| description 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. | |
