1. Department of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave., Tehran 15875–4413, Iran
2. Department of Physics, University of Wisconsin–Madison, Madison, WI 53706, USA
3. School of Electronics and Telecommunications, Hanoi University of Science and Technology, 01 Dai Co Viet, Hanoi, Vietnam
4. Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran 14155–6447, Iran