Pumping material for cassette based dialysis and pumping mechanism using same

Abstract

A fluid pumping mechanism in one embodiment includes a fluid reservoir, and a monolayer film extending over a portion of the fluid reservoir, wherein fluid is moved through the reservoir by movement of the film from a first position to a second position, the film including a first polyolefin. In another embodiment the fluid pumping mechanism includes a fluid reservoir; and a multiple layer film extending over a portion of the fluid reservoir, wherein fluid is moved through the reservoir by movement of the film from a first position to a second position, the film including an inner layer and an outer layer, the inner layer including an ethylene containing polymer.

1 . A fluid pumping mechanism comprising;
 a fluid reservoir; and   a monolayer film extending over a portion of the fluid reservoir, wherein fluid is moved through the reservoir by movement of the film from a first position to a second position, the film including a first polyolefin.   
   
   
       2 . The mechanism of  claim 1 , wherein the first polyolefin is selected from the group consisting of: (i) homopolymers and copolymers obtained by polymerizing a first alpha-olefin containing from 2 to 20 carbon atoms; (ii) ethylene homopolymers and ethylene copolymers. 
   
   
       3 . The mechanism of  claim 2 , wherein the ethylene copolymer is an ethylene and second alpha-olefin copolymer. 
   
   
       4 . The mechanism of  claim 3 , wherein the second alpha-olefin has from 4 to 8 carbons. 
   
   
       5 . The mechanism of  claim 4 , wherein the ethylene and second alpha-olefin copolymer has a density less than 0.915 g/cc. 
   
   
       6 . The mechanism of  claim 2 , wherein the ethylene copolymer is a copolymer of ethylene with a comonomer selected from the group of lower alkyl acrylates, lower alkyl substituted alkyl acrylates and vinyl acetate. 
   
   
       7 . The mechanism of  claim 2 , wherein the first polyolefin is selected from the group consisting of propylene homopolymers and propylene copolymers. 
   
   
       8 . The mechanism of  claim 1 , wherein the film has at least one attribute selected from the group consisting of: (i) an elongation of from about 5% to about 40%; (ii) a modulus of elasticity of less than 20,000 psi; (iii) being deformed by a piston to move fluid through the reservoir at a rate that will not vary from the first stroke to the 10,000 th  stroke by more than 15% by volume; (iv) a heat transfer coefficient of greater than 0.20 Watts/minute-Kelvin for a film having a thickness of 5 mils; (v) a textured finish; (vi) a substantially constant modulus of elasticity over a temperature range of from 5-40° C.; (vii) is thermoformed; and (viii) is capable of being sterilized by gamma irradiation or ethylene oxide sterilization. 
   
   
       9 . The mechanism of  claim 1 , wherein the film is moved from a first position to a second position with a plunger and wherein the plunger does not stick to the film. 
   
   
       10 . The mechanism of  claim 1 , wherein the fluid reservoir is defined by a pumping cassette. 
   
   
       11 . The mechanism of  claim 10 , wherein the pumping cassette is fabricated from a first polymer selected from the group consisting of homopolymer and copolymers of cyclic olefin containing polymers and homopolymers and copolymers of bridged polycylic hydrocarbon containing polymers. 
   
   
       12 . The mechanism of  claim 10 , wherein the cassette is selected from homopolymers, copolymers of norbornene, and a copolymer of norbornene and a third alpha-olefin. 
   
   
       13 . The mechanism of  claim 12 , wherein the third alpha-olefin is ethylene. 
   
   
       14 . The mechanism of  claim 10 , wherein the cassette is fabricated from a polymer blend of a first component of a norbornene and ethylene copolymer and a second component of an ethylene and fourth alpha-olefin copolymer. 
   
   
       15 . The mechanism of  claim 14 , wherein the fourth alpha-olefin has from 4 to 8 carbons. 
   
   
       15 . The mechanism of  claim 14 , wherein the first component is present in an amount by weight of from 30% to about 99% by weight of the blend and the second component is present in an amount from 1% to about 70% by weight of the blend. 
   
   
       16 . The mechanism of  claim 1 , further comprising a tubing in fluid communication with the fluid reservoir. 
   
   
       17 . The mechanism of  claim 16 , wherein the tubing is fabricated from a second polyolefin. 
   
   
       18 . The mechanism of  claim 17 , wherein the second polyolefin is selected from the group consisting of: (i) homopolymers; (ii) copolymers obtained by polymerizing a fifth alpha-olefin containing from 2 to 20 carbon atoms; and (iii) ethylene homopolymers and ethylene copolymers. 
   
   
       19 . The mechanism of  claim 18 , wherein at least one of: (i) the ethylene copolymer is an ethylene and sixth alpha-olefin copolymer; (ii) the sixth alpha-olefin has from 4 to 8 carbons; and (iii) the ethylene and sixth alpha-olefin copolymer is obtained using a metallocene catalyst. 
   
   
       20 . The mechanism of  claim 18 , wherein the second polyolefin is: (i) a blend of polyolefin polymers; (ii) a blend of two m-ULDPE resins; or (iii) a blend of three m-ULDPE resins. 
   
   
       21 . The mechanism of  claim 16 , wherein the tubing is at least one of: (i) fabricated from a material having a density less than 0.915 g/cc; (ii) formed by an extrusion process; and (iii) capable of being sterilized by gamma irradiation or ethylene oxide sterilization. 
   
   
       22 . The mechanism of  claim 1 , which is used in a therapy selected from the group consisting of: continuous flow peritoneal dialysis, automated peritoneal dialysis, tidal flow peritoneal dialysis, hemofiltration and hemodialysis. 
   
   
       23 . A fluid pumping mechanism comprising;
 a fluid reservoir; and   a multiple layer film extending over a portion of the fluid reservoir, wherein fluid is moved through the reservoir by movement of the film from a first position to a second position, the film including an inner layer and an outer layer, the inner layer including an ethylene containing polymer.   
   
   
       24 . The mechanism of  claim 23 , wherein the inner layer is at least one of: an ethylene homopolymer; an ethylene copolymer; and an ethylene alpha-olefin copolymer having a density less than 0.915 g/cc. 
   
   
       25 . The mechanism of  claim 23 , wherein the outer layer is a polymer, metal foil or paper. 
   
   
       26 . The mechanism of  claim 23 , wherein the fluid reservoir is defined by a frame and the film is attached to the frame. 
   
   
       27 . The mechanism of  claim 26 , wherein the film is attached to the frame by heat sealing. 
   
   
       28 . The mechanism of  claim 23 , further comprising a tubing in fluid communication with the reservoir. 
   
   
       29 . The mechanism of  claim 28 , wherein the reservoir is defined by a frame and the tubing is connected to the frame by solvent bonding. 
   
   
       30 . The mechanism of  claim 23 , which is used in a therapy selected from the group consisting of: continuous flow peritoneal dialysis, automated peritoneal dialysis, tidal flow peritoneal dialysis, hemofiltration and hemodialysis.