Method and an arrangement in connection with vaporizing an anaesthetic
AssigneeInstrumentarium Corp.
InventorAntti Sarela
Life of this patent
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Abstract
The invention relates to a method and an arrangement in connection with vaporizing an anaesthetic. The invention comprises a vaporizing chamber for an anaesthetic liquid to be vaporized and means for mixing vaporized anaesthetic with fresh gas and delivering the mixture to be inhaled by a patient. To stabilize the temperature of the anaesthetic liquid in the vaporizing situation, an air flow enhancing the transfer of heat energy between the anaesthetic liquid within the vaporizing chamber and air outside the vaporizing chamber is applied to at least one exterior surface of the vaporizing chamber in forced circulation.
Claims38
A method for providing a quantity of heat to a low temperature boiling point liquid anaesthetic to compensate for temperature reductions resulting from vaporization of such a liquid anaesthetic and to stabilize the temperature of the anaesthetic and the generation of a gaseous anaesthetic from the liquid anaesthetic, the vaporization occurring in an anaesthetic containing chamber having a wall capable of transferring heat, said method consuming low amounts of power and comprising the step of:
- forcing the passage of 0.5-5 m.sup.3 /min. of ambient air along the wall of the chamber to transfer, from the air to the liquid anaesthetic, a quantity of heat that stabilizes the generation of gaseous anaesthetic from the liquid anaesthetic by vaporization of the latter.
A method of administering an anaesthetic to a patient, the anaesthetic administered to the patient being obtained from a vaporizable liquid anaesthetic having a low temperature boiling point, said method comprising the steps of:
- providing a main flow stream of breathable gas from a gas source means to the patient;
- providing a chamber containing the vaporizable, liquid anaesthetic, said chamber having a wall capable of transferring heat;
- vaporizing the liquid anaesthetic to form a gaseous anaesthetic in the chamber;
- forcing the passage of 0.5-5 m.sup.3 /min. of ambient air along the wall of the chamber to transfer, from the air to the liquid anaesthetic, a quantity of heat that compensates for vaporization induced temperature reductions in the liquid anaesthetic and that stabilizes the vaporization of the liquid anaesthetic to the gaseous anaesthetic;
- diverting a portion of the main flow stream of breathable gas through the chamber to entrain the gaseous anaesthetic;
- returning the diverted portion to the main flow stream;
- and
- administering the main flow stream of breathable gas containing the anaesthetic to the patient.
Apparatus for providing a quantity of heat to a low temperature boiling point liquid anaesthetic to compensate for temperature reductions resulting from vaporization of the liquid anaesthetic and to stabilize the temperature of the anaesthetic and the generation of a gaseous anaesthetic from the liquid anaesthetic, said apparatus comprising:
- a chamber containing the liquid anaesthetic and gaseous anaesthetic generated therefrom, said chamber having a wall capable of transferring heat, said chamber having an inlet and an outlet for passing a gas flow stream through said chamber to entrain the gaseous anaesthetic;
- and
- means forcing the passage of 0.5-5 m.sup.3 /min. of ambient air along the wall of the chamber to transfer, from the air to the liquid anaesthetic, a quantity of heat that stabilizes the generation of gaseous anaesthetic from the liquid anaesthetic by vaporization of the latter in the chamber.
Apparatus for administering an anaesthetic entrained in a breathable gas to a patient, said breathable gas being supplied by a gas source means, said apparatus comprising:
- means connectable to said gas source means and providing a main flow stream of breathable gas from the gas source means to the patient;
- a chamber containing a vaporizable, liquid anaesthetic having a low temperature boiling point, and gaseous anaesthetic generated therefrom, said chamber having a wall capable of transferring heat and having an inlet and an outlet;
- means coupled to said chamber inlet and outlet for diverting a portion of the main flow stream of breathable gas through the chamber to entrain the gaseous anaesthetic;
- and
- means for forcing the passage of 0.5-5 m.sup.3 /min. of ambient air along the wall of the chamber to transfer, from the air to the liquid anaesthetic, a quantity of heat that compensates for vaporization induced temperature reductions in the liquid anaesthetic and that stabilizes the generation of gaseous anaesthetic from the liquid anaesthetic by vaporization of the latter.
Dependencies are inferred from the claim text.