Patent ID: 12186685

While various embodiments have been described and illustrated, the detailed description is not to be construed as being limited hereto. Various modifications can be made to the embodiments by those skilled in the art without departing from the true spirit and scope of the disclosure as defined by the claims.

DETAILED DESCRIPTION

As shown inFIG.1, the application of an acoustic field on particles2within a chamber between an acoustic wave generator16and a reflector4induces a movement of said particles2, allowing to gather said particles2at a node of said acoustic field.

In this example, ultrasonic waves are generated in a chamber between a reflector4and a wall5associated with an acoustic wave generator16coupled with a transmitter layer. This enables the creation of an acoustic pressure node in the center of the chamber (depending on the chosen frequency at which the acoustic wave generator16operates) and therefore of acoustic radiation forces (ARF). The ARF push the particles2towards the pressure node with a force of up to a hundred times gravity equivalent. The particles2suspended in the fluid will then migrate to the sound pressure node and can then remain trapped in this position.

A plurality of acoustic nodes can be created in the chamber, said acoustic nodes can be located at the center of the chamber, or off the center of the chamber.

This is particularly advantageous as it allows the isolation of particles2within a fluid without any mechanical force, filtration, or centrifugation steps that could damage said particles2, especially if said particles2are fragile like cells.

In the first embodiment shown inFIG.2andFIG.3, the system1according to the invention comprises:a first container11comprising an inlet111and an outlet112;a second container12comprising an inlet121and an outlet122;a first transfer device13and a second transfer device14, wherein the first container11is fluidly connected to an inlet133of the first transfer device13and the second container12is fluidly connected to an inlet143of the second transfer device14, each of the first and second transfer devices13,14comprising:a chamber131,141;three outlets134,135,144,145comprising a first central outlet134,144for fluid enriched with said given group of particles and two second peripheral outlets135,145for fluid depleted of said given group of particles;pumps15configured to regulate flow rates at the inlets111,121,133,143.

FIG.3shows a schematic larger-scale view of the chamber131or141of the transfer devices13,14comprised in the system represented inFIG.2.

In this embodiment, the first and second containers11,12are each configured to comprise a fluid, the fluid comprised in the first container11being enriched with at least one group of particles and the fluid comprised in the second container12being depleted of said group of particles.

In this embodiment, operating the system1comprises the following: a volume of fluid is introduced in the first container11and a volume of fluid is introduced in the second container12; an acoustic field is applied to said fluid by generating acoustic waves inside the chamber131,141of each of the first and second transfer devices13,14; then the fluid contained in the first container11is transferred into the chamber131of the first transfer device141, and the fluid contained in the second container12is simultaneously transferred into the chamber141of the second transfer device14, whereby a given group of particles migrates to a sound pressure node in the chamber13,14created by the generation of an acoustic field in said chamber131,141and are delivered at the central outlet134,144whereas other components of the fluid are delivered on the sides of the chamber131,141at the peripheral outlets135,145; the fluid enriched with said given group of particles, collected from the central outlet134,144of the first and second transfer devices13,14, is transferred into the first container11, and the fluid depleted of said given group of particles, collected from the peripheral outlets135,145of the first and second transfer devices13,14, is simultaneously transferred into the second container. The respective volumes of fluid in the first and second containers are kept constant during operating through the regulation of the flow rate of the fluid circulating in the system1, obtained by means of the pumps15, as a function of measurements representative of the volume of fluid in the first container11and/or the second container12.

This embodiment is particularly advantageous as the given group of particles is separated from other components of the fluid without using any mechanical force, thus preventing any damage to said given group of particles.

This embodiment is particularly advantageous as the flow rates at the inlets111,121,133,143of the containers and chambers are regulated to ensure that the volume of fluid in each of said containers11,12stays constant at all times, preventing an inopportune emptying of one of said containers11,12. By keeping these volumes constant, the volumes and particle concentrations of the final products are perfectly controlled.

As shown inFIG.3, in this embodiment, each transfer device13,14comprises:a chamber131,141configured to be associated with an acoustic wave generator16for generating acoustic waves;a reflector located opposite said at least one acoustic wave generator16, the reflector being the air3surrounding the chamber131,141in this example; andthree outlets134,135,144,145comprising a first central outlet134,144for fluid enriched with said given group of particles and two second peripheral outlets135,145for fluid depleted of said given group of particles.

In this embodiment, the chamber131,141of each transfer device13,14extends along a longitudinal axis (x), has a cross section with a width measured along a first transverse axis (y) and a thickness measured along a second transverse axis (z) perpendicular to the first transverse axis, the width being greater than or equal to the thickness, the chamber131,141having first and second walls132,136,142,146along the second transverse axis (z). The chamber131,141has a thickness between 350 and 450 μm, a width between 0.7 and 2.1 cm and a length between 1 and 6 cm and the walls132,136,142,146are made of PMMA.

In this embodiment, the fluid is introduced at the inlet133,143of the chamber131,141. The flow rate at the inlet133,143of the chamber131,141ranges between 0.4 and 0.6 mL/min. The acoustic generator16associated with said chamber131,141generates acoustic waves having a frequency ranging between 1.8 and 2 MHz in the chamber131,141that are reflected by the reflector being the air3located at the outside of the chamber131,141. This creates at least one pressure node in the chamber131,141allowing a selective migration of a given group of particles towards the central outlet134,144while the other components of the fluid are evacuated at the peripheral outlets135,145. The acoustic wave generator16can be coupled with a transmitter layer (not represented inFIG.3).

