Expiratory limb for a breathing circuit

• US 20040099268A1
• Filed: 07/18/2003
• Published: 05/27/2004
• Est. Priority Date: 05/10/2000
• Status: Active Grant

• Current Assignee: Fisher & Paykel Healthcare Limited
• Original Assignee: Fisher & Paykel Healthcare Limited
• Inventors: Smith, Daniel John, Baldwin, David Peter, Powell, Kevin Blake, Millar, Gavin Walsh
• Granted Patent: US 7,140,366 B2
• Time in Patent Office: Days
• US Class Current: 128/203.16
• CPC Class Codes: A61M 16/08 Bellows; Connecting tubes having means for taking samples G01N1/22; Water traps; Patient circuits
• CPC Class Codes: A61M 16/0808 Condensation traps
• CPC Class Codes: A61M 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 16/0875 Connecting tubes
• CPC Class Codes: A61M 16/0883 Circuit type
• CPC Class Codes: A61M 16/1045 Devices for humidifying or heating the inspired gas by using recovered moisture or heat from the expired gas
• CPC Class Codes: A61M 16/1065 in the expiratory path
• CPC Class Codes: A61M 2039/082 Multi-lumen tubes
• CPC Class Codes: A61M 2205/7536 allowing gas passage, but preventing liquid passage, e.g. liquophobic, hydrophobic, water-repellent membranes
• CPC Class Codes: A61M 2207/00 Methods of manufacture, assembly or production
• CPC Class Codes: A61M 2207/10 Device therefor
• CPC Class Codes: A61M 2230/432 partial CO2 pressure (P-CO2)
• CPC Class Codes: A61M 39/08 Tubes; Storage means specially adapted therefor
• CPC Class Codes: B29C 48/0019 combined with shaping by flattening, folding or bending
• CPC Class Codes: B29C 48/04 Particle-shaped making granules B29B9/00
• CPC Class Codes: B29C 48/07 Flat, e.g. panels
• CPC Class Codes: B29C 48/09 Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• CPC Class Codes: B29C 48/301 having reciprocating, oscillating or rotating parts
• CPC Class Codes: B29C 48/32 with annular openings, e.g. for forming tubular articles
• CPC Class Codes: B29C 53/585 the cross-section varying along their axis, e.g. tapered, with ribs, or threads, with socket-ends
• CPC Class Codes: B29C 53/64 : and moving axially
• CPC Class Codes: B29C 53/68 : with rotatable winding feed member
• CPC Class Codes: B29C 53/70 : and moving axially
• CPC Class Codes: B29L 2023/007 : Medical tubes other than catheters catheters B29L2031/7542
• CPC Class Codes: B29L 2031/753 : Medical equipment; Accessories therefor bloodbags, medical bags B29L2031/7148; artificial eyes B29L2011/0008

Abstract

A breathing circuit component includes an inlet, an outlet and an enclosing wall. The enclosing wall defines a gases passageway between the inlet and the outlet. At least a region of the enclosing wall is formed from a breathable material that allows the passage of water vapour without allowing the passage of liquid water or respiratory gases. The breathing circuit component may be the expiratory limb of a breathing circuit.

Claims

1. A breathing circuit limb including:

an inlet,

an outlet, and

an enclosing wall defining a substantially singular exhalation flow passage between said inlet and said outlet, at least a region of said enclosing wall being of a material that allows the passage of water vapour without allowing the passage of liquid water or respiratory gases, and

a water vapour flow path from said exhalation flow passage to ambient air through said material.

2. A breathing circuit limb as claimed in claim 1 wherein said material is selected from:

(a) hydrophilic thermoplastics,

(b) perfluorinated polymers

(c) woven treated fabrics.

3. A breathing circuit limb as claimed in claim 1 wherein said material is a perfluorinated polymer membrane.

4. A breathing circuit limb as claimed in claim 1 wherein said material is a hydrophilic polyester block copolymer.

5. A breathing circuit limb as claimed in claim 1 wherein said flow passage is a conduit and said region or regions is or are distributed over the length of said conduit.

6. A breathing circuit limb as claimed in claim 5 wherein said region or regions are elongate and run at least a substantial part of the length of said conduit.

7. A breathing circuit limb as claimed in claim 5 including a series of said regions spaced along the length of said conduit.

8. A breathing circuit limb as claimed in claim 5 wherein said conduit including said regions is extruded.

9. A breathing circuit limb as claimed in claim 8 wherein the entire of said extruded conduit is of a material that allows the passage of water vapour without allowing the passage of liquid water or respiratory gases.

10. A breathing circuit limb as claimed in claim 8 wherein said regions of a material that allows the passage of water vapour without allowing the passage of liquid water or respiratory gases are one or more longitudinal strips running the complete length of said conduit.

11. A breathing circuit limb as claimed in claim 5 wherein said conduit includes at least one helically wound polymer tape or strip, part or all of said strip being of a material that allows the passage of water vapour without allowing the passage of liquid water or respiratory gases, respective edges of adjacent turns of said strip being adjoining or overlapping and bonded.

12. A breathing circuit limb as claimed in claim 5 wherein said conduit includes at least one longitudinal strip, part or all of said strip being of a material that allows the passage of water vapour without allowing the passage of liquid water or respiratory gases, said strip or strips extending parallel to the axis of said conduit, edges of said strip or strips adjoining or overlapping to form an enclosed tube and bonded.

13. A breathing circuit limb as claimed in claim 5 wherein said conduit is a blown film tube of a material that allows the passage of water vapour without allowing the passage of liquid water or respiratory gases.

14. A breathing circuit limb as claimed in any one of claims 10 to 13 including lateral reinforcement against crushing.

15. A breathing circuit limb as claimed in claim 14 wherein said lateral reinforcement includes a plurality of annular corrugations distributed over the length of said conduit.

16. A breathing circuit limb as claimed in claim 14 wherein said lateral reinforcement is a helical bead or a series of annular ring beads or ribs distributed over the length of said conduit.

17. A breathing circuit limb as claimed in claim 11 including lateral reinforcement against crushing wherein said lateral reinforcement is a helical bead disposed over said adjoining or overlapping edges between turns of strip.

18. A breathing circuit limb as claimed in claim 14 wherein said lateral reinforcement is a skeletal reinforcing structure within said conduit.

19. Apparatus for forming a breathing circuit conduit comprising:

a former, onto which a tube wall can be deposited and which advances said deposited tube wall in an advance axis and rotates said deposited tube wall about said advance direction, the speed of said advance and the speed of said rotation together defining a pitch,

at least one film laying head which deposits a film on said former, the combined width of said film deposited by said film laying heads being wider than said pitch such that adjacent turns of laid film overlap to form an overlap seam,

a bead laying head for each said film laying head, each said bead laying head laying a reinforcing bead on an overlap seam,

an axial thread laying head, said thread laying head fitted over and around said former and carrying a plurality of thread feeds, each thread feed allowing the drawing of a thread from a reserve, and

a rotator to rotate said axial thread laying head at substantially the same speed as the expected rotation speed of said tube.

20. Apparatus as claimed in claim 19 wherein, in said advance direction, said bead laying head precedes said thread laying head.

21. Apparatus as claimed in claim 19 wherein, in said advance direction, said bead laying head succeeds said thread laying head.

22. Apparatus as claimed in claim 21 including at least one, but less than the number of said bead laying heads, reinforcement laying head, between said thread laying head and said bead laying head in said advance direction, said reinforcement laying head depositing a mesh tape onto said former, the combined width of said mesh tapes deposited by said mesh laying heads being greater than said pitch.