KR101769451B1 - Apparatus and method for measuring deformability of red blood cells - Google Patents

Apparatus and method for measuring deformability of red blood cells Download PDF

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KR101769451B1
KR101769451B1 KR1020160028025A KR20160028025A KR101769451B1 KR 101769451 B1 KR101769451 B1 KR 101769451B1 KR 1020160028025 A KR1020160028025 A KR 1020160028025A KR 20160028025 A KR20160028025 A KR 20160028025A KR 101769451 B1 KR101769451 B1 KR 101769451B1
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강양준
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조선대학교산학협력단
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Abstract

A microfluidic device comprising a blood supply part filled with a blood sample and an erythrocyte deformability measurement part; A micro pump connected to the blood supply part for pumping a blood sample and connected to the microfluidic device to supply a pumped blood sample; And a pressure measuring device connected to the microfluidic device. The pressure measuring device measures the pressure in the microfluidic device according to the fluidity of the blood sample passing through the microfluidic device, thereby evaluating the deformability of the red blood cells. Compared with the measurement method of erythrocyte deformability, it is possible to detect a very local erythrocyte deformity abnormality by having a sub-population difference detection function using a microfluidic filtration channel (MFC).

Description

[0001] Apparatus and method for measuring red cell deformity [

[0001] The present invention relates to an apparatus and a method for measuring red blood cell deformity, and more particularly, to a red blood cell deformability measuring apparatus and a measuring method using the red blood cell deformability measuring apparatus including a microfluidic device, a micropump and a pressure measuring apparatus, And measuring a change in the pressure in the microfluidic device due to the flowability of the blood passing through the erythrocyte measuring unit with a pressure measuring device to evaluate erythrocyte deformability of the blood sample.

In the systemic circulation, about 80% of the total pressure drop occurs within the microcirculation, including the arteriolar and capillary networks, where oxygen, nutrients and waste products are exchanged. In the microcirculation, blood flow strongly depends on the geometric shape of the blood vessel and on the biophysical properties including the viscosity, the viscous elasticity, the hematocrit, the deformability, the coherence and the erythrocyte sedimentation rate (ESR). The rheological and rheological properties of blood are associated with blood diseases and disorders, including hypertension, sickle cell anemia, and diabetes. Among the blood components, red blood cells (RBC) can be greatly modified by several factors including low cytoplasmic viscosity, high surface area and volume ratio, and sufficiently flexible membranes. Because of the high deformability, the RBC has the ability to pass through a capillary network whose size is smaller than the diameter of the RBC. However, blood diseases cause a significant reduction in RBC deformability. Low deformity interferes with or prevents blood flow in the capillaries, which ultimately leads to organ deterioration. On the other hand, malaria parasites cause structural and epidemiological modifications in host RBCs. These changes lead to low deformability and increased adhesion to endothelial cells, which contributes to the capillary clogging of the organ, which is essential for vital maintenance. Among the biophysical properties of blood, RBC deformity is considered as a promising biomarker for monitoring deformation in pathological conditions. Here, the major issue raised for efficient deformation measurements is that certain subpopulations of RBCs will contribute well to pathological symptoms. Therefore, the high throughput and quantitative agreement of a particular subpopulation is required for the efficient detection of the deformability of blood samples containing RBCs.

To meet these needs, various methods of measuring the deformability of several RBCs have been performed as follows.

As shown in FIG. 14, laser diffractometry (Ektacytometry) is used to measure erythrocyte deformability. Couette flow conditions in Co-cylinder and laser rotational imaging technique are used to increase the shear stress (Rheoscan-D300 (Rheomeditech, Seoul, Korea)), which measures the RBC strain by the ratio of the short axis of the ellipse, and a vacuum pump at Poiseuille flow condition using a microfluidic chip as shown in FIG. (Rheodyn SSD (Myrenne Gmbh, Roetgen, Germany)] is used to adjust the fluid flow and to evaluate the RBC deformability with the ratio of elliptical length / short axis as the shear stress increases. However, there is a problem that it is difficult to detect a sub-population difference because the above methods are averaged over all based on population.

