A collaborative robotic uterine positioning system for laparoscopic hysterectomy: Design and experiments

Background: Uterus manipulation is a lengthy and tedious task that is usually performed by a human assistant during laparoscopic hysterectomy. Note that the performance of the assistant may decrease with time. Moreover, under this approach, the primary surgeon does not have direct control over the uterus position. He/she can only verbally request the assistant to place it on a particular configuration. Methods: A robotic system composed of a 3 degrees-of-freedom uterine positioner is developed to assist in changing configuration of the uterus during laparoscopic hysterectomy. The developed system has a remote centre of motion structure; independently controlling the uterus motion with one joint at the time is allowed. Results: From the lab experiments, it is found that the robot shows better performance in retaining the uterus position and shows quicker response to the surgeon's instruction. Cadaver studies have been conducted to evaluate the feasibility of the robot. The robot was also applied to real patients in a clinical study. Conclusions: The robot is capable of assisting in uterus manipulation during laparoscopic hysterectomy. However, its user friendliness can be improved by simplifying the docking procedure. Furthermore, a more ergonomic user interface is desired.