Cartridges and systems for outside-in flow in membrane-based therapies

Abstract

Embodiments of the invention pertain to cartridges, systems and methods for performing hemodialysis and related extracorporeal blood treatment modalities and therapies, in which blood flows in the inter fiber space and dialysate flows in the lumens of hollow fibers. Appropriate connectors and fitting orientations may be provided. There may be provided orbital distributors, fanning of fibers, and features to promote uniformity of fiber spacing in the fiber bundle. Orbital distributors may contain contoured surfaces, flow redirectors, non-uniform-conductance flow elements, through-wall distributors, and other features. There may be subdivision of the fiber bundle into two groups of fibers with separate control fluid to each group. Appropriate systems may be provided for various therapies. Flow past the fibers may be parallel, transverse or other configuration. These various features may enable long-term application to all dialysis and ultrafiltration related therapies, and also to other therapies and to applications including implantables, portables and wearables.

1 .- 44 . (canceled) 
     
     
         45 . A cartridge, comprising:
 a housing;   a fiber bundle comprising a plurality of fibers contained inside said housing, at least some of said fibers being hollow and being made of semi-permeable membranes having respective fiber lumens and fiber exteriors, wherein inter fiber space comprises space inside said housing between said fibers;   a first fluid flow compartment comprising said lumens of said hollow fibers; and   a second fluid flow compartment comprising said inter fiber space,   wherein said housing comprises a first housing port near a first end of said housing, and a second housing port near a second end of said housing,   wherein said second fluid flow compartment comprises an orbital distributor comprising an orbital channel and an access region accessing said fiber bundle,   further comprising, between said orbital channel and said access to said fiber bundle, a non-uniform-conductance flow element whose conductance varies as a function of position with respect to a circumferential angle.   
     
     
         46 . The cartridge of  claim 45 , wherein said second fluid flow compartment comprises, in sequence in an axial direction starting closest to an adjacent end of said cartridge, said orbital channel, said non-uniform conductance flow element, and said access region. 
     
     
         47 . The cartridge of  claim 45 , wherein said second fluid flow compartment comprises, in sequence in an axial direction starting closest to an adjacent end of said cartridge, said access region, said non-uniform conductance flow element, and said orbital channel. 
     
     
         48 . The cartridge of  claim 45 , wherein said non-uniform-conductance flow element has a lesser conductance near said housing port and a greater conductance away from said housing port. 
     
     
         49 . The cartridge of  claim 45 , wherein said non-uniform-conductance flow element has a conductance that varies with angular position around an orbital distributor circumference in a manner that is symmetric about a plane that passes through said housing port and passes through a longitudinal axis of said housing. 
     
     
         50 . The cartridge of  claim 45 , wherein said non-uniform-conductance flow element has a maximum conductance at or near 180 degrees away from one of said housing ports. 
     
     
         51 . The cartridge of  claim 45 , wherein said non-uniform-conductance flow element comprises ribs whose geometry provides non-uniform-conductance. 
     
     
         52 . The cartridge of  claim 45 , wherein said non-uniform-conductance flow element comprises ribs that are distributed non-uniformly in their locations with respect to circumferential angle. 
     
     
         53 .- 62 . (canceled) 
     
     
         63 . A cartridge, comprising:
 a housing;   a plurality of fibers contained inside said housing, at least some of said fibers being hollow and being made of semi-permeable membranes having respective fiber lumens and fiber exteriors, wherein inter fiber space comprises space inside said housing between said fibers,   a port connected to a side of said housing; and   an orbital distributor inside said housing and connected to said port, wherein said orbital distributor comprises a circumferential internal wall,   wherein a surface of an interior of said port aligns with or smoothly transitions with a surface of an interior of said orbital distributor.   
     
     
         64 . The cartridge of  claim 63 , wherein, in cross-section, said orbital distributor has a bottom that is U-shaped or has a rounded corner. 
     
     
         65 .- 175 . (canceled) 
     
     
         176 . A cartridge, comprising:
 a housing, said housing having a housing supply port and a housing discharge port; and   a plurality of fibers contained inside said housing, at least some of said fibers being hollow and being made of semi-permeable membranes having respective fiber lumens and fiber exteriors, a first fluid flow compartment comprising said lumens of said hollow fibers; and   a second fluid flow compartment comprising an inter fiber space that touches said fiber exteriors,   wherein flow from said housing supply port to said housing discharge port is, at a midplane of said cartridge, generally perpendicular to a lengthwise direction of said plurality of fibers,   wherein said cartridge further comprises a flow resistance element between said housing supply port and said inter fiber space, or between said inter fiber space and said housing discharge port, said flow resistance element causing said flow in said inter fiber space to be more uniform than would occur without said flow resistance.   
     
     
         177 . The cartridge of  claim 176 , wherein said flow resistance element has a uniform flow resistance everywhere. 
     
     
         178 . The cartridge of  claim 176 , wherein said flow resistance element has a flow resistance that differs among various places in said flow resistance element, said flow resistance element causing said flow in said inter fiber space to be more uniform than would occur if said flow resistance had a uniform flow resistance. 
     
     
         179 . The cartridge of  claim 176 , wherein said fibers have a Molecular Weight cut-off of less than approximately 50,000 Daltons. 
     
     
         180 . The cartridge of  claim 176 , wherein said housing supply port and said housing discharge port are directed generally perpendicularly to a long direction of said plurality of fibers, and are in-line with each other. 
     
     
         181 . The cartridge of  claim 176 , wherein said housing supply port and said housing discharge port are directed generally perpendicularly to a long direction of said plurality of fibers, and are offset with respect to each other. 
     
     
         182 . The cartridge of  claim 176 , wherein said housing supply port and said housing discharge port are directed generally parallel to each other and are offset with respect to each other. 
     
     
         183 . A tube set comprising:
 the cartridge of  claim 176 ;   tubing connected to said cartridge; and   at least one component selected from the group consisting of: a tube that is positioned and adapted to be operated by a roller of a peristaltic pump; a volume balancing chamber; a control valve; a check valve; a filter; a pinch-clip; an air bleed; a priming component; a drip chamber; a pressure-transmitting pod; a sensor; and an electrical connection.   
     
     
         184 . A filtration system, comprising:
 the cartridge of  claim 176 , wherein said housing supply port is connected to a blood supply line and said housing discharge port is connected to a blood discharge line,   further comprising a dialysate connection from a dialysate system to lumens of at least some of said plurality of fibers, or an ultrafiltrate removal line connecting to lumens of at least some of said plurality of fibers.   
     
     
         185 . A method of performing extracorporeal blood treatment, comprising:
 providing the cartridge of  claim 176 ;   supplying blood to one of said first housing port and said second housing port and removing blood from the other of said first housing port and said second housing port; and   supplying dialysate to or removing ultrafiltrate from lumens of at least some of said plurality of fibers.   
     
     
         186 .- 194 . (canceled)