KR20170123832A - Apparatus and method for multiple measurement of blood biophysical property based on microfluidic device - Google Patents

Abstract

The present invention relates to an apparatus and a method for multiple measurement of blood biophysical properties based on a microfluidic device. The apparatus of the present invention is an apparatus for multiple measurement of blood biophysical properties including a channel through which the measurement target fluid and a standard fluid pass, and which is disposed in the microfluidic device to measure viscosity, viscoelasticity, deformability of red blood cells, and coagulation of the red blood cells of a measurement target fluid, wherein the channel includes a first side channel and a second side channel which are disposed in the microfluidic device at predetermined intervals, a bridge channel which connects between the first and second side channels, a deformability chamber provided in the first side channel under the bridge channel, and a viscosity chamber provided in the second side channel under the bridge channel, upper end portions of the first and second side channels become inlets of the measurement target fluid and the standard fluid, and lower end portions of the first and second side channels and a portion connected between a second side channel inlet and the bridge channel become outlets. Therefore, the apparatus according to the present invention calculates blood volume using information on a flow rate (<U>_1) of blood flown into the deformability chamber of the first side channel before closing the outlet of the first side channel, quantifies coagulation of the red blood cells using changes in deformability of the red blood cells and image intensities within the viscosity chamber through the calculated blood volume, and measures viscoelasticity and viscosity of blood after closing the outlet of the first side channel.

Description

Technical Field [0001] The present invention relates to an apparatus and a method for measuring multiple biological properties of a blood based on a microfluidic device,

The present invention relates to an apparatus and a method for measuring multiple biological values of blood based on a microfluidic device, and more particularly, to a method and apparatus for measuring multiple biological values of blood based on a microfluidic device, comprising a first side channel having a deformable chamber, A microfluidic device capable of measuring the multi-biological value of blood, which is regarded as an early diagnostic index of cardiovascular disease, by injecting blood and saline into the side channel and the bridge channel connecting them, And more particularly, to a multi-biological value measuring apparatus and a measurement method for blood based on the same.

1. Summary of the Invention

In 2009, the number of patients with cardiovascular diseases such as hypertension, diabetes, and heart disease increased by 7.5%, 4.7%, and 3.5%, respectively, to 4.59 million and 1.78 million, respectively, . According to the American Heart Association, cardiovascular disease is the first cause of death in modern people (48%) and the second cause of death in Korea (37.5%).

In particular, cardiovascular diseases such as arteriosclerosis, myocardial infarction, and cerebral hemorrhage occur suddenly without any pre-symptom, leading to death or serious complications. However, since it is difficult to diagnose only by conventional biochemical detection method, biophysical diagnosis technology is needed to effectively cope with the early diagnosis.

In recent years, there has been an increasing number of reports of blood viscosity and cardiovascular disease correlations with blood viscosity (viscosity, viscoelasticity, hematocrit, deformability, coherence, etc.) , The measurement of blood viscosity is important for the diagnosis of cardiovascular disease and for monitoring the progress of the disease.

2. Research Trends of the Present Invention

Conventional viscometers are expensive for laboratories and require relatively high sample consumption (~ mL) and measurement time (~ hr), and repeated viscosity measurement is required for accurate measurement. In addition, it is difficult to apply it in a clinical field by a method of washing after measurement of blood viscosity. On the other hand, the microfluidic device-based viscometer has unique advantages such as sample, accuracy, similarity with actual flow, absence of free surface, and one-time, and thus has high potential in clinical application.

In order to measure the viscosity of a fluid to be measured, various methods have been proposed based on a pressure drop due to a friction loss caused by fluid flow in a microfluidic channel. The proposed method has a direct method to calculate viscosity by directly measuring the pressure drop by using a pressure sensor, (2) by a viscosity difference between a reference fluid and a sample fluid, There is a method of detecting the movement of the interface and measuring the viscosity at the ratio occupied by each fluid. In addition, a counting channel is provided in a microfluidic channel array, and the fluid is counted by the viscosity difference of the fluid to be measured with respect to the reference fluid using the concept of hydrodynamic flow compartment. There is a way to measure the fluid viscosity by counting the number of channels filled in the channel. Finally, a method has been proposed for measuring the viscosity of a fluid flowing through a bridge circuit using a wheatstone-bridge circuit based on a microfluidic device.

