Patent ID: 7285106

Claim:
A mid-dilution hemodiafiltration/hemofiltration cartridge comprising: a cartridge body having a first end and an opposing second end, said cartridge body being in communication with a blood inlet and a blood outlet and a dialysate inlet and outlet; a first hemodiafiltration stage including a first filtering element disposed between said first and second ends of said cartridge body, said blood inlet communicating with said first filtering element at said first end so that blood flows through said first filtering element toward said second end; a second hemofiltration stage including a second filtering element disposed between said first and second ends of the cartridge body, said blood outlet communicating with said second filtering element; a separating wall disposed between the first and second ends of the cartridge body and partitioning the body into the first hemodiafiltration stage and the second hemofiltration stage, the separating wall including an orifice to provide communication between the first hemodiafiltration stage and the second hemofiltration stage; and an inter-stage connector disposed at said second end of said cartridge body and defining an inter-stage header space, said inter-stage header space permitting blood that has been discharged from said first hemodiafiltration stage to flow through said second filtering element to said blood outlet, said inter-stage connector having a substitution fluid inlet port for reception of a solution for diluting the blood prior to the blood entering said second filtering element of said second stage, wherein dialysate fluid enters from said dialysate inlet and flows through said first hemodiafiltration stage, through the orifice, and then flows into said second hemofiltration stage and out said dialysate outlet associated with said second hemofiltration stage.