Breathing circuits having unconventional respiratory conduits and systems and methods for optimizing utilization of fresh gases

• US 20050039747A1
• Filed: 09/16/2004
• Published: 02/24/2005
• Est. Priority Date: 09/24/2001
• Status: Active Grant

• Current Assignee: Ambu A/S (AMBU)
• Original Assignee: F-Concepts, LLC
• Inventors: Fukunaga, Blanca M., Fukunaga, Alex S., Fukunaga, Atsuo F.
• Granted Patent: US 7,275,541 B2
• Time in Patent Office: Days
• US Class Current: 128/204.180
• CPC Class Codes: A61M 16/00 Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes stimulating the respiratory movement by mechanical, pneumatic or electrical means, iron lungs combined with gas breathing means A61H31/00
• CPC Class Codes: A61M 16/0045 Means for re-breathing exhaled gases, e.g. for hyperventilation treatment
• CPC Class Codes: A61M 16/0078 Breathing bags
• CPC Class Codes: A61M 16/0081 Bag or bellow in a bottle
• CPC Class Codes: A61M 16/01 specially adapted for anaesthetising A61M16/104, A61M16/18 take precedence
• CPC Class Codes: A61M 16/08 Bellows; Connecting tubes having means for taking samples G01N1/22; Water traps; Patient circuits
• CPC Class Codes: A61M 16/10 Preparation of respiratory gases or vapours
• CPC Class Codes: A61M 16/105 Filters A61M16/047, A61M16/22 take precedence; water traps A61M16/08
• CPC Class Codes: A61M 16/22 Carbon dioxide-absorbing devices ; Other means for removing carbon dioxidecartridges with absorbing substances for respiratory apparatus A62B19/00
• CPC Class Codes: Y10S 128/911 Unilimb inhalation-exhalation breathing tubes
• CPC Class Codes: Y10S 128/912 Connections and closures for tubes delivering fluids to or from the body

Abstract

A breathing circuit comprising first and second conduits, wherein at least one of the conduits is a non-conventional conduit. In an embodiment, a multilumen unilimb breathing circuit has first and second conduits, wherein when the proximal ends of said first and second conduits are each connected to an inlet and outlet fitting, respectively, axial extension or contraction of the second conduit causes a corresponding axial extension or contraction of the first conduit. In an embodiment, at least one of said conduits is coiled. In another embodiment, a coiled conduit is contained within an outer flexible conduit that is axially extendable and compressible, forming a unilimb, multilumen respiratory circuit. The outer flexible conduit may be pleated to provide for non-rebounding axial extension and contraction. The multilumen respiratory circuit can provide a variable rebreathing volume. In an embodiment, at least one tube in a multilumen respiratory conduit is radially collapsible and radially expandable to a maximum radius for carrying respiratory gases to and from a patient. In an embodiment, first and second conduits are formed of accordion-like pleated tubing, wherein both conduits can be connected to a proximal fitting or proximal terminal at their proximal end; in an embodiment, the first and second accordion-like pleated tubes can also be connected to a common distal fitting. The methods and systems can be used to administer anesthesia and for other purposes.

Claims

1. A multilumen, unilimb breathing circuit comprising first and second conduits, each of said conduits having a proximal and a distal end, wherein said proximal end of said first conduit can be operatively connected to an inlet for respiratory gases and said second conduit can be operatively connected to an outlet for respiratory gases, and said distal ends of said first and second conduits can be operatively connected to a distal fitting for connection to a patient, and axial extension or contraction of said second conduit causes a corresponding axial extension or contraction of said first conduit, wherein upon axial extension of said second conduit from a first compressed axial conformation to a second expanded axial conformation, or vice versa, said second conduit will retain said second conformation, and said first conduit will expand or contract in length with corresponding axial expansion or contraction of said second conduit, wherein said first and second conduits are proximal to the breathing circuit distal fitting.

2. The circuit of claim 1, wherein said first conduit comprises a coiled tube.

3. The circuit of claim 1, wherein at least a portion of said first conduit is contained within said second conduit.

4. The circuit of claim 1, having an arrangement selected from the group consisting of (a) wherein said second conduit comprises a second coiled tube, (b) wherein at least a portion of said first conduit comprises a first coiled tube coiled about at least a portion of said second conduit, (c) wherein said second conduit comprises a second coiled tube, wherein said first and second tubes have distal and proximal ends, and the distal ends of said first and second tubes are operatively connected, and (d) wherein said second conduit comprises a second coiled tube, wherein at least a portion of said first and second tubes are in parallel coiled relationship.