Also, as shown in FIG. 16, a method of measuring erythrocyte deformability using a membrane filter and a pressure sensor, in which individual RBCs pass through a membrane filter as a result of passage or passage failure in a pore diameter A method of measuring the change in fluid pressure at the RBC volume or membrane entrance with a pressure sensor has been proposed. The method of measuring the RBC volume is performed by measuring the time required for all blood samples to pass through the membrane filter and the RBC volume passed through the membrane filter for a period of time. However, these methods have a disadvantage in that the pellet size of the membrane filter is large and the reproducibility and repeatability are low and the blockage of the pores frequently occurs due to the influence of the WBC and the aggregated platelets, have.

(Reid H et al., Journal of Clinical Pathology, 855-858, 1976) by measuring the pressure by measuring the pressure of the RBC through the membrane by gravity, This is because the use of a membrane filter has a problem that the pore size is large in process dispersion and the repeatability and reproducibility are low. As shown in FIG. 17, a blood sample was prepared and a membrane clogging issue due to WBC and platelets was excluded using RBCs in 1x PBS suspension (Hematocrit = 3%), hematocrit (Keita Odashiro et al., Clinical Hypertension, 2015, 21:17). However, since the pressure sensor is in contact with the blood, contamination occurs, and the pressure sensor is separated and cleaned and calibrated There is a problem that it is necessary.

Also, as shown in FIG. 18, a microfluidic filtration method is used in which a microfluidic device is manufactured using a MEMS technique so that a channel size is made constant, minimizing the process dispersion problem (YC Chen et al., Microfluid. Nanofluid. , 2010, 585-591). However, there is a problem that it is impossible to quantitatively evaluate fluid flow according to RBC deformability. As shown in FIG. 19, a method of injecting a blood sample of a constant volume into a microfluidic channel and evaluating the deformability of the RBC by the number of captured RBCs in a channel with a lapse of a predetermined time (Sergey S. Shevkoplyas et al , Lab Chip, 2007, 914-920). However, this has a problem that it can be used only in a laboratory equipped with a microscope and a camera.

Korean Patent Publication No. 10-2003-0032809 Korean Patent Registration No. 10-0676694 U.S.Patent Patent Publication No. 08,100,672

DISCLOSURE Technical Problem The present invention has been made in order to solve all of the above problems, and its object is to provide a sensor-based and one-time measurement method for measuring erythrocyte deformability, which is one of the main indicators of early diagnosis of cardiovascular diseases, .

In order to achieve this object, the present invention proposes a method for quantitatively measuring the deformability of erythrocytes (i.e., in-situ) outside the laboratory, and the proposed method includes a blood injection unit and an erythrocyte measurement unit The red blood cell deformability measuring device is constituted by the microfluidic device, the micropump and the pressure measuring device, and the microfluidic filtration channel (MFC) of the microfluidic device is used to induce red blood cell clogging in the channel according to the deformability of the red blood cell , And when a change in the blood flow (or fluid resistance) occurs, it is used to evaluate the red cell deformity. That is, it is possible to provide a pressure sensor at the upper end of the microfluidic filtration channel (MFC) to measure the erythrocyte deformability by measuring the pressure instead of measuring the change in the blood flow, and to measure three parameters from the measured pressure, The deformation of red blood cells can be quantified using a constant time integral ([P int ]) for number, maximum pressure and pressure.

According to an aspect of the present invention, there is provided an erythrocyte deformability measuring apparatus comprising: a microfluidic device composed of a blood supply part and a red blood cell measuring part to which a blood sample is filled; A micro pump connected to the blood supply part for pumping a blood sample and connected to the microfluidic device to supply a pumped blood sample; And a pressure measuring device connected to the microfluidic device, wherein the pressure in the microfluidic device is measured by the pressure measuring device according to fluidity of the blood sample passing through the microfluidic device, thereby evaluating the deformability of the red blood cell. .

In addition, the erythrocyte measuring unit may include a microfluidic channel (MFC) and a microfluidic channel (MFC) through which the microfluidic channel and the pressure measurement device are connected, J) to measure the change in the pressure in the sensor connection port according to the fluidity of the blood through the pressure measuring device to evaluate the deformability of the red blood cells.

