1. Department of Geriatric Medicine, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, P.R. China;
2. National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, P.R. China; and
3. Department of Respiration, Hospital of Tai'an Traditional Chinese Medicine, Tai'an, Shandong Province, P.R. China.