Yan, Pingping, Clinical Skills Center, Hainan Medical University, Hainan Haikou 570100, China Yan, Pingping, Clinical Skills Center, Hainan Medical University, Hainan Haikou, 570100, China Yi, Zhengjin, Department of Urology, Pangang Group General Hospital, Sichuan, 617023, China Yu, Yiying, The First Clinical College of Hainan Medical University, Haikou 570100, China Yu, Yiying, The First Clinical College of Hainan Medical University, Haikou, 571100, China