RESISTANCE MATCHING IN A PATIENT CIRCUIT

• US 20110226246A1
• Filed: 11/21/2009
• Published: 09/22/2011
• Est. Priority Date: 12/11/2008
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Paul, Zachary Dean, Ho, Peter Chi Fai
• Granted Patent: US 8,813,745 B2
• Time in Patent Office: Days
• US Class Current: 128/204.18
• CPC Class Codes: A61M 16/0066 Blowers or centrifugal pumps
• CPC Class Codes: A61M 16/0069 the speed thereof being controlled by respiratory parameters, e.g. by inhalation
• CPC Class Codes: A61M 16/0075 Bellows-type
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/04 Tracheal tubes catheters in general A61M25/00
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/0666 Nasal cannulas or tubing devices for improving normal breathing through the nose A61F5/08; nose filters A62B23/06; outside holding devices A61M25/02
• CPC Class Codes: A61M 16/0875 Connecting tubes
• CPC Class Codes: A61M 16/12 by mixing different gases
• CPC Class Codes: A61M 16/20 Valves specially adapted to medical respiratory devices
• CPC Class Codes: A61M 16/204 used for inhalation control
• CPC Class Codes: A61M 16/208 Non-controlled one-way valves, e.g. exhalation, check, pop-off non-rebreathing valves
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2202/0208 Oxygen
• CPC Class Codes: A61M 2202/0275 Nitric oxide [NO]

Abstract

A system configured to deliver pressurized gas to an airway of a subject in accordance with a predetermined therapeutic algorithm. The system includes a pressure generator that generates a pressurized flow of breathable gas and a circuit that communicates the pressurized flow of breathable gas from the pressure generator to the airway of the subject. In order to facilitate the delivery of the pressurized gas to the airway of the subject in accordance with the predetermined therapeutic algorithm, a resistance of the circuit to gas flow is supplemented so that the overall resistance of the circuit is at or near a predetermined level.

Claims

1. A circuit that defines a gas flow path between a pressure generator and an airway of a subject to enable the provision of gas from the pressure generator to the airway of the subject, the circuit comprising:

an interface appliance configured to provide gas to and receive gas from an airway of a subject, the interface appliance forming a flow path between a conduit interface opening and one or more subject interface openings, wherein the one or more subject interface openings communicate gas between the airway of the subject and the interior of the interface appliance, and wherein the flow path formed by the interface appliance between the conduit interface opening and the one or more subject interface openings has a first resistance to gas flow;

a conduit that forms a flow path between a first opening and a second opening, wherein the first opening receives gas from a pressure generator, wherein gas within the flow path formed by the conduit is communicated to the conduit interface opening of the interface appliance via the second opening, and wherein the flow path formed by the conduit between the first opening and the second opening has a second resistance to gas flow; and

a flow limiting feature disposed within the circuit, the flow limiting feature providing a supplemental resistance to gas flow within the circuit, and wherein the overall resistance to gas flow within the circuit is a function, at least in part, of an aggregation of the first resistance, the second resistance, and the supplemental resistance, and wherein the flow limiting feature is configured such that the supplemental resistance increases the overall resistance to gas flow within the circuit to a predetermined resistance.

2. The circuit of claim 1, wherein the one or more flow limiting features comprise at least one flow limiting feature formed integrally on the interface appliance.

3. The circuit of claim 2, wherein the at least one flow limiting feature formed integrally on the interface appliance comprises a restriction on gas flow formed at or near the conduit interface opening.

4. The circuit of claim 1, further comprising a removable resistance module forming a flow path between a first module opening and a second module opening, the removable resistance module having at least one of the one or more flow limiting feature disposed in the flow path between the first module opening and the second module opening, wherein removable resistance module is selectably insertable into the circuit to increase the overall resistance to gas flow within the circuit.

5. The circuit of claim 4, wherein the removable resistance module is selectably insertable into the circuit by releasably engaging the first module opening with the first opening of the conduit.

6. The circuit of claim 4, wherein the removable resistance module is selectably insertable into the circuit by releasably engaging the first module opening with the conduit interface opening of the interface appliance.

7. The circuit of claim 6, wherein the removable resistance module is further selectably insertable into the circuit by releasably engaging the second module opening with the second opening of the conduit.

8. The circuit of claim 4, further comprising a connection module that connects the flow path formed by the conduit with the flow path formed by the interface appliance, the connection module forming one or more exhaust openings configured to exhaust gas exhaled by the subject from the circuit, wherein the connection module has a third resistance to gas flow, and wherein the overall resistance to gas flow within the circuit is a function, at least in part, of an aggregation of the first resistance, the second resistance, the third resistance, and the supplemental resistance.

9. The circuit of claim 8, wherein the removable resistance module is selectably insertable into the circuit by releasably engaging the first module opening with the connection module.

10. The circuit of claim 1, further comprising a plurality of removable resistance modules, wherein each of the removable resistance modules forms a flow path that is selectably insertable into the circuit and includes at least one of the one or more flow limiting features.

