9 research outputs found

    A PSO Application in Skull Prosthesis Modelling by Superellipse

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    This paper presents a method to create the geometric model of skull defects to be applied in anatomic prosthesis modelling. The approach is to generate an image that represents the missing information in the skull when bone's defect is non-symmetric. We are proposing the use of superellipse concept to recover the parameters that represents the geometric shape of a skull bone curvature in tomography. If the superellipse is properly adjusted in each computed tomography slice, the arcs that represent the piece of missing bone can be modelled in 3D. The problem is that many similar ellipses can be created, and the best solution must be found. This research applies the Particle Swarm Optimization (PSO) algorithm in order to find the best solution for each tomographic slice. Once the solution found for each slice, the whole 3D missing information can be virtually rebuilt as an adjusted prosthesis model image

    A PSO Application in Skull Prosthesis Modelling by Superellipse

    Get PDF
    This paper presents a method to create the geometric model of skull defects to be applied in anatomic prosthesis modelling. The approach is to generate an image that represents the missing information in the skull when bone`s defect is non-symmetric. We are proposing the use of superellipse concept to recover the parameters that represents the geometric shape of a skull bone curvature in tomography. If the superellipse is properly adjusted in each computed tomography slice, the arcs that represent the piece of missing bone can be modelled in 3D. The problem is that many similar ellipses can be created, and the best solution must be found. This research applies the Particle Swarm Optimization (PSO) algorithm in order to find the best solution for each tomographic slice. Once the solution found for each slice, the whole 3D missing information can be virtually rebuilt as an adjusted prosthesis model image

    AUTONOMOUS CT REPLACEMENT METHOD FOR THE SKULL PROSTHESIS MODELLING

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    The geometric modeling of prosthesis is a complex task from medical and engineering viewpoint. A method based on CT replacement is proposed in order to circumvent the related problems with the missing information to modeling. The method is based on digital image processing and swarm intelligence algorithm. In this approach, a missing region on the defective skull is represented by curvature descriptors. The main function of the descriptors is to simplify the skull’s contour geometry; and they are defined from the Cubic Bezier Curves using a meta-heuristic process for parameter’s estimation. The Artificial Bee Colony (ABC) optimization technique is applied in order to evaluate the best solution. The descriptors from a defective CT slice image are the searching parameters in medical image databases, and a similar image, i.e. with similar descriptors, can be retrieval and used to replace the defective slice. Thus, a prosthesis piece is automatically modeled with information extracted from distinct skulls with similar anatomical characteristics

    A DATA-MINING BASED METHOD FOR THE GAIT PATTERN ANALYSIS

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    The paper presents a method developed for the gait classification based on the analysis of the trajectory of the pressure centres (CoP) extracted from the contact points of the feet with the ground during walking. The data acquirement is performed ba means of a walkway with embedded tactile sensors. The proposed method includes capturing procedures, standardization of data, creation of an organized repository (data warehouse), and development of a process mining. A graphical analysis is applied to looking at the footprint signature patterns. The aim is to obtain a visual interpretation of the grouping by situating it into the normal walking patterns or deviations associated with an individual way of walking. The method consists of data classification automation which divides them into healthy and non-healthy subjects in order to assist in rehabilitation treatments for the people with related mobility problems

    A CAD-BASED CONCEPTUAL METHOD FOR SKULL PROSTHESIS MODELLING

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    The geometric modeling of a personalized part of the tissue built according to individual morphology is an essential requirement in anatomic prosthesis. A 3D model to fill the missing areas in the skull bone requires a set of information sometimes unavailable. The unknown information can be estimated through a set of rules referenced to a similar yet known set of parameters of the similar CT image. The proposed method is based on the Cubic Bezier Curves descriptors generated by the de Casteljou algorithm in order to generate a control polygon. This control polygon can be compared to a similar CT slice in an image database. The level of similarity is evaluated by a meta-heuristic fitness function. The research shows that it is possible to reduce the amount of points in the analysis from the original edge to an equivalent Bezier curve defined by a minimum set of descriptors. A study case shows the feasibility of method through the interoperability between the prosthesis descriptors and the CAD environment