However, the conventional methods described above can not measure the blood viscosity using a commercial viscometer after blood is collected from a closed fluidic circuit such as hemodialysis and cardiopulmonary-bypass procedure do. At this time, the flow rate or shear rate of the blood is lost. In addition, there is a difference in blood viscosity due to the influence of the viscosity depending on the channel size (that is, the Fahraeus-Lindqvist effect). For this reason, viscosity measurements are being made at various channel shear rates to minimize the effect of the Fahraeus-Lindqvist effect.

In addition, it is difficult to measure the viscosity accurately due to changes in blood characteristics and artifacts due to blood storage time after blood clotting, and information on the pulsatility and viscoelasticity is provided because there is no information on dynamic changes in flow rate and pressure. And can not simultaneously measure the viscosity, viscoelasticity and cohesiveness among the biological properties of the blood, which are highly correlated with circulatory diseases.

Moreover, due to periodic blood sampling and laboratory measurements in the closed fluid circuit, there is a problem that the blood remaining in the fluid circuit is gradually reduced, making it difficult to continuously monitor for a long time due to physiological problems.

3. Necessity and Importance of the Present Invention

Since blood biochemical values are relatively high in the symptoms of hypertension, diabetes and smoking, which are known as risk factors of cardiovascular disease, blood bioassay is necessary for early diagnosis of cardiovascular disease patients without previous symptoms.

It is necessary to develop a biosensor for blood biocompatibility that can be applied for clinical monitoring and early diagnosis of disease progression of cardiovascular disease patients. In other words, since conventional commercial viscometers are limited in clinical application to blood biosynthetic value, it is necessary to develop a biosensor for measurement of blood biological value based on a microfluidic device having various advantages.

The proposed methods for the measurement of blood biological values based on microfluidic devices have disadvantages such as 1) viscosity difference due to Fahraeus effect, 2) loss of pressure, flow rate, and pulse information, and 3) difficulty in monitoring for a long time. It is necessary to develop biosensor measurement biosensor based on microfluidic device which has the characteristics such as accurate, reliable, easy & easy operation by improving these disadvantages.

Ultimately, it provides accurate and reliable blood biological value using a small amount of blood sample in the field (hospital) for monitoring and pre-diagnosis of the health condition of cardiovascular disease patients, Development of a measurement biosensor is needed.

Korean Patent Registration No. 10-0830653 Korean Patent Registration No. 10-1123959

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made in order to solve all of the above problems, and its object is to provide a blood multi-biocompatible, viscous, erythrocyte deformable and erythrocyte- And to provide a device and a method for measuring a multiple biological value of blood based on a microfluidic device which can be simultaneously measured by injecting blood and saline into a deformable chamber and a viscous chamber of a channel.

In order to achieve the above-mentioned object, the apparatus for measuring multi-biological property of blood based on the microfluidic device of the present invention is characterized in that the microfluidic device is provided with a microfluidic device for measuring the viscosity, viscoelasticity, erythrocyte deformability, Wherein the channel comprises a first side channel and a second side channel which are respectively disposed at predetermined intervals in the microfluidic device, and the first side channel and the second side channel are arranged at predetermined intervals in the microfluidic device, A bridge channel is provided between the first and second side channels, a deformable chamber is provided in the first side channel below the bridge channel, and a viscous chamber is provided in the second side channel, The upper side of the second side channel inlet and the bridge channel are connected to each other, In that this outlet is characterized.

And a microchannel disposed in the deformable chamber and the viscous chamber, respectively.

It is preferable that a minimum gap between channels of the microchannel in the deformable chamber is 2 占 퐉, a height is 4 占 퐉, and a minimum gap between channels of the microchannel in the viscous chamber is 50 占 퐉.

It is preferable that the fluid to be measured is blood, and the reference fluid is saline.

The microchannel further includes a micro filter disposed in each of the injection ports of the first and second side channels.

The syringe pump may further include respective syringe pumps for injecting blood and saline through the injection ports of the first and second side channels.

A valve connected to a lower end of the first side channel and the second side channel, and a discharge port between the second side channel and the bridge channel, and more specifically, a pinch valve.

