[1] Rigshosp, Dept Clin Neurophysiol, Danish Ctr Sleep Med, Glostrup, Denmark
[2] Tech Univ Denmark, Dept Elect Engn, Lyngby, Denmark
[3] Univ Bologna, Dept Biomed & Neuromotor Sci, Bologna, Italy
[4] AUSL Bologna, IRCCS Inst Neurol Sci, Bologna, Italy
[5] Rigshosp, Danish Ctr Sleep Med, Dept Clin Neurophysiol, Glostrup, Denmark