System and method for blood separation by microfluidic acoustic focusing

Patent metadata

Field	Value
Publication number	US-2019388606-A1
Application number	US-201816236404-A
Country	US
Kind code	A1
Filing date	Dec 29, 2018
Priority date	Mar 8, 2013
Publication date	Dec 26, 2019
Grant date	—

Abstract

Systems and methods for cleansing blood are disclosed herein. The methods include acoustically separating undesirable particles bound to capture particles from formed elements of whole blood. After introducing the capture particles to whole blood containing undesirable particles, the whole blood and capture particles are flowed through a microfluidic separation channel. At least one bulk acoustic transducer is attached to the microfluidic separation channel. A standing acoustic wave, imparted on the channel and its contents by the bulk acoustic transducer, drives the formed elements and undesirable particles bound to capture particles to specific aggregation axes. After aggregating the particles, the formed elements exit the separation channel through a first outlet and are returned to the patient. The undesirable particles, bound to the capture particles, exit through a second outlet and can be discarded to saved for later study.

First claim

What is claimed is:

1 . A blood cleansing device comprising:
a microfluidic separation channel defined in a thermoplastic and having an upstream end and downstream end, the microfluidic separation channel comprising:
a first inlet configured to introduce flowing whole blood into a proximal end of the microfluidic separation channel, the whole blood including plasma, a plurality of formed elements and a plurality of undesirable particles;
a first outlet at the downstream end of the microfluidic separation channel positioned substantially along a longitudinal axis of the microfluidic separation channel;
a second outlet at the downstream end positioned adjacent a first wall of the microfluidic separation channel; and
an acoustic transducer positioned adjacent to the microfluidic separation channel to generate a standing acoustic wave across a particle migration region of the microfluidic separation channel, wherein a width of the microfluidic separation channel is between about 30% and 45% of a wavelength of the standing acoustic wave.

2 . The blood cleansing device of claim 1 , wherein the width of the microfluidic separation channel is between about 30% and about 35% of the wavelength of the standing acoustic wave applied to the microfluidic separation channel.

3 . The blood cleansing device of claim 1 , wherein a thickness of a wall is between about 35% and about 45% of the wavelength of the standing acoustic wave applied to the microfluidic separation channel.

4 . The blood cleansing device of claim 1 , wherein the standing acoustic wave is generated transverse to a flow of blood through the particle migration region of the microfluidic separation channel.

5 . The blood cleansing device of claim 1 , further comprising a capture particle injector configured to introduce a plurality of lipid-based capture particles into the whole blood before the whole blood reaches the particle migration region of the microfluidic separation channel.

6 . The blood cleansing device of claim 5 , comprising a reservoir in fluidic communication with the capture particle injector.

7 . The blood cleansing device of claim 6 , wherein the reservoir contains a plurality of the lipid-based capture particles.

8 . The blood cleansing device of claim 6 , wherein the reservoir contains a mixture of materials, which when directed by the capture particle injector into the whole blood, form the lipid-based capture particles.

9 . The blood cleansing device of claim 8 , wherein the materials in the mixture comprise a affinity molecule, a lipid, and a fluid with a density less than about 1 g/cm 3 .

10 . The blood cleansing device of claim 5 , wherein the lipid-based capture particles have significantly different acoustophoretic mobility than that of formed elements of blood.

11 . The blood cleansing device of claim 5 , wherein the capture particle injector comprises a microfluidic nozzle.

12 . The blood cleansing device of claim 5 , wherein the capture particle injector comprises a porous membrane.

13 . The blood cleansing device of claim 1 , wherein the second and third outlets merge at a fourth outlet.

14 . A method of cleansing blood comprising:
flowing whole blood, including plasma, a plurality of formed elements, and a plurality of undesirable particles, into an inlet of a microfluidic separation channel defined in a thermoplastic; selecting a wavelength of a standing acoustic wave such that a predetermined width of the microfluidic separation channel is between 30% an 45% of the wavelength of the standing acoustic wave; and applying the standing acoustic wave transverse to a direction of flow of the whole blood through the microfluidic separation channel such that the formed elements aggregate toward the axial center of the microfluidic separation channel.

15 . The method of claim 14 , wherein the width of the microfluidic separation channel is between about 30% and about 35% of the wavelength of the standing wave applied to the microfluidic separation channel.

16 . The method of claim 14 , wherein a thickness of the wall is between about 35% and about 45% of the wavelength of the standing wave applied to the microfluidic separation channel.

17 . The method of claim 14 , further comprising introducing a plurality of lipid-based capture particles into the whole blood such that the lipid-based capture particles bind to a plurality of the undesirable particles.

18 . The method of claim 14 , further comprising collecting the formed elements of the whole blood at a first outlet positioned at a downstream end of the microfluidic separation channel at about the axial center of the microfluidic separation channel.

19 . The method of claim 14 , further comprising collecting the capture particles through at least a second outlet positioned at the downstream end of the microfluidic separation channel adjacent to the at least one wall along which the capture particles are aggregated.

20 . The method of claim 14 , wherein the capture particles comprise an affinity molecule anchored to a lipid bilayer encapsulating a fluid.

Assignees

• Charles Stark Draper Laboratory Inc

Inventors

• Fiering Jason O
• Sundaram Shivshanker
• Meuller Andrew

Classifications

• B01D2221/10

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• B01D21/28

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• A61M1/3678

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• B01D21/283

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• A61M1/362

  changing physical properties of target cells by binding them to added particles to facilitate their subsequent separation from other cells, e.g. immunoaffinity · CPC title