The micropump is connected to the micropump through an outlet connection port connected to the blood supply part and to the micropump through an inlet connection port connected to the sensor connection port.

It is preferable that the pressure measuring device is constituted by an electric circuit and a pressure sensor.

In addition, it is preferable that the blood supply part injects the blood sample into the blood injection space through the funnel by laminating the glass substrate and the blood injection part formed with the blood injection space, connecting the funnel to the blood injection space.

It is preferable that the blood injecting portion is made of a polymer.

Preferably, the sensor connection port is formed by stacking a glass substrate, a blood reservoir having a blood reservoir and a sealing portion on the blood reservoir, and a tube penetrating the sealing portion is connected to the pressure sensor.

It is preferable that the blood storage portion and the sealing portion are made of a polymer.

And a filtration channel disposed in the sensor connection port and through which blood samples pass, wherein the filtration channels are arranged in a row with a plurality of fine microstructures arranged in two rows side by side, wherein the microstructures have a cylindrical shape, It is preferable that the interval and height between the cylindrical pillars of the fine strut are 10 mu m.

In addition, the microfluidic filtration channel (MFC) is installed at a smaller size than the filtration channel to allow a blood sample to pass through for measurement of erythrocyte deformability. The microfluidic filtration channel (MFC) includes a plurality of microfluidic channels , And the fine strut is formed by connecting one of the corners of the triangular column and the pentagonal column so that the gap therebetween is zigzag, the minimum gap between the fine struts is 2 占 퐉 and the maximum gap is 10 占 퐉 desirable.

The measuring method of the present invention for measuring the deformability of erythrocytes using the measuring apparatus described above comprises the steps of: supplying a blood sample to a blood supply portion of a microfluidic device; Pumping a blood sample supplied to the blood supply unit by a micro pump and injecting the blood sample into an erythrocyte measurement unit of the microfluidic device; Measuring a change in pressure in the microfluidic device which changes according to fluidity of a blood sample passing through the erythrocyte measurement unit using a pressure measuring device to evaluate erythrocyte deformability; And discharging the blood sample passed through the erythrocyte measuring unit to the discharging portion of the microfluidic device.

The step of measuring erythrocyte deformability may further include supplying a blood sample into the sensor connection port of the microfluidic device and injecting the blood sample into the filtration channel; Injecting a blood sample passed through the filtration channel into a microfluidic filtration channel of a microfluidic device; And measuring a change in pressure in the sensor connection port according to fluidity of the blood sample injected into the microfluidic filtration channel and passing through the microfluidic filtration channel using a pressure measuring device to evaluate erythrocyte deformability.

Preferably, the pressure measuring device comprises an electric circuit and a pressure sensor, and the pressure sensor measures the change in the pressure in the sensor connecting port.

It is also preferable that the blood sample is filled with air in the sensor connection port.

According to the apparatus and method for measuring red blood cell deformability of the present invention, as compared with the method of measuring erythrocyte deformability, a sub-population difference detection function using a microfluidic filtration channel (MFC) There is an effect that detection is possible.

Further, it is possible to prevent the pressure sensor of the pressure measuring device from contacting with the blood sample due to the air filled in the sensor connection port of the microfluidic device, thereby preventing the pressure sensor from being contaminated, It is effective.

In addition, it is possible to quantitatively evaluate the fluid flow according to the deformability of the RBC, and the evaluation according to the deformability of the RBC can be performed in a simple one-off manner outside the laboratory.