In addition, the method for measuring multiple biological values of blood on the basis of the microfluidic device of the present invention is characterized in that the measurement target fluid and the reference fluid, which are disposed in the microfluidic device so as to simultaneously measure the viscosity, erythrocyte deformability, viscoelasticity, And a bridge channel connecting the first side channel, the second side channel, and the side channel through which the measurement target fluid passes, Wherein the fluid to be measured is supplied to part of the second side channel through the bridge channel; Injecting a reference fluid through the injection port of the second side channel having the viscous chamber to fill the fluid with the fluid to be measured; And measuring the biocompatibility of the blood before and after closing the outlet of the first side channel and the second side channel and the outlet between the second side channel and the bridge channel.

Preferably, the fluid to be measured is injected into the injection port in the form of a periodic pulse, and the reference fluid is injected into the injection port with constant flow rate control.

The opening and closing of the discharge port between the discharge port of the first and second side channels and the second side channel and the bridge channel is preferably performed by a valve.

It is preferable that blood is used as the fluid to be measured, and saline is used as the reference fluid.

In addition, it is preferable that only the red blood cells are injected by the microfilters disposed at the injection port of the first side channel, and the contaminants of the saline solution are removed by the microfilter disposed at the injection port of the second sidechannel.

The step of measuring multi-biological values of the blood further comprises the steps of: opening the outlet between the first side channel and the second side channel and the bridge channel; periodically opening and closing the outlet of the second side channel; 1 < / _RTI > information of the blood flowing into the deformable chamber of the side channel of the first side channel, quantifying the deformability of the red blood cells, measuring the erythrocyte cohesiveness, Preferably, the outlet between the two side channels and the bridge channel is closed and the outlet of the second side channel is open, after which the viscoelasticity and viscosity of the blood are measured.

The erythrocyte deformability measurement of the blood can be performed by setting a specific region of interest (ROI) at an arbitrary position of the inlet of the deformable chamber and measuring the blood flow velocity at a specific time (t _s = 10 &lt; / RTI &gt; min) of the volume of blood injected into the deformable chamber (V _DC ).

The measurement of erythrocyte cohesion of the blood is also preferably performed by evaluating erythrocyte cohesiveness by monitoring the image intensity (< I >) change in a particular region of interest (ROI) within the viscous chamber of the second side channel.

-A_Low), A_Ratio= A_Upp/A_Low의 4가지 특성치에 의해 정량화하는 것이 바람직하다.Further, the erythrocyte cohesiveness is a value (A _Low = I ₀ * t _s ) obtained by integrating the change rate of the image intensity with time (Slope =? I /? T) and the minimum value standard of the image intensity over a certain period of time (t _s = , A value obtained by subtracting A _Low from a value obtained by integrating image intensity for 100 seconds (A _Upp =

-A _Low ), and A _Ratio = A _Upp / A _Low .

The viscoelasticity measurement of the blood is performed by measuring the flow velocity (< u > u) of a specific region of interest (ROI) at the upper side of the first side channel and quantifying the viscoelasticity of the blood by measuring the time constant according to the transient response desirable.

The viscosity of the blood is preferably measured by measuring the number of blood-filled channels (N _Blood ) in the viscous chamber of the second side channel.

According to the multi-biological value measuring device and measuring method of blood based on the microfluidic device of the present invention, it is possible to simultaneously measure changes in four blood biological values of viscosity, viscoelasticity, erythrocyte deformability and erythrocyte cohesiveness, There is an effect that can be monitored continuously and repeatedly.

In addition, by measuring the multi-biological value of blood using a microfluidic device, which is a disposable biochip, there is no need for a separate washing process.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing the operation of three pinch valves connected to a discharge wave control file and an outlet of an injection flow control device for blood and saline based on a microfluidic device according to the present invention.
FIG. 2 is a view showing a procedure according to a method of measuring erythrocyte deformability and cohesiveness of a multiple blood biological value using a multi-biological value measuring device for blood based on a microfluidic device according to the present invention
FIG. 3 is a view showing a method for measuring erythrocyte deformability and erythrocyte cohesiveness of blood using the apparatus for measuring a biological value of blood of the present invention
Figure 4 is a graph showing the change in blood flow (< U > _l ) over time measured at the inlet of the deformable chamber of the first side channel of the microfluidic device
FIGS. 5A and 5B are photographs of a deformable chamber showing a time-dependent change in image intensity (< I &gt;) for a particular region of interest (ROI) in a deformable chamber of a first side channel of a microfluidic device; As a graph, changes in blood flocculation due to the addition of dextran solution to blood samples
6 is a view showing a method of measuring the viscosity and viscoelasticity of blood using the apparatus for measuring multi-biological value of blood of the present invention
FIG. 7 is a graph showing mathematical modeling for determining the viscoelasticity of blood under transient shear flow conditions; FIG.
8 is a graph showing the change of the flow rate (< U &_gt; _u ) according to the blood flow rate
Figure 9 is a graph and mathematical modeling for viscosity measurement of blood under steady shear flow conditions;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of an apparatus and method for measuring multi-biological value of blood based on a microfluidic device 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.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an apparatus for measuring a biological bio-value of blood based on a microfluidic device according to the present invention. FIG.

As shown in FIG. 1, an apparatus for measuring a biological bio-value of blood based on a microfluidic device according to the present invention includes a microfluidic device 1 as an "H" device, which mimics a Wheatstone- (Right side in the figure) of the first side channel 2, the second side channel 3, and the H-shaped center connection portion, that is, The connection between the first side channel (2) and the second side channel (3) is constituted by a bridge channel (4). The upper ends of the first side channel 2 and the second side channel 3 are injection ports 5a and 5b and the lower ends of the first side channel 2 and the second side channel 3 are respectively discharge ports 6a and 6b. Further, there is also a discharge port 6c between the second side channel 2 and the bridge channel 4.

A fluid to be measured such as blood is injected into the injection port 5a of the first side channel 3 through the syringe pump 7a and another syringe pump 5b is injected into the injection port 5b of the second side channel 4. [ 7b) to inject a reference fluid such as saline. The microfilters 2a and 3a are disposed in the first and second side channels 2 and 3 so that when the fluid to be measured and the saline solution are injected, Are injected by the filter 2a of the micro first side channel 2. The filter 3a of the second side channel 3 serves to prevent the foreign matter contained in the saline solution from being injected. A deformable chamber 9 for measuring the deformability of the blood is provided below the bridge channel 4 on the first side channel 2 and a deformable chamber 9 for measuring the deformability of the blood below the bridge channel 4 is provided on the second side channel 3. [ A viscous chamber 10 for viscosity measurement is provided. In the deformable chamber 9 and the viscous chamber 10, microchannels 9a and 10a, which are arranged at minute intervals and have a gap g _dc (g _vc ) between the channels, are respectively disposed.

The outlet 6a of the first side channel 2 is connected to the pinch valve A so that the outlet 6a can be opened or closed through the pinch valve A, 9). &Lt; / RTI &gt; The pinch valve B is connected to the discharge port 6b of the second side channel 3 and the discharge port 6c between the second side channel 3 and the bridge channel 4 is connected to the pinch valve C The discharge ports 6b and 6c can be opened or closed through the pinch valves B and C so that the flow of blood and / or saline passing through the viscous chamber 10 can be controlled .

The blood as the fluid to be measured and the saline solution as the standard fluid are supplied to the microfluidic system using the syringe pumps 7a and 7b by the multi-biological value measuring apparatus based on the microfluidic device of the present invention as described above, Viscosity, viscoelasticity, deformability and erythrocyte coherency of blood are simultaneously measured by injecting the microfilters 2a and 3a while filtering the device 1, and specific procedures for implementing this are as follows. same.

 First, the blood (fluid to be measured) and the saline solution (reference fluid) whose viscosities are known are filled in the disposable syringe and mounted on the syringe pumps 7a and 7b, respectively, for injection into the microfluidic device 1.

As described above, the microfluidic device 1 is constituted by the first side channel 2, the second side channel 3 and the bridge channel 4 in the "H" shape mimicking the Wheatstone bridge circuit When the blood and the saline solution are injected into the first side channel 2 and the second side channel 3 of the microfluidic device 1 respectively, And the second side channel 3 on the right side is filled with blood and saline through the bridge channel 4.

The syringe pump (7a) (7b) for using each blood-filled first side channel of the microfluidic device (1) as a periodic pulse in the form of a flow rate of a syringe _{"Q 0 → 0 → Q 0} " formula ( 2 is injected through the injection port 5a and the syringe filled with saline is injected through the injection port 5b into the second side channel 3 of the microfluidic device 1 with constant flow rate control.

