In vitro evaluation of stereoscopic liver surface reconstruction.

Introduction: Tracking abdominal motion of organs is an important factor in image-guided navigation systems. The paper presents the evaluation methodology of a practical approach to measure liver motion, both respiratory and laparoscopic, with a tool guided in the operating room.

Aim: Evaluation of the methodology of a practical approach to measure liver motion, both respiratory and laparoscopic, with a tool guided in the operating room.

Material And Methods: The presented evaluation method is based on standard operating room equipment, i.e. laparoscopic cameras. We decided to use two rigid cameras to gain stereo in order to reconstruct characteristic points by triangulation. Our research aim was to survey the impact of three parameters on reconstruction accuracy: the number of calibration points, the imprecision of camera assembly, and the difference in resolution of images.

Results: Three calibration chessboard configurations were tested. The reconstructed landmark positions and residual mean square errors were presented in three phantom poses: the reference position, translated position and rotated position.

Conclusions: The presented approach is a development of the previous work. Our research proved the importance of a rigid stereo camera system and the use of high definition image resolution for both stages, namely calibration and reconstruction.