Online Temporal Synchronization of Pose and Endoscopic Video Streams

摘要

Computer assisted navigation systems that combine real-time endoscopy images with pre-operative volumetric data sets aim at improving the physician's understanding of the underlying anatomical structures. To achieve accurate and safe guidance these systems are required to provide a consistent representation of the physical world. This implies that all data streams are synchronized. In our case, we are dealing with synchronization of tracking data and a video stream obtained by a tracked endoscope. Previously, such synchronization was obtained pre-operatively using phantoms. This type of approach assumes a constant latency between the data streams and is less desirable for clinical use due to the required additional hardware. In this work we describe an online temporal synchronization method. The method is based on the observation that in clinical practice the endoscope is not in constant motion. By identifying corresponding stationary points in the video and tracking streams temporal synchronization can be performed online in a manner that is transparent to the user. Initial evaluation of our approach in a laboratory study has shown that it provides comparable estimates to a phantom based approach we had previously proposed.