Realtime Organ Tracking for Endoscopic Augmented Reality Visualization Using Miniature Wireless Magnetic Tracker
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 mag
- PDF / 4,506,966 Bytes
- 8 Pages / 430 x 660 pts Page_size
- 57 Downloads / 218 Views
Division of Image Analysis, Graduate School of Medicine, Osaka University, Japan Department of Urology, Kyoto Prefectural University of Medicine, Kyoto, Japan 3 Cleveland Clinic, Cleveland, OH, USA 4 Graduate School of Medical Sciences, Kyushu University, Japan
2
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.
1
Introduction
Laparoscopic partial nephrectomy is a minimally invasive technique to remove a renal tumor. In order to remove the tumor completely and preserve healthy tissues as much as possible, augmented reality (AR) visualization of the CT image where the resection line is depicted would be useful because the boundary between healthy tissues and the tumor is not clear by endoscopic observation [1]. However, the surgeon holds up the kidney and changes its direction during resection of the tumor to confirm the resection line from several viewpoints. Therefore, realtime tracking of the kidney motion is required to superimpose the CT image onto live endoscopic images accurately. Magnetic trackers are suitable to track objects inside the body. Conventional wired magnetic trackers have been used to track flexible tubular instruments like a catheter or a bronchoscope [2][3]. However, they have not been employed to track organ motion because it is necessary to pass the wire through the body. Recently, a wireless magnetic tracker, which is called the Calypso 4-D localization system (Calypso Medical Technologies, Inc., Seattle, WA, USA), has been developed and applied to tracking of the prostate motion during the radiation T. Dohi, I. Sakuma, and H. Liao (Eds.): MIAR 2008, LNCS 5128, pp. 359–366, 2008. c Springer-Verlag Berlin Heidelberg 2008
360
M. Nakamoto et al.
therapy [4][5][6]. Three miniature magnetic sensors, which are called “transponders”, are implanted into the prostate beforehand, and then their 3D positions are measured in realtime. Although the measurement and gating methods for internal organ motion caused by respiration were proposed [7][8][9][10], these methods assume periodical and regular motion. Since organ motion caused by surgical operation is not periodical and regular unlike the organ motion caused by respiration, the Calypso system is suitable for this purpose. Our objective is to evaluate feasibility of endoscopic
Data Loading...