11. A method of providing a circuit that defines a gas flow path between a pressure generator and an airway of a subject to enable the provision of gas from the pressure generator to the airway of the subject, the method comprising:

configuring a circuit that forms a flow path for delivering gas from a pressure generator to an airway of the subject, the circuit comprising;

an interface appliance configured to provide gas to and receive gas from an airway of a subject, the interface appliance forming a flow path between a conduit interface opening and one or more subject interface openings, wherein the one or more subject interface openings communicate gas between the airway of the subject and the interior of the interface appliance, and wherein the flow path formed by the interface appliance between the conduit interface opening and the one or more subject interface openings has a first resistance to gas flow; and

a conduit that forms a flow path between a first opening and a second opening, wherein the first opening receives gas from a pressure generator, wherein gas within the flow path formed by the conduit is communicated to the conduit interface opening of the interface appliance via the second opening, and wherein the flow path formed by the conduit between the first opening and the second opening has a second resistance to gas flow; and

supplementing the overall resistance of the circuit to gas flow so that the overall resistance of the circuit to gas flow reaches a predetermined resistance, wherein supplementing the overall resistance of the circuit comprises including within the circuit one or more flow limiting features, the one or more flow limiting features providing a supplemental resistance to gas flow within the circuit that increases the overall resistance of the circuit to the predetermined resistance.

12. The method of claim 11, further comprising connecting the circuit to a pressure generator.

13. The method of claim 12, further comprising operating the pressure generator such that gas is delivered to the subject from the pressure generator via the circuit.

14. The method of claim 11, wherein the one or more flow limiting features comprise at least one flow limiting feature formed integrally on the interface appliance.

15. The method of claim 14, wherein the at least one flow limiting feature formed integrally on the interface appliance comprises a restriction on gas flow formed at or near the conduit interface opening.

16. The method of claim 11, wherein including within the circuit one or more flow limiting features comprises selectably inserting a removable resistance module into the circuit, the removable resistance module forming a flow path between a first module opening and a second module opening, the removable resistance module having at least one of the one or more flow limiting feature disposed in the flow path between the first module opening and the second module opening.

17. The method of claim 16, wherein the removable resistance module is selectably inserted into the circuit at least in part by releasably engaging the first module opening with the first opening of the conduit.

18. The method of claim 16, wherein the removable resistance module is selectably inserted into the circuit at least in part by releasably engaging the first module opening with the conduit interface opening of the interface appliance.

19. The method of claim 18, wherein the removable resistance module is further selectably inserted into the circuit at least in part by releasably engaging the second module opening with the second opening of the conduit.

20. The method of claim 16, wherein the circuit further comprises a connection module that connects the flow path formed by the conduit with the flow path formed by the interface appliance, the connection module forming one or more exhaust openings configured to exhaust gas exhaled by the subject from the circuit, the connection module having a third resistance to gas flow, and wherein the overall resistance to gas flow within the circuit is a function, at least in part, of an aggregation of the first resistance, the second resistance, the third resistance, and the supplemental resistance.

21. The method of claim 20, wherein the removable resistance module is selectably inserted into the circuit by releasably engaging the first module opening with the connection module.

22. A circuit that defines a gas flow path between a pressure generator and an airway of a subject to enable the provision of gas from the pressure generator to the airway of the subject, the circuit comprising:

means for interfacing the circuit with the airway of a subject to provide gas to and receive gas from the airway of the subject, wherein the means for interfacing has a first resistance to gas flow;

means for conveying gas between a pressure generator and the means for interfacing, wherein the means for conveying gas has a second resistance to gas flow; and

means for limiting gas flow within the circuit, the means for limiting gas flow providing a supplemental resistance to gas flow within the circuit, and wherein the overall resistance to gas flow within the circuit is a function, at least in part, of an aggregation of the first resistance, the second resistance, and the supplemental resistance, and wherein the means for limiting gas flow are configured such that the supplemental resistance increases the overall resistance to gas flow within the circuit to a predetermined resistance.

23. The circuit of claim 22, wherein the means for limiting gas flow within the circuit comprise at least one flow limiting feature formed integrally on the means for interfacing.

24. The circuit of claim 23, wherein the at least one flow limiting feature formed integrally on the means for interfacing comprises a restriction on gas flow formed at or near an opening in the means for interfacing through which gas from the means for conveying gas passes to enter the means for interfacing.

25. The circuit of claim 22, further comprising a means for increasing the circuit resistance that is selectably insertable into the circuit to increase the overall resistance to gas flow within the circuit.

26. The circuit of claim 25, wherein the means for increasing the circuit resistance is releasably engagable with the means for conveying.

27. The circuit of claim 25, wherein the means for increasing the circuit resistance is releasably engagable with the means for interfacing.

28. The circuit of claim 27, wherein the means for increasing the circuit resistance is further releasably engagable with the means for conveying.

29. The circuit of claim 25, further comprising means for connecting the means for conveying with the means for interfacing, the means for connecting comprising means for exhausting gas exhaled by the subject from the circuit, wherein the means for connecting has a third resistance to gas flow, and wherein the overall resistance to gas flow within the circuit is a function, at least in part, of an aggregation of the first resistance, the second resistance, the third resistance, and the supplemental resistance.

30. The circuit of claim 29, wherein the means for increasing the circuit resistance is releasably engagable with the means for connecting.

31. The circuit of claim 25, means for increasing the circuit resistance comprises a plurality of removable resistance modules, wherein each of the removable resistance modules forms a flow path that is selectably insertable into the circuit and includes at least one flow limiting feature.