1 is a schematic configuration diagram of an erythrocyte deformability measuring apparatus according to an embodiment of the present invention
Fig. 2 is a schematic detailed cross-sectional view of the blood supply portion of Fig. 1
Figure 3 is a schematic cross-sectional view of the sensor connection port portion of Figure 1
Figure 4 is a schematic perspective view of the filtration channel in the sensor connection port of Figure 1;
Figure 5 is a schematic perspective view of the microfluidic filtration channel in the measurement chamber of Figure 1,
Figure 6 is a mathematical modeling of the red blood cell deformability, (a) is when the red blood cell deformability preferred (P F> P H) ( b) is when the red blood cell deformability bad (P F <P H)
FIG. 7 is a graph showing changes in pressure over time with respect to good erythrocyte deformability
8 is a graph showing a change in pressure with time for a case where the erythrocyte deformability is bad
9 is a graph showing the time constant and the maximum pressure tendency graph according to the erythrocyte deformability
10 is an electric circuit for measuring pressure using a pressure sensor
11 shows a pressure measurement device composed of a pressure sensor, an analog electric circuit and a microfluidic device
Fig. 12 is a graph showing the change in pressure according to an increase in flow rate of a blood sample
13 is a schematic configuration diagram of an erythrocyte deformability measuring apparatus according to another embodiment of the present invention
14 is a view schematically showing a method of measuring erythrocyte deformability of an example using conventional laser diffraction
15 is a view schematically showing a method of measuring erythrocyte deformability of another example using conventional laser diffraction
16 is a view schematically showing a method of measuring erythrocyte deformability using a conventional membrane filter and a pressure sensor
17 is a view schematically showing a method of measuring red cell deformity using a conventional membrane and a pressure sensor
18 is a view schematically showing a method of measuring erythrocyte deformability of an example using a conventional microfluid filtration method
19 is a view schematically showing a method of measuring erythrocyte deformability in another example using the conventional microfluid filtration method

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of an apparatus and method for measuring red blood cell deformability according to the present invention will be described in detail with reference to the accompanying drawings. It is to be understood that the present invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to inform.

FIG. 2 is a schematic detailed cross-sectional view of the blood supply portion of FIG. 1, and FIG. 3 is a schematic cross-sectional view of the sensor connection port portion of FIG. 1, FIG. 4 is a schematic perspective view of a filtration channel in the sensor connection port of FIG. 1, and FIG. 5 is a schematic perspective view of a microfluid filtration channel in the measurement chamber of FIG.

As shown in FIG. 1, an erythrocyte deformability measuring apparatus according to an embodiment of the present invention basically comprises a microfluidic device 1, a micropump 2, and a pressure measuring device 3.

The microfluidic device 1 includes a blood supply part A filled with a blood sample and an erythrocyte deformability measurement part J and is connected to an outlet connection port B of the blood supply part A by a micro pump The inlet port C of the microcomputer 2 is connected and the inlet connection port E of the red blood cell deformability measuring section J is connected to the outlet port D of the micropump 2 to supply the pumped blood sample . The erythrocyte deformability measuring unit J is formed by integrally connecting a sensor connection port F, a microfluidic filtration channel (HFC) H and a discharge port I to the inlet connection port F. [

The pressure measuring device 3 is composed of an electric circuit and a pressure sensor, and the pressure sensor is connected to the sensor connection port F of the red blood cell deformability measuring part J.

When the blood sample is injected and filled into the blood supply part A of the microfluidic device 1 with the thus configured erythrocyte deformability measurement device of the present invention, the blood sample is pumped by the micropump 2, Is supplied to the sensor connection port (F) of the microfluidic device (1) so as to be filled with air. The blood sample filled with the air in the sensor connection port F passes through the filtration channel G and the microfluidic filtration channel M in the sensor connection port F and is discharged to the discharge part I The change in the pressure in the sensor connection port F depending on the flowability of the blood sample passing through the filtration channel G and the microfluidic filtration channel H is measured by the pressure sensor of the pressure measurement device 3 Evaluate the deformability of red blood cells.

At this time, the filtration channel G is used for filtering WBCs and debris larger than RBCs, and the microfiltration channel MFC H is used for directly evaluating the red blood cell deformability.

2, the blood supply part A is constructed by laminating a glass substrate 4 and a blood injection part 6 formed with a blood injection space 5, A funnel 7 is connected to the entrance of the blood injection space 5 of the unit 6 and a certain amount of blood sample is dropped into the blood injection space 5 through the funnel 7 to be injected.

