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

• US 8,097,162 B2
• Filed: 11/17/2010
• Issued: 01/17/2012
• 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:
  US12/948,284
• Publication Number:
  US 20110062083A1
• Time in Patent Office: 426 Days
• Field of Search: 210/97, 210/137, 210/200, 210/203, 210/209, 210/511, 210/644, 210/645, 210/646, 210/647, 210/649, 210/650, 210/651, 210/643, 210/634, 210/767, 210/806, 604/5.01, 604/5.04, 604/6.01, 604/6.02, 604/6.09, 604/6.11, 422/81, 422/82, 422/99, 209/155, 209/196
• 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 system for performing blood treatment, comprising:

a rectangular membraneless channel with inlet and outlet ends spaced apart across a length of the membraneless channel, the membraneless channel having a fluid inlet at the inlet end for receiving blood, and first, second, and third fluid outlets at the outlet end;

the fluid inlet being connected to a patient access for receiving blood;

the first and second fluid outlets being disposed on opposite facing walls of the membraneless channel at the outlet end, the first and second fluid outlets each having a filter therein forming a portion of a respective one of the opposite walls;

each of the filters being configured and arranged so that it forms a single continuous interior-facing surface with a respective one of the facing walls of the membraneless channel;

an external channel connected to the first and second fluid outlets and configured to receive and combine the flow of plasma leaving the membraneless channel through the first and second outlets; and

the third fluid outlet receiving the blood and being located between the first and second fluid outlets across a depth which is perpendicular to the length;

wherein each of the filters has a regular array of pores whose diameters are less than 800 nm, each pore defining a non-serpentine, non-branching channel;

wherein the depth is between 75 and 300 microns, and the membraneless channel has a width, perpendicular to the depth, that is at least ten times the depth; and

the external channel being configured to convey the combined flow of plasma to a secondary treatment device with a membrane that extracts water from the combined flow of plasma and returns the result back to the membraneless channel.

2. The system of claim 1, wherein the filters are configured to block blood cells from leaving the membraneless channel.

3. A method for performing blood treatment, comprising:

passing blood from a patient through a rectangular membraneless channel with inlet and outlet ends spaced apart across a length of the membraneless channel, the membraneless channel having a fluid inlet at the inlet end for receiving blood, and first, second, and third fluid outlets at the outlet end;

passing plasma from the blood in the membraneless channel through the first and second fluid outlets which are disposed on opposite facing walls of the membraneless channel at the outlet end, the first and second fluid outlets each having a filter therein forming a portion of a respective one of the opposite walls;

each of the filters being configured and arranged so that it forms a single continuous interior-facing surface with a respective one of the facing walls of the membraneless channel, the rate of flow of blood in the passing being sufficient to move cells along interior facing surfaces of the first and second outlet filters;

combining the flow of plasma leaving the membraneless channel through the first and second fluid outlets and conveying the combined flow of plasma to a secondary treatment device with a membrane;

extracting water from the combined flow of plasma and returning a result back to the membraneless channel; and

conveying blood from the membraneless channel through the third fluid outlet, which is located between the first and second fluid outlets across a depth which is perpendicular to the length, back to the patient;

wherein each of the filters has a regular array of pores whose diameters are less than 800 nm, each pore defining a non-serpentine, non-branching channel; and

wherein the depth is between 75 and 300 microns and the membraneless channel has a width, perpendicular to the depth, that is at least ten times the depth.

4. The method of claim 3, wherein the filters block blood cells from leaving the membraneless channel.