International Society for Industrial Process Tomography

Feature Estimation in Electrical Impedance Tomography using Boundary Element Method and Exact Derivatives

S. Vergara^1*, D. Sbarbaro¹, M. Vauhkonen²

¹ Universidad de Concepción, Departamento de Ingeniería Eléctrica (Edmundo Larenas 219, Concepción, Región del Bio-bio, Chile)

² University of Eastern Finland, Department of Applied Physics, POB 1627, FI-70211, Kuopio, Finland)

^*Email: svergara@udec.cl

ABSTRACT

This work describes a parametric method based on boundary element model for feature estimation using EIT measurements. The method achieves a considerable reduction in the problem dimension and calculation Arial. The features are estimated by using the exact Jacobian obtained from boundary elements integrals. Simulation and experimental examples illustrate the method accuracy in the estimation of the position and conductivity of a known circular shape object.A sensitivity analysis of the solution, with respect to the use of wrong known inclusion size, conductivity and medium conductivity, shows the importance of using accurate prior information. For instance, setting a wrong ratio between the medium and the inclusion conductivities, leads to estimates having the opposite locations compared to the real ones. Larger average absolute errors were obtained in the experimental case; however, these were less than 1.3% of the tank radius and with a standard deviation less than 1.5%. The maximum number of iterations to find the optimal solution in the experimental case was four with average value less than three iterations.

Keywords Boundary elements, feature estimation, electrical impedance tomography.

Industrial Application General