IRCT20151228025732N65 IRCT 2021-05-05 Semnan University of Medical Sciences Comparison of the effect of Nasal high frequency oscillatory ventilation(nHFO) with Nasal synchronized intermittent positive airway pressure(SiPAP) in the treatment of preterm infants with respiratory distress syndrome weighing less than 1500 g Comparison of the effect of nHFO with SiPAP in the treatment of preterm infants with respiratory distress syndrome weighing less than 1500 g 2021-03-21 anticipated 60 Complete https://irct.ir/trial/54730 interventional Randomization: N/A, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment. N/A Respiratory Distress Syndrome. Intervention 1: Intervention group 1: In the nHFO group, according to the protocol, infants with Bi nasal prong and CNO device (Medin company) are subjected to non-invasive mechanical ventilation by oscillation and periodic opening and closing of the air outlet valve. Intervention 2: Intervention group 2: In the SiPAP group, according to the protocol, the IFD (Viasys Healthcare) injector is installed with a prong suitable for the baby and is subjected to this intervention using the SiPAP (Viasys Healthcare) support system. The Graseby capsule is placed between the umbilicus and the xiphoid appendage. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is There is no more information.