[1] Azienda Osped Senese, Dipartimento Pediat Ostetricia & Med Riprod, Sez Pediat Prevent & Neonatol, I-53100 Siena, Italy
[2] Perrino Hosp Azienda Osped A Di Summa, Div Paediat, Brindisi, Italy
[3] Natl Res Council Italy, Lecce Sect, CNR, IFC,Clin Physiol Inst, Lecce, Italy
[4] Masimo Corp, Clin Res, Irvine, CA USA