KR102057329B1 - Control system based on image processing for position control of microfludics - Google Patents

Abstract

Disclosed by the present invention is an image processing-based control system for microfluidic position control. The system includes: a microfluidic system which sequentially operates reagents and samples as a channel LOC platform including a pumping unit and a microchannel unit having a moving passage and a fluid inlet; and a smartphone or embedded system which precisely controls the position of microfluid through an image analysis in order to control the fluid to stop moving when arriving at a particular location of interest (ROI) by capturing an image, in which microfluid reaches a specific position, by a camera on a microfluidic system having a reaction chamber, and controls the positional movement of microfluid by driving the pump drive unit and a roller through a position controller, image analysis software, and the camera to selectively open and close a specific value (valve 1, 2, 3, 4) depending on the position of a moving pressure roller driven by a pump drive unit with the principle of a microvalve and a pump. The image processing-based control system provides improved precision and stability.

Description

Control system based on image processing for position control of microfludics

The present invention relates to an image processing based control system for microfluidic position control, and more particularly, to fabricate a microfluidic device for diagnosing a disease, i) using a microvalve and a micropump using a local compression principle of a roller. Ii) Smart with a camera and image analysis SW for image measurement and analysis when controlling microfluidic devices using programmable smartphones or embedded systems. Equipped with a phone or embedded system platform, and controls the opening and closing of the micro-channel valves (valve 1,2, 3, 4) of the micro-fluid by analyzing the position of the microfluid through the image processing and analysis, and driving the pump drive and rollers, Imaging for microfluidic position control, which controls the microfluidic movement so that the microfluid is accurately positioned in the reaction chamber It will be based on the control system.

Recently, microfabricated microstructures required for sensing or actuating are manufactured using semiconductor manufacturing process technology, and signal processing circuits are integrated therein to provide high performance, multifunctional micro-mechanical systems (MEMS, Micro). Electro Mechanical System) is being implemented.

Using this MEMS technology, a small lab on a chip (LOC) that integrates microchips, medical and microfluidic analyzers on a few centimeters of chips can be used for medical micro-diagnosis and drug injection in the fields of biology, chemistry, medicine and genetic engineering. Much research is being conducted to utilize the system.

Lab on a chip (LOC) is a technology in which a drop of liquid, such as blood, is dropped on a small chip to move the liquid into a microscopic tube to analyze and diagnose the disease with a drop of blood.

As such, substantial research on micron-sized sensors or actuators is largely driven by the emergence of Micro Electro Mechanical Systems (MEMS) technology.

Recently, with the launch of various commercial products manufactured by MEMS technology and the rapid expansion of the market, it is recognized as a core technology that can cause a new industry. In particular, so-called integrated micro-mechanical systems (iMEMS, integrated MEMS), in which sensors or actuators are manufactured simultaneously with integrated circuits (ICs) using silicon-based micro-mechanical system technology, have emerged.

A micro pump has a function of flowing a small amount of fluid in a desired direction. A micro pump mainly includes a micro-TAS (Micro Total Analysis System), a lab-on-a-chip (LOC), and the like. It is used in trace fluid transportation and control fields related to MEMS (Bio-Micro Electro Mechanical System) field.

Until now, many methods of transporting fluid by forming a pressure gradient using a rotational force of a motor have been used in the macro domain. However, it is difficult to use an actuator such as a motor having a relatively large volume in a micro-sized lab-on-a-chip (LOC) system. In order to overcome this, there is a need to design a micro pump having a simple shape and easy to manufacture in a micro size.

The micro pump is divided into the active type that requires power and the passive type that does not require power. The active method enables precise flow rate control through the control of the power supply, and requires high reliability and quick response like an insulin injector. An expensive element to be used is used.

Micro pumps are manufactured using silicon as the main material and require high manufacturing costs.

The passive method enables fluid transfer using natural phenomena such as capillary force. The passive method is suitable for low-cost or disposable devices. However, the passive pump using capillary force is a material that constitutes the microfluidic channel. It must be hydrophilic and is generally used for fluid transfer into microfluidic channels with SiO ₂ layers on the surface.

In addition, existing micropumps include Piezo electric, Thermo pneumatic, Bimetallic, Bubble type, etc., but micropumps have some limitations. First, the pumping speed of the micro pump is slow. A slow flow rate that the micropump sucks into is a problem because the desired reaction does not occur quickly in the Lap on a Chip (LOC). Second, existing micropumps have a very complex internal structure despite their low efficiency.