5. The circuit of claim 1, wherein said first and second conduits have a common proximal fitting at the proximal ends thereof.

6. The circuit of claim 5, wherein said first and second conduits have a common distal fitting at the distal ends thereof.

7. The circuit of claim 6, wherein said distal fitting provides for fluid connection of the distal end of said first conduit to said distal end of said second conduit.

8. The circuit of claim 7, wherein said distal fitting provides for adjustment of the axial distance between the connection of said distal end of said first conduit with said distal fitting and the connection of said distal end of said second conduit with said distal fitting.

9. The circuit of claim 1, wherein said second conduit comprises accordion-like pleated tubing.

10. The circuit of claim 6, wherein said second conduit comprises accordion-like pleated tubing.

11. The circuit of claim 1, wherein said first and second conduits comprise accordion-like pleated tubing.

12. The circuit of claim 11, further comprising a filter.

13. The circuit of claim 12, wherein said circuit has a distal and a proximal end and said filter is located at said proximal end of said circuit.

14. A multilumen breathing circuit comprising first and second tubes, each of said tubes having a proximal and a distal end, wherein said proximal end of said first tube can be connected to an inlet for respiratory gases and said proximal end of said second tube can be connected to an outlet for respiratory gases, wherein at least one of said tubes can radially collapse when not in use.

15. The circuit of claim 14, wherein said tubes have an arrangement selected from the group consisting of (a) at least a portion of one tube is contained within another of said tubes, and (b) said tubes are connected at periodic locations on their exteriors, and (c) said tubes are connected at the distal end by a distal fitting and at least a portion of said tubes are substantially spaced apart.

16. The circuit of claim 14, wherein said at least one tube that can radially collapse, when inflated at pressures encountered in providing assisted ventilation and/or anesthesia to humans and other mammals, has a compliance of less than about 20%.

17. The circuit of claim 14, wherein said at least one tube that can radially collapse, when inflated at pressures encountered in providing assisted ventilation and/or anesthesia to humans and other mammals, has a compliance of less than about 10%.

18. The circuit of claim 14, wherein said at least one tube that can radially collapse has a minimum cross-sectional area when fully inflated and can collapse when not in use so that the collapsed cross-sectional area of said minimum cross-sectional area when fully inflated is less than about 90% of said inflated cross-sectional area.

19. The circuit of claim 17, wherein said at least one tube that can radially collapse has a minimum cross-sectional area when fully inflated and can collapse when not in use so that the collapsed cross-sectional area of said minimum cross-sectional area when fully inflated is less than about 10% of said inflated cross-sectional area.

20. A multilumen, unilimb breathing circuit having a machine end and a patient end, comprising first and second conduits, and having a distal fitting at said patient end, each of said conduits having a proximal and a distal end, wherein said proximal end of said first conduit can be connected to a machine inlet for respiratory gases and said second conduit can be connected to a machine outlet for respiratory gases, wherein flows passing through said conduits will merge proximate to or in said distal fitting, and axial extension or contraction of said second conduit causes a corresponding axial extension or contraction of said first conduit, wherein upon axial extension of said second conduit from a first compressed axial conformation to a second expanded axial conformation, or vice versa, said second conduit will retain said second conformation, and said first conduit will expand or contract in length with corresponding axial expansion or contraction of said second conduit, wherein the airflow resistance of said first and second conduits is sufficiently low to meet the requirements for at least one of the group consisting of spontaneous ventilation or assisted ventilation.

21. The circuit of claim 20, wherein the compliance is sufficiently small to meet the requirements for at least one of the group consisting of spontaneous ventilation or assisted ventilation.

22. The circuit of claim 20, wherein said circuit has at least one characteristic selected from the group consisting of (a) at least a portion of said first conduit is contained within said second conduit, and (b) wherein the compliance is sufficiently small to meet the requirements for at least one of the group consisting of spontaneous ventilation or assisted ventilation.

23. The circuit of claim 20, wherein said first and second conduits have a common proximal fitting at the proximal ends thereof.

24. The circuit of claim 22, wherein said first and second conduits have a common proximal fitting at the proximal ends thereof.

25. The circuit of claim 20, wherein said first and second conduits have a common proximal terminal at the proximal ends thereof.

26. The circuit of claim 22, wherein said first and second conduits have a common proximal terminal at the proximal ends thereof.

