Fluid filter and method of making same

A filter assembly of a conventional size convenient for positioning on the arm of a patient, and for use in the filtering of intravenous fluids during the administration of such fluids comprising:

• a substantially planar housing comprising:
• a pair of flexible sheets sealed together around their peripheries;
• a flexible filter pouch in said housing formed from porous membrane filter media having a pore size not greater than 0.22 microns, said pouch comprising a first flexible frame member sealed around its periphery to one side of said filter membrane and a second flexible frame member sealed around its periphery to the other side of said filter membrane, each frame members having at least one opening therein exposing a substantial surface area of said filter membrane, said filter membrane and said frame members being folded substantially in half and having seal means along two edges adjacent the folded edge so that the edge of said pouch opposite said folded edge defines a fluid opening in said pouch, said folded pouch providing a sufficiently low pressure drop thereacross, so as to eliminate the requirement of a fluid pump to force said fluids through said assembly, said flexible sheets of said housing adapted to be compressed together with said flexible pouch therebetween for facilitating the priming of the filter assembly to substantially eliminate any air space within said housing;
• fluid inlet means extending into said housing in fluid communication with the interior of said filter pouch through said fluid opening;
• and fluid outlet means extending from said housing in fluid communication with the interior of said housing external of said filter pouch.

A filter assembly of a conventional size convenient for positioning on the arm of a patient, and for use in the filtering of intravenous fluids during the administration of such fluids comprising:

• a closed housing;
• a flexible filter pouch in said housing, said pouch formed from a porous membrane filter media having a pore size not greater than 0.22 microns, a porous support material overlying one surface of said filter media and a flexible frame member overlying the opposite surface of said filter media, said frame member having at least one opening exposing a substantial surface area of said filter media, said frame, support material and filter media all being folded substantially in half and being sealed along two edges adjacent the folded edge to form said pouch so that the edge of said pouch opposite said folded edge defines a fluid opening in said pouch, said folded pouch providing a sufficiently low pressure drop thereacross, so as to eliminate the requirement of a fluid pump to force said fluids through said assembly, fluid inlet means extending into said housing in fluid communication with the interior of said filter pouch through said fluid opening;
• and fluid outlet means extending from said housing in fluid communication with the interior of said housing external of said filter pouch;
• whereby, fluid may pass through said fluid inlet means into the interior of said filter pouch, pass through said opening of said frame, said filter media and said support material of said pouch into the interior of said housing external of said pouch and then exit from said house through said fluid outlet means.

A filter assembly of a conventional size convenient for positioning on the arm of a patient, and for use in the filtering of intravenous fluids during the administration of such fluids comprising:

• a substantially planar housing comprising a pair of flexible plastic sheets sealed together around their peripheries;
• a flexible filter pouch in said housing, said pouch formed from a porous polycarbonate film having a pore size not greater than 0.22 microns and a sheet of porous, flexible support material overyling at least one surface of said film, said support material and said film being folded substantially in half and being sealed together with said flexible sheets along two edges adjacent said folded edge, said pouch having a fluid opening in the end opposite said folded edge, said folded pouch providing a sufficiently low pressure drop thereacross, so as to eliminate the requirement of a fluid pump to force said fluid through said assembly;
• fluid inlet means extending into said housing in fluid communication with the interior of said filter pouch through said fluid opening;
• and fluid outlet means extending from said housing in fluid communication with the interior of said housing external of said filter pouch, whereby said flexible plastic sheets are adapted to be compressed together with said flexible filter pouch therebetween for facilitating the priming of the filter assembly to substantially eliminate any air space within said housing.