1. From the Department of Anesthesiology, University Hospital RWTH Aachen University, Aachen, Germany
2. Department of Heart Surgery, University Hospital RWTH Aachen, Aachen, Germany
3. Medical Faculty, Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, RWTH Aachen University, Aachen, Germany
4. Department of Intensive Care, University Hospital RWTH Aachen University, Aachen, Germany