Innovative Electromagnetic Catheter Tracking using Magnetoresitive sensors and Field-Free-Point method

A two-dimensional ElectroMagnetic Tracking (EMT) method for catheter localization aiming at reducing X-ray exposure is presented. The approach combines magnetic Field-Free-Point (FFP) generation with giant magnetoresistance (GMR) sensors integrated at the catheter tip to measure its position. Several FFP trajectories are designed and assessed: Cartesian, Lissajous, Spiral, and a tailored Archimedean spiral (Aspiral). Numerical simulations and a dedicated experimental platform are used to compare FFP trajectory performance and system feasibility. Evaluation relies on Voronoi-based analysis, spatial accuracy maps, and catheter-tracking tests. Two orthogonal pairs of Helmholtz coils produce a time-varying magnetic field whose FFP moves along continuous trajectories. The catheter position is determined by detecting the instants when both directional sensors simultaneously output zero signals. Simulations and experiments show strong agreement in spatial accuracy and reproducibility. With 10 positions acquired every second, the Aspiral trajectory provided the best trade-off between coverage and precision, yielding median tracking errors of 1.6 mm in simulation and 4.6 mm experimentally. The complete EMT setup was validated in 2D, demonstrating spatial and temporal performance close to clinical needs and establishing a reproducible framework for optimizing FFP trajectories and coil design. System has many potential improvements, including faster electronics.