A method of injecting blood into the microfluidic device 1 in a pulse form and simultaneously measuring the viscosity, viscoelasticity, deformability, and erythrocyte cohesiveness of the blood by injecting the saline solution while constantly controlling the flow rate will be described in detail. same.

FIG. 2 is a view showing a procedure according to a method for measuring multiple blood biological values using a multi-biological value measuring device for blood based on a microfluidic device according to the present invention.

As shown in Fig. 2, when blood is injected into the first side channel 2 of the microfluidic device 1, the first side channel 2 is filled with blood. Further, the pinch valves A and C are opened, and the pinch valve B is periodically opened and closed in accordance with the injection flow rate.

In this way, only blood is injected into the first side channel 2 to measure erythrocyte deformability and coherency, and erythrocyte coherency is measured by setting a specific region of interest (ROI) at the upper end of the viscous chamber 10 and quantifying the image intensity. One of the pinch valves A and C is in an open state and the other pinch valve B is temporarily opened / closed when blood is in an ON state.

The four biological values of blood viscosity, viscoelasticity, erythrocyte deformability, and coherence are measured as follows depending on whether or not the pinch valves A, B, and C are closed.

The first since the outlet of the side channel and the second channel side and a bridge between the outlet channel is open, and a second side channel is periodically opened and closed, T <t ₃ Under conditions, erythrocyte deformability and cohesiveness are measured.

The outlet between the first side channel and the second side channel and the bridge channel is open and the outlet of the second side channel is periodically opened and closed and then into the deformable chamber 9 of the first side channel 2 the by measuring the _(l <U>), the flow rate of the blood flowing, and to calculate the flow rate (<U> _l), the volume of the injected blood into the deformable chamber (9) by using the information, to quantify the red cell deformability deformation .

In addition, erythrocyte cohesiveness evaluates the coherency of the red blood cells by monitoring the image intensity (< I > d _c ) change of a particular region of interest (ROI) within the viscous chamber 10.

After the outlet between the first side channel and the second side channel and the bridge channel is closed and the outlet of the second side channel is opened, the viscoelasticity and viscosity of the blood are measured under the condition of T > t ₃ .

First, the viscoelasticity of blood closes the pinch valves A and C, and after the pinch valve B is opened, under the periodic fluctuating blood flow conditions, the blood in the specific region of interest (ROI) by measuring the flow rate _{(<U> u),} and measuring the time constant of the transient response is measured by quantifying the viscoelasticity of the viscoelasticity of blood.

Also, the viscosity of the blood is measured by measuring the number of channels (N _Blood ) filled with blood in the viscous chamber 10 of the second side channel 3, whereby the viscosity of the blood is measured.

The process of measuring the deformability, viscoelasticity, erythrocyte cohesiveness and viscosity of each of the above blood will be described in more detail with reference to the drawings.

FIG. 3 is a view showing a method for measuring the red blood cell deformability and cohesiveness of blood using the apparatus for measuring bio-values of blood of the present invention.

3, the deformability of the blood, that is, the deformability of erythrocytes, can be quantified by measuring the flow rate (<U> _l ) of blood injected into the deformable chamber 9 of the first side channel 2 .

First, only the red blood cells are passed through the microfilters 2a and 2b disposed at the injection ports 5a and 5b of the first and second side channels 2 and 3, 2 side channels (2) and (3). The minimum gap of the microfilters 2a and 2b was set to 10 μm and the minimum gap of the microchannel 9a composed of a plurality of microchannels 9 in the deformable chamber 9 was 2 μm g _dc = 2 mu m). In addition, the height of the microchannel 9a was set at 4 mu m.

A region of interest (ROI), that is, a specific region of interest is set at an arbitrary position of the entrance of the deformable chamber 9, and blood flow velocity is measured using micro-PIV (Particle Image Velocimetry). The blood volume (i.e., V _DC ) injected into the deformable chamber 9 for a specific time (t _s = 10 min) using the measured blood flow rate data as shown in Fig. 4 can be calculated as shown in the following equation (1).

In the above equation (1), A _c is the cross-sectional area of the microchannel 9a.

Thus, the deformability of each blood (red blood cell) can be compared by calculating the volume of blood calculated using Equation (1) above.

4 is a graph showing the change in blood flow (< U > _l ) with time measured at the inlet of the deformable chamber of the first side channel of the microfluidic device.

FIGS. 5A and 5B are photographs of a deformable chamber showing a time-dependent change in image intensity (< I >) for a particular region of interest (ROI) in a deformable chamber of a first side channel of a microfluidic device; As a graph, it is a change in the cohesion of the blood with the addition of dextran solution to the blood sample.

5, in order to measure the cohesiveness of blood under the condition of periodic change (Q ₀ ? 0? Q ₀ ) of blood flow, a viscous chamber (not shown) provided in the second side channel 3 of the microfluidic device 1 The outlet 5a of the first side channel 2 is periodically opened and closed by the pinch valve A so as to eliminate the flow rate passing through the first side channel 2, Then, the red blood cells flocculate and disperse by the periodic fluctuation of the blood flow rate. To quantify this, a specific ROI can be selected, and the cohesiveness of the blood can be evaluated from the graph of the image intensity over time based on the selected ROI.

-A_Low), A_Ratio= A_Upp/A_Low의 4가지 특성치에 의해 정량화하는 것이 바람직하다.To evaluate the coagulability of blood, control samples were prepared by adding red blood cells to saline, and Dextran 10 mg / mL was added to the saline solution to increase the cohesiveness of the blood. As shown in FIGS. 5A and 5B, the Dextran-added blood <I> shows a steady state in a very short time compared to the control sample. From the above example, it can be seen that, after the outlet 5a of the first side channel 2 is closed with the pinch valve A, the flow of the blood in any particular region of interest ROI within the deformable chamber 9, By measuring image intensity (< I &gt;), it is sufficient to quantify blood coagulation, i.e. coagulation of red blood cells. As shown in (C) of Figure 5, the cohesion of the blood is the rate of change of intensity of the image according to the increase in time (Slope = ΔI / Δt), a value integrated for a certain period of time (t _s = 100s) to a minimum value based on the image intensity (A _Low = I ₀ * t _s ), the value obtained by integrating the image intensity for 100 seconds minus A _Low (A _Upp =

-A _Low ), and A _Ratio = A _Upp / A _Low .

6 is a view showing a method of measuring the viscosity and viscoelasticity of blood using the multi-biological value measuring device for blood of the present invention. Using a syringe pump, saline is injected constantly. Further, the pinch valves A and C are closed, and the pinch valve B is opened.

Figure 7 measures the viscoelasticity of blood under transient shear flow conditions when the blood flow is changed from Q _{0 to} 0. This viscoelasticity is measured by measuring the velocity of the blood by performing micro-PIV in a certain region of the first side channel 2 of the microfluidic device 1 and measuring the time constant from the transient response according to the periodic change of the blood flow rate time constant to measure the viscoelasticity of the blood.

Modeling can be done using a discrete fluid element for the transient response of the blood flow as shown in FIG. R _Blood and C _Blood are equivalent fluid resistance and compliance. Also, tube compliance was modeled as C ₀ . Using the mass conservation law based on point A, the relationship between the injection flow rate (Q _Blood ) and the pressure (P) is given by the following equation (2).

The flow rate Q flowing to the first side channel 2 is Q = P / R _Blood , and substituting this into the above equation (2) yields the following equation (3).

In the above equation (3), the flow rate Q is Q = A < U > u.

In the above equation (4),? = R _Blood (C ₀ + C _Blood ).

From the equation (4) thus derived, the time constant ([lambda]) can be calculated from the transient response of the blood flow rate. The time constant can be calculated from the transient response of the flow velocity U due to the variation of the blood flow rate as shown in FIG. From this time-series relation we can compute the compliance (C _Blood ) due to the viscoelasticity of the blood.

Figure 9 is a graph and diagram showing mathematical modeling for viscosity measurement of blood under steady shear flow conditions.

Referring to FIG. 9, blood and saline flow through the viscous chamber 10 of the second side channel 3 under steady shear flow conditions at the blood flow rates Q ₂ and Q ₁ . At this time, the viscosity of blood can be measured by measuring the number of channels filled with blood (N _Blood ). The minimum gap of the channels formed by a plurality of channels in the viscous chamber 10 was set to 50 μm (ie, g _vc = 50 μm).

When the blood flow is Q _Blood = Q ₀ , the filled width of the blood is measured as N _Blood (or N _PBS ). The viscosity and the flow rate of the saline solution are given by Q _PBS = Q ₀ and μ _PBS , respectively. Considering the same channel height with the same pressure enhancement (i.e., ΔP _Blood = ΔP _PBS ) and low aspect ratio (ie, width (W)> depth (h)] for both fluids, Is μ _Blood = μ _PBS · [N _Blood / N _PBS ].

