Intracoronary UltraSound (IVUS) imaging allows to obtain high resolution images of internal part of coronary arteries. This tool is unique in the possibility to explore internal vessel structures of the coronary wall, being a powerful tool for diagnosis [1]. Since the coronary vessel is moving due to the periodical contraction and expansion of heart muscles, the acquired images present dierent artifacts. One of the most severe problems is the longitudinal oscillation of the IVUS catheter inside the vessel. To alleviate this problem, ECG-gating has been proposed. The goal of gating is to have subsequent frames that represent the internal vessel section in stable position and avoid the repetition of frames; that is to generate an image sequence in which the artifacts due to the heart beat have been removed while, possible translation due to vessel tortuosity can still be present. This paper presents a simple and ecient model of catheter longitudinal movement together with a fast and robu...