1. Department of Geriatrics, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China (mainland)
2. Department of Cardiology, Yantaishan Hospital, Yantai, Shandong, China (mainland)
3. Department of Health Care, Qingdao Municipal Hospital (East), Qingdao, Shandong, China (mainland)
4. Department of Cardiology Electrocardiography, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China (mainland)
5. Qingdao Municipal Health Science and Technology Education Center, Qingdao, Shandong, China (mainland)
6. Department of Ophthalmology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China (mainland)