Frequently, telemanipulators are applied at hospitals for minimally invasive surgery, which is of particular advantage for the patients. These robot-supported systems allow for remote interventions. The precision and free moving space of surgical instruments are enhanced by the use of telemanipulators. Based on his experience, the surgeon decides where to place the telemanipulator, which movements it is to make, and where to access the body of the patient. Due to the limited view during operation and the complex kinematics of the telemanipulators used, however, undesired collisions of the robot arms may occur. Scientists of the Institute for Process Control and Robotics optimize the position of access and the position of the telemanipulator system in order to minimize the risk of such collisions, to increase mobility, and to ensure best possible view of the surgeon. Collision prevention is based on a simulation environment that combines the patient model with the kinematic model of the telemanipulator. For collision-free operation, three parameters are determined: The positions of accesses to the patient, the initial configuration of the telemanipulator, and the orientation of the patient table. To obtain realistic results, the model is extended by individual patient data. The calculated place of access is projected directly onto the body of the patient. This is accomplished by methods of extended reality. Based on previous operations, the course of the next operation is calculated.In case the surgeon deviates from this course during operation, the system can offer a navigation help and show a path for collision-free operation. In this way, safety and efficiency of operative interventions are increased significantly.