This embodiment is particularly advantageous as an acoustic field is generated within the chamber131by the acoustic wave generator16. As explained inFIG.1, this simple arrangement allows the isolation of particles within a fluid without any mechanical force, filtration, or centrifugation steps that could damage said particles, especially if said particles are fragile like cells.

In the second embodiment shown inFIG.4, the elements similar to those of the first embodiment bear identical references. The system1of the second embodiment differs from the first embodiment in that each transfer device13,14comprises only two outlets. More precisely, the system1according to the second embodiment of the invention comprises:a first container11comprising an inlet111and an outlet112;a second container12comprising an inlet121and an outlet122;a first transfer device13and second transfer device14, wherein the first container11is fluidly connected to an inlet133of the first transfer device13and the second container12is fluidly connected to an inlet143of the second transfer device14, each of the first and second transfer devices13,14comprising:a chamber131,141;two outlets134,135,144,145comprising a first outlet134,144for fluid enriched with said given group of particles and a second outlet135,145for fluid depleted of said given group of particles;pumps15configured to regulate flow rates at the inlets of the first and second containers and the chambers111,121,133,143.

In this embodiment, the first and second containers11,12are each configured to comprise a fluid, the fluid comprised in the first container11being enriched with at least one group of particles and the fluid comprised in the second container12being depleted of said group of particles.

In this embodiment, the respective volumes of fluid in the first and second containers11,12are kept constant at all times.

This embodiment is particularly advantageous as the flow rates at the inlets of the containers and chambers111,121,133,143are regulated to ensure that the volume of fluid in each of said containers11,12stays constant at all times, preventing an inopportune emptying of one of said containers11,12.

As shown inFIG.5, the method of the invention comprises the following steps:providing a system1of the invention;applying an acoustic field by generating acoustic waves inside each chamber131,141of the first and second transfer devices13,14, by means of each acoustic wave generator16;simultaneously transferring the fluid contained in the first container11to the first transfer device13, and transferring the fluid contained in the second container12to the second transfer device14;simultaneously transferring the fluid enriched with at least one group of particles, collected from the first outlet(s), to the first container11and the fluid depleted of said group of particles, collected from the second outlet(s), to the second container12.

In addition, the flow rates at the inlets111,121,133,143of the first and second containers11,12and the chambers131,141are regulated so that the respective volumes of fluid in the first and second containers11,12are kept constant during the steps of the method.

As illustrated above, the method of the invention is a simple and fast method for separating at least one group of particles from a fluid without any dilution required. Furthermore, no steps of filtration, centrifugation or any steps requiring mechanical forces are needed during said method. This prevents damage to the group of particles to be separated.

EXAMPLES

The present invention is further illustrated by the following examples. The following examples are implemented, in particular, using the system ofFIGS.2and3.

Example 1

Platelet Enrichment

Materials and Methods

Platelet rich plasma is injected in equal amount in the first and second container of the present invention, hence each of them holds 50% of the total amount of platelets in the system. The platelet concentration may vary from high concentration to diluted samples. The platelets have an average diameter of 2 μm.

A flow is induced through the transfer devices by the flowing means. The flow control means are activated so each container holds a constant volume of fluid through the process with the flow rate controlled accordingly. The flow in the transfer devices inlets is kept within 0.4 to 0.6 mL/min. The transfer devices chambers have a thickness between 350 and 450 μm, a width between 0.7 and 2.1 cm and a length between 1 and 6 cm.

An acoustic force field is induced in the transfer device by means of the acoustic wave generator. The frequency of the acoustic wave is set between 1.8 and 2 MHz with a sinusoidal waveform.

Results

The first container is enriched with platelets while the second container is depleted of platelets until a predefined platelet level is reached in the second container. After 2.5 hours of processing, the first container holds between 60 and 80% of the platelets while the second container holds between 20 and 40% of the platelets.

Example 2

Blood Fractionation

Materials and Methods

Diluted whole blood is injected in equal amount in the first and second container of the present invention, hence each of them holds 50% of the total amount of blood cells in the system. The concentration of blood cell may vary from high concentration to diluted samples. Red blood cells have an average diameter of 6 μm while the platelets have an average diameter of 2 μm.

A flow is induced through the transfer devices by the flowing means. The flow control means are activated so that each container holds a constant volume of fluid through the process with the flow rate controlled accordingly. The flow in the transfer devices inlets is kept within 0.6 to 1 mL/min. The transfer devices chambers have a thickness between 350 and 450 μm, a width between 0.7 and 2.1 cm and a length between 1 and 6 cm.

An acoustic force field is induced in the transfer device by means of the acoustic wave generator. The frequency of the acoustic wave is set between 1.8 and 2 MHz with a sinusoidal waveform. This acoustic force field induce the migration of red blood cells toward the central outlet while the platelets tend to stay in the lateral outlets.

Results

The first container is enriched with red blood cells while the second container is depleted of red blood cells until a predefined red blood cell level is reached in the second container. After 2.5 hours of processing, the first container holds between 95 and 99% of the red blood cells while the second container holds between 1 and 5% of the red blood cells.