3, the sensor connection port F includes a blood reservoir 9 in which a glass substrate 4 and a blood reservoir space 8 are formed, and a sealing portion 10 on the blood reservoir 9 A deep hole h is formed in the sealing portion 10 so as to prevent the blood sample from contacting with the pressure sensor so that the tube 11 is inserted through the hole h, And a blood sample is supplied to the microfluidic filtration channel (MFC) H through the blood storage space 8 of the sensor connection port F at the inlet connection port E connected to the micropump 2 . The blood storing part 9 and the sealing part 10 are made of the same polymer as the blood injecting part 6 and the blood storing part 9 and the sealing part 10 are combined with each other by an adhesive, .

As shown in FIG. 4, the filtration channel G, which is installed in the sensor connection port F and into which the blood sample is injected, is constituted by arranging a plurality of cylindrical micro pillars 12a arranged in two rows side by side staggered , And the spacing and height between the cylinders of the cylindrical fine column 12a are preferably 10 占 퐉.

As shown in FIG. 5, the microfluidic filtration channel (MFC) H, which is installed at a smaller size than the filtration channel G, has a plurality of microstructures, which are formed by connecting one of the corners of a triangular column and a pentagonal column, (12b) are arranged at regular intervals. The gap between the fine struts (12b) is formed in a zigzag shape, and the minimum gap between them is 2 占 퐉 and the maximum gap is 10 占 퐉.

Next, a measuring method for quantifying and evaluating erythrocyte deformability using the erythrocyte deformability measuring apparatus according to an embodiment of the present invention as described above will be described.

When blood is supplied to the blood reservoir 9 of the sensor connection port F, air existing in the blood reservoir 8 of the sensor connection port F is present on the blood sample due to the difference in density of the blood sample and air . At this time, the air existing in the upper part of the blood sample is compressed according to the pressure acting on the sensor connection port (F). Therefore, the blood sample is filled in the blood storage space 8 by the volume reduction by the compression of the air. However, the pressure in the sensor connection port F is constantly adjusted by the blood flow of the microfluidic filtration channel (MFC) H. That is, the volume (or the reduced volume due to air compression) at which the blood sample is filled in the sensor connection port F is determined according to the fluidity in the microfluidic filtration channel (MFC) H, The air present in the upper part of the blood sample blocks the inflow of blood to the pressure sensor connected to the sensor connection port (F). Therefore, there is no contamination of the pressure sensor by the blood, and it is not necessary to separately clean the pressure sensor.

If the deformability of erythrocytes is good according to the fluidity of the blood sample in the microfluidic filtration channel (MFC) (H), microfluidic filtration by the clogging or blocking of the microfluidic filtration channel (MFC) The blood flow is kept constant without clogging of the channel (MFC) H. That is, the pressure in the sensor connection port F does not gradually increase but remains constant.

However, if the deformability of the red blood cells is poor, the clogging gradually increases in the microfluidic filtration channel (HFC), and the red blood cells that do not pass through the microfluid filtration channel (H) (H) inlet, which increases the pressure of the microfluidic filtration channel (MFC) (H). The pressure difference between the sensor connection port F and the microfluidic filtration channel M (that is,? P = P F -P H , P F = the pressure of the sensor connection port F, As the pressure of P H = the pressure of the microfluidic filtration channel (MFC) (H) gradually decreases, the blood flow rate to the microfluidic filtration channel (MFC) (H) gradually decreases. As a result, the flow of blood from the sensor connection port F to the microfluidic filtration channel (MFC) H is stopped. However, since the blood sample is continuously injected into the sensor connection port F by the operation of the micropump 2, the pressure P F of the sensor connection port F gradually increases. Under the condition that the pressure of the sensor connection port F is higher than the pressure of the microfluidic filtration channel (MFC) H (i.e., P F > P H ).

As described above, the blood flow in the microfluidic filtration channel (MFC) H is determined according to the deformability of the red blood cells, and the blood flow in the microfluidic filtration channel (MFC) . That is, the deformability of the red blood cells can be evaluated by measuring the change of the pressure using the pressure sensor of the pressure measuring device 3 connected to the sensor connection port F.

FIG. 6 is a mathematical modeling according to erythrocyte deformability. FIG. 6 (a) shows the case where the erythrocyte deformability is good (P F > P H ) and FIG. 6 (b) shows the case where the erythrocyte deformability is bad (P F <P H ).

