Image Reconstruction in Open-EIT by Combining Inversion Mapping and Sparse Contour Representation

This article presents an image reconstruction method for open electrical impedance tomography (OEIT) combined with inversion mapping and contour representation to address the profile and medium distribution measurement requirements of adhesion cavitation. Electrodes are arranged on the surface of an axisymmetric blunt body to form the Open-EIT sensor. To guarantee the accuracy of forward modeling in image reconstruction, the infinite domain outside the sensor is transformed into a disk by an equivalent dedicated inversion mapping. Then, the cavity contour is obtained using a customized B-spline-based sparse reconstruction method. Finally, the medium distribution to be reconstructed is confined within the contour to improve the imaging speed and resolution, which is then mapped back to the original infinity domain. Theoretical analysis and simulation demonstrate that the forward model maintains physical consistency after the inversion mapping, and the detection sensitivity is nearly ten times higher than that before the mapping. Simulations and experiments were conducted to verify the effectiveness of the proposed method, where the contour and its inside distribution can be better reconstructed in each specified case compared to other typical methods. The aforementioned method establishes a viable and effective approach for monitoring the cavitation occurrence on the surface of underwater vehicles.