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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Recycling Krylov subspaces for efficient large-scale electrical impedance tomography

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Autor(es):
Motta Mello, Luis Augusto [1] ; de Sturler, Eric [2] ; Paulino, Glaucio H. [3] ; Nelli Silva, Emilio Carlos [1]
Número total de Autores: 4
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Dept Mechatron & Mech Syst Engn, Sch Engn, BR-05508 Sao Paulo - Brazil
[2] Virginia Tech, Dept Math, Blacksburg, VA 24061 - USA
[3] Univ Illinois, Dept Civil & Environm Engn, Newmark Lab, Urbana, IL 61801 - USA
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING; v. 199, n. 49-52, p. 3101-3110, 2010.
Citações Web of Science: 11
Resumo

Electrical impedance tomography (EIT) captures images of internal features of a body. Electrodes are attached to the boundary of the body, low intensity alternating currents are applied, and the resulting electric potentials are measured. Then, based on the measurements, an estimation algorithm obtains the three-dimensional internal admittivity distribution that corresponds to the image. One of the main goals of medical EIT is to achieve high resolution and an accurate result at low computational cost. However, when the finite element method (FEM) is employed and the corresponding mesh is refined to increase resolution and accuracy, the computational cost increases substantially, especially in the estimation of absolute admittivity distributions. Therefore, we consider in this work a fast iterative solver for the forward problem, which was previously reported in the context of structural optimization. We propose several improvements to this solver to increase its performance in the EIT context. The solver is based on the recycling of approximate invariant subspaces, and it is applied to reduce the EIT computation time for a constant and high resolution finite element mesh. In addition, we consider a powerful preconditioner and provide a detailed pseudocode for the improved iterative solver. The numerical results show the effectiveness of our approach: the proposed algorithm is faster than the preconditioned conjugate gradient (CG) algorithm. The results also show that even on a standard PC without parallelization, a high mesh resolution (more than 150,000 degrees of freedom) can be used for image estimation at a relatively low computational cost. (C) 2010 Elsevier B.V. All rights reserved. (AU)

Processo FAPESP: 01/05303-4 - Novas estratégias em ventilação artificial: diagnóstico e prevenção do barotrauma/biotrauma através da tomografia de impedância elétrica (TIE)
Beneficiário:Marcelo Britto Passos Amato
Linha de fomento: Auxílio à Pesquisa - Temático
Processo FAPESP: 08/51070-0 - Gláucio Hermogenes Paulino | University of Illinois at Urbana Champaign - Estados Unidos
Beneficiário:Emílio Carlos Nelli Silva
Linha de fomento: Auxílio à Pesquisa - Pesquisador Visitante - Internacional
Processo FAPESP: 05/00270-1 - Estudo da obtenção de imagens de tomografia por impedância elétrica através do método de otimização topológica aliado a métodos probabilísticos
Beneficiário:Luis Augusto Motta Mello
Linha de fomento: Bolsas no Brasil - Doutorado