  Robotic automation has the potential to assist human surgeons in performing
suturing tasks in microsurgery, and in order to do so a robot must be able to
guide a needle with sub-millimeter precision through soft tissue. This paper
presents a robotic suturing system that uses 3D optical coherence tomography
(OCT) system for imaging feedback. Calibration of the robot-OCT and
robot-needle transforms, wound detection, keypoint identification, and path
planning are all performed automatically. The calibration method handles pose
uncertainty when the needle is grasped using a variant of iterative closest
points. The path planner uses the identified wound shape to calculate needle
entry and exit points to yield an evenly-matched wound shape after closure.
Experiments on tissue phantoms and animal tissue demonstrate that the system
can pass a suture needle through wounds with 0.27 mm overall accuracy in
achieving the planned entry and exit points.
