Conference Paper

Realtime Organ Tracking for Endoscopic Augmented Reality Visualization Using Miniature Wireless Magnetic Tracker.

DOI: 10.1007/978-3-540-79982-5_39 In proceeding of: Medical Imaging and Augmented Reality, 4th International Workshop, MIAR 2008, Tokyo, Japan, August 1-2, 2008, Proceedings
Source: DBLP

ABSTRACT Organ motion is one of the problems on augmented reality (AR) visualization for endoscopic surgical navigation system. However,
the conventional optical and magnetic trackers are not suitable for tracking of internal organ motion. Recently, a wireless
magnetic tracker, which is called the Calypso 4-D localization system has been developed. Since the sensor of the Calypso
system is miniature and implantable, position of the internal organ can be measured directly. This paper describes AR system
using the Calypso system and preliminary experiments to evaluate the AR system. We evaluated distortion error caused by the
surgical instruments and misalignment error of superimposition. Results of the experiments shows potential feasibility and
usefulness of AR visualization of moving organ using the Calypso system.

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    ABSTRACT: Augmented reality (AR), a useful visualization technique, is reviewed based literatures. The AR research methods and applications are surveyed since AR was first developed over forty years ago. Recent and future AR researches are proposed which could help researchers of decide which topics should be developed when they are beginning their own researches in the field.
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    ABSTRACT: We present an image-guided intervention system based on tracked 3D elasticity imaging (EI) to provide a novel interventional modality for registration with pre-operative CT. The system can be integrated in both laparoscopic and robotic partial nephrectomies scenarios, where this new use of EI makes exact intra-operative execution of pre-operative planning possible. Quick acquisition and registration of 3D-B-Mode and 3D-EI volume data allows intra-operative registration with CT and thus with pre-defined target and critical regions (e.g. tumors and vasculature). Their real-time location information is then overlaid onto a tracked endoscopic video stream to help the surgeon avoid vessel damage and still completely resect tumors including safety boundaries. The presented system promises to increase the success rate for partial nephrectomies and potentially for a wide range of other laparoscopic and robotic soft tissue interventions. This is enabled by the three components of robust real-time elastography, fast 3D-EI/CT registration, and intra-operative tracking. With high quality, robust strain imaging (through a combination of parallelized 2D-EI, optimal frame pair selection, and optimized palpation motions), kidney tumors that were previously unregistrable or sometimes even considered isoechoic with conventional B-mode ultrasound can now be imaged reliably in interventional settings. Furthermore, this allows the transformation of planning CT data of kidney ROIs to the intra-operative setting with a markerless mutual-information-based registration, using EM sensors for intraoperative motion tracking. Overall, we present a complete procedure and its development, including new phantom models - both ex vivo and synthetic - to validate image-guided technology and training, tracked elasticity imaging, real-time EI frame selection, registration of CT with EI, and finally a real-time, distributed software architecture. Together, the system allows the surgeon to concentrate on intervention completion with less time pressure.
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