Recycling Krylov subspaces for efficient large-scale electrical impedance tomography

Autor(es)

Motta Mello, Luis Augusto ^[1] ; de Sturler, Eric ^[2] ; Paulino, Glaucio H. ^[3] ; Nelli Silva, Emilio Carlos ^[1]

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

• 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