Attitude tracking using an integrated inertial and optical navigation system for hand-held surgical instruments

Navigation devices are essential components for Image Guided Surgeries(IGS). The optical navigation system has been widely used to guide surgical tools in image-based navigation surgery due to its easy usage and high accuracy. However, optical tracking becomes frequently blind when its line-of-sight between the cameras and the optical markers is occluded. In this paper, a sensor fusion system with inertial navigation and optical navigation systems is proposed to estimate the attitude of surgical tools with markers in spite of optical occlusion situations. Specially, sensor fusion algorithms based on Extended Kalman Filter and sensor calibration algorithms are proposed. To resolve an axis alignment problem between optical tracker and IMU sensor, a coordinate axis calibration method are presented. A series of experimental results shows its effectiveness under optical occlusion.