Dr.Tian Jian Lu is a professor at the School of Aerospace,Xi’anJiaotong University,Xi’an,China.Dr.Feng Xu is a professor at theKey Laboratory of Biomedical Information Engineering of Ministry ofEducation,School of Life Science and Technology,Xi’an JiaotongUniversity.Dr.Ting Wen is now an engineer at Shell Global SolutionsInc.Dr.Lu and Dr.Xu are also affiliated with Biomedical Engineeringand Biomechanics Center,Xi’an Jiaotong University.