In Point of Care (POC), an on-site medical examination system, a Lap on a chip (LOC) has attracted attention as a means of medical examination. These lap on a chips use disposable products for hygienic reasons. Conventional micropumps are disadvantageous for mass production due to complicated manufacturing methods and operating principles, and are difficult for non-experts to use. There was a lack of technology to move to the location.

As a related art 1, "programmable micro pump" is registered in Patent Registration No. 10-1635459. Programmable micro pump relates to a controllable micro pump, comprising: a micro pump for injecting and moving a fluid, the micro pump comprising a fluid inlet for injecting a fluid and a moving passage of the injected fluid, pumping in communication with the moving passage It provides a controllable micropump including a pump having a space and moving pressurizing means for varying the volume of the pumping space to control the movement of fluid in the microchannel portion.

Controllable micro pump

In the micro pump to inject and move the fluid,

Comprising a fluid inlet for injecting fluid and a moving passage of the injected fluid,

The moving passage has a branch passage branched into at least one,

The branch passage has a valve function to open and close the inner passage by the moving pressure means 130, but the fine channel portion having a valve function to bend the opening and closing portion by the moving pressure means 130 by refracting some branch passages ( 110);

A pumping part 120 having a pumping space in communication with the movement passage; And

Moving pressure means 130 for varying the volume of the pumping space to control the movement of the fluid in the micro-channel portion.

1 is a schematic cross-sectional view of a controllable micropump.

The micro pump is composed of a microchannel unit 110, a pumping unit 120 and the moving pressure means 130. The microchannel unit 110 includes a fluid inlet 111 and a movement passage 112, and the pumping unit 120 includes a pumping space 121.

The microchannel unit 110 has a movement passage 112 of the injected fluid, the movement passage 112 is connected to the fluid inlet 111 for entering and exiting the fluid.

The fluid inlet 111 serves as an inlet to inject fluid from the outside, and the fluid injected into the fluid inlet 111 is transferred to the pumping unit 120 through the movement passage 112, that is, pumping. When the negative pressure is generated through the unit 120, the fluid near the fluid inlet 111 moves to the movement path 112.

The fluid inlet 111 is preferably made to face upward to more easily inject the fluid.

The movement path 112 of the microchannel unit 110 may take the form of a minute passage and have a straight or bent shape. The microchannel unit 110 may have a movement passage 112 for moving the fluid injected into the fluid inlet 111 to the place where the pumping unit 120 is located.

The microchannel unit 110 may be connected to the fluid inlet 111 and the movement passage 112 to be integrally communicated with each other, instead of separately connected to the movement passage 112. The fluid moved to 120 may be moved in a more hermetic state without affecting the outside.

In addition, the end of the fluid inlet 111 is preferably formed to face upward. Since the fluid inlet 111 is formed to face upward, it may be easier to inject the fluid.

The pumping unit 120 is directly connected to the movement path 112, the fluid is moved by the positive or negative pressure generated by the pumping unit 120. That is, a pumping space 121 is formed by pressing a specific portion of the pumping unit 120 by the moving pressing means 130, and the volume of the pumping space 121 may be varied. Due to the movement of the volume is made variable, the fluid introduced into the variable of the volume is moved.

The pumping unit 120 is formed of a larger space than the movement passage 112, the pumping space 121 is formed in communication with the movement passage 112, the size of the volume by the movement of the moving pressure means 130 The space other than the pumping space that is variable is formed with a hole opened to the outside. It is possible to freely change the volume of the pumping space 121 by the pressure of the moving pressing means 130.

The moving pressurizing unit 130 serves to change the volume of the pumping space 121 by pressing and moving on the pumping unit 120.

The moving pressure means 130 may be selectively rotated with pressure on the pumping unit 120 to adjust the volume of the pumping space 121, such as a roller may be used. The volume of the pumping space 121 may be adjusted by rolling with pressure on the pumping unit 120 using a roller as the moving pressing means 130. Accordingly, the fluid introduced through the fluid inlet 111 can move the fluid to a desired position by rolling the roller.

The movement of the movable pressing means can be more precisely controlled. Instead of moving it by a human hand or the like, the moving pressing means can be precisely moved after programming by using a medium such as a computer.

As a related art 2, "liquid sample analysis device" is registered in Patent Registration No. 10-1770796.

It is necessary to separate noncellular plasma from whole blood in order to react reagents with blood for blood analysis and to prevent interference by red blood cells during the detection of certain substances. Bench-top centrifuges are widely used to separate plasma from whole blood, but the size, weight, and number of equipment used for clinical testing for point-ofcare should be minimized, so only blood samples are prepared. It is very difficult to move the centrifuge in order to do so. In addition, the most common way to get blood for personal health care, such as monitoring blood glucose levels, is to poke a finger with a lancet, the amount of blood obtained is too small to use a centrifuge.

