Two-stage cylindrical magnetic localization with neural network calibration for wearable capsule endoscopy
摘要
Accurate localization of wireless capsule endoscopy is essential for reliable gastrointestinal diagnosis, yet magnetic tracking systems are often degraded by sensor distortions, misalignment, and patient motion in wearable settings. This study presents a magnetic localization framework that combines cylindrical magnetic field modelling with neural network–based sensor calibration to improve robustness under wearable operating conditions. By exploiting the structural properties of cylindrical magnetic field representations, the proposed approach decouples axial and transverse components of the magnetic field, enabling staged estimation of magnetic capsule position and orientation with improved numerical stability. A data-driven calibration model is employed to compensate for nonlinear sensor distortions arising from hard-iron effects, soft-iron effects, and dynamic misalignment. Experimental validation using a four-sensor wearable array demonstrates a mean static localization error of 0.12 cm and