Magnetic Localization for Tracking Cardiac Catheters in Time-Critical Surgical Operations

Accurate intraoperative localization of heart catheters is crucial for the success of time-critical cardiac procedures. Traditional imaging techniques, such as fluoroscopy and conventional coronary angiography, expose patients and clinicians to ionizing radiation and require contrast agents, increasing procedural complexity and risk. To circumvent some of these challenges, there is growing interest in utilizing magnetic sensor arrays to track catheters equipped with miniature magnets. However, existing approaches face critical challenges including high computational complexity, susceptibility to external magnetic noise, restricted tracking range, poor localization performance outside the physical boundary of the array. This study presents a new magnetic localization system using a hall-effect sensor array. It employs a hybrid localization strategy; integrating Weighted Centroid-Based Localization for precise tracking within the physical boundary of the sensor array and a two-dimensional Gaussian Function for accurate extrapolation outside the sensor array. A dynamic switching mechanism between two localization methods ensures accurate magnet localization across the entire operational space. Experimental validation was performed at a data acquisition and processing rate of 1 Hz. Experiments with a robotic arm moving a permanent magnet along a predefined 2D-trajectory demonstrate accurate localization within (<2 mm) and outside(<5 mm) the sensor array up to 80 mm elevations. These findings suggest that the detection range of magnetic sensor arrays can be extended without increasing the number of sensors. Future work will focus on reducing localization error below 1 mm, extending localization to three dimensions and integrating adaptive noise filtering techniques to make the system more robust in operation rooms with background noise.