Design and validation of a multi-angle planar surface electrode system for electrical impedance tomography

Electrical impedance-based imaging techniques offer a noninvasive and radiation-free alternative for assessing internal tissue structures. In this study, a novel bioimpedance measurement (BIM) system featuring a planar concentric ring electrode configuration was proposed to improve the spatial resolution and practicality of traditional electrical impedance tomography (EIT) approaches. Inspired by the 360° scanning principle of computed tomography (CT), the system enables multiangle current injection and voltage measurement through a structured stimulation protocol. A total of 32 electrodes, arranged in four concentric rings, were used to capture impedance variations across different angular perspectives, enhancing the detection of localized anomalies. The system was validated through both simulation and experimental studies. Simulations conducted using the EIDORS environment demonstrated successful localization of inhomogeneities within a modeled medium, whereas experimental tests using a saline-filled tank and embedded objects confirmed the system's practical effectiveness. Data acquired from the system were reconstructed into impedance images via the Gauss-Newton algorithm with total variation regularization, followed by image processing steps for improved visualization and boundary identification. The proposed system combines a cost-effective hardware design with a robust measurement and image reconstruction framework, offering a portable and accurate solution for biomedical diagnostics and laboratory research. The results highlight its potential for clinical and nonclinical applications requiring noninvasive monitoring.