Portable gas powered positive pressure breathing apparatus and method
View Patent ↗A portable positive pressure breathing apparatus includes a demand valve with a supply inlet port adapted to be connected to a pressurized source of oxygen and an outlet port adapted to be connected to the inlet of a patient's breathing appliance. The demand valve further includes a reference chamber and a valve assembly responsive to the reference chamber/appliance inlet pressure differential for connecting/disconnecting the inlet port to and from the outlet port. At least one manually adjustable back pressure regulator is connected to the pressure source and the reference chamber for setting the pressure in the reference chamber (and inlet to the breathing appliance) at a selected level above atmospheric pressure.
1. A pressure regulator, comprising:
a demand valve comprising:
a gas inlet port;
a gas outlet port;
a main valve in fluid communication with the inlet port and the outlet port; and
a pneumatically actuated control valve configured to open and close the main valve in response to patient inhalation and exhalation cycles; and
an adjustable back pressure regulator coupled to the pneumatically actuated control valve and configured to control a reference pressure in the pneumatically actuated control valve thereby allowing for response to patient exertion.
2. A bi-level pressure regulator for controlling gas flow to a patient, the regulator comprising:
a demand valve pneumatically responsive to patient breathing based on a reference pressure, wherein the demand valve opens during inhalation and closes during exhalation;
a selector valve in fluid communication with the demand valve;
a first back pressure regulator in fluid communication with the selector valve; and
a second back pressure regulator in fluid communication with the selector valve,
wherein, the bi-level pressure regulator allows for controlling patient back pressure during both inhalation and exhalation.
3. The regulator of claim 2 , wherein, the demand valve includes a reference chamber and the selector valve is in fluid communication with the reference chamber and controls the reference pressure therein.
4. The regulator of claim 3 , wherein, the selector valve is configured to select a lower of the first and second back pressure regulator settings during inhalation.
5. The regulator of claim 4 , wherein the selector valve is configured to select the first back pressure regulator setting during exhalation.
6. The regulator of claim 3 , wherein the first and second back pressure regulators are adjustable.
7. The regulator of claim 3 , wherein the first back pressure regulator is adjustable and the second back pressure regulator is a preadjusted back pressure regulator.
8. The regulator of claim 6 , wherein the adjustable back pressure regulators include rotatable knobs to control the back pressure setting.
9. A positive pressure patient mask comprising:
a patient valve comprising:
an inlet passage;
an inlet/outlet chamber;
an inhalation check valve adapted to permit gas flow from the inlet passage into the inlet/outlet chamber during inhalation;
a diaphragm valve positioned between a diaphragm chamber and the inlet/outlet chamber, the diaphragm valve comprising:
a diaphragm having an effective area acted on by pressure in the diaphragm chamber, the effective area being defined by a first diameter; and
a valve member positioned within the periphery of the diaphragm and being configured to contact an annular valve seat of the inlet/outlet chamber, the valve seat having a second diameter equal to the median diameter of the annular valve seat,
wherein, the first and second diameters are substantially equal.
10. The mask of claim 9 , further comprising a passage configured for conducting gas from the inlet passage to the diaphragm chamber, the diaphragm chamber configured to provide pneumatic dampening to the valve member.
11. The mask of claim 10 , further comprising an exhaust port arranged downstream of the valve seat.
12. The mask of claim 11 , wherein the exhaust port is rotatable about the patient valve such that expired air can be directed as desired by a patient.
13. The mask of claim 12 , wherein the exhaust port is rotatable through an angle of approximately 300 degrees.
14. The mask of claim 11 , wherein, upon exhalation, the inhalation check valve is adapted to close causing the diaphragm valve to open allowing expired air to pass through the exhaust port.
15. The mask of claim 14 , further comprising an exhaust casing surrounding the valve seat.