Anesthesia rebreathing apparatus including improved reservoir means
First Claim
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 and including 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;
means mounting said overflow valve means in close proximity to said elongated breathing tube means second end;
elongated overflow tube means, substantially coextensive 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;
a reservoir assembly including outer wall means enclosing a volume and inner wall means partitioning said volume into first and second hermetically isolated chambers, said inner wall means being flexible for transmitting pressures between said chambers;
means for communicating said first chamber with said breathing tube means second end;
said overflow valve means including 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;
means for selectively communicating the pressure in said second chamber to said control port;
container means having a flexible wall capable of being manually squeezed to increase the pressure therein; and
means for communicating the pressure in said container means to said reservoir assembly second chamber.
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Accused Products
Abstract
Apparatus useful in a general anesthesia rebreathing system comprised of a disposable portion easily coupled to and decoupled from a permanent portion. The disposable portion includes 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 (pop-off) 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. 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. The reservoir comprises one chamber of an assembly including two hermetically isolated chambers. The second chamber communicates through a selector valve means with either (1) a flexible container which can be squeezed by an attending anesthetist or (2) a mechanical ventilator. The pop-off valve is operable in two different modes, i.e. (1) as a manually controlled variable orifice for spontaneous ventilation and (2) as an automatically controlled valve responding to a positive control pressure for manually assisted or mechanically controlled ventilation. The control pressure is obtained from the second chamber of the reservoir assembly.
53 Citations
10 Claims
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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 and including 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;
means mounting said overflow valve means in close proximity to said elongated breathing tube means second end;
elongated overflow tube means, substantially coextensive 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;
a reservoir assembly including outer wall means enclosing a volume and inner wall means partitioning said volume into first and second hermetically isolated chambers, said inner wall means being flexible for transmitting pressures between said chambers;
means for communicating said first chamber with said breathing tube means second end;
said overflow valve means including 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;
means for selectively communicating the pressure in said second chamber to said control port;
container means having a flexible wall capable of being manually squeezed to increase the pressure therein; and
means for communicating the pressure in said container means to said reservoir assembly second chamber.
- 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;
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2. The system of claim 1 wherein said means for communicating the pressure in said container means to said second chamber includes a manual valve means having first and second input ports and on an output port;
- means coupling said output port to said second chamber;
means coupling said container means to said first input port; and
means adapted to couple said second input port to a mechanical ventilator.
- means coupling said output port to said second chamber;
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3. The system of claim 1 wherein said reservoir assembly outer wall means is rigid.
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4. The system of claim 1 including an opening in said reservoir assembly outer wall;
- and lid means adapted to fit over and seal said opening, said lid means including a fitting extending into said volume and a flexible bag detachably sealed to said fitting.
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5. The system claim 1 wherein said means for selectively communicating said second chamber to said control port includes a controller means having selectable first and second input ports and an output port;
- means coupling said controller means output port to said control port;
means coupling said second chamber to said controller means first input port; and
means exposing said controller means second input port to ambient pressure.
- means coupling said controller means output port to said control port;
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6. The system of claim 1 wherein said breathing tube means includes first and second breathing tubes having open first and second ends;
- patient communication means defining a passageway therethrough 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 assembly first chamber.
- patient communication means defining a passageway therethrough having first and second open ends;
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7. Anesthesia rebreathing apparatus useful in combination with a source of fresh anesthesia gases, said apparatus comprising:
- a gas overflow valve, having input and exhaust ports, mounted proximate to said fresh gas source;
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;
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 in communication 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;
a reservoir assembly including outer wall means enclosing a volume and inner wall means partitioning said volume into first and second hermetically isolated chambers, said inner wall means being flexible for transmitting pressures between said chambers;
container means having a flexible wall capable of being manually squeezed to increase the pressure therein;
means for communicating the pressure in said container means to said reservoir assembly second chamber; and
means for communicating said first chamber with said breathing tube means second end.
- a gas overflow valve, having input and exhaust ports, mounted proximate to said fresh gas source;
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8. The apparatus of claim 7 wherein said reservoir assembly outer wall means is rigid.
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9. The apparatus of claim 7 wherein said means for communicating said first chamber with said breathing tube means second end includes a fitting extending into said volume through said reservoir assembly outer wall means;
- and wherein said inner wall means comprises a flexible bag detachably sealed to said fitting.
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10. The apparatus of claim 7 wherein said breathing tube means includes first and second breathing tubes having open first and second ends;
- patient communication means defining a passageway therethrough 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 assembly first chamber.
- patient communication means defining a passageway therethrough having first and second open ends;
Specification