An end effector state estimation system for use in minimally invasive surgery (MIS) applications performs sensing and prediction algorithms to determine and visualize the state of an implantable therapeutic device during deployment. The end effector state estimation system includes a flexible elongate member, a therapeutic device coupled to a distal portion of the flexible elongate member, a sensor that measures at least one parameter related to the deployment state of the therapeutic device, and a processor. The processor receives image data from an imaging system representative of the therapeutic device positioned within the body cavity of the patient and the at least one parameter from the sensor, determines the deployment state of the therapeutic device based on the image data and the at least one parameter, outputs a graphical representation of the deployment state of the therapeutic device.