1. Laboratory of Instrumentation , University of Sciences and Technology Houari Boumediene , Algiers , Algeria
2. Department of Textile Technology , University of Borås , 50190 , Borås , Sweden
3. Dept. for Clinical Science , Intervention and Technology, Karolinska Institute , 14186 Stockholm , Sweden
4. Dept. Biomedical Engineering , Karolinska University Hospital , 14186 Stockholm , Sweden