A method for tracking position of features of a moving organ from at least one sequence of image frames of the moving organ involves identifying at least a first feature and a second feature of the organ in a reference image frame. Fins, bridge the spacing between each of the plurality of runs and extend oppositely from outwardly facing sides, ; of the first and last runs, ;, ; and are bonded to the tubing. The positioning device can be calibrated automatically, fast and accurately using the system.