1. Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Karlsruhe, Germany
2. Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Germany
3. West German Heart and Vascular Center, University Hospital Essen, Germany
4. Medizinische Klinik IV at Städtisches Klinikum Karlsruhe, Academic Teaching Hospital of the University of Freiburg, Germany