Against this background, various types of lab on-a-chip (LOC) techniques have been proposed for preparing plasma on-chip for POC blood analysis. First, the density difference between plasma and red blood cells Techniques for separating plasma and erythrocytes by inertia, erythrocyte sedimentation or on-chip centrifugation have been proposed. Hemodynamic separation, such as plasma skimming or Fahraeus-Lindqvist effects, has also been proposed. A method of geometrically separating erythrocytes using bead packing or existing filter integration has been proposed.

For POC clinical diagnosis, a device that separates plasma from blood must have such performance as rapid separation, high yield and small power consumption. In addition, for POC applications, plasma isolated from conventional blood analysis devices or techniques must be delivered on site without additional equipment. Therefore, a device that separates plasma from whole blood obtained with a finger prick without additional equipment may be used for POC clinical trials. Very preferred as a method of replacing the separator.

In addition, in order to provide pumping pressure for extracting and delivering plasma from blood obtained from the finger, microfluidic actuators need to be integrated on the device. Currently developed pumping parts are mainly classified into two types: active and passive pumps. However, the active pumping unit uses external energy to change the volume of the microchamber by the piezoelectric transducer, air pressure or elastic restoring force. The passive pumping unit uses internal or stored energy of a material such as a hydrophilic surface or gas absorption instead of using external energy. Manual microfluid actuation is widely used to construct disposable POC devices because disposable devices are highly desirable for clinical testing to prevent contamination of the sample. However, there is a great need to make active microfluidic devices simpler with low cost plastic substrates in order to allow fluids to work faster in a controlled manner.

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The liquid sample analyzing apparatus of the prior art 2 relates to a liquid sample analyzing apparatus capable of performing a sample analysis procedure consisting of a complex chemical reaction step on a fine substrate, the substrate portion comprising an upper plate and a lower plate; A microchannel portion, which is a flow path disposed between a bottom surface of the upper plate and an upper surface of the lower plate; An injection filter part comprising a sample inlet and a filter formed by penetrating an upper plate at one end of the microchannel part, and an interval corresponding to an algorithm for determining a point of time for the movement of a sample flowing in the communication channel and the microchannel part communicating with the microchannel part; A reaction sample composed of a plurality of elastic projections arranged in a sequential, a moving pressure roller for pressing the elastic projections while moving along the upper portion of the sample attracting portion, and a moving pressure roller driving unit, the reaction having a series of complex procedures Provided is a liquid sample analysis apparatus, in which experiments can be automatically performed inside microchips.

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Liquid Sample Analysis Device

A substrate portion comprising an upper plate and a lower plate bonded to each other;

A channel disposed between the bottom surface of the upper plate and the upper surface of the lower plate, the channel consisting of a main channel and at least one branch channel connected to the main channel;

A sample injection unit formed by passing an upper plate at one end of the microchannel unit;

A communication channel communicating with the microchannel unit and formed by connecting one or more chambers in parallel, and at an interval corresponding to an algorithm for determining a moving time and a reaction time of a sample flowing in the microchannel unit. A sequential sample attracting portion formed of a plurality of elastic protrusions arranged side by side and having the same length or different lengths so as to correspond to an algorithm for determining a moving time and a reaction time of a sample flowing in the microchannel portion;

A moving pressure roller which moves along the upper portion of the sequential sample attracting portion and presses the elastic protrusion to protrude the elastic protrusion into a communication channel below the elastic protrusion;

A driving part in which the moving pressure roller and the substrate part are variably installed so as to vary the moving pressure roller or the substrate part; And

Consists of a valve unit for suppressing or promoting the introduction of the sample inside the branch flow path into the main flow path,

The valve portion is formed of a second elastic protrusion formed on the upper portion of the branch passage, the moving pressure roller is configured to suppress or promote the introduction of the sample inside the branch flow passage into the main flow passage by pressing the second elastic projection.

* Need for research

Coronary artery disease is a lesion in which the blood flow to the myocardium is impaired due to atherosclerosis of atherosclerosis (arterioscclerosis). Coronary arteries are classified into right coronary artery, left anterior descending artery and left parotid artery.

Risk factors include smoking, hyperlipidemia, diabetes, high blood pressure, obesity, lack of exercise, and stress.

Acute Coronary Syndrome (ACS) refers to coronary artery disease such as acute myocardial infarction caused by clogged coronary arteries and insufficient blood supply to the heart. Angina pectoris and myocardial infarction ( myocardial infraction).

