1. Institute of Optical Materials and Technologies, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
2. Faculty of Information Technology and Communication Sciences, Tampere University, 33720 Tampere, Finland
3. Department of Vascular Surgery, Sofiamed University Hospital, 1797 Sofia, Bulgaria
4. Department of Electronics Engineering, Aligarh Muslim University, Aligarh 202001, India
5. Electronics and Telecommunications Research Institute, 218 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea