| 摘要 |
The pulmonary oxygen flow control system delivers oxygen from a source of pressure to a nasal cannula worn by the patient. Between the source and the nasal cannula is a pendant flow structure which includes an orifice followed by a gas dynamic valve. When the downstream pressure in the cannula is high, the gas dynamic valve diverts the oxygen flow through the orifice to a flexible reservoir. Upon inhalation, the pressure at the cannula falls so that the gas dynamic valve delivers the orifice flow to the cannula and also utilizes a Venturi effect to withdraw oxygen from the reservoir and deliver it to the cannula. The cannula has nasal tubes which have angular faces and which are positioned farther into the nares to deliver the oxygen more efficiently. |
