Systems and methods of blood-based therapies having a microfluidic membraneless exchange device

A method of performing a blood treatment, comprising:

• establishing a flow of blood and extraction fluid in a channel such that the blood and extraction fluid are in direct contact and such that entering and exiting flows of each of the blood and extraction fluid into and from the channel are established, respectively, at opposing ends of the channel, the exiting flow of extraction fluid containing blood proteins diffused there into;
• conveying a portion of the extraction fluid in the extraction fluid exiting flow to the extraction fluid entering flow and further passing the extraction fluid portion across a membrane at a pressure such as to expel water and uremic toxins therethrough;
• and
• permitting proteins to concentrate in the extraction fluid such that a quantity of the blood proteins leaving the channel in the extraction fluid exiting flow is substantially equal to the quantity of the blood proteins returned to the channel entering flow.

A method of performing a blood treatment, comprising:

• passing, through a channel, blood from a patient and an extraction fluid, such that the blood and extraction fluid are in direct contact without mixing, the channel being configured such that substantial quantities of albumin and uremic toxins move from the blood into the extraction fluid;
• placing the extraction fluid in contact with a membrane under pressure and, as a result, passing water and uremic toxins in the extraction fluid through the membrane;
• placing processed extraction fluid in direct contact with blood;
• and
• permitting the albumin to concentrate in the extraction fluid such that the substantial quantities of albumin are returned to the blood in the placing, wherein the flow of blood and extraction fluid in the channel during the passing, and the configuration of the channel, are such that blood is isolated from the channel walls by the extraction fluid and such that upon exiting the channel, a quantity of urea in the blood is substantially the same as a quantity of urea in the extraction fluid.

A method of performing a blood treatment, comprising:

• placing blood and an extraction fluid in non-mixing direct contact to produce a resulting extraction fluid containing non-cellular components, including albumin, transferred from the blood into the second extraction fluid;
• removing the resulting extraction fluid from contact with the blood;
• subjecting the resulting extraction fluid to a medical process including flowing the resulting extraction fluid alone a membrane with a transmembrane pressure sufficient to ultrafilter the resulting extraction fluid such that albumin is concentrated therein;
• and
• placing the ultrafiltered extraction fluid back in direct contact with the blood such that at least the albumin is returned to the blood by diffusion resulting from the concentration of the at least the albumin in the ultrafiltered extraction fluid.