1. Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
2. Department of Anesthesiology and Intensive Care Medicine, University Medical Center of Schleswig-Holstein Campus Kiel, Kiel, Germany
3. Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China; and
4. Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany