1. Department of Thoracic Surgery, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
2. Department of Operation Room, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China
3. Departments of Operation Room, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, P.R. China