ANESTHESIA REBREATHING APPARATUS

• US 3,814,091 A
• Filed: 01/17/1972
• Issued: 06/04/1974
• Est. Priority Date: 01/17/1972
• Status: Expired due to Term

• Current Assignee: Melvyn L. Henkin
• Original Assignee: Melvyn L. Henkin
• Inventors: Henkin, Melvyn L.
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Recla, Henry J.
• Application Number:
  US05/218,337
• Time in Patent Office: 869 Days
• Field of Search: 128/188,191,202,203,204,272,277,145,145.6,145.5,145.7,145.8,142.4,211,210,207 251/557 116/67 137/557
• US Class Current: 128/202.22
• CPC Class Codes: A61M 16/0078 Breathing bags
• CPC Class Codes: A61M 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 16/104 specially adapted for anaesthetics A61M16/18 takes precedence
• CPC Class Codes: F16L 55/04 Devices damping pulsations or vibrations in fluids F16L55/02 takes precedence
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y10S 128/909 Breathing apparatus with means for preventing patient cross-contamination

Abstract

A general anesthesia rebreathing system comprised of a disposable portion easily coupled to and decoupled from a permanent portion. The disposable portion includes conventional breathing tubing for coupling a source of fresh gas, as from an anesthesia machine, to a patient and in addition an overflow tube for coupling the patient end of the system to an overflow (popoff) valve, preferably mounted on the machine and constituting part of the permanent portion. The overflow tube entrance is located close to the patient end of the system and in communication with the tubing which conveys expired gas to a reservoir, such as a conventional breathing bag, mounted at the machine end. The arrangement assures that the patient'"'"''"'"'s initially expired dead space gas is conveyed by the tubing to the reservoir with subsequently expired alveolar gas being exhausted through the overflow tube and pop-off valve.

Claims

1. An anesthesia system for coupling a fresh gas supply means to a patient'"'"''"'"'s airway, said system including elongated breathing tube means having an open first end adapted to communicate with said airway and an open second end adapted to communicate with said supply means, said breathing tube means providing a flow path in the direction from said airway to said supply means and from said supply means to said airway;

overflow valve means having an input port and an exhaust port;

means mounting said overflow valve means in close proximity to said elongated breathing tube means second end; and

elongated overflow tube means, substantially co-extensive with said breathing tube means, having an open first end in communication with said breathing tube means in close proximity to the first end thereof and an open second end coupled to said overflow valve means input port, said overflow tube means providing a flow path in the direction from said breathing tube means to said overflow valve means.

2. The system of claim 1 including reservoir means having an entrance opening;

and means for communicating said reservoir means entrance opening with said breathing tube means second end.

3. The system of claim 2 including an overpressure relief means for permitting gas flow therepast in response to a positive pressure differential between first and second surfaces thereof;

and means exposing said overpressure relief means first surface to said breathing tube means first end and said second surface to ambient pressure.

4. The system of claim 2 including an overpressure relief means for permitting gas flow therepast in response to a positive pressure differential between first and second surfaces thereof;

means exposing said overpressure relief means first surface to the pressure in said first or second tube means and said second surface to ambient pressure;

said overpressure relief means including means for producing an audible alarm in response to gas flow therepast.

5. The system of claim 2 including means responsive to the pressure in said first tube means exceeding a threshold value for producing an audible alarm. 6. The system of claim 2 including a face mask having a single output port;

and a tubular elbow means coupling said mask output port to said first breathing tube first end.

7. The system of claim 2 wherein said reservoir means includes a first flexible wall defining a first chamber;

a second flexible wall defining a second chamber disposed so as to include at least a portion of said first flexible wall; and

wherein said reservoir entrance opening is formed in said first flexible wall for communication with said first chamber; and

a second opening formed in said second flexible wall for communication with said second chamber.

8. The system of claim 2 wherein said overflow valve means includes valve element means normally seated to hermetically isolate said input and exhaust ports and responsive to a positive pressure exceeding a first threshold from said input to said exhaust side of said valve element means for unseating said valve element means to permit gas flow therepast.

9. The system of claim 8 wherein said overflow valve means includes a control port;

and means responsive to the application of a positive pressure exceeding a second threshold to said control port for seating said valve element means independent of the pressure differential between said input and exhaust sides of said valve element means.

10. The system of claim 9 including means for selectively communicating the pressure available at said overflow valve means input port to said control port.

11. The system of claim 9 wherein said reservoir means includes a closed flexible outer wall;

a flexible septum wall peripherally sealed to the interior of said outer wall to define first and second hermetically isolated chambers;

said entrance opening existing in said outer wall and communicating with said first chamber;

a second opening existing in said outer wall and communicating with said second chamber; and

means for selectively communicating the pressure available in said second chamber to said control port.

