A calibration method of position and orientation errors for an endoscopic tracking system

摘要

Methods of position tracking based on magnetic field monitoring have been widely studied. The application of electromagnetic tracking (EMT) in endoscopic procedures not only has high requirements for position accuracy but also has a great demand for orientation accuracy. Accurate orientation information can provide more clues for shape fitting of the endoscope, especially when coils are placed at the front end of the endoscope for front end shape reconstruction. However, few methods have been proposed to calibrate position and orientation errors at the same time, while most methods are focused on position error correction. This paper presents a new method showing that by separating the tracking space into grids and calibrating the grid-sensing coil position and orientation parameters (GSCPOP), the position and orientation accuracy can be improved simultaneously by means of iterative computation. Compared to the uncalibrated method, position accuracy showed a 285% improvement, and orientation accuracy showed a 129% improvement.