Patent ID: 8225796

Claim:
A nasal cannula for supplying a respiratory gas to a patient, the nasal cannula comprising: a pair of supply lines which each have a head adjacent a leading end thereof with a discharge opening therein for discharging a respiratory gas, and an opposite end of each of the pair of supply lines being connectable to a respiratory gas source; wherein each head is formed integrally with and from the same material as the pair of supply line and each head comprises a leading tapered section and a trailing cylindrical section, the cylindrical section having a generally cylindrical surface which is sized to be snugly received and retained within one of the nasal cavities of the patient, each head has a maximum width dimension of between 0.345 of an inch (0.88 cm) and 0.70 of an inch (1.8 cm) and a length of between 0.30 of an inch (0.76 cm) and 0.60 of an inch (1.5 cm), an exterior surface of each head has a plurality elongate troughs formed therein, and each of the plurality of elongate troughs extends parallel to one another and is formed in the generally cylindrical surface of the head; each of the plurality elongate troughs is formed by a pair of adjacent planar side surfaces which diverge away from a common elongate valley toward a pair of spaced apart but adjacent elongate ridges having maximum outside diameters coequal with the maximum outside diameter of each head to partially define one of the plurality of leakage passages, the plurality elongate troughs form, once inserted into the respective nasal cavity, a plurality of leakage passages, to facilitate exhausting of excess respiratory gas supplied to the patient through the leakage passage while maintaining a positive pressure within a respiratory passage of the patient at least during exhalation by the patient; the pair of supply lines being connected with one another by a central bridge member; and opposed front and rear walls of at least one of the heads have an aligned aperture therein which facilitates passage of a pressure sensing probe through the head and into the nasal cavity of the patient.