| 摘要 |
An oxygen therapy apparatus for supply of oxygen to patients. The device comprises an inlet port (17) for receiving high pressure oxygen from a cylinder and an outlet port (1) for supplying oxygen to a patient, typically via a single tube cannula (not shown). Three valves control the supply of oxygen to the patient: a diaphragm valve (42) senses the pressure at the outlet (1) and, in particular senses whether the patient is inhaling or exhaling. A valve (36) controls the supply of oxygen to the patient via an inlet jet (25) which is selectably closed by a piston (20) incorporating a flexible seat (24). Movement of the piston (20) is in turn controlled by a pilot valve (37) in dependence on the state of the diaphragm valve (42). The device gives a pulsed output to the patient during inhalation, but shuts off during exhalation to economise on the use of oxygen. |
