A Multidomain Virtual Framework for Sacral Neuromodulation: Integration of CT-Based Anatomical Modeling, Electrode Placement Optimization, and Closed-Loop Device Simulation

Abstract

Sacral neuromodulation (SNM) has emerged as an effective third-line therapy for overactive bladder (OAB), fecal incontinence (FI), neurogenic lower urinary tract dysfunction (NLUTD), and nonobstructive urinary retention. However, challenges remain in lead placement accuracy, stimulation efficiency, and device longevity. In this work, we present a comprehensive virtual framework that integrates medical imaging, 3D anatomical modeling, Multiphysics simulation, and system-level instrumentation to optimize SNM therapy. A pelvic CT scan was segmented using 3D Slicer to reconstruct patient-specific anatomy of the sacral plexus and bladder. The reconstructed model was imported into Fusion 360, where realistic 3D geometries were developed and five distinct electrode placements were virtually designed. COMSOL Multiphysics was employed to analyze electric field distribution, current density, and activation zones, enabling objective quantification of placement efficacy. Additionally, a complete instrumentation framework was simulated, including wireless power transfer, microcontroller-based stimulation control, rectification, and closed-loop feedback from bladder sensors. Results indicated that electrode placements within 3 mm of the sacral plexus and an insertion angle of 35–40° achieved superior response scores and minimized revision risk. The integration of anatomical modeling with device-level circuit simulation highlights a pathway toward patient-specific, adaptive, and energy-efficient neuromodulation. This multi-domain approach enhances the translational potential of SNM, offering insights into both clinical efficacy and engineering feasibility.