The prevalence of acute coronary syndrome in Korea is 6.4 (per 1,000 population) and the total number of patients is 310,000. This is an increase of 42% compared to 2004. Accordingly, the cost of patients and society due to acute coronary syndrome is KRW 1.25 trillion per year as of 2011.

In particular, it is expected that the incidence of acute coronary syndrome caused by chronic diseases such as diabetes and obesity will continue to increase as the number of patients with chronic diseases increases due to the aging of the population.

Troponin I (cTnI) is found only in the heart and flows into the blood when the myocardium is necrotic. When diagnosing myocardial infarction in clinical practice, cTnI test is a useful marker to confirm the numerical change, but the low concentration of measurement requires a high-precision diagnostic device with high reliability.

In addition, microfluidics are used in devices that perform various biochemical and immunological analyzes by injecting a very small amount of various reagents into a substrate on which microfluidic channels can be flowed.

Although microfluidic devices have shown many advantages and superiority through many studies, there are still few success cases of commercialized products and are limited to the technical field proven at the laboratory level. The main reason why it is difficult to commercialize the technology is that the reproducibility and stability are inferior due to the bubble generation or the position control difficulty that occurs when controlling the microfluid.

Microfluidic devices need to control microfluidic fluids, and many existing studies drive microfluidic devices by mounting microvalve and pump in an external system.

However, valves and pumps mounted outside the chip are less accurate in controlling very small amounts of fluid and are difficult to correct when errors occur in fluid control.

In order to prevent this, when the microvalve and the pump are integrated in the mesophilic device, it is difficult to implement it at low cost to meet the characteristics of the microfluidic device that is used and discarded once to prevent contamination of the sample.

Therefore, the microfluidic device is controlled to be precisely positioned in the reaction chamber using image measurement and analysis by using a smartphone or an embedded system that can be programmed to control the position of the microfluid. This requires a system that accurately diagnoses coronary artery disease with high reliability.

Patent Registration No. 10-1635459 (Registration date June 27, 2016), "Programmable Micro Pump", Kwangwoon University Industry-Academic Cooperation Foundation, Shim Jun-seop, Lim Sung-bin, Kim Sang-chan Patent Registration No. 10-1770796 (Registration date August 17, 2017), "Liquid Sample Analysis Device", Kwangwoon University Industry-Academic Cooperation Foundation, Shim Jun-seop, Jin Kyung-jun, Lim Sung-bin

In order to solve this fundamental problem, an object of the present invention is to manufacture a microfluidic device for disease diagnosis, i) using a micropump and a micropump using a local compression principle of a roller, Operating a valve, and ii) having a smartphone or embedded system platform with a camera and image analysis SW for image measurement and analysis when controlling a programmable microfluidic device, and Location analysis and pump drive and rollers to control the opening and closing of microvalve, microfluidic movement to ensure that the microfluids are accurately positioned in the reaction chamber, iii) providing a precise immunodiagnostic platform for diagnosing coronary artery disease. To provide an image processing based control system for microfluidic position control .

This study derives the hypothesis that the microfluidic control system can be constructed precisely and stably by recognizing and solving the fluid control error based on artificial intelligence when the problem situation occurs to solve the fundamental problem of the microfluidic device.

In order to achieve the object of the present invention, an image processing based control system for microfluidic position control comprises a microchannel unit having a fluid inlet port and a moving passage, and a LOC platform including a pumping unit and reagents and samples. Microfluidic system for sequentially moving; And photographing an image of the microfluid reaching the specific position with a camera on the microfluidic system having the reaction chamber to set the region of interest (reaction chamber positions A, B, C, D) at one or more specific positions, and In order to control the movement of the fluid so that the fluid is located in the region of interest, it is possible to precisely control the position of the microfluid through image analysis, and to drive the roller using the camera and image analysis SW and the pump drive for the fluid position A system for controlling the movement of microfluidics,
The microfluidic system
A micro pump (11) having a pump bumper (20) of elastic projections on the path of each channel valve of the plurality of micro valves (valve 1,2, 3, 4); Enzyme substrate supply valve 13, secondary wash valve 14 with valve bumper 1, secondary antibody valve 15 with valve bumper 2, primary wash with valve bumper 3 (19-3) A pumping unit having a valve 16 and having the pump driving unit and the roller;
Using the principle of the microvalve and pump, the specific substrate valves 1,2,3,4 of the pumping part are selectively opened and closed according to the position of the moving pressure roller, and the enzyme substrate supply valve 13, 2 of the pumping part. The reagent is introduced by connecting to the primary washing valve 14, the secondary antibody valve 15, and the primary washing valve 16 through a