Image Reconstruction for ECT Based on Extended Sensitivity Matrix

Image reconstruction for electrical capacitance tomography (ECT) is usually based on a sensitivity matrix. To reduce the effect of soft-filed property of ECT and enhance the quality of reconstructed images, a new image reconstruction method for ECT based on an extended sensitivity matrix is proposed. The elements used in constructing the sensitivity matrix are a set of block bases instead of each individual pixel. Using the new block basis approach, an iterative algorithm for image reconstruction in ECT is implemented with a 12-electrode square ECT sensor. The performance of the new approach is evaluated according to the simulation and experimental results. Preliminary results show that the image reconstruction based on an extended sensitivity matrix with a suitably designed block basis can improve the image quality and stability compared with the Landweber iteration algorithm based on the conventional one-pixel basis.