A Multimagnetic Source Tracking System Based on Light Spectrum Optimizer for Intraoperative Puncture Navigation

Abstract

Abstract. With the increasing detection rate of nodules, the demand for early diagnosis and ablation using puncture techniques is rising. To enhance the precision of puncture procedures, a multimagnetic source tracking system has been developed for tracking the position and orientation of a puncture needle of a puncture robot. In the puncture biopsy or radio frequency ablation of chest and abdominal nodules, the puncture needles utilized are characterized by a relatively small diameter. To address this requirement, a cylindrical magnetic sensor measuring 6.3 mm in length and 0.3 mm in diameter has been designed and implemented. Based on the discrete superposition theory of magnetic fields, a mathematical model characterizing the magnetic vector of multiple magnetic sources and position and orientation of the magnetic sensor is established. To process weak signals across a wide dynamic range, a multistage gain automatic adjustment circuit and dual phase-locked demodulation circuit are developed. Additionally, digital synthesis technology and a stable excitation drive circuit ensure precise alternating magnetic field generation. To address the nonlinear, overdetermined system of equations in electromagnetic tracking model, a self-tuning light spectrum optimizer algorithm is explored. Experiments show a position root-mean-square error (RMSE) of 0.0075 m ± 0.0036 m and an angular RMSE of 1.81 deg ± 0.87 deg, demonstrating high-precision tracking suitable for advanced puncture surgery localization.