Conference Paper

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

DOI: 10.1007/978-3-540-79982-5_39 Conference: 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: Organ segmentation and motion simulation of organs can be useful for many clinical purposes such as organ study, diagnostic aid, therapy planning or even tumor destruction. In this paper we present a full workflow starting from a CT-Scan resulting in kidney motion simulation and tumor tracking. Our method is divided into three major steps: kidney segmentation, surface reconstruction and animation. The segmentation is based on a semi-automatic region-growing approach that is refined to improve its results. The reconstruction is performed using the Poisson surface reconstruction and gives a manifold three-dimensional (3D) model of the kidney. Finally, the animation is accomplished using an automatic mesh morphing among the models previously obtained. Thus, the results are purely geometric because they are 3D animated models. Moreover, our method requires only a basic user interaction and is fast enough to be used in a medical environment, which satisfies our constraints. Finally, this method can be easily adapted to magnetic resonance imaging acquisition because only the segmentation part would require minor modifications.
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    ABSTRACT: Motion simulation of an organ can be useful in some cases like organ study, surgery aid or tumor destruction. When using a non-invasive way of tumor destruction through transcutaneous transmition of waves, it is primordial to keep the wave beam focused on the tumor. When the tumor is not in movement, such a task is trivial. But when the tumor is located in a moving organ like the kidney, motion simulation is necessary. We present here an original method to obtain the kidney motion simulation: this is done using a mesh morphing (we consider the kidney has already been segmented and reconstructed for three different phases of the respiratory cycle). Such an approach allows a smooth transition between the different kidney models, resulting in a motion simulation. Thus, the method is purely geometric and does not need any kind of markers or tracking device. It gives directly a full 3D simulation and models are animated in real time. Finally, our approach is automatic and fast, so that it can easily be used in a medical environment.

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