Methods of assisting an operator to perform a surgical procedure include inserting at least one surgical tool into a surgical environment of a human body. The 3D spatial position of the surgical tool within the surgical environment is estimated in real time, and movement of the surgical tool is detected. The spatial position of the surgical tool within the surgical environment is controlled using a controller, including by determining using image processing whether each of the detected movements is an ALLOWED movement or a RESTRICTED movement based on a predetermined rule stored in a database in communication with the controller.