A novel method and system for stereotactic surgical procedures

A novel three-dimension (3-D) augmented reality system using autostereoscopic images was developed for surgical navigation. The 3D images are created by computer reconstruction and the polarized stereo projection system, which provides geometrically accurate 3-D spatial images and reproduces motion parallax with polarized eyeglasses. The spatially projected 3-D images are superimposed onto the surgical area and viewed via two semitransparent mirrors. A set of accurate spatial image registration methods based on the coordinate transformation relationship of the world coordinate system, the CT image coordinate system, the view plane coordinate system of VtkCamera and the image plane coordinate system of projectors were developed for registration of 3D virtual images and corresponding lesion areas. Preliminary phantom experiments showed that the average errors of 4 selected reference points are 1.6548mm, 1.8956mm, 2.5630mm, 2.3560mm (observer' heigh 1650mm) and 1.8648mm, 3.1614mm, 2.3904mm, 2.6416mm (observer' height: 1750mm) which meet the clinical requirement. Trapezium distortion of the projectors is 0.6 pixel distance. The differences of observers' height, interpupillary distance and motion have little effect on the accuracy of registration. Part of the human eye may have automatic focusing function thus increasing the actual registration accuracy.