1. Ilmenau University of Technology,Department of Mechanical Engineering,Ilmenau,Germany
2. University of Duisburg-Essen,Department of Electronic Components and Circuits,Duisburg,Germany
3. University Medicine Essen,Chair of Sleep and Telemedicine,Ruhrlandklinik,Essen,Germany
4. University Medicine Essen,Department of Pneumology,Ruhrlandklinik,Essen,Germany