Knowledge-based planning of port positions for minimally invasive surgery

The success of a minimally invasive intervention strongly depends on the position of the incision in the abdominal wall for inserting the instruments and the endoscopic camera. A new knowledge-based system for planning these ports is presented. First time, the positioning of the surgeon and the camera assistant in respect to the patient is included. Modeling of the patient, the intervention and the optimization criteria are described. The intervention model is inferred from recorded trajectories of the surgical instruments. As an example application rectal resection is chosen. The optimization is performed with the Seed Throwing Optimization meta-heuristic. A new set of criteria for optimal setup configuration is presented, including ergonomic working directions, collision avoidance and reachability of target areas. The combination of these criteria using a t-norm is described. The optimized port positions are projected on the patient's abdomen with an augmented reality system. The time needed for the planning algorithm was measured and is sufficient. The results show that the computed configuration leads to maximum access in the operation field in the narrow pelvis, maximum separation dexterity for the surgeon and the camera assistant and allows an ergonomic completion of the intervention.