Hollow fiber blood oxygenator

A hollow fiber oxygenator, comprising:

• a bundle of hollow fibers open at each end thereof for ducting gas therethrough;
• a housing disposed around said bundle and open on a first end thereof, said housing being made of a material which allows heat transfer therethrough;
• a plurality of tubular, coaxial heat exchange coils surrounding said housing;
• a casing enclosing said coils, with said casing having an open end surrounding the first end of said housing, said casing and said housing forming an annular passage therebetween, said housing having a plurality of apertures for liquid communication between said annular passage and spaces between said fibers, the ends of said bundle of fibers being sealed between adjacent fibers so that a liquid flow path is formed through said annular passage and through the bundle in the spaces between the fibers;
• a ring-shaped cover fitting onto and sealed with the casing and the housing to close the end of said annular passage adjacent the first end of said housing;
• and
• a gas cap disposed radially within said cover and enclosing the first end of said housing, said cover and said cap being separable components so that said flow path may be pressure tested with said cover in place while said cap is not yet installed and so that the ends of said fibers are accessible for the sealing of leaks in said hollow fibers.

An upright hollow fiber oxygenator, comprising:

• a fiber bundle positioned around a supporting core having a top end and a bottom end and an axis extending therebetween, the bundle including hollow gas permeable fibers each having an open top end, an open bottom end, and a hollow interior, the top ends of the fibers being adjacent the top end of the core and the bottom ends of the fibers being adjacent the bottom end of the core, wherein said fibers are positioned so as to intersect one another;
• an interior housing surrounding said bundle, said interior housing being made of a material which allows heat transfer therethrough;
• upper potting means to seal the outside of the top ends of each of said fibers in said bundle to one another and to seal the bundle to the tp end of the core and to the surrounding interior housing thereabout;
• lower potting means to seal the outside of the bottom ends of each of said fibers in said bundle to one another and to seal the hollow fiber bundle to the bottom end of the core and to the surrounding interior housing thereabout, wherein the upper and lower potting means, the core and the interior housing together define an enclosed fiber bundle unit, the top and bottom ends of each of said fibers in the fiber bundle being open to the hollow interiors of said fibers;
• a gas inlet port to allow gas passage into the hollow interiors of said fibers at one end of the fibers and a gas outlet port to permit gas passage from the hollow interiors of said fibers at the opposite end of said fibers;
• a heat exchanger unit which surrounds and receives the fiber bundle unit, said heat exchanger unit comprising a plurality of heat exchange coils which surround and are in heat exchange contact with said fiber bundle unit;
• and
• an outer housing enclosing said heat exchanger unit, said outer housing having a fluid inlet port and a fluid outlet port connected to said plurality of heat exchange coils for passage of a heat transfer fluid therethrough.

A hollow fiber oxygenator, comprising:

• an enclosed fiber bundle unit comprising:
• a bundle of hollow fibers open at the ends thereof for ducting gas therethrough;
• an inner housing around said fiber bundle, said bundle and said housing being dimensioned and positioned such that said bundle has been axially inserted into said housing;
• and
• means defining a fluid inlet and means defining a fluid outlet in said inner housing for ducting fluid through spaces between said hollow fibers;
• a heat exchanger unit comprising:
• an outer housing spaced from sand surrounding said inner housing;
• a plurality of separate tubular coils positioned along a common axis in said outer housing and defining an inner cavity corresponding in size to an exterior of said inner housing, said fiber bundle unit being concentrically positioned within said cavity, said fiber bundle unit in heat exchange contact with said heat exchanger unit and cooperating with said heat exchanger unit to define a fluid flow path around said coils, wherein at least one end of each of said coils terminates in a header providing a mixing chamber for a fluid entering said coils;
• and
• a fluid inlet and a fluid outlet for ducting fluid through said coils.

A hollow fiber oxygenator, comprising:

• a fluid tight outer housing having a blood inlet port at a bottom end of said housing, and a pair of fluid headers with a pair of fluid ports in communication with each of said headers;
• a plurality of separate, heat exchange coils stacked coaxially along a common axis within said outer housing and having input and output ends which terminate in said fluid headers so that fluid can be circulated through said coils to control the temperature of said coils, said stacked coils defining an inner cavity;
• an encased fiber bundle concentrically placed within said cavity in heat transfer relation with said coils, said encased fiber bundle comprising:
• a center core with means defining a plurality of apertures adjacent a bottom end to allow fluid communication between the bottom end of said center core and said fiber bundle, said center core having an obstruction between opposing ends of said core preventing gas and fluid communication between said apertures in a top end of said core;
• a plurality of hollow fibers wound on said center core to form a bundle of fibers, said fibers being open at the upper and lower ends thereof;
• an interior housing enclosing an outside of said fiber bundle, said fibers being compressed between said core and an inside of said interior housing, said interior housing having means defining at least one aperture adjacent a top end to provide fluid communication with said fiber bundle, said interior housing, fiber bundle, and center core being sealed at the ends thereof to define a gas flow path through the inside of said hollow fibers and further defining a fluid flow path around the outside of the hollow fibers in said fiber bundle and through said at least one aperture in said interior housing and said apertures in said center core, wherein a fluid passing through said gas flow path does not mix with a fluid passing through said fluid flow path, said interior housing further cooperating with said outer housing to define a fluid flow path around the exterior of said heat exchange coils, wherein said interior housing is positioned concentrically within said coils;
• and
• top and bottom caps cooperating with said outer housing, said interior housing, and said fiber bundle to define a gas flow path through said hollow fibers.