[1] Univ Barcelona, Unitat Biofis & Bioengn, Fac Med & Ciencies Salut, Barcelona, Spain
[2] CIBER Enfermedades Resp, Madrid, Spain
[3] Inst Invest Biomed August Pi Sunyer, Barcelona, Spain
[4] Hosp Clin Barcelona, Sleep Lab, Barcelona, Spain
[5] Univ Missouri, Dept Child Hlth, Sch Med, Columbia, MO 65201 USA
[6] Barcelona Inst Sci & Technol, Inst Bioengn Catalonia, Barcelona, Spain