Oxygen mixing in a blower-based ventilator

• US 6,123,074 A
• Filed: 07/24/1997
• Issued: 09/26/2000
• Est. Priority Date: 09/03/1996
• Status: Expired due to Term

• Current Assignee: RIC INVESTMENTS LLC (Respironics Incorporated)
• Original Assignee: Respironics Incorporated
• Inventors: Srock, James D., Hete, Bernie F.
• Primary Examiner(s): Weiss, John G.
• Assistant Examiner(s): WEISS JR, JOSEPH
• Application Number:
  US08/899,432
• Time in Patent Office: 1,160 Days
• Field of Search: 128/203.14, 128/203.22, 128/203.25, 128/204.21, 128/204.23, 128/204.26, 128/205.11
• US Class Current: 128/205.11
• CPC Class Codes: A61M 16/0066 Blowers or centrifugal pumps
• CPC Class Codes: A61M 16/0866 Passive resistors therefor
• CPC Class Codes: A61M 16/107 in the inspiratory path
• CPC Class Codes: A61M 16/12 by mixing different gases
• CPC Class Codes: A61M 16/202 electrically actuated
• CPC Class Codes: A61M 16/204 used for inhalation control
• CPC Class Codes: A61M 16/209 Relief valves
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit

Abstract

An oxygen mixing arrangement for or in a pressure support ventilator, in which a modular oxygen-providing assembly is selectively insertable into a greater respiration apparatus. Mixing accuracy and controllability is maintained by using gas supplies that have a wide range of pressures. Further, oxygen leakage is minimized by connecting the modular oxygen-providing assembly at a point of the respiration circuit of the greater respiration apparatus that is downstream from a valving arrangement normally used for venting patient exhaust flow and for controlling system pressure by venting excess gas flow to the ambient atmosphere.

Claims

1. An apparatus for delivering pressurized gas to an airway of a patient, said apparatus comprising:

gas flow generating means for providing a gas flow;

a primary conduit operatively coupled to said gas flow generating means to communicate said gas flow to an airway of a patient; and

means for providing supplemental gas concomitantly with said gas flow that includes;

a supplemental conduit adapted to carry a flow of said supplemental gas,

a coupling member joining one end of said supplemental conduit and said primary conduit at a first location generally downstream of said gas flow generating means for introducing said flow of said supplemental gas into said primary conduit at said first location, and

regulating means for controlling said flow of said supplemental gas from said supplemental conduit to said primary conduit such that said flow of said supplemental gas from said supplemental conduit to said primary conduit is enabled responsive to a net flow of gas in said primary conduit at said first location being in a direction generally away from said gas generating means, and such that said flow of said supplemental gas from said supplemental conduit to said primary conduit is disabled responsive to said net flow of gas in said primary conduit at said first location being in a direction other than away from said gas generating means.

2. The apparatus according to claim 1, wherein said supplemental gas includes oxygen.

3. The apparatus according to claim 1, wherein said means for providing supplemental gas includes means for selecting a concentration of said supplemental gas to be delivered to said primary conduit, and wherein said regulating means continually adjusts said flow of said supplemental gas into said primary conduit so as to provide said selected concentration of said supplemental gas to a patient.

4. The apparatus according to claim 1, wherein said regulating means advances said flow of said supplemental gas at a rate that is directly proportional to said magnitude of said gas flow in said primary conduit.

5. The apparatus according to claim 1, wherein said means for providing supplemental gas comprises a modular section selectively attachable and detachable with respect to a remainder of said apparatus.

6. The apparatus according to claim 5, wherein said modular section comprises at least two modular sub-sections, each being selectively attachable and detachable with respect to one another.

7. The apparatus according to claim 6, wherein one of said modular sub-sections comprises said regulating means and another one of said modular sub-sections comprises said means for introducing supplemental gas into said conduit means.

8. An apparatus for delivering pressurized gas to an airway of a patient, said apparatus comprising:

gas flow generating means for providing a gas flow;

means for providing supplemental gas concomitantly with said gas flow that includes regulating means for controlling a flow of said supplemental gas as a function of at least one of a magnitude of said gas flow and a direction of said gas flow;

conduit means, operatively coupled to said gas flow generating means, for delivering said gas flow to an airway of a patient,

pressure control means associated with one of said gas flow generating means and said conduit means for controlling a pressure of said gas flow in said conduit means;

venting means associated with said conduit means for selectively venting gas from said conduit means;

directing means associated with said conduit means for directing at least a portion of said gas flow in said conduit means through said venting means responsive to an exhalation by a patient; and

preventing means associated with said means for providing supplemental gas for preventing a direct transfer of said supplemental gas to said venting means.

9. The apparatus according to claim 8, wherein said preventing means includes means for substantially blocking said flow of said supplemental gas into said conduit means responsive to detection of one of net airflow from a patient and a zero flow in said conduit means.

10. A method of delivering pressurized gas to an airway of a patient, comprising:

providing a primary gas flow to a patient via a gas flow generator;

carrying said primary gas flow to such a patient in a primary conduit providing a supplemental gas flow

introducing said supplemental gas flow into said primary conduit at a first location in said primary conduit generally downstream of said gas flow generator;

enabling said supplemental gas flow to flow into said primary conduit responsive to a net flow of gas in said primary conduit at said first location being in a direction generally away from said gas generator; and

disabling said supplemental gas flow from flowing into said primary conduit responsive to said net flow of gas in said primary conduit at said first location being in a direction other away from said gas generator.

11. The method according to claim 10, wherein said supplements gas includes oxygen.

12. An apparatus for delivering pressurized gas to an airway of a patient, said apparatus comprising:

a gas flow generator that provides a primary gas flow;

a primary conduit operatively coupled to said gas flow generator and adapted to provide said primary gas flow to a patient;

a sensor operatively coupled to said primary conduit to detect a rate of said primary gas flow in said primary conduit and to output a flow signal indicative thereof

a supplemental conduit adapted to carry a supplemental gas flow;

a coupling member joining one end of said supplemental conduit to said primary conduit at a first location generally downstream of said gas flow generator for introducing said supplemental gas flow into said primary conduit at said first location;

a valve operatively coupled to said supplemental conduit to control said flow of supplemental gas therein, wherein said valve is actuated responsive to a supplemental gas flow control signal;

a processor operatively coupled to said sensor and said valve, wherein said processor determines a net flow of gas in said primary conduit at said first location based on said flow signal from said sensor, wherein said processor causes said valve to open allowing said supplemental gas flow to enter said primary conduit at said first location responsive to said net flow of gas in said primary conduit at said first location being in a direction generally away from said gas flow generator, and wherein said processor causes said valve to close preventing said supplemental gas flow from entering said primary conduit responsive to said net flow of gas in said primary conduit at said first location being in a direction other away from said gas flow generator.