AI-Optimized Inductive Coupling Coil Design for Safe Wireless Power Transfer in Implantable Medical Devices: An Interdisciplinary Engineering–Healthcare Approach

Implantable Medical Devices (IMDs) are constrained by finite battery life, making periodic replacement surgeries a recurring clinical and economic burden. Near-field Wireless Power Transfer (WPT) provides a practical pathway to reduce these interventions by enabling transcutaneous, non-contact energy delivery; however, implant packaging constraints and tissue-related losses impose a coil-geometry-dependent efficiency trade-off. This study compares circular and square planar inductive coils for IMD power links operating at 13.56 MHz using MATLAB-based analytical modeling for self- and mutual-inductance estimation and Simulink simulations of a Series–Series resonant topology. Under equal transmitter/receiver footprint constraints, performance was evaluated using Power Transfer Efficiency (PTE) across clinically relevant separation distances. Simulation results indicate that square coils achieve higher inductance and coupling, delivering improved PTE at short-to-moderate implant depths (<20 mm) and better utilization of rectangular IMD housings. In contrast, circular coils exhibit smoother field distribution and greater robustness to misalignment, resulting in more stable performance under positional variability. The findings provide a practical basis for selecting coil geometries according to implant depth and enclosure form factor, and demonstrate an accessible workflow for early-stage IMD power-link assessment using analytical and circuit-level tools prior to full-wave electromagnetic modeling or experimental validation.