As described above, the multi-biological property measuring device for blood based on the microfluidic device of the present invention includes a syringe pump, a microfluidic device, and a camera for monitoring blood flow in the microfluidic device, The device has an H shape that mimics a Wheatstone-bridge electrical circuit and has an inlet and outlet for injecting and discharging two fluids, blood as the fluid to be measured and saline as the reference fluid, a deformable chamber for measuring the deformability of the blood, And a viscous chamber for measurement. A pinch valve was also connected to the outlet to regulate blood flow through the deformable chamber.

Experimental procedures and methods for measurement of multiple biological values of blood by such a measuring device are as follows. Blood (fluid to be measured) and saline solution (reference fluid) are filled in a disposable syringe and then mounted on a syringe pump. Using the syringe pump, the blood is injected into the microfluidic device in the form of periodic pulses, and the saline solution is injected at a constant flow rate. After the microfluidic device is filled with blood and saline, the multiple biological values of the blood are measured through the blood flow before and after closing the discharge port of the microfluidic device.

As described above, the method of quantifying blood through the above-described experimental procedure and method is performed as follows, by dividing the outlet of the microfluidic device with the pinch valve before and after closing.

[Before closing the outlet with pinch valve]: T <t ₃

1) Erythrocyte deformity: Measure the flow rate (<U> _l ) of blood flowing into the deformable chamber until the outlet is blocked by a pinch valve. This flow rate information is used to calculate the volume of blood injected into the deformable chamber to quantify the deformability of the red blood cells.

2) Erythrocyte cohesion: Evaluates the cohesion of erythrocytes by monitoring image intensity (<I>) changes within a particular region of interest (ROI) within the deformable chamber.

[After closing the outlet with pinch valve]: T> t ₃

3) Blood viscoelasticity: After closing the outlet with a pinch valve, measure the blood flow (<U> _u ) in a particular region of interest (ROI) at the top of the first side channel of the microfluidic device under periodic fluctuating blood flow conditions And the viscoelasticity of the blood is quantified by measuring the time constant due to the transient response.

4) Blood viscosity: The blood viscosity is measured by measuring the number of channels filled with blood (N _Blood ) in the viscous chamber.

As described above, the apparatus and method for measuring biological value of blood based on a microfluidic device according to the present invention have been described with reference to the drawings. However, the present invention is limited by the embodiments and the drawings disclosed herein It is needless to say that various modifications can be made by those skilled in the art within the scope of the technical idea of the present invention.

1: microfluidic device 2: first side channel
2a, 3a: Microfilter 3: Second side channel
4: bridge channel 5a, 5b:
6a, 6b, 6c: Outlets 7a, 7b: Syringe pumps
9: deformable chamber 9a, 10a: microchannel
10: Viscous chamber A, B, C: Pinch valve

Claims (19)

