1. Epstein Department of Industrial and Systems Engineering Viterbi School of Engineering University of Southern California Los Angeles CA 90089 USA
2. Alfred E. Mann Institute for Biomedical Engineering University of Southern California Los Angeles CA 90089 USA
3. Department of Mechanical Engineering San Diego State University San Diego CA 92182 USA
4. School of Optical and Electronic Information Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 China