Marcelo Rudek

CT slice retrieval by shape ellipses descriptors for skull repairing

This paper addresses the problem of automated prosthesis modelling and manufacturing, whose machining parameters are based on images extracted from different medical databases. The specific case of 3D surface restoration of a defective skull was used as study case. A method based on adjusted ellipses on skull bone curvature performs the symbolic representation of searching parameters. The superellipse concept permits to define geometric parameters to fit an ellipse on each Computed Tomography slice. Those ellipse descriptors can be used as a template for the retrieval of similar images from databases whose parameters match the sampled image. The similarity is measured according to the best fitness values through an optimization algorithm. The slices found by similarity are retrieved from all databases in order to build the 3D model. Experiments show that the proposed method is a promising technique for content based image retrieval.

A Prosthesis Design Based on Genetic Algorithms in the Concurrent Engineering Context

Concurrent engineering is an important philosophy in achieving better time to market in new product development. While the use of design teams is achieving some success there is a need for modern software tools which support the design process to be radically improved. In this context, the research explores the use of three-dimensional images reconstructed from computed tomography that provides support for prosthesis modeling in CAD (Computer-Aided Design) system. This article presents a method for using a genetic algorithm (GA) that improves the virtual modeling applied to prosthesis conception. In the context, the GA was used to fit an ellipse in order to fill completely a defect in a skull. The bone piece that was missed in skull could be virtually created using the arcs extracted from the adjusted ellipses for each tomographic slice and it can generates profiles from the cloud of points in order to build a 3D geometric model using a CAD system. A synthetic image of the missing bone piece was built using the GA to fill its defect in the skull.

A Reasoning System to Support the Dental Implant Planning Process

The technological evolution over the last decades brought the necessity of integration among different areas of knowledge and an example is the integration between the Odontology and Engineering in order to find new solutions to improve the surgical process of dental implants. This work proposes a reasoning system to support the implant planning process based on tomographic images which offers support to the dentist. The system creates a three dimensional model of the dental arch and interact with the dentist supporting him in the selection of the most appropriate implant. So, the reasoning proceedings is divided into stages, the first is for selecting the region of interest inside the bone and the second is for defining the implant which should be used. This system is a planning tool to assist the dentist during the pre-operative, it will help him in the decision making. The article’s main contributions are: i) conception and development of a computational reasoning tool that supports the process of dental implantation; ii) the interactivity in the development of surgical planning through a three-dimensional geometric model of the dental arch; iii) the reduction of surgical time.

Geometric modeling from the medical images in the CAD system to support prosthesis design

This paper presents an individual designing prosthesis for surgical use and proposes a methodology for such design through mathematical extrapolation of data from digital images obtained via tomography of individual patients bones. Individually tailored prosthesis designed to fit particular patient requirements as accurately as possible should result in more successful reconstruction, enable better planning before surgery and consequently fewer complications during surgery. Fast and accurate design and manufacture of personalized prosthesis for surgical use in bone replacement or reconstruction is potentially feasible through the application and integration of several different existing technologies, which are each at different stages of maturity. Initial case study experiments have been undertakeSn to validate the research concepts by making dimensional comparisons between a bone and a virtual model produced using the proposed methodology and a future research directions are discussed.

Development of White Goods Parts in a Concurrent Engineering Environment Based on DFM/DFA Concepts

The classical way to manage the product development processes for massive production has been changing as the high pressure for cost reduction, higher quality standards and market seeking for innovation lead to the necessity of new tools for development control. This context and the learning from the automotive, aerospace industries and others segments were the starting point to understand and apply manufacturing and assembly oriented designs to ease the task of generate goods and from this to obtain at least part of the expected results. This paper demonstrates the applicability of the concepts of Concurrent Engineering and DFM/DFA (design for manufacturing and assembly) in the development of products and parts for the White Goods industry in Brazil (major appliances as refrigerators, cookers and washing machines), showing one case concerning to the development and releasing of a component. Finally, it shows, shortly, how using these techniques as a solution had provided cost savings and reduction in delivery time.