As shown in FIG. 6, the pressure acting on the sensor connection port F was mathematically modeled using a lumped parameter model. Here, the flow rate and the fluidic resistance are denoted by Q and R, respectively. "F" and "H" are respectively a sensor means connected to the port (F) and the fine fluid filter channel (MFC) (H), and each pressure is represented by P F, and P H. The compliance by the air present in the sensor connection port F is indicated by C air . The flow rate between the sensor connection port (F) and the microfluidic filtration channel (MFC) (H) is indicated by Q D.

Figure 7 shows a graph of the change in pressure over time for good erythrocyte deformability.

6 (a), when the deformability of the red blood cells is good, the pressure of the microfluidic filtration channel (MFC) H is lower than the pressure of the sensor connection port F, so that the fluid flow is kept constant. Here, the fluid resistance is modeled as R low for the microfluidic filtration channel (MFC) (H). Using the mass conservation law, the following equations (1) and (2) are derived for the node (F) and the node (H).

Figure 112016022629013-pat00001

Figure 112016022629013-pat00002

The above equation (2) is substituted into the equation (1) and rearranged as the pressure (P F ) for the sensor connection port (F).

Figure 112016022629013-pat00003

If the time constant (?) (I.e.,? = 2R Low C air ) is used in Equation (3), it can be simplified to Equation (4).

Figure 112016022629013-pat00004

When the initial condition (P F [t? 0] = 0) is applied to Equation (4), the pressure relation for the sensor connection port F is derived as shown in Equation (5).

Figure 112016022629013-pat00005

7, the transient response of the pressure is determined by the time constant λ and the steady state (or maximum pressure) pressure is P F (t → ∞) = 2R Low Q . That is, it is possible to quantify the flow change of the microfluidic filtration channel (MFC) H due to the deformation of the red blood cells using "λ and P F , max " from the pressure data measured at the sensor connection port (F).

FIG. 8 is a graph showing a change in pressure with time for the case where the erythrocyte deformability is bad.

6 (b), when the deformability of erythrocytes is bad, the pressure in the microfluidic filtration channel (MFC) H is detected by continuous clogging on the microfluidic filtration channel (MFC) Becomes higher than the pressure of the connection port F (that is, P F <P H ), the fluid flow is stopped (that is, Q D = 0). Using the mass conservation law for Node (F), the following equation (6) is derived.

Figure 112016022629013-pat00006

In Equation (6), when the initial condition P F [t? T 0 ] = P F0 is used, the pressure relation of the sensor connection port F is derived as shown in Equation (7).

Figure 112016022629013-pat00007

According to Equation (7), the pressure of the sensor connection port F is continuously increased. 8, the volume at which the blood sample is filled from the micropump 2 gradually increases (i.e., V Bad > V Good ). After a certain time (t = t th ) (F) is greater than the pressure of the microfluidic filtration channel (MFC) (H) (i.e., P F > P H ). At this time, the blood flow starts again (i.e., Q D > 0) and the pressure at the sensor connection port F becomes lower over time.

That is, from the analysis through mathematical modeling as described above, it can be quantified to the maximum pressure when the deformability of erythrocytes is bad.

FIG. 9 shows a graph of time constant and maximum pressure tendency according to erythrocyte deformability.

As described above, mathematical modeling of the pressure at the sensor connection port (F) has shown that the deformability of red blood cells can be quantified using "time constant and maximum pressure". That is, as shown in Figure 9, the more deteriorated the red blood cell deformability, the time constant (i.e., λ 1 <λ 2 <λ 3 <λ 4) and the maximum pressure (i.e., P F, max, 1 <P F, max, 2 &lt; P F, max, 3 &lt; P F, max, 4 ). It is possible to quantify erythrocyte deformability using this.

In addition, we want to be able to evaluate the deformability of red blood cells using the value (P INT ) obtained by integrating the time trace of the pressure (P F ) of the sensor connection port (F) for a certain period of time. That is, P INT is derived as follows.

Figure 112016022629013-pat00008

Three factors (λ, P F, max and P INT ) have been proposed to quantify the deformability of red blood cells as described above.

