Abstract: Physics and mathematics model for three-dimensional bladder filling estimation are constructed for electrical impedance tomography.Verification was carried out with combined Tikhonov regularization algorithm.Reconstruction results with high spatial resolution,high stability and enhanced anti-noise performance were obtained.With Laplacian analysis of calculation results,boundary was extracted and processed.As a result,integration boundary surface fragments were extracted from high noise background in morphological characteristics of the object.Ultimately,three-dimensional image reconstruction was achieved.Compared with two-dimensional imaging,it provided spatial position,height and spatial contrast for qualitative analysis.

Key words: combined regularization, Laplacian function, boundary extraction, 3D electrical impedance tomography, bladder filling estimation