Circular Needle and Needle-holder Localization for Computer-aided Suturing in Laparoscopic Surgery

摘要

Usual localization and registration techniques cannot be used for suturing in laparoscopic surgery. The small size of the needle and the interactions with the tissues do not allow to use conventional sensors. Moreover, the possible modifications of the positions of the needle after the needle has been introduced into the abdomen, makes the use of usual vision-based registration techniques impossible. In this paper, we present methods to obtain the necessary information by using a color endoscopic camera. So as to simplify the detection and reconstruction problems, the needle-holder is modelled as a cylinder and equipped with passive markers, and the needle is colored. Image processing techniques allow to get an elliptical representation of the image of the needle. From this ellipse and apparent contours of the cylinder, the 3D poses can be obtained. These poses and the needle handling parameters are computed by minimizing the projection error in the images and by using a numerical iterative technique : virtual visual servoing.