Patent ID: 6880556

Claim:
An apparatus for supplying an oxygen therapeutic gas, comprising: a cylinder for containing a pressurized oxygen therapeutic gas; a nasal cannula, adapted to be introduced into a nasal passage of a patient; a conduit extending between the cylinder and the nasal cannula for directing the oxygen therapeutic gas to the nasal cannula from the cylinder; a valve, provided on the conduit, for allowing and blocking the fluid communication between the cylinder and the nasal cannula; a pressure sensor, provided on the conduit downstream of the valve, for detecting the pressure in the conduit; an orifice, provided on the conduit upstream of the valve, for regulating pressure in the conduit upstream of the valve; and a controller for controlling the operation of the valve in synchronization with the respiration of a patient based on changes in pressure detected by the pressure sensor, the controller comparing respiratory frequency with a threshold to increase volume of the oxygen therapeutic gas for each respiration in step when the respiratory frequency is larger than the threshold.