Optimization of the Multi-Channel Surface Electrogram Acquisition for Noninvasive Uterine Electrophysiology Imaging

The goal of optimizing electrogram acquisition in electrophysiology imaging is to minimize the number of electrodes used, determine their optimal placement, and ensure accurate imaging.

We quantitatively evaluated the impact of the electrode number and placement on the accuracy of human uterine peristalsis imaging (UPI) using adapted minimum nonzero eigenvalue pursuit (MNEP), adapted maximal projection on minimum eigenspace (MPME), and a distance-based baseline method. Specifically, we assessed the accuracy of the uterine surface electrogram imaged by UPI while maintaining the original 128-electrode UPI placement as a constraint. Subsequently, we expanded our analysis to the entire body surface of the subjects, removing the constraint of the initial UPI electrode placement to explore a generalized optimized electrode placement strategy.

The MPME method demonstrated superior performance compared to other approaches under both constrained and unconstrained optimization. For UPI, the optimal electrode configuration should prioritize a dense concentration of electrodes on the lower abdomen, close to the uterus, where the most informative bioelectrical signals are captured. At the same time, it is important to maintain a distribution of electrodes along the edges of the upper abdominal, lateral sides, and posterior regions. This spatial distribution preserves the geometric contour of the torso and supports comprehensive, multi-angle observation of uterine electrical activity. By combining signal fidelity with spatial coverage, this balanced placement strategy enhances the UPI accuracy.

The adapted MPME method guided a novel electrode placement strategy for electrophysiological imaging, achieving substantial improvements in imaging accuracy while reducing system complexity and cost.