Analysis of Current Patterns to Determine the Bladder Volume by Electrical Impedance Tomography (EIT)

Abstract

A non-invasive method based on Electrical Impedance Tomography (EIT) is represented here to determine the bladder volume which indicates the volume of urine. Two different current patterns using with EIT i.e. opposite pattern and adjacent pattern (which is more popular) were investigated by simulation on six 3D-realistic models including bone, rectum, and bladder. Sixteen electrodes were attached by two-plane configuration. Five geometries of the bladder having different volumes were used to determine the boundary voltage response to the conductivity change. A case of the bladder volumes was used to determine the performance of image reconstruction of these patterns. The simulation result shows a strong correlation between the voltage responses and the volume changes, in inverse manner. Using the opposite pattern conducted larger amplitude voltage response than using the adjacent pattern, and resulted in higher sensitivity in the upper mid-region between the electrode planes. The reconstruction image of both patterns can clearly locate the bladder. The reconstructed bladder in the case of using the opposite pattern is larger in amplitude than using the adjacent pattern. However, the image of the opposite pattern has more artifacts at the boundary. This is probably due to the incomparable number of current patterns and measurements of each pattern, and the insufficiency of the current flow patterns of the opposite pattern designed in this study. The higher sensitivity to noise and error of the opposite pattern is probably another cause as well. © 2020 ACM.