There is provided a multi-biological value measuring apparatus for blood, in which a channel through which a fluid to be measured and a reference fluid pass is arranged in a microfluidic device so as to simultaneously measure viscosity, viscoelasticity, erythrocyte deformability and erythrocyte cohesiveness of the fluid to be measured,
Wherein the channel comprises a first side channel and a second side channel which are respectively disposed at predetermined intervals in the microfluidic device and the first and second side channels are connected by a bridge channel, The first side channel has a deformable chamber and the second side channel has a viscous chamber. The upper ends of the first and second side channels serve as an inlet for a fluid to be measured and a reference fluid, and a lower end and a second side channel inlet And a portion connected between the bridge channels serves as a discharge port. The apparatus for measuring multiple biological properties of blood based on a microfluidic device. The method according to claim 1,
Further comprising a microchannel disposed in the deformable chamber and the viscous chamber, respectively, to measure the biological bioavailability of the blood based on the microfluidic device. 3. The method of claim 2,
Wherein a minimum gap between the channels of the microchannels in the deformable chamber is 2 占 퐉 and a height is 4 占 퐉 and a minimum gap between the channels of the microchannels in the viscous chamber is 50 占 퐉. Multiblasticity measuring device. The method according to claim 1,
Wherein the fluid to be measured is blood, and the reference fluid is saline. 5. The method of claim 4,
Further comprising a microfilter disposed in the inlet of the first and second side channels, respectively, for measuring the biological bioavailability of the blood based on the microfluidic device. 5. The method of claim 4,
Further comprising: a syringe pump for injecting blood and saline through each of the injection ports of the first and second side channels. 7. The method according to any one of claims 1 to 6,
Further comprising a valve connected to a lower end of the first side channel and the second side channel and to an outlet between the second side channel and the bridge channel. 8. The method of claim 7,
Wherein the valve is a pinch valve. &Lt; RTI ID = 0.0 &gt; 8. &lt; / RTI &gt; Connecting the first side channel and the second side channel through which the fluid to be measured and the reference fluid, which are disposed in the microfluidic device, are simultaneously measured to measure the viscosity, erythrocyte deformability, viscoelasticity and erythrocyte cohesiveness of the fluid to be measured, A method for measuring multiple biological values of blood using a bridge channel,
Injecting and filling the fluid to be measured through the injection port of the first side channel having the deformable chamber and supplying the fluid to be measured to a part of the second side channel through the bridge channel;
Injecting a reference fluid through the injection port of the second side channel having the viscous chamber to fill the fluid with the fluid to be measured; And
And measuring the biocompatibility of the blood before and after closing the outlet of the first side channel and the second side channel and the outlet between the second side channel and the bridge channel. A method for measuring multiple biological properties of blood based on. 10. The method of claim 9,
Wherein the fluid to be measured is injected into the injection port in the form of a periodic pulse and the reference fluid is injected into the injection port with constant flow rate control. 10. The method of claim 9,
Wherein the opening and closing of the outlet between the outlet of the first and second side channels and the second side channel and the bridge channel is made by a valve. 12. The method according to any one of claims 9 to 11,
Wherein the fluid to be measured is blood, and the reference fluid is saline. 13. The method of claim 12,
Wherein only the red blood cells are injected by the micro filter disposed at the inlet of the first side channel and the contaminants of the saline solution are removed by the micro filter disposed at the inlet of the second side channel Methods for measuring multiple biological values of blood. 13. The method of claim 12,
Wherein the step of measuring the multi-biological value of the blood comprises:
Wherein the outlet of the first side channel and the second side channel and the bridge channel is open and the outlet of the second side channel is periodically opened and closed after which the flow rate of blood entering the deformable chamber of the first side channel <U> ₁ ) Calculate blood volume using information, quantify red cell deformity, measure red cell cohesiveness,
Wherein the outlet of the second side channel is closed and the outlet of the second side channel is opened to measure the viscoelasticity and viscosity of the blood. Methods for measuring multiple biological properties of a blood sample. 15. The method of claim 14,
The erythrocyte deformability measurement of the blood is performed by setting a specific region of interest (ROI) at an arbitrary position in the deformable chamber entrance and measuring the blood flow velocity at a specific time (t _s = 10) using the blood flow velocity information measured by micro-PIV (Particle Image Velocimetry) (V _DC ) of the blood injected into the deformable chamber during a predetermined period of time (min). 15. The method of claim 14,
Wherein the measurement of erythrocyte cohesion of the blood is performed by evaluating erythrocyte cohesiveness by monitoring image intensity (< I &gt;) change in a particular region of interest (ROI) within the viscous chamber of the second side channel. Methods for measuring multiple biological values of blood. 17. The method of claim 16,
The erythrocyte cohesiveness is a value (A _Low = I ₀ * t _s ) obtained by integrating the rate of change of the image intensity with time (Slope =? I /? T), the minimum value standard of the image intensity for a certain period of time (t _s = A value obtained by subtracting A _Low from the value obtained by integrating image intensity for 100 seconds (A _Upp =

-A _Low ), and A _Ratio = A _Upp / A _Low . A method for measuring multiple biological properties of blood based on a microfluidic device. 15. The method of claim 14,
The viscoelasticity measurement of the blood is performed by measuring the flow rate (< u > u) of a specific region of interest (ROI) at the upper side of the first side channel and quantifying the viscoelasticity of the blood by measuring the time constant according to the transient response A method for measuring multiple biological properties of blood based on a microfluidic device. 15. The method of claim 14,
Wherein the viscosity measurement of the blood is performed by measuring the number of blood-filled channels (N _Blood ) in the viscous chamber of the second side channel.

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