Averaging position algorithm of an independent rotating coils based electromagnetic tracking system

When it comes to the navigation tool for minimally invasive surgery, electromagnetic tracking has prominent advantages and features over the traditional endoscope and X-ray imaging. The electromagnetic tracking system using two DC pulsed independent rotating coils to generate two changing magnetic fields alternately can track the position and orientation of the magnetic sensor based on an non-iterative algorithm. However, owing to the restrain of the step size and the distortion of the magnetic field, the coils cannot be pointing at the sensor accurately in the real system. Thus the problem of low resolution area is raised. In this paper, an optimized position algorithm, averaging position algorithm, is proposed to solve the problem of the non-coplanar two coils and the low resolution area. The simulation results demonstrate that the overall static position tracking accuracy was improved by 97.1%, from 11.722 cm to 0.336 cm, when the pointing angle inaccuracy is 0.346°. Further real system research based on the optimized position algorithm should be conducted to offer better navigation performance for the minimally invasive surgery.