1. Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
2. George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
3. Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
4. Department of Biomedical Engineering, National Yang-Ming University, Taipei 11221, Taiwan
5. Department of Radiation Oncology, Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan 33004, Taiwan