10 shows an electric circuit for measuring pressure using a pressure sensor.

As shown in Fig. 10, in order to measure at a low pressure condition when using a pressure sensor (sensitivity = 1 mV / kPa) installed together with an analog electric amplifier circuit, amplification must be performed using an OP amp (Operational Amplifier) . 2) First, a Wheatstone bridge circuit is constructed to remove the DC voltage of the pressure sensor, and a variable resistor R4 is installed and adjusted. Thereafter, by using the resistors R1 and R2, the voltage is amplified to measure the pressure acting on the sensor connection port F as a voltage. Here, the output voltage of the OP amp is derived as shown in Equation (9).

Figure 112016022629013-pat00009

11 shows a pressure measuring device composed of a pressure sensor, an analog electric circuit and a microfluidic device.

As shown in FIG. 11, the pressure measuring device installed the output voltage of the pressure sensor connected to the sensor connection port (F) on the PCB substrate using an analog electric circuit. That is, a pressure sensor is attached to a PCB substrate to constitute a pressure measuring device, and a microfluidic device is connected to the pressure sensor.

12 is a graph showing a pressure change measurement with increasing flow rate of a blood sample.

To evaluate the performance of the pressure sensor, the pressure was measured while increasing the injection flow rate. As shown in FIG. 12, it was confirmed that the pressure increased proportionally with increasing flow rate under a flow rate of 5 mL / h or more. In other words, according to the hydrodynamic relation, the pressure is proportional to the flow rate, so that it is confirmed that the fluid pressure change in the microfluidic device can be sufficiently monitored by using the proposed analog circuit and pressure sensor.

13 is a schematic configuration diagram of an apparatus for measuring red blood cell deformability according to another embodiment of the present invention.

As shown in FIG. 13, the apparatus for measuring erythrocyte deformability according to another embodiment of the present invention comprises a blood sample storage container, a pump, a pressure measuring device, and a microfluidic device. The pressure measuring device "installs the pressure measurement container" vertically so that it can be separated by the density difference between the air and the blood. The air is located above the blood, and the blood flow is constant due to the compression of the air and the pneumonia. Further, since the blood and the pressure sensor are cut off by the air, there is no contamination problem and it is not necessary to clean the pressure sensor. Calibration of the pressure sensor is also not necessary. Instead, the inside of the "pressure measuring vessel" is cleaned with nitrogen. Since the microfluidic device is fabricated in a single use, a cleaning procedure is not necessary.

The method of quantifying and evaluating erythrocyte deformability using the erythrocyte deformability measuring apparatus according to another embodiment of the present invention is the same as the measuring method using the erythrocyte deformability measuring apparatus of the above embodiment.

As described above, the apparatus and method for measuring red blood cell deformability according to the present invention have been described with reference to the drawings. However, the present invention is not limited to the embodiments and drawings disclosed in the present specification, It is needless to say that various modifications can be made by those skilled in the art within the scope of the present invention.

1: microfluidic device 2: micropump
3: Pressure measuring device 4: Glass substrate
5: blood injection space 6: blood injection part
7: Funnel 8: Blood storage space
9: blood storage part 10: sealing part
11: tube 12a.12b: fine strut
h: hole

Claims (20)

