Apparatus for enhancement of oxygen and/or air flow control to nasal prongs
Nasal cannula apparatus, includes in an inlet tubular fitting sized and configured to directly endwise connect to a source of oxygen, or oxygen and air. The fitting defines an inlet flow passage area A, having a 15 mm external diameter. A pair of tubular prongs is operatively connected with the inlet fitting, and receivable in an infant's nostrils to deliver oxygen, or oxygen and air flow to the infant, the prongs each having flow passing area A 3 , and A 1 >>A 3 .
1. An improvement for a nasal cannula apparatus that includes a pair of tubular prongs receivable in an infant's nostrils to deliver oxygen, or oxygen and air flow to the infant, said prongs each having flow passing area A 3 , the improvement comprising
a) an inlet tubular adaptor sized and configured to directly endwise connect to a source of oxygen, or oxygen and air, said adaptor defining an inlet flow passage area A 1 and said adaptor having a 15 mm external diameter,
b) said adaptor defining two like outlet flow passages operatively connectible with said nasal cannula apparatus incorporating said prongs, there being two parallel venturi passages intervening between said adaptor inlet flow passage and outlets defined by said adaptor outlet flow passages, said venturi passages having overall width less than a diameter of said inlet flow passage defined by the adaptor, said adaptor outlet flow passages each having area
A 2 , where A 1 >A 2 >A 3 .
2. The improvement of claim 1 wherein said prongs are elongated and have lengthwise curvature.
3. The improvement of claim 1 including cushion structure through which the prongs extend to cushion against nasal surfaces.
4. The improvement of claim 1 including sealing structure through which the prongs extend.
5. The improvement of claim 1 wherein each said adaptor outlet flow passage has an associated external diameter less than 15 mm.