference with reproduction and original CAD model.

Applicable image-based reconstruction of three-dimensional (3D) objects offers many interesting industrial as well as private use cases, such as augmented reality, reverse engineering, 3D printing and simulation tasks. Unfortunately, image-based 3D reconstruction is not yet applicable to these quite complex tasks, since the resulting 3D models are single, monolithic objects without any division into logical or functional subparts. This thesis aims at making image-based 3D reconstruction feasible such that captures of standard cameras can be used for creating functional 3D models. The research presented in the following does not focus on the fine-tuning of algorithms to achieve minor improvements, but evaluates the entire processing pipeline of image-based 3D reconstruction and tries to contribute at four critical points, where significant improvement can be achieved by advanced human-computer interaction: (i) As the starting point of any 3D reconstruction process, the object of interest (OOI) that should be reconstructed needs to be annotated. For this task, novel pixel-accurate OOI annotation as an interactive process is presented, and an appropriate software solution is released. (ii) To improve the interactive annotation process, traditional interface devices, like mouse and keyboard, are supplemented with human sensory data to achieve closer user interaction. (iii) In practice, a major obstacle is the so far missing standard for file formats for annotation, which leads to numerous proprietary solutions. Therefore, a uniform standard file format is implemented and used for prototyping the first gaze-improved computer vision algorithms. As a sideline of this research, analogies between the close interaction of humans and computer vision systems and 3D perception are identified and evaluated. (iv) Finally, to reduce the processing time of the underlying algorithms used for 3D reconstruction, the ability of artificial neural networks to reconstruct 3D models of unknown OOIs is investigated. Summarizing, the gained improvements show that applicable image-based 3D reconstruction is within reach but nowadays only feasible by supporting human-computer interaction. Two software solutions, one for visual video analytics and one for spare part reconstruction are implemented. In the future, automated 3D reconstruction that produces functional 3D models can be reached only when algorithms become capable of acquiring semantic knowledge. Until then, the world knowledge provided to the 3D reconstruction pipeline by human computer interaction is indispensable.

Die vorliegende Arbeit befasst sich mit der Entwicklung und Umsetzung von Methoden und Werkzeugen zur Bereitstellung von Modellen und Randbedingungen für die Konstruktion individueller Langzeit-Knochenimplantate (Konstruktionsvorbereitung). Grundlage dabei ist, dass die Planung aus medizinischer Sicht z.B. durch einen Chirurgen und die Konstruktion unter technischen Aspekten z.B. durch einen Konstrukteur getrennt erfolgt. Hierfür wird ein erarbeitetes Planungskonzept vorgestellt, welches sowohl die geplanten geometrischen Merkmale, als auch weiterführende Metadaten beinhaltet (Randbedingungen). Die Übergabe dieser Planungsdaten an die Konstruktion erfolgt über eine dafür entworfene Formatbeschreibung im Kontext der Schnittstelle zwischen Mediziner und Ingenieur. Weiterführend wird die Notwendigkeit von speziellen Funktionen für die Konstruktion von individuellen Implantaten in der Arbeitsumgebung des Konstrukteurs (z.B. Modelliersystem – CAD) am Beispiel der konturlinienbasierten Modellrekonstruktion erörtert. Die gesamtheitliche Basis bildet eine durchgängig digitale Prozesskette zur Datenaufbereitung, Konstruktion und Fertigung. Die Anwendbarkeit der Methoden und zweier umgesetzter Demonstratoren wurde innerhalb eines interdisziplinär angelegten Projektes am realen Patientenfall bestätigt.

With the evolution of the techniques of acquisition of Three-Dimensional (3D) image it became possible to apply these in more and more areas, as well as to be used for research and hobbyists due to the appearance of low cost 3D scanners. Among the application of 3D acquisitions is the reconstruction of objects, which allows for example to redo or remodel an existing object that is no longer on the market. Another rise tech is industrial robot, that is highly present in the industry and can perform several tasks, even machining activities, and can be applied in more than one type of operation. The purpose of this work is to acquire a 3D scene with low-cost scanners and use this acquisition to create the tool path for roughing a workpiece, using an industrial robot for this machining task. For the acquisition, the Skanect software was used, which had satisfactory results for the work, and the exported file of the acquisition was worked on the MeshLab and Meshmixer software, which were used to obtain only the interest part for the milling process. With the defined work object, it was applied in Computer Aided Manufacturing (CAM) software, Fusion 360, to generate the tool path for thinning in G-code, which was converted by the RoboDK software to robot code, and this also allowed to make simulation of the machining with the desired robot. With the simulation taking place as expected, it was implemented in practice, performing the 3D acquisition machining, thus being able to verify the machining technique used. Furthermore, with the results of acquire, generation of toolpath and machining, was possible to validate the proposed solution and reach a conclusion of possible improvements for this project.<br>Com a evolução das técnicas de aquisição de imagem 3D tornou-se possível aplicá-las em cada vez mais áreas, bem como serem utilizadas por pesquisadores e amadores devido ao surgimento de scanners 3D de baixo custo. Entre as aplicações de aquisições 3D está a reconstrução de objetos, o que permite, por exemplo, refazer ou remodelar um objeto existente que não está mais no mercado. Outra tecnologia em ascensão é o robô industrial, que está muito presente na indústria e pode realizar diversas tarefas, até mesmo atividades de fabrico, e ser aplicado em mais de um tipo de operação. O objetivo deste trabalho é adquirir uma cena 3D com scanners de baixo custo e utilizar esta aquisição para criar o caminho da ferramenta para o desbaste de uma peça, utilizando um robô industrial nesta tarefa de usinagem. Para a aquisição foi utilizado o software Skanect, que obteve resultados satisfatórios para o trabalho, e o arquivo exportado da aquisição foi trabalhado nos softwares MeshLab e Meshmixer, os quais foram utilizados para obter apenas a parte de interesse para o processo de fresagem. Com o objeto de trabalho defino, este foi aplicado em software CAM, Fusion 360, para gerar o caminho de ferramentas para o desbaste em G-code, o qual foi convertido pelo Software RoboDK para código de rôbo, e este também permitiu fazer simulação da maquinação com o rôbo pretendido. Com a simulação ocorrendo de acordo com o esperado, esta foi implementada em prática, realizando a maquinação da aquisição 3D, assim podendo verificar a técnica de maquinação utilizada. Além disso com os resultados de aquisição, geração de toolpath e maquinação, foi possível validar a solução proposta e chegar a uma conclusão de possíveis melhorias para este projeto.