1 Robotic Minimally Invasive Surgery Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 611731, China.
2 Department of Anesthesiology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 611731, China.
3 Department of Hepatobiliary and Pancreatic Surgery, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 611731, China. Electronic address: yangchong@uestc.edu.cn.