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US 5,938,929 AGranted
Polysulfone hollow fiber semipermeable membrane
AssigneeToray Industries, Inc.
InventorsMasaaki Shimagaki, Fumiaki Fukui, Takeshi Sonoda, Koji Sugita
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AssigneeToray Industries, Inc.
InventorsMasaaki Shimagaki, Fumiaki Fukui, Takeshi Sonoda, Koji Sugita
Estimating the term…
Respective hollow fiber membranes suitable for use in removing undesired contaminants from blood, in particular in an artificial kidney, have: (1) per membrane area of 1.6 m.sup.2, in vitro clearances for urea and phosphorus respectively of .gtoreq.195, and .gtoreq.180, ml/min, a .beta..sub.2 -microglobulin clearance .gtoreq.44 ml/min and an albumin permeability .ltoreq.0.5%; (2) an albumin permeability .ltoreq.1.5% and an overall mass transfer coefficient Ko.gtoreq.0.0012 cm/min; and (3) a vitamin B.sub.12 dialyzance of .gtoreq.135 ml/min and an albumin permeability .ltoreq.3%. The membranes can be prepared by spinning hollow fibers from a spinning solution comprising a polysulfone, a hydrophilic polymer, a solvent and water, the spinning solution having a viscosity x at 30.degree. C. of 25-130 poise and a quantity y % of water given by: -0.01x+1.45.ltoreq.y.ltoreq.-0.01x+2.25. The membranes can be incorporated into a hemodialyzer module by a method in which they are preimpregnated with a wetting agent, thereafter kept separate from one another by spacers and then inserted in the module.
A hollow fiber membrane characterized by,
In a method, for the treatment of blood to remove therefrom undesired material, in which blood is separated from dialysate by a hollow fiber membrane capable of allowing selective passage across said membrane the improvement comprising using a hollow fiber membrane characterized by
A polysulfone hollow fiber semipermeable membrane characterized by an albumin permeability of less than 1.5% and, in a dextran diffusion test using a dextran having a molecular weight of 10,000 and after 1 hour circulation of bovine serum, and overall mass transfer coefficient Ko of at least 0.0012 cm/min, and having a .beta.-microglobulin clearance of at least 44 ml/min, per membrane area of 1.8 m2.
In a method for treatment of blood to remove therefrom undesired material, in which blood is separated from dialysate by a hollow fiber membrane capable of allowing selective passage across said membrane characterized by an albumin permeability of less than 1.5% and, in a dextran diffusion test using a destran having a molecular weight of 10,000 and after 1 hour circulation of bovine serum, and overal mass transfer coefficient Ko of at least 0.0012 cm/min, and having a .beta.-microglobulin clearance of at least 44 ml/min, per membrane area of 1.8 m2.
A polysulfone hollow fiber membrane containing a hydrophilic polymer in the membrane characterized by an albumin permeability of no more than 3.0% and a vitamin B.sub.12 dialyzance of at least 135 ml/min per membrane area of 1.3 m.sup.2, the vitamin B.sub.12 dialyzance being measured during dialysis using, as perfusate, an aqueous solution containing urea and vitamin B.sub.12 at a perfusate flow rate of 200 ml/min, and using, as a dialyate, water at a dialysate flow rate of 500 ml/min and a filtration speed of 10 ml/min.
In a method, for the treatment of blood to remove therefrom undesired material, in which blood is separated from dialysate by a hollow fiber membrane capable of allowing selective passage across said membrane the improvement comprising using a hollow fiber membrane containing in the membrane a hydrophilic polymer and characterized by an albumin permeability of no more than 3.0% and a vitamin B.sub.12 dialyzance of at least 135 ml/min per membrane area of 1.3 m.sup.2, the vitamin B.sub.12 dialyzance being measured during dialysis of blood containing added urea and vitamin B.sub.12 at a blood flow rate of 200 ml/min, using water as a dialysate at a dialysate flow rate of 500 ml/min and a filtration speed of 10 ml/min.
Dependencies are inferred from the claim text.