[1] Med Univ Vienna, Dept Cardiac Surg, Vienna, Austria
[2] TU Wien, Inst Mech & Mechatron, Div Proc Control & Automat, Vienna, Austria
[3] Klin Favoriten, Div Cardiol, Vienna, Austria
[4] Med Univ Vienna, Dept Anaesthesia Intens Care Med & Pain Med, Vienna, Austria
[5] Med Univ Graz, Dept Surg, Div Cardiac Surg, Graz, Austria
[6] Med Univ Vienna, Dept Cardiac Surg, AKH Wien, Wahringer Gurtel 18-20, A-1090 Vienna, Austria