1 Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing 100730, China.
2 Institute for Medical Device Standardization Administration, National Institutes for Food and Drug Control, Beijing 100050, China.
3 Department of Critical Care Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China.
4 Department of Critical Care Medicine, The First Hospital of Tsing Hua University, Beijing 100016, China.