12. The system of claim 2 wherein said reservoir means includes a closed flexible outer wall;

a flexible septum wall peripherally sealed to the interior of said outer wall to define first and second hermetically isolated chambers;

said entrance opening existing in said outer wall and communicating with said first chamber; and

a second opening existing in said outer wall and communicating with said second chamber.

13. The system of claim 12 wherein at least a portion of said reservoir means outer wall is transparent and wherein said septum wall is visible therethrough.

14. The system of claim 2 including a closed section of elastic tubing;

and means communicating the interior of said section of elastic tubing with the interior of said breathing tube means.

15. The system of claim 20 wherein said section of elastic tubing is concentrically mounted around the exterior of a portion of said breathing tube means;

means sealing at least one end of said section of elastic tubing to said breathing tube means; and

wherein said means communicating the interior of said section and the interior of said breathing tube means comprises an opening defined in said breathing tube means between the sealed ends of said section.

16. The system of claim 15 including elastic band means mounted around said section of elastic tubing with said opening in said breathing tube means between said elastic band means and said one sealed end for holding said section to said breathing tube means;

and gas leakage means formed in said section on the side of said elastic band means remote from said opening.

17. The system of claim 2 wherein said breathing tube means includes first and second breathing tubes having open first and second ends;

patient communications means defining a passageway there through having first and second open ends;

means forming a gas flow path between the first ends of said first And second breathing tube means and the first end of said passageway; and

means for communicating the second end of said second breathing tube means with said reservoir means entrance opening.

18. The system of claim 17 including a unidirectional expiratory gas valve means operatively disposed between said passageway first end and said first tube means first end for preventing gas flow in said first tube means in a direction from the second to the first end thereof;

and a unidirectional inspiratory gas valve means operatively disposed between said second tube means second end and said reservoir means entrance opening for preventing gas flow in said second tube means in a direction from the first to the second end thereof.

19. The system of claim 18 including means responsive to the pressure in said first or second tube means exceeding a threshold value for producing an audible alarm.

20. The system of claim 18 including a canister having open first and second ends respectively in communication with said inspiratory gas valve means and said reservoir entrance opening, said canister having CO2 absorber material therein.

21. The system of claim 18 including an overpressure relief means for permitting gas flow therepast in response to a positive pressure differential between first and second surfaces thereof;

and means exposing said overpressure relief means first surface to said passageway first end and said second surfaces to ambient pressure.

22. The system of claim 18 including an overpressure relief means for permitting gas flow therepast in response to a positive pressure differential between first and second surfaces thereof;

means exposing said overpressure relief means first surface to the pressure in said first or second tube means and said second surface to ambient pressure;

said overpressure relief means including means for producing an audible alarm in response to gas flow therepast.

23. The system of claim 18 wherein said expiratory valve means comprises a housing having an input port and a first output port and including passage means extending therebetween;

a valve member;

valve seat means formed within said passage means; and

means mounting said valve member in said passage means adjacent said valve seat means for permitting gas flow therepast only in response to a positive pressure differential between said input and said first output port.

24. The system of claim 8 wherein said expiratory valve means housing includes a second output port in communication with said first output port;

and means coupling said expiratory valve means second output port to said overflow tube means first end.

25. The system of claim 23 including an overpressure relief means for permitting gas flow therepast in response to a positive pressure differential between first and second surfaces thereof;

and means mounting said overpressure relief means in said expiratory valve means housing with the first surface thereof exposed to said input port and with the second surface thereof exposed to ambient pressure.

26. The system of claim 17 wherein said patient communication means comprises a face mask having a single output port;

and wherein said means forming a gas flow path includes Y-piece means having a single input port and first and second paths respectively coupling said input port to first and second output ports; and

a tubular elbow means coupling said mask output port to said Y-piece means input port.

27. The system of claim 26 including an expiratory valve means positioned in said Y-piece means first passage between said input port and said first output port;

said expiratory valve means including;

a valve member;

valve seat means formed within said first passage; and

means mounting said valve member in said first passage adjacent said valve seat means for permitting gas flow therepast only in response to a positive pressure differential between said Y-piece means input port and first output port.

28. The system of claim 27 wherein said Y-piece means includes a third output port in communication with said first output port;

means coupling said third output port to said overflow tube means first end;

an overpressure relief means for permitting gas flow in response to a positive pressure differential between first and second surfaces thereof; and

means mounting said overpressure relief means in said Y-piece means with the first surface thereof exposed to said input port and with the second surface thereof exposed to ambient pressure.

