Dialyzer

Abstract

The present invention is related to hemodialysis, and more particularly, to a dialyzer with improved efficiency of mass transfer across a dialysis membrane utilizing microchannel separation provided in accordance with embodiments of the present invention. In accordance with an embodiment, a dialyzer is provided comprising a plurality of semipermeable membrane sheets and a plurality of flow separators. The membrane sheets and flow separators are arranged in alternating configuration and coupled into a laminae stack defining a plurality of parallel microchannel layers. Each microchannel layer comprises a plurality of first microchannels and a plurality of second microchannels. The first and second microchannels of each microchannel layer are in fluid communication with each other via one of the plurality of membrane sheets therebetween. The dialyzer is characterized as having a high surface to volume ratio and a high mass transfer coefficient.

1 . A dialyzer comprising;
 a plurality of semipermeable membrane sheets, each of the semipermeable membrane sheets having a sheet first side and a sheet second side opposite the sheet first side and a sheet first end and a sheet second end opposite the sheet first end; and   a plurality of flow separators, each flow separator being an elongated member, at least two flow separators depend from each of the sheet first side and sheet second side of each of the plurality of semipermeable membrane sheets, the at least two flow separators being spaced a predetermined distance apart and substantially parallel therewith, a sheet first side of one of the semipermeable membrane sheets being adjacent a sheet second side of another one of the semipermeable membrane sheets such that respective flow separators of adjacent semipermeable membrane sheets are in facing relationship and coupled together therefore defining coupled flow separators, wherein the plurality of semipermeable membrane sheets and coupled flow separators define alternating first microchannel layers comprising substantially parallel first microchannels and second microchannel layers comprising substantially parallel second microchannels, each first microchannel and each second microchannel being defined by two of the plurality of semipermeable membrane sheets and respective flow separators, the first microchannels and second microchannels extending from each of the sheet first end to the sheet second end, the first microchannels and second microchannels being in fluid communication with each other via one of the plurality of semipermeable membrane sheets therebetween, the first microchannels operable for receiving a first fluid stream comprising blood and the second microchannels operable for receiving a second fluid stream comprising dialysate.   
     
     
         2 . The dialyzer of  claim 1 , wherein the first microchannels of each first microchannel layer are parallel therewith and the second microchannels of each second microchannel layer are parallel therewith. 
     
     
         3 . The dialyzer of  claim 2 , wherein the first microchannels and second microchannels are parallel therewith. 
     
     
         4 . The dialyzer of  claim 2 , wherein the first microchannels and second microchannels are orthogonal therewith. 
     
     
         5 . The dialyzer of  claim 1 , further comprising a first header and a second header, the first header comprising an inlet in fluid communication with the first microchannels at the first end and an outlet in fluid communication with the second microchannels at the first end, the second header comprising an inlet in fluid communication with the second microchannels at the second end and an outlet in fluid communication with the first microchannels at the second end. 
     
     
         6 . The dialyzer of  claim 1 , further comprising a first header and a second header, the first header comprising a first inlet in fluid communication with the first microchannels at the first end and a second inlet in fluid communication with the second microchannels at the first end, the second header comprising a first outlet in fluid communication with the first microchannels at the second end and a second outlet in fluid communication with the second microchannels at the second end. 
     
     
         7 . A dialysis system, comprising:
 blood-handling apparatus;   dialysate-handling apparatus;   a dialyzer, the dialyzer comprising a plurality of semipermeable membrane sheets, each of the semipermeable membrane sheets having a sheet first side and a sheet second side opposite the sheet first side and a sheet first end and a sheet second end opposite the sheet first end; and   a plurality of flow separators, each flow separator being an elongated member, at least two flow separators depend from each of the sheet first side and sheet second side of each of the plurality of semipermeable membrane sheets, the at least two flow separators being spaced a predetermined distance apart and substantially parallel therewith, a sheet first side of one of the semipermeable membrane sheets being adjacent a sheet second side of another one of the semipermeable membrane sheets such that respective flow separators of adjacent semipermeable membrane sheets are in facing relationship and coupled together therefore defining coupled flow separators, wherein the plurality of semipermeable membrane sheets and coupled flow separators define alternating first microchannel layers comprising substantially parallel first microchannels and second microchannel layers comprising substantially parallel second microchannels, each first microchannel and each second microchannel being defined by two of the plurality of semipermeable membrane sheets and respective flow separators, the first microchannels and second microchannels extending from each of the sheet first end to the sheet second end, the first microchannels and second microchannels being in fluid communication with each other via one of the plurality of semipermeable membrane sheets therebetween, the first microchannels operable for receiving a first fluid stream comprising blood and the second microchannels operable for receiving a second fluid stream comprising dialysate, the blood-handling apparatus being in fluid communication with the first microchannels, and the dialysate-handling apparatus being in fluid communication with the second microchannels.   
     
     
         8 . The dialysis system of  claim 7 , the blood-handling apparatus operable to supply blood to the first microchannels at a the sheet first end and withdraw blood from the first microchannels at the sheet second end, and the dialysate-handling apparatus operable to supply dialysate to the second microchannels at the sheet second end and withdraw dialysate from the second microchannels at the sheet first end. 
     
     
         9 . The dialysis system of  claim 7 , the blood-handling apparatus operable to supply blood to the first microchannels at the sheet first end and withdraw blood from the first microchannels at the sheet second end, and the dialysate-handling apparatus operable to supply dialysate to the second microchannels at the sheet first end and withdraw dialysate from the second microchannels at the sheet second end. 
     
     
         10 . A dializer, comprising:
 a plurality of first microchannels; and   a plurality of second microchannels, each first microchannel and each second microchannel being defined by two semipermeable membrane sheets and two flow separators, each of the first microchannels and second microchannels being in fluid communication with each other via at least one of the two semipermeable membrane sheets, the first microchannels being operable for receiving a first fluid stream comprising blood and the second microchannels operable for receiving a second fluid stream comprising dialysate.   
     
     
         11 . The dialyzer of  claim 10 , wherein the first microchannels and second microchannels are parallel therewith. 
     
     
         12 . The dialyzer of  claim 10 , wherein the first microchannels and second microchannels are orthogonal therewith. 
     
     
         13 . The dialyzer of  claim 10  wherein the flow of blood through the set of first microchannels is countercurrent to the flow of dialysate through the set of second microchannels. 
     
     
         14 . The dialyzer of  claim 10  wherein the flow of blood through the set of first microchannels is concurrent to the flow of dialysate through the set of second microchannels. 
     
     
         15 . The dialyzer of  claim 10  wherein the flow of blood through the set of first microchannels is crosscurrent to the flow of dialysate through the set of second microchannels.