Heuristic Estimation of Electromagnetically Tracked Catheter Shape for Image-Guided Vascular Procedures

摘要

In our previous work we presented a novel image-guided surgery (IGS) system, Kit for Navigation by Image Focused Exploration (KNIFE). KNIFE has been demonstrated to be effective in guiding mock clinical procedures with the tip of an electromagnetically tracked catheter overlaid onto a pre-captured bi-plane fiuoroscopic loop. Representation of the catheter in KNIFE differs greatly from what is captured by the fluoroscope, due to distortions and other properties of fiuoroscopic images. When imaged by a fluoroscope, catheters can be visualized due to the inclusion of radiopaque materials (i.e. Bi, Ba, W) in the polymer blend. However, in KNIFE catheter location is determined using a single tracking seed located in the catheter tip that is represented as a single point overlaid on pre-captured fiuoroscopic images. To bridge the gap in catheter representation between KNIFE and traditional methods we constructed a catheter with five tracking seeds positioned along the distal 70 mm of the catheter. We have currently investigated the use of four spline interpolation methods for estimation of true catheter shape and have assesed the error in their estimation of true catheter shape. In this work we present a method for the evaluation of interpolation algorithms with respect to catheter shape determination.