Stress Analysis at Trocar and Endoscope Interface Using Computational Simulation: A Preliminary Study

Minimally invasive robotic surgery (MIRS) procedures are performed through small incisions on patient´s body and provide the advantages of considerably reduced tissue trauma and shorter recovery time. However, loss of haptic feedback is one of the major drawbacks of minimally invasive robotic surgery. Surgeons may not always be able to control the force applied by the robotic arm because of lack of sense of tissue resistance. This study aims at determining stresses at the trocar/endoscope interface in order to limit the range of forces applied by robot on patient´s skin and to avoid its inadvertent injury. Simulation of the robot movement was done using a computer aided design (CAD) software. Simulation results suggest that, due to mechanical advantage, contact forces calculated around the trocar are at least 10 times higher than the force applied on the robot arm. Therefore, surgeons need to be cautious to avoid too much pressure on patient´s skin by applying high force to the robot arm.