1. Department of Electronic Engineering, Hanyang University, Seoul, South Korea
2. Department of Electronic Engineering, Applied Bioelectronics Laboratory, Hanyang University, Seoul, South Korea
3. Hanyang University, Seoul, South Korea
4. Tesla Laboratory at Gwangju Institute of Technology, Gwangju, South Korea
5. Department of Biomedical Engineering and the Department of Electronic Engineering, Hanyang University, Seoul, South Korea