3-D Intraoperative Shape Mapping of Flexible Ferromagnetic Guidewires Using a Hybrid Magnetic-Fluoroscopic Approach

During vascular interventional surgery, challenges such as unclear device morphology and difficulty in identifying distal orientation are frequently encountered. To address these issues, this study proposes a novel method for 3-D shape estimation of interventional devices. The approach utilizes a flexible ferromagnetic-tipped guidewire, which exhibits mechanical properties similar to conventional guidewires, to estimate its shape by correlating the magnetic field distribution with the guidewire’s geometry. Due to the nonlinear relationship between the magnetic field and the guidewire shape, image and physical constraints were applied to refine the estimation. Experimental results demonstrated high accuracy and stability, with root-mean-square error (RMSE) and Hausdorff distance both below 1 mm, surpassing existing methods. Notably, this technique requires no built-in sensors or additional wiring, and the fluoroscopic images used are standard in clinical practice, ensuring minimal interference with clinical procedures. This makes the method highly suitable for vascular interventional navigation.