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| Author(s): |
Luís Augusto Motta Mello
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Escola Politécnica (EP/BC) |
| Defense date: | 2005-04-07 |
| Examining board members: |
Emilio Carlos Nelli Silva;
Marcelo Britto Passos Amato;
Raúl González Lima
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| Advisor: | Emilio Carlos Nelli Silva |
| Field of knowledge: | Engineering - Biomedical Engineering |
| Indexed in: | Banco de Dados Bibliográficos da USP-DEDALUS |
| Location: | Universidade de São Paulo. Biblioteca Central da Escola Politécnica; EPBC/FD-4005; Universidade de São Paulo. Escola Politécnica. Biblioteca de Engenharia Mecânica, Naval e Oceânica; EPMN/FD-4005 |
| Abstract | |
Na Electrical Impedance Tomography device allows us to obtain impedance values (represented by images) of the interior of a body through electric potential measurements on the electrodes on the contour of the body, when a current density is applied to an electrode following a load (or current) pattern (adjacent, diametrical, etc.). Several load cases, that is, several geometrical configurations in applying current and a reference point can be used to obtain the images. In this work, the author implemented an algorithm to study the applicability of Topology Optimization Method on obtaining Electrical Impedance Tomography images. A three-dimensional model describes physically the body and the current flow inside this body. In the Topology Optimization Method framework, an objective function is defined, which expresses the difference between measured electric potentials on electrodes and computed electric potentials on numerical electrodes, disposed on the contour of finite element discretized body. An electrical impedance initial guess is provided for the algorithm and an iterative process is carried out until the convergence is achieved. There are no restrictions about the domain geometry since the Finite Element Method is used. The electrical impedance of the human epidermis outermost layer can cause discrepancies between measured and calculated potentials, under the same conditions. For this reason, an accurate electrode model was proposed. (AU) | |