Patent ID: 8128822

Claim:
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, 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 dialyzer further comprising a first header and a second header, the first header comprising an inlet in fluid communication with the first microchannels at the sheet first end and an outlet in fluid communication with the second microchannels at the sheet first end, the second header comprising an inlet in fluid communication with the second microchannels at the sheet second end and an outlet in fluid communication with the first microchannels at the sheet second end.