    3D positioning and dimensioning method based on digital images

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    Orientador: Paulo Roberto Gardel KurkaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia MecanicaResumo: O trabalho apresenta um método baseado em imagens digitais para a determinação da posição espacial e do volume ocupado por um sólido. O objetivo é conhecer estes parâmetros sem a necessidade da reconstrução tridimensional completa do objeto. A aplicação da técnica proposta é baseada nas projeções da imagem do objeto a ser medido. O processo se baseia na utilização de uma caixa de contorno (bounding box) que pode ser ajustada sobre uma região de interesse na imagem. A posição desta caixa de contorno descreve a orientação espacial do objeto, e as suas dimensões espaciais definem o volume aproximado do sólido. O trabalho propõe um método para ajustar as arestas da caixa de contorno sobre as bordas do objeto, usando como referencial os pontos de fuga que formam os vértices da caixa de contorno. Os vértices formam um conjunto reduzido de pontos e a reconstrução tridimensional destes pontos permite definir um polígono retangular no espaço que representa as informações métricas do objeto real. O contexto do trabalho se situa no campo da visão computacional e processamento de imagens utilizando um conjunto de ferramentas aplicadas à teoria de reconstrução 3D. São apresentados os resultados obtidos da aplicação do método para imagens reais, bem como é descrita uma aplicação do método em um ambiente de manufatura integradaAbstract: This work presents a method based on digital images to determine the spatial position and volume occupied by a solid. The objective is to find these parameters without a complete tri­dimensional reconstruction of the object. The application of this technique is based on the image projections of a solid target. The process is based on a contour bounding box that is adjusted around a region of interest. The box position describes the object spatial orientation and its spatial dimensions can define the approximated volume. The work proposes a method to adjust the contour box lines on the object borders using vanishing points as reference to form each vertex of the bounding box. The vertices form a reduced set of points and the 3D reconstruction of such points can define a rectangular polygon in the space representing the metric information about the real object. The work is within the context of computer vision and image processing by the use of a set of 3D reconstruction tools. Results obtained of the application of this method to real images are presented, as well as an application to an integrated manufacturing processDoutoradoProjeto MecanicoDoutor em Engenharia Mecânic

    A PSO Application in Skull Prosthesis Modelling by Superellipse

    No full text
    This paper presents a method to create the geometric model of skull defects to be applied in anatomic prosthesis modelling. The approach is to generate an image that represents the missing information in the skull when bone's defect is non-symmetric. We are proposing the use of superellipse concept to recover the parameters that represents the geometric shape of a skull bone curvature in tomography. If the superellipse is properly adjusted in each computed tomography slice, the arcs that represent the piece of missing bone can be modelled in 3D. The problem is that many similar ellipses can be created, and the best solution must be found. This research applies the Particle Swarm Optimization (PSO) algorithm in order to find the best solution for each tomographic slice. Once the solution found for each slice, the whole 3D missing information can be virtually rebuilt as an adjusted prosthesis model image

    Proposal for a Preliminary Model of Integrated Product Development Process Oriented by Green Supply Chain Management

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    For sustainable product development, activities related to the selection of raw materials, product design, manufacturing, packaging, and distribution must be considered in a way that respects environmental limits and implements alternatives to reduce the consumption of natural resources. Due to this context, companies have sought to create environmentally sustainable alternatives for products and processes, once exposed to government, market, and regulatory pressures. Given this scenario, the question of this study is presented: Is it possible to define a conceptual model from existing models in the literature that guides companies in their Integrated Product Development Process (IPDP) and is oriented by Green Supply Chain Management (GSCM)? To answer the research problem question, a preliminary model integrating the IPDP and GSCM themes was presented. The elaboration of the preliminary model was only possible from the systematic literature review and content analysis previously carried out and presented in the general data in this article. The general aim of the study is to present a preliminary model in which IPDP is oriented to GSCM. As specific objectives, this study intends to present models previously published that have some relation to the IPDP related to green design, green purchase, green manufacturing, green distribution, and reverse logistics, which are related to GSCM; in addition, it presents guidelines to integrate the stages of product development and GSCM to reduce the environmental impact. The contribution of the preliminary model for companies is to present criteria that reduce the environmental impact of products in different GSCM activities within the IPDP. The contribution of this study is to present an analysis of the existing models, which will be the basis for the development of a conceptual model
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