Cardiac MR in Robotic Heart Surgery for Preoperative Identification of the Target Vessel and Precise Port Placement - A Theoretical Model - Bergmann, P; Huber, S; Segl, H; Maechler, H; Reiter, U; Reiter, G; Rienmueller, R; Oberwalder, P; Rigler, B (The Thoracic and Cardiovascular Surgeon, 2003)