Systems and methods of microfluidic membraneless exchange using filtration of extraction outlet streams

• US 8,257,593 B2
• Filed: 12/20/2011
• Issued: 09/04/2012
• Est. Priority Date: 05/22/2006
• Status: Expired due to Fees

• Current Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Original Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Inventors: Leonard, Edward F., West, Alan C., Aucoin, Christian Paul, Nanne, Edgar E.
• Primary Examiner(s): Kim, John
• Application Number:
  US13/332,040
• Publication Number:
  US 20120103901A1
• Time in Patent Office: 259 Days
• Field of Search: 210/97, 210/137, 210/200, 210/203, 210/209, 210/511, 210/643, 210/644, 210/645, 210/646, 210/647, 210/649, 210/650, 210/651, 210/634, 210/767, 210/806, 604/5.01, 604/5.04, 604/6.01, 604/6.02, 604/6.09, 604/6.11
• US Class Current: 210/643
• CPC Class Codes: A61M 1/14 Dialysis systems; Artificial kidneys; Blood oxygenators semi-permeable membranes characterised by the material, manufacturing processes therefor B01D71/00 ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 1/1696 with dialysate regeneration
• CPC Class Codes: A61M 1/32 Oxygenators without membranes
• CPC Class Codes: A61M 2205/7563 with means preventing clogging of filters
• CPC Class Codes: A61M 2206/11 Laminar flow
• CPC Class Codes: A61P 7/08 Plasma substitutes; Perfusion solutions; Dialytics or haemodialytics; Drugs for electrolytic or acid-base disorders, e.g. hypovolemic shock artificial tears A61P27/04
• CPC Class Codes: B01D 11/0492 Applications, solvents used
• CPC Class Codes: B01D 11/0496 by extraction in microfluidic devices
• CPC Class Codes: G01N 2030/0045 normal, i.e. diffusion or thermal FFF

Abstract

A device, system and method for exchanging components between first and second fluids by direct contact in a microfluidic channel. The fluids flow as thin layers in the channel. One of the fluids is passed through a filter upon exiting the channel and is recycled through a secondary processor which changes the fluid'"'"'s properties. The recycled fluid is reused for further exchange. The filter excludes blood cells from the recycled fluid and prevents or limits clogging of the filter. The secondary processor removes metabolic waste and water by diafiltration.

Claims

1. A method of performing ultrafiltration, comprising:

pumping blood from a human patient into a microfluidic channel to generate a shear flow across the face of filters forming opposite facing walls of the microfluidic channel, the shear flow in the microfluidic channel being maintained at a sufficient magnitude to prevent the clogging of the filters;

drawing plasma through the filters and removing water and uremic toxins from the plasma by passing the same through an ultrafilter at a higher shear rate than would be tolerated by blood due to the concomitant rate of hemolysis; and

returning dehydrated plasma to the patient.

2. The method of claim 1, wherein the ultrafilter is a microfiber bundle type dialyzer.

3. The method of claim 1, wherein the microfluidic channel has a depth across the direction of blood therethrough of 300 microns or less.

4. The method of claim 1, wherein the microfluidic channel has a depth across the direction of blood therethrough of about 100 microns.

5. The method of claim 1, wherein the width of the microfluidic channel across the direction of flow is at least ten times the depth.

6. The method of claim 1, wherein each of the filters forming opposite facing walls has an array of holes that are less than 800 nm.

7. The method of claim 1, wherein each of the filters forming opposite facing walls has a regular array of holes that are less than 800 nm.

8. The method of claim 1, further comprising pumping the plasma, the pumping controlling a rate of the drawing.