1. Health Care Department, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250355, P.R. China
2. Health Care Department, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250011, P.R. China
3. Department of Anesthesiology, Jinan Center Hospital, Jinan, Shandong 250013, P.R. China