A microfluidic device composed of a blood supply part filled with a blood sample and an erythrocyte deformability measurement part;
A micro pump connected to the blood supply part for pumping a blood sample and connected to the microfluidic device to supply a pumped blood sample; And
And a pressure measuring device connected to the microfluidic device,
Measuring a pressure in the microfluidic device according to fluidity of a blood sample passing through the microfluidic device using the pressure measuring device to evaluate the deformability of the red blood cell,
The erythrocyte deformability measuring unit is integrally connected to a sensor connection port to which a micro pump and a pressure measuring device are connected, a microfluidic filtration channel (MFC)
Measuring a change in pressure in the sensor connection port according to fluidity of blood passing through the microfluidic filtration channel (MFC) through the sensor connection port filled with air by the pressure measuring device to evaluate deformability of the red blood cells,
The microfluidic channel (MFC) is installed in the sensor connection port and has a size smaller than that of the filtration channel. The microfluidic channel (MFC) is composed of a plurality of micropores And measuring an erythrocyte deformability. delete The method according to claim 1,
Wherein the micro-pump is connected to the micro-pump through an outlet connection port connected to the blood supply part, and is connected to the micro-pump through an inlet connection port connected to the sensor connection port. The method according to claim 1,
Wherein the pressure measuring device comprises an electric circuit and a pressure sensor. The method according to claim 1,
Wherein the blood supply part is formed by stacking a glass substrate and a blood injection part formed with a blood injection space, connecting a funnel to the blood injection space, and injecting a blood sample into the blood injection space through the funnel. 6. The method of claim 5,
Wherein the blood injecting unit comprises a polymer. The method according to claim 1,
Wherein the sensor connection port is formed by stacking a glass substrate, a blood reservoir having a blood reservoir and a sealing portion on the blood reservoir, and a tube passing through the sealing portion is connected to the pressure sensor. 8. The method of claim 7,
Wherein the blood storage part and the sealing part are made of a polymer. delete The method according to claim 1,
Wherein the filtration channel comprises a plurality of fine strands arranged in two rows side by side staggered from each other. 11. The method of claim 10,
Wherein the fine strut has a cylindrical shape. 12. The method of claim 11,
And the spacing and height between the cylinders of the fine strut are 10 占 퐉. delete delete The method according to claim 1,
Wherein the fine strut is formed by connecting one of the corners of the triangular column and the pentagonal column so that the gap therebetween is zigzag. 16. The method of claim 15,
Wherein the minimum clearance between the fine struts is 2 占 퐉 and the maximum gap is 10 占 퐉. A measuring method for measuring deformability of erythrocytes using the measuring device according to any one of claims 1, 3 to 8, 10 to 12, 15 and 16,
Supplying a blood sample to a blood supply portion of the microfluidic device;
Pumping a blood sample supplied to the blood supply unit by a micro pump and injecting the blood sample into the erythrocyte deformability measuring unit of the microfluidic device;
Measuring a change in pressure in the microfluidic device which changes according to fluidity of a blood sample passing through the erythrocyte deformability measurement unit using a pressure measuring device to evaluate erythrocyte deformability; And
And discharging the blood sample passed through the erythrocyte deformability measuring unit to the discharging portion of the microfluidic device. 18. The method of claim 17,
Measuring the erythrocyte deformability comprises:
Supplying a blood sample into the sensor connection port of the microfluidic device and injecting the blood sample into the filtration channel;
Injecting a blood sample passed through the filtration channel into a microfluidic filtration channel of a microfluidic device;
Further comprising the step of measuring a change in pressure in a sensor connection port according to fluidity of a blood sample injected into and passed through the microfluidic filtration channel using a pressure measuring device to evaluate erythrocyte deformability. 18. The method of claim 17,
Wherein the pressure measuring device comprises an electric circuit and a pressure sensor, and the change in pressure in the sensor connection port is measured by the pressure sensor. 18. The method of claim 17,
And a blood sample is filled in the sensor connection port together with air.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108855256A (en) * 2018-04-25 2018-11-23 南开大学 A kind of micro-fluidic chip and its method detecting erythrocyte deformability
KR20200000315A (en) 2018-06-22 2020-01-02 광주과학기술원 Apparatus and method for measuring deformability of red blood cells

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
Blood flow in non-circular microchannel under pulsating condition(N.Kumar, ResearchGate Vol.4, 2014)
Cellular-scale hydrodynamics(M.Abkarian, Biomed.Mater.3, 2008)
Tunable Microfluidic Devices for Hydrodynamic Fractionation of Cell and Beads(jafar Alv., Sensors, 2015)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108855256A (en) * 2018-04-25 2018-11-23 南开大学 A kind of micro-fluidic chip and its method detecting erythrocyte deformability
CN108855256B (en) * 2018-04-25 2020-06-02 南开大学 Microfluidic chip and method for detecting deformability of red blood cells
KR20200000315A (en) 2018-06-22 2020-01-02 광주과학기술원 Apparatus and method for measuring deformability of red blood cells

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