Finite element modelling and image reconstruction for Lorentz force electrical impedance tomography

摘要

Objective: We propose a numerical framework to simulate the Lorentz force electrical impedance tomography (LFEIT) measurements on accurate electrode models and an image reconstruction scheme for which data on two pairs of electrodes are sufficient. Approach: The adopted finite element-based complete electrode model encompasses the electrode's geometry and contact impedance, accounting for the power losses at the contact interface. For image reconstruction, we suggest an approach based on a modified J-substitution algorithm that requires LFEIT and impedance measurements on two pairs of sensors, essentially necessitating no more than three boundary electrodes. Main results: The results of our simulation study suggest that electrode modelling has a significant impact on the measurements and electrode model inaccuracies may be detrimental to the image reconstruction. For image reconstruction, we suggest an approach based on a modified J-substitution algorithm that requires LFEIT and impedance measurements on two pairs of sensors, essentially necessitating no more than three boundary electrodes. Significance: This allows for shorter acquisition times, less sonication noise during the acoustic modulation, a simpler measurement setup, and eventually a more succinct and efficient image reconstruction process.