Systems and methods for increasing convective clearance of undesired particles in a microfluidic device

Patent metadata

Field	Value
Publication number	US-10039875-B2
Application number	US-201414568666-A
Country	US
Kind code	B2
Filing date	Dec 12, 2014
Priority date	Jan 11, 2013
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

A microfluidic device for increasing convective clearance of particles from a fluid is provided. A network of first channels can be separated from a network of second channels by a first membrane. The network of first channels can also be separated from a network of third channels by a second membrane. Fluid containing an analyte can be introduced in the network of first channels. Infusate can be introduced into the network of second channels, and waste-collecting fluid can be introduced into the network of third channels. A pressure gradient can be applied in a direction perpendicular to the direction of fluid flow in the network of first channels, such that the analyte is transported from the network of first channels into the network of third channels through the second membrane.

First claim

What is claimed is:

1. A method for filtering a first liquid containing an analyte to provide a filtered liquid containing less analyte than the first liquid, the method comprising:
introducing, by a blood introduction device communicatively coupled to a processor, the first liquid into an inlet of one or more First Channels;
introducing, by a filtrate introduction device communicatively coupled to the processor, infusate into at least one Second Channel complementary to the one or more First Channels, such that at least some of the infusate flows from the at least one Second Channel through a first membrane and into the one or more First Channels, wherein the first liquid and the infusate are introduced such that the volume of fluid in each of the one or more First Channels is substantially constant along a length of the one or more First Channels, responsive to the processor controlling the blood introduction device and the filtrate introduction device to maintain the substantially constant volume of fluid along the length of the one or more First Channels;
introducing waste-collecting fluid into at least one Third Channel complementary to the one or more First Channels such that at least some of the analyte in the first liquid is transported through a second membrane into the at least one Third Channel, the at least one Third Channel including a first structural support to limit deformation of the second membrane; and
collecting the filtered liquid from an outlet of one or more of the First Channels.

2. The method of claim 1 , wherein introducing the first liquid comprises introducing blood.

3. The method of claim 2 , wherein introducing the blood, the infusate, and the waste collecting fluid results in convective hemofiltration of the blood.

4. The method of claim 2 , further comprising extracting the blood from a patient and returning filtered blood to the patient.

5. The method of claim 2 , wherein the blood and the infusate are introduced such that hematocrit of the blood is substantially constant throughout the one or more First Channels.

6. The method of claim 2 , further comprising controlling, by an operator, a hematocrit profile of the blood as it flows through the one or more First Channels.

7. The method of claim 2 , wherein the blood is introduced such that a fluid shear rate in the one or more First Channels is within a range of about 300 inverse seconds to about 3000 inverse seconds.

8. The method of claim 1 , wherein the first liquid and the infusate are introduced such that a pressure gradient across the first membrane is substantially constant along the length of the at least one Second Channels.

9. The method of claim 1 , wherein the first liquid and the infusate are introduced such that fluid flow in the one or more First Channels is substantially laminar.

10. The method of claim 1 , wherein the one or more First Channels include an anticoagulant coating on its walls.

11. The method of claim 1 , wherein the first liquid and the infusate are introduced such that a pressure in the at least one Second Channel is greater than a pressure in the one or more First Channels, and the pressure in the one or more First Channels is greater than a pressure in the at least one Third Channel.

12. The method of claim 1 , wherein each First Channel has a height in the range of about 50 microns to about 500 microns, a width in the range of about 50 microns to about 900 microns, and a length in the range of about 3 centimeters to about 20 centimeters.

13. The method of claim 1 , wherein the introduction of the first liquid, the infusate, and the waste-collecting fluid results in a net infusion of fluid into the one or more First Channels from the at least one Second Channel and a net outflow of fluid from the one or more First Channels into the at least one Third Channel.

14. The method of claim 1 , further comprising monitoring at least one of a pressure and flow rate of the first liquid as the first liquid flows through the one or more First Channels.

15. The method of claim 1 , wherein the infusate is introduced into the at least one Second Channels in a direction perpendicular to a direction of fluid flow in the one or more First Channels.

16. The method of claim 1 , comprising adjusting a flow rate of the infusate into the at least one Second Channels.

17. The method of claim 16 , comprising measuring a pressure in the one or more First Channels, and wherein adjusting the flow rate of the infusate comprises adjusting the flow rate based on the measured pressure in the one or more First Channels.

18. The method of claim 17 , wherein adjusting the pressure in the one or more First Channels comprises maintaining a pressure in the one or more First Channels suitable for maintaining blood health.

Assignees

• Charles Stark Draper Laboratory Inc

Inventors

• Dibiasio Christopher
• Harjes Daniel I
• Charest Joseph L
• Borenstein Jeffrey T

Classifications

• A61M2205/3331

  Pressure; Flow · CPC title

• B01L3/502753

  characterised by bulk separation arrangements on lab-on-a-chip devices, e.g. for filtration or centrifugation · CPC title

• A61M2205/0244

  Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology · CPC title

• B01D63/088

  Microfluidic devices comprising semi-permeable flat membranes · CPC title

• A61M1/34

  Filtering material out of the blood by passing it through a membrane, i.e. hemofiltration or diafiltration · CPC title