In-line fluid heating apparatus with gradation of heat energy from inlet to outlet

An apparatus for heating parenteral fluids for intracorporeal delivery to a patient, comprising:

• a cassette means for transferring heat to parenteral fluids flowing therethrough, the cassette means comprising:
• passageway means having top and bottom sides and defining a thin, planar elongated, sinuous flow path having top and bottom sides and an inlet end and an outlet end, such that a thin sheet of parenteral fluid enters the inlet end, travels through the flow path, and exits the outlet end;
• a first flexible, heat conductive membrane means supported on one of the top or bottom sides of the passageway means and providing heat transfer to one of the top and bottom sides of the flow path;
• and
• a second flexible, heat conductive membrane means supported on the other of the top or bottom sides of the passageway means, and providing heat transfer to the other of the top and bottom sides of the flow path, said passageway means holding the first and second conductive membranes means in spaced relation one from the other;
• and
• a heating means in contact with one of said first and second heat conductive membrane means for generating heat energy for transfer to the parenteral fluid in the elongated flow path, said heating means comprising:
• a first and a second heating element means for generating a gradation of heat energy such that more heat energy is available for transfer to the parenteral fluid at the inlet end of the sinuous flow path than is available for transfer to the parenteral fluid at the outlet end of the sinuous flow path, each heating element means having a shape that is essentially a mirror image of the elongated sinuous flow path, said first heating element means being disposed essentially both vertically offset from and in alignment with said top side of the elongated flow path, said second heating element means being disposed essentially both vertically offset from and in alignment with said bottom side of the elongated flow path.

An apparatus for heating parenteral fluids for intracorporeal delivery to a patient, comprising:

• a cassette means for transferring heat to parenteral fluids flowing therethrough, the cassette means comprising:
• passageway means having top and bottom sides and defining a thin, planar, elongated, sinuous flow path having top and bottom sides and an inlet end and an outlet end, such that a thin sheet of parenteral fluid enters the inlet end, travels through the flow path, and exits the outlet end;
• a first flexible, heat conductive membrane means supported on one of the top or bottom sides of the passageway means and providing heat transfer to one of the top and bottom sides of the flow path;
• and
• a second flexible, heat conductive membrane means supported on the other of the top or bottom sides of the passageway means, and providing heat transfer to the other of the top and bottom sides of the flow path, said passageway means holding the first and second conductive membrane means in spaced relation one from the other;
• and
• a heating means in contact with at least one of said first and second heat conductive membrane means for generating heat energy, said heating means comprising:
• a heating element means for generating a gradation of heat energy such that more heat energy is available for transfer to the parenteral fluid at the inlet end of the elongated flow path than is available for transfer to the parenteral fluid the outlet end of the elongated flow path, said heating means having a shape that is essentially mirror image of the elongated sinuous flow path, and the heating element means being disposed essentially both vertically offset from and in alignment with at least one of the top or bottom sides of the elongated flow path.

An apparatus for heating parenteral fluids for intracorporeal delivery to a patient, comprising:

• a cassette means for transferring heat to parenteral fluids flowing therethrough, the cassette means comprising:
• passageway means having top and bottom sides and defining a thin, planar sinuous flow path having top and bottom sides and an inlet end and an outlet end, such that a thin sheet of parenteral fluid enters the inlet end, travels through the flow path, and exits the outlet end;
• a first thin, flexible metallic foil conductive membrane means supported on one of the top or bottom sides of the passageway means and providing heat transfer to one of the top and bottom sides of the flow path;
• and
• a second thin, flexible metallic foil conductive membrane means supported on the other of the top or bottom sides of the passageway means, and providing heat transfer to the other of the top and bottom sides of the flow path, said passageway means holding the first and second thin, flexible metallic foil conductive membrane means in spaced relation one from the other;
• and
• heating means in contact with said first and second thin, flexible metallic foil conductive membrane means for generating heat energy, said heating means comprising:
• a first and a second heating element means for generating a gradation of heat energy such that more heat energy is available for transfer to the parenteral fluid at the inlet end of the serpentine flow path than is available for transfer to the parenteral fluid at the outlet end of the serpentine flow path, each of which has a shape that is essentially a mirror image of the serpentine flow path, said first heating element means being disposed essentially both vertically offset from and in alignment with said top side of the serpentine flow path, said second heating element means being disposed essentially both vertically offset from and in alignment with said bottom side of the serpentine flow path.