27. The circuit of claim 23, wherein said first and second conduits have a common distal fitting at the distal ends thereof.

28. The circuit of claim 24, wherein said first and second conduits have a common distal fitting at the distal ends thereof.

29. The circuit of claim 25, wherein said first and second conduits have a common distal fitting at the distal ends thereof.

30. The circuit of claim 26, wherein said first and second conduits have a common distal fitting at the distal ends thereof.

31. The circuit of any one of claims 20-30, wherein said second conduit comprises accordion-like pleated tubing.

32. The circuit of claim 31, wherein said first conduit comprises accordion-like pleated tubing.

33. The circuit of claim 31, wherein the type of said circuit is selected from the group consisting of a Mapleson type circuit, and a circle circuit.

34. The circuit of claim 32, wherein the type of said circuit is selected from the group consisting of a Mapleson type circuit, and a circle circuit.

35. The circuit of claim 31, wherein said first conduit comprises a coiled tube.

36. The circuit of claim 35, wherein the type of said circuit is selected from the group consisting of a Mapleson type circuit, and a circle circuit.

37. The circuit of claim 35, further comprising a filter.

38. The circuit of claim 31, further comprising a filter.

39. The circuit of claim 38, wherein said filter is located at said proximal end of said circuit.

40. The circuit of claim 39, wherein said conduits, said distal fitting, and said proximal fitting or said proximal terminal are bonded together to form an integral circuit.

41. A multilumen, unilimb breathing circuit having a machine end and a patient end, comprising first and second conduits, a distal fitting at said patient end, and a proximal fitting at said machine end, each of said conduits having a proximal and a distal end, wherein said proximal end of said first conduit can be connected to a machine inlet for respiratory gases and said second conduit can be connected to a machine outlet for respiratory gases via said proximal fitting, said distal ends of said first and second conduits being operatively connected to each other, wherein flows passing through said conduits will merge proximate to or in said distal fitting, and axial extension or contraction of said second conduit causes a corresponding axial extension or contraction of said first conduit, wherein upon axial extension of said second conduit from a first compressed axial conformation to a second expanded axial conformation, or vice versa, said second conduit will retain said second conformation, and said first conduit will expand or contract in length with corresponding axial expansion or contraction of said second conduit, wherein said first and second conduit comprise accordion-like pleated tubing, at least a portion of said first conduit is contained within said second conduit, and said proximal fitting is directly connected to the proximal ends of said first and second conduits.

42. The circuit of claim 41, wherein said operative connection of said distal ends of said first and second conduits is selected from the group consisting of said distal ends of said first and second conduits being connected to said distal fitting, and said distal end of said second conduit being connected to said distal fitting and said distal end of said first conduit being connected to the interior of said second conduit proximate to the connection of said second conduit to said distal fitting.

43. The circuit of claim 42, further comprising a filter.

47. The circuit of any one of claims 41, 42, 44, and 45, wherein at least one of said conduit connections to one another, to said distal fitting, to said proximal terminal, and to said proximal fitting is bonded.

44. A multilumen, unilimb breathing circuit having a machine end and a patient end, comprising first and second conduits, a distal fitting at said patient end, and a proximal terminal at said machine end, each of said conduits having a proximal and a distal end, wherein said proximal end of said first conduit can be connected to a machine inlet for respiratory gases and said second conduit can be connected to a machine outlet for respiratory gases via said proximal terminal, said distal ends of said first and second conduits being operatively connected to each other, wherein flows passing through said conduits will merge proximate to or in said distal fitting, and axial extension or contraction of said second conduit causes a corresponding axial extension or contraction of said first conduit, wherein upon axial extension of said second conduit from a first compressed axial conformation to a second expanded axial conformation, or vice versa, said second conduit will retain said second conformation, and said first conduit will expand or contract in length with corresponding axial expansion or contraction of said second conduit, wherein said first and second conduit comprise accordion-like pleated tubing, at least a portion of said first conduit is contained within said second conduit, and said proximal terminal is directly connected to the proximal ends of said first and second conduits.

45. The circuit of claim 44, wherein said operative connection of said distal ends of said first and second conduits is selected from the group consisting of said distal ends of said first and second conduits being connected to said distal fitting, and said distal end of said second conduit being connected to said distal fitting and said distal end of said first conduit being connected to the interior of said second conduit proximate to the connection of said second conduit to said distal fitting.

46. The circuit of claim 45, further comprising a filter.