Robust trocar identification and its application in robotic minimally invasive surgery

Background In minimally invasive surgery (MIS), instruments pass through trocars which are installed through the incision points. This forms a fulcrum effect and imposes significant constraint. For robotic manipulative operations, the real-time trocar information is a prerequisite. Systems acquire this knowledge either with a prior registration procedure or through coordinated control of their joints. Methods A robust and real-time trocar identification algorithm based on least square (LS) algorithm was proposed in the context of human-robot co-manipulation scenario. Results Both in vitro and in vivo experiments were performed to verify the effectiveness of the proposed algorithm. The estimated trocar coordinates expressed in the robot base frame were further leveraged to implement an instrument gravity compensation function. Conclusions An LS based approach can be employed to robustly estimate the real-time trocar information so as to implement more practical robotic functions.