Pressure control in CPAP treatment or assisted respiration

• US 6,526,974 B1
• Filed: 08/22/2000
• Issued: 03/04/2003
• Est. Priority Date: 09/18/1995
• Status: Expired due to Term

• Current Assignee: Resmed Limited (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: Brydon, John William Ernest, Bachak, Miroslav, Wickham, Peter John Deacon, Hollis, Shane Douglas
• Primary Examiner(s): Lewis, Aaron J.
• Assistant Examiner(s): Weiss, Jr., Joseph
• Application Number:
  US09/642,824
• Time in Patent Office: 924 Days
• Field of Search: 128/204.18, 128/204.21, 128/204.23, 128/204.24, 128/205.24, 415/1, 415/10, 415/15, 415/17, 415/203, 415/206, 415/148, 415/159, 137/102, 137/625.18
• US Class Current: 128/205.24
• CPC Class Codes: A61M 16/0057 Pumps therefor
• CPC Class Codes: A61M 16/0066 Blowers or centrifugal pumps
• CPC Class Codes: Y10T 137/2544 Supply and exhaust type
• CPC Class Codes: Y10T 137/86558 Plural noncommunicating flow paths

Abstract

The pressure of breathable gas exiting a flow generator is controlled by adjusting the efficiency of the flow generator. In one embodiment, a baffle plate of a control element can restrict the open entry area of a motor driven turbine of the flow generator. In another embodiment, the degree of opening of the mouth of the flow generator inlet is automatically adjustable in response to the needs of the user, hence creating a pneumatic impedance, and which simultaneously controls, in the same manner, the impedance of the outlet of the device.

Claims

1. A controllable flow generator for supplying breathable pressurized gas, the flow generator comprising:

a housing with an inlet to receive the gas;

a blower within the housing in communication with the inlet;

a motor coupled to drive the blower, thereby pressurizing and providing the received gas to a passageway in communication with the housing; and

a valving system in communication with the passageway, the valving system including a movable control member within the valving system, an entrance in communication with the passageway, an exiting port, and a vent positioned between the entrance and the exiting port in controlled gas communication with atmosphere, wherein

in an inspiratory mode of operation, the movable control member is movable to increase an open area of the entrance while decreasing the open area of the vent, thereby controllably directing the gas introduced into the valving system via the entrance to a desired degree to the exiting port, and

in an expiratory mode of operation, the movable control member is movable to increase the open area of the vent while decreasing the open area of the entrance, thereby controllably directing gas introduced into the valving system via the entrance and gas introduced into the valving system via the exiting port to a desired degree to the vent.

2. The flow generator of claim 1, wherein the movable control member is pivotable.

3. A valving system comprising:

an entrance, an exiting port, and a vent positioned between the entrance and the exiting port in controlled gas communication with atmosphere; and

a movable control member in communication with the entrance, exiting port and vent,

wherein in an inspiratory mode of operation, the movable control member is movable to increase an open area of the entrance while decreasing the open area of the vent, thereby controllably directing the gas introduced into the valving system via the entrance to a desired degree to the exiting port, and

in an expiratory mode of operation, the movable control member is movable to increase the open area of the vent while decreasing the open area of the entrance, thereby controllably directing gas introduced into the valving system via the entrance and gas introduced into the valving system via the exiting port to a desired degree to the vent.

4. The valving system of claim 3, wherein the movable control member is pivotable.