29. An anesthesia circuit useful in combination with a source of fresh anesthesia gases and a gas overflow valve, having input and exhaust ports, mounted proximate to said fresh gas source, said circuit comprising:

elongated breathing tube means having an open second end adapted to communicate with said fresh gas source and an open first end adapted to communicate with a patient'"'"''"'"'s airway, said breathing tube means providing a flow path in the direction from said airway to said fresh gas source and from said gas source to said airway; and

an elongated overflow tube means of substantially the same length as said breathing tube means, having an open first end in communication with said breathing tube means proximate to the first end thereof and an open second end adapted to communicate with said overflow valve input port, said overflow tube means providing a flow path in the direction from said breathing tube means to said overflow valve.

30. The system of claim 29 including reservoir means having an entrance opening;

and means for communicating said reservoir means entrance opening with said breathing tube means second end.

31. The system of claim 30 wherein said reservoir means includes a closed flexible outer wall;

a flexible septum wall peripherally sealed to the interior of said outer wall to define first and second hermetically isolated chambers;

said entrance opening existing in said outer wall and communicating with said first chamber; and

a second opening existing in said outer wall and communicating with said second chamber.

32. The system of claim 30 including a section of elastic tubing;

and means communicating the interior of said section of elastic tubing with the interior of said breathing tube means.

33. The system of claim 32 wherein said section of elastic tubing is concentrically mounted around the exterior of a portion of said breathing tube means;

means sealing at least one end of said section of elastic tubing to said breathing tube means; and

wherein said means communicating the interior of said section and the interior of said breathing tube means comprises an opening defined in said breathing tube means between the sealed ends of said section.

34. The system of claim 33 including elastic band means mounted around said section of elastic tubing with said opening in said breathing tube means between said elastic band means and said one sealed end for holding said section to said breathing tube means;

and gas leakage means formed in said section on the side of said elastic band means remote from said opening for permitting gas leakage therepast.

35. The system of claim 34 wherein said gas leakage means includes means for producing an audible alarm in response to gas leakage therepast.

36. The system of claim 30 wherein said breathing tube means includes first and second breathing tubes having open first and second ends;

patient communication means defining a passageway there through having first and second open ends;

means forming a gas flow path between the first ends of said first and second breathing tube means and the first end of said passageway; and

means for communicating the second end of said second breathing tube means with said reservoir means entrance opening.

37. The system of claim 36 including a unidirectional expIratory gas valve means operatively disposed between said passageway first end and said first tube means first end for preventing gas flow in said first tube means in a direction from the second to the first end thereof;

and a unidirectional inspiratory gas valve means operatively disposed between said second tube means second end and said reservoir means entrance opening for preventing gas flow in said second tube means in a direction from the first to the second end thereof.

38. The system of claim 37 including a canister having open first and second ends respectively in communication with said inspiratory gas valve means and said reservoir entrance opening, said canister having CO2 absorber material therein.

39. The system of claim 37 including an overpressure relief means for permitting gas flow therepast in response to a positive pressure differential between first and second surfaces thereof;

and means exposing said overpressure relief means first surface to said passageway first end and said second surface to ambient pressure.

40. The system of claim 26 including an overpressure relief means for permitting gas flow therepast in response to a positive pressure differential between first and second surfaces thereof;

means exposing said overpressure relief means first surface to the pressure in said first or second tube means and said second surface to ambient pressure;

said overpressure relief means including means for producing an audible alarm in response to gas flow therepast.

41. The system of claim 37 wherein said expiratory valve means comprises a housing having an input port and a first output port and including passage means extending there between;

a valve member;

valve seat means formed within said passage means; and

means mounting said valve member in said passage means adjacent said valve seat means for permitting gas flow therepast only in response to a positive pressure differential between said input and said first output port.

42. The system of claim 41 wherein said expiratory valve means housing includes a second output port in communication with said first output port;

and means coupling said expiratory valve means second output port to said overflow tube means first end.

43. The system of claim 36 wherein said patient communication means comprises a face mask having a single output port;

and wherein said means forming a gas flow path includes Y-piece means having a single input port and first and second paths respectively coupling said input port to first and second output ports; and

a tubular elbow means coupling said mask output port to said Y-piece means input port.

44. The system of claim 43 including an expiratory valve means positioned in said Y-piece means first passage between said input port and said first output port;

said expiratory valve means including;

a valve member;

valve seat means formed within said first passage; and

, means mounting said valve member in said first passage adjacent said valve seat means for permitting gas flow therepast only in response to a positive pressure differential between said Y-piece means input port and first output port.

45. The system of claim 44 wherein said Y-piece means includes a third output port in communication with said first output port;

means coupling said third output port to said overflow tube means first end;

an overpressure relief means for permitting gas flow in response to a positive pressure differential between first and second surface thereof; and

, means mounting said overpressure relief means in said Y-piece means with the first surface thereof exposed to said input port and with the second surface thereof exposed to ambient pressure.