1. Geiselgasteig Ambulance, Grünwald, Munich, Germany
2. Institute for Medical Engineering and Information Processing, University of Koblenz, Koblenz, Germany
3. Institute of Applied Physics, University of Tübingen, Tübingen, Germany
4. University Hospital of Erlangen, Transfusion and Haemostaseology Department, Erlangen, Germany
5. Department of Cardiology and Cardiovascular Diseases, University of Tübingen, Tübingen, Germany