A new robotic uterine positioner for laparoscopic hysterectomy with passive safety mechanisms: Design and experiments

In this paper, we present a new robotic uterine positioner for total laparoscopic hysterectomy. The robot is designed to actively position the patient´s uterus during surgery, a lengthy and tedious task that is traditionally performed by a human assistant. Safety is simply the most important concern when developing robots for surgical purposes; we address this concern in the design of our robot from a mechanical perspective. To this end, we develop a 3-DOF robotic uterine positioner with an in-body remote center of motion (RCM); this key feature allows to prevent injuries to the patient when large motions occur at the cervix. A linearly-actuated arc-guided RCM mechanism is introduced to guarantee the rigidity and stability of the robot; The system´s design allows to manipulate the uterus in a decoupled manner, thus control complexity can be reduced. Passive safety mechanisms are also implemented in all DOF of the robot in order to limit the interaction forces with the patient. Experiments, including an ex-vivo test conducted with cadaver, are conducted to verify the robot´s performance.