A robotic medical system for controlling a shapeable instrument (6, 33) within an anatomical region, the robotic medical system comprising: the shapeable instrument (6, 33), where the shapeable instrument includes at least a working section and one or more positioning elements that move the shapeable instrument (6, 33), a controller including a master input device, where the controller generates a position control signal in response to the master input device to position the working section at a desired position; one or more actuators operatively coupleable to the one or more positioning elements, where the actuators manipulate the positioning elements based on the position control signal to drive at least a first portion of the shapeable instrument (6,33) to position the working section toward the desired position; and a fiber optic localization system configured to obtain a plurality of localized shape data from the first portion of the shapeable instrument (6, 33); where the controller generates a signal based upon a difference between the localized shape data and a desired configuration of the first portion of the shapeable instrument (6,33); and where the shapeable instrument comprises an elongate instrument body and an optic fiber of the fiber optic localization system; and characterized in that the optic fiber of the fiber optic localization system is coupled in a constrained manner to the elongated instrument body by at least a proximal constraint and a more distal constraint and two intermediary constraints, wherein the constraints are positioned along the length of the elongate instrument body, and wherein the constraints are configured to disallow axial movement of the optic fiber relative to the elongate instrument body at the location of the respective constraint, wherein the constraints form three segments between the constraints such that longitudinal strain in the optic fiber is isolated within each of the three segments of the optic fiber along the elongate instrument body. the shapeable instrument (6, 33), where the shapeable instrument includes at least a working section and one or more positioning elements that move the shapeable instrument (6, 33), a controller including a master input device, where the controller generates a position control signal in response to the master input device to position the working section at a desired position; one or more actuators operatively coupleable to the one or more positioning elements, where the actuators manipulate the positioning elements based on the position control signal to drive at least a first portion of the shapeable instrument (6,33) to position the working section toward the desired position; and a fiber optic localization system configured to obtain a plurality of localized shape data from the first portion of the shapeable instrument (6, 33); where the controller generates a signal based upon a difference between the localized shape data and a desired configuration of the first portion of the shapeable instrument (6,33); and where the shapeable instrument comprises an elongate instrument body and an optic fiber of the fiber optic localization system; and characterized in that the optic fiber of the fiber optic localization system is coupled in a constrained manner to the elongated instrument body by at least a proximal constraint and a more distal constraint and two intermediary constraints, wherein the constraints are positioned along the length of the elongate instrument body, and wherein the constraints are configured to disallow axial movement of the optic fiber relative to the elongate instrument body at the location of the respective constraint, wherein the constraints form three segments between the constraints such that longitudinal strain in the optic fiber is isolated within each of the three segments of the optic fiber along the elongate instrument body.