1. Department of Electrical Engineering, Faculty of Engineering, Universitas Andalas, Padang City, Indonesia
2. School of Electrical Engineering and Informatics, Institut Teknologi Bandung, Bandung, Indonesia
3. Sekolah Tinggi Ilmu Kesehatan MERCUBAKTIJAYA, Padang City, Indonesia
4. Electrical and Electronic Engineering Department, University of Nottingham Malaysia, Semenyih, Selangor, Malaysia
5. Medical Faculty, Universitas Andalas, Padang City, Indonesia