Conduit with heated wick

• US 20040118401A1
• Filed: 10/14/2003
• Published: 06/24/2004
• Est. Priority Date: 06/21/2000
• Status: Active Grant

• Current Assignee: Fisher & Paykel Healthcare Limited
• Original Assignee: Fisher & Paykel Healthcare Limited
• Inventors: Smith, Daniel John, Baldwin, David Peter
• Granted Patent: US 8,037,882 B2
• Time in Patent Office: Days
• US Class Current: 128/204.17
• 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 16/0816 Joints or connectors
• 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 16/0891 Closed circuit, e.g. for anaesthesia
• 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 16/1075 by influencing the temperature A61M16/1045 takes precedence
• CPC Class Codes: A61M 16/1095 in the connecting tubes
• CPC Class Codes: A61M 16/142 with semi-permeable walls separating the liquid from the respiratory gas
• CPC Class Codes: A61M 2205/0238 the material being a coating or protective layer
• CPC Class Codes: A61M 2205/3653 by Joule effect, i.e. electric resistance
• CPC Class Codes: A61M 2205/7527 liquophilic, hydrophilic
• CPC Class Codes: A61M 2207/10 Device therefor

Abstract

A conduit for a breathing circuit includes a heater associated, at least in part, with a hydrophilic layer. The purpose of the heater is to evaporate any condensed liquid collecting in the conduit, which is first sucked up by the hydrophilic layer. The heated wick reduces the risk of collected water being passed to the patient and causing choking fits or discomfit. It is preferred that the heated wick lies freely in the conduit to settle at low points in the conduit where condensation may collect.

Claims

1. A conduit for a breathing circuit including heating means located within said conduit, said heating means comprising an elongate heating element covered with an inner electrical insulating layer and at least partially covered with an outer hydrophilic layer, there being no means for direct supply of water or fluid to said hydrophilic layer from outside said conduit.

2. A conduit as claimed in claim 1, wherein said hydrophilic layer is formed so as to absorb water due to its structure.

3. A conduit as claimed in claim 2 wherein said heating means lies freely in said conduit to settle over at least some of its length at low points in said conduit where condensed water vapour may collect.

4. A conduit as claimed in claim 2 wherein said conduit is an expiratory conduit and said heating means is located in an expiratory flow path of said conduit and at least a length of said conduit has a conduit wall wherein at least a region of said conduit wall is of a breathable material.

5. A conduit as claimed in claim 4 wherein said at least a region is or are distributed over said length of said conduit.

6. A conduit as claimed in claim 3 wherein said conduit is an expiratory conduit and said heating means is located in an expiratory flow path of said conduit and at least a length of said conduit has a conduit wall wherein at least a region of said conduit wall is of a breathable material.

7. A conduit as claimed in claim 6 wherein said at least a region is or are distributed over said length of said conduit.

8. A conduit as claimed in claim 1, wherein said hydrophilic layer is a braided sheath.

9. A conduit is claimed in claim 2, wherein said hydrophilic layer is a braided sheath.

10. A conduit is claimed in claim 3, wherein said hydrophilic layer is a braided sheath.

11. A conduit is claimed in claim 4, wherein said hydrophilic layer is a braided sheath.

12. A breathing circuit as claimed in claim 1, wherein said breathing circuit is a coaxial breathing circuit including an inner conduit and an outer conduit, the inner conduit located within the outer conduit, such that one of an inspiratory or expiratory flow paths are provided within the inner conduit and the other of the inspiratory or expiratory flow paths is provided between the inner conduit and the outer conduit and at least a region of the wall of said inner conduit is of a breathable material.