Mask Pressure Regulation in Cpap Treatment and Assisted Respiration by Dynamic Control of Mask Vent Flow

• US 20110155133A1
• Filed: 03/29/2006
• Published: 06/30/2011
• Est. Priority Date: 04/01/2005
• Status: Active Grant

• Current Assignee: ResMed Pty Ltd. (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: Kenyon, Barton John, Oates, John David, Goeldi, Benriah, Barnes, Adrian
• Granted Patent: US 9,901,703 B2
• Time in Patent Office: Days
• US Class Current: 128/204.21
• CPC Class Codes: A61M 16/0009 with sub-atmospheric pressure, e.g. during expiration
• CPC Class Codes: A61M 16/0012 by Venturi means
• CPC Class Codes: A61M 16/0066 Blowers or centrifugal pumps
• CPC Class Codes: A61M 16/0093 by adsorption, absorption or filtration
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/0622 having an underlying cushion
• CPC Class Codes: A61M 16/0633 with forehead support
• CPC Class Codes: A61M 16/0672 Nasal cannula assemblies for oxygen therapy
• CPC Class Codes: A61M 16/0825 with ball-sockets
• CPC Class Codes: A61M 16/0883 Circuit type
• CPC Class Codes: A61M 16/1055 bacterial
• CPC Class Codes: A61M 16/1065 in the expiratory path
• CPC Class Codes: A61M 16/202 electrically actuated
• CPC Class Codes: A61M 16/22 Carbon dioxide-absorbing devices ; Other means for removing carbon dioxidecartridges with absorbing substances for respiratory apparatus A62B19/00
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2206/14 Static flow deviators in tubes disturbing laminar flow in tubes, e.g. archimedes screws
• CPC Class Codes: A61M 2230/432 partial CO2 pressure (P-CO2)

Abstract

An air delivery system includes an air flow generator to provide a pressurized flow of air, a patient interface to provide a seal with the patient'"'"'s face in use, an air delivery conduit to interconnect the air flow generator and the patient interface, and a controllable vent valve to control venting from the patient interface. The vent valve is controlled to maintain a substantially constant air flow in the air delivery conduit and the air flow generator.

Claims

1. An air delivery system, comprising:

an air flow generator to provide a pressurized flow of air;

a patient interface to provide a seal with the patient'"'"'s face in use;

an air delivery conduit to interconnect the air flow generator and the patient interface; and

a controllable vent valve to control venting from the patient interface, wherein the vent valve is controlled to maintain a substantially constant air flow in the air delivery conduit and the air flow generator.

2. The air delivery system according to claim 1, wherein the air flow generator includes an air turbine that is driven by a controllable electric motor.

3. The air delivery system according to claim 2, wherein the electric motor is controllable by a constant pressure control so that the air flow generator delivers pressured air at a constant pressure.

4. The air delivery system according to claim 3, further comprising a pressure profile to be applied to the constant pressure control, the pressure profile being configured to establish pressure delivered by the air flow generator.

5. The air delivery system according to claim 1, wherein the air flow generator includes a flow measuring element to provide a representation of air flow through the air flow generator.

6. The air delivery system according to claim 5, wherein the vent valve is controllable by a constant flow control, the constant flow control being adapted to receive feedback from the flow measuring element, and selectively adjust the vent valve to maintain the substantially constant air flow.

7. The air delivery system according to claim 6, further comprising a flow profile obtained from the constant flow control.

8. The air delivery system according to claim 1, wherein the vent valve is located external to the flow generator.

9. The air delivery system according to claim 1, wherein the vent valve is located within the flow generator.

10. The air delivery system according to claim 9, wherein the vent valve is communicated with the patient interface by a return vent conduit.

11. The air delivery system according to claim 1, wherein the patient interface includes an inlet port communicated with the air delivery conduit for air delivery and an outlet port communicated with the controllable vent valve for air venting.

12. The air delivery system according to claim 11, wherein at least one of the inlet port and the outlet port includes a one-way valve to prevent reverse air flow from the patient to the flow generator.

13. The air delivery system according to claim 2, wherein the electric motor is controllable by a constant power control so that the air flow generator operates at constant power.

14. The air delivery system according to claim 13, further comprising an adaptive flow control to monitor a setting of the vent valve and to selectively adjust the constant power control to optimize air flow provided by the air flow generator.

15. The air delivery system according to claim 14, wherein the adaptive flow control is configured to establish a minimum air flow sufficient for CPAP therapy.

16. The air delivery system according to claim 13, further comprising a pressure sensor that senses pressure at the patient interface.

17. The air delivery system according to claim 16, wherein the pressure sensor is located within the flow generator and communicated with the patient interface through a pressure sensing tube.

18. The air delivery system according to claim 16, wherein the vent valve is controllable by a valve control, the valve control being adapted to receive feedback from the pressure sensor and to selectively adjust the vent valve to maintain constant pressure at the patient interface and hence to maintain the substantially constant air flow.

19. The air delivery system according to claim 18, further comprising a flow profile obtained from the vent valve, the flow profile configured to be used as an input an autosetting algorithm that selectively adjusts a mask pressure set point via the valve control.

20. The air delivery system according to claim 19, wherein the flow profile is obtained from a filtered setting of the vent valve.

21. The air delivery system according to claim 13, wherein the vent valve is located within the flow generator.

22. The air delivery system according to claim 21, wherein the vent valve is communicated with the patient interface by a return vent conduit.

23. The air delivery system according to claim 2, wherein the controllable electric motor is controllable by a constant rpm control so that the air flow generator operates at constant rpm.

24. A method for delivering pressurized air to a patient, the method comprising:

delivering pressurized air to a patient interface; and

controlling venting from the patient interface to maintain a substantially constant air flow in the air delivery conduit and the air flow generator.

25. The method according to claim 24, further comprising delivering pressured air at a constant pressure.

26. The method according to claim 25, further comprising measuring flow of the delivered air, and selectively controlling venting from the patient interface based on the measured flow to maintain the substantially constant air flow.

27. The method according to claim 24, further comprising measuring pressure at the patient interface, and selectively controlling venting from the patient interface based on the measured pressure to maintain the substantially constant air flow.

28. The method according to claim 24, further comprising monitoring a venting setting, and selectively controlling delivered air to establish a minimum air flow sufficient for CPAP therapy.

29. The method according to claim 24, further comprising obtaining a flow profile of venting, and inputting the flow profile to an autosetting algorithm that selectively controls venting.

30. The method according to claim 24, wherein the delivery of pressurized air is controlled by a constant pressure, constant rpm, or constant power control.

31. A method for delivering pressurized air to a patient, the method comprising:

delivering pressurized air to a patient interface; and

controlling venting from the patient interface to maintain a substantially constant pressure at the patient interface.