Zheng Guo is a Professor and Director at Department of Orthopedics, Tangdu Hospital, Air Force Medical University, Xi’an, Shaanxi, China. Ling Wang is a Professor at Department of Mechanical Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi, China. Bin Liu is the Director of the GBA Center for Medical Device Evaluation and Inspection,National Medical Products Administration, Shenzhen, Guangdong, China.