This paper proposes a path correction method for surgical robotic systems performing needle handoff manipulations as part of autonomous execution of surgical suturing. During handoff motions, the position and orientation of the needle is subject to perturbations from the idealized planned pose due to uncertainties in camera-robot calibration and needle localization. If, after a perturbation, the system needs to perform subsequent needle regrasp(s), but the robot still follows the originally planned trajectory out of the path planner [1], it has a lower chance of gripping the needle properly. In order to accommodate these unpredictable needle pose perturbations, the proposed path correction method works locally to direct the needle from the wrong pose to the original pose by partial replanning of the robot motion. The reliability of the proposed method is evaluated with three sets of experiments in a simulation environment.

The development of autonomous or semi-autonomous surgical robots stands to improve the performance of existing teleoperated equipment, but requires fine hand-eye calibration between the free-moving endoscopic camera and patient-side manipulator arms (PSMs). A novel method of solving this problem for the da Vinci® robotic surgical system and kinematically similar systems is presented. First, a series of image-processing and optical-tracking operations are performed to compute the coordinate transformation between the endoscopic camera view frame and an optical-tracking marker permanently affixed to the camera body. Then, the kinematic properties of the PSM are exploited to compute the coordinate transformation between the kinematic base frame of the PSM and an optical marker permanently affixed thereto. Using these transformations, it is then possible to compute the spatial relationship between the PSM and the endoscopic camera using only one tracker snapshot of the two markers. The effectiveness of this calibration is demonstrated by successfully guiding the PSM end effector to points of interest identified through the camera. Additional tests on a surgical task, namely grasping a surgical needle, are also performed to validate the proposed method. The resulting visually-guided robot positioning accuracy is better than the earlier hand-eye calibration results reported in the literature for the da Vinci® system, while supporting intraoperative update of the calibration and requiring only devices that are already commonly used in the surgical environment.

This paper presents algorithms for three-dimensional tracking of surgical needles using the stereo endoscopic camera images obtained from the da Vinci® Surgical Robotic System. The proposed method employs Bayesian state estimation, computer vision techniques, and robot kinematics. A virtual needle rendering procedure is implemented to create simulated images of the surgical needle under the da Vinci ® robot endoscope, which makes it possible to measure the similarity between the rendered needle image and the real needle. A particle filter algorithm using the mentioned techniques is then used for tracking the surgical needle. The performance of the tracking is experimentally evaluated using an actual da Vinci® surgical robotic system and quantitatively validated in a ROS/Gazebo simulation thereof.