“…Ever since Gregory et al (1971) showed the beneficial effect of CPAP application in IRDS several devices have been described mainly to avoid the complications of tracheal tubes (Ackerman et al, 1974;Agostino et al, 1973; Barrie, 1973;Baum and Roberton, 1974;Caliumi-Pellegrini et al, 1974;Chernick and Vidyasagar, 1972;Dunn, 1974;Fanaroffet al, 1973;Harris, 1972;Kattwinkel et al, 1973; Olinsky, MacMurray and Swyer, 1973;Rhodes and Hall, 1973;Salle et al, 1974 mixer allows adjustment of the oxygen concentration from 21 %, i.e. pure air, to 100%, the flow meter adjustment of gas flow through the face chamber.…”