Fuzzy-Memetic Approach for Prediction of Chaotic Time Series and Nonlinear Identification

This paper presents the configuration of a fuzzy system of Takagi-Sugeno-Kang type based on optimization through a memetic algorithm. The memetic algorithm is composed by a fast evolutionary programming combined with simulated annealing algorithm. The fuzzy-memetic system is evaluated for two case studies: (i) prediction of chaotic system with maps involving non-differentiable functions called Lozi map, and (ii) identification of a system composed of a nonlinear continuous stirred tank reactor. Simulations deal the estimation and validation procedures of dynamic model based on fuzzy-memetic system. The performance of the fuzzy-memetic system for case studies in time series prediction and nonlinear identification are presented and discussed.

Conceptual Reasoning Model for Supporting Strategic Planning of Dental Implant Surgical Process

The technological evolution over the last decades brought the necessity of integration between different areas of knowledge; an example of this is the integration between the Odontology and Engineering in order to find new solutions to improve the surgical process of dental implants. This work proposes a conceptual reasoning model for supporting strategic planning of dental implant which offers support to the dentist through a three-dimensional geometric modeling of the dental arch (bone, nerves, existing teeth) allowing the realization in advance of the strategic planning of the surgical process. In this geometric modeling the reasoning system interacts with the dentist presenting the bones density, nerve location, among others features, becoming, in this way, a tool that will assist the dentist in the decision-making process. The proposed model creates an auxiliary mask that will work as a guide for locating and positioning the implants making the procedure quicker and less painful. The article’s main contributions are: i) conception and development of a computational reasoning tool that supports the process of dental implantation; ii) the interactivity in the development of surgical planning through a three-dimensional geometric model of the dental arch; iii) the reduction of surgical time and the patient’s recovery time.

A Geometric Modelling in the CAD System from the Medical Images to Support Prosthesis Design

This paper discusses the feasibility of individually designing human prosthesis for surgical use and proposes a methodology for such design through mathematical extrapolation of data from digital images obtained via tomography of individual patient’s bones. Individually tailored prosthesis designed to fit particular patient requirements as accurately as possible should result in more successful reconstruction, enable better planning before surgery and consequently fewer complications during surgery. Fast and accurate design and manufacture of personalized prosthesis for surgical use in bone replacement or reconstruction is potentially feasible through the application and integration of several different existing technologies, which are each at different stages of maturity. Initial case study experiments have been undertaken to validate the research concepts by making dimensional comparisons between a bone and a virtual model produced using the proposed methodology. Future research directions are discussed in the final section of this paper.

Proposal for an image-based software system for dental implant positioning

The technological development in healthcare experienced in actual days has relationship with the integration of many knowledge areas, fundamentally by searching new solutions in order to improve the quality of life of the society. Examples of this reality appears in medicine and engineering areas, where the computer-assisted techniques works together to solve many healthcare problems. In the surgical procedures context as well, as in dental implant planning, the surgeon still determine some parameters according to his personal experience, where only the visualization of the problems through Computed Tomography images are not enough to ensure the success of the procedure. Thus, this research aims to propose a computational model, as a decision support tool, in order to define a more appropriate positioning for dental implants. This is a fundamental part to determination of the necessary parameters for the process planning because the information is obtained automatically straight from image processing. The prototype presented in this work comprises a user-friendly interface, which allows dentists to observe the bone and dental structure in multi-perspective images. Also, it determines the implant location by an automatic procedure without intervention of dentist. The text shows a study case with the autonomous determination of an implant position.

Proposal for a Specialist System for Dental Implant Based on Images

The technological development experienced in recent ages is due the integration of many areas of knowledge, by the search for new solutions in order to improve the life of society. Example of these facts are the areas of health and engineering, where several computer-assisted techniques are being used to not only translate and simulate human reality, but also assist in surgical procedures. However, in dental implant planning, the surgeon still determine some parameters according to your experience, based on Computed Tomography images visualization and clinical studies, which are not enough to ensure the success of the implant procedure. Thus, this research aims to create a computational tool, that supports the decision in order to define the positioning more appropriate for a unit dental implant and also assist in the determination of the all necessary parameters of the implant planning process, based on image processing techniques. The specialist system implemented and presented in this work comprises a simple interface, which also allows the user to visualize the bone and dental structure of patients in much perspective, execute the models that determine the implant location in an automatic way and few depending on the interaction with dentist. The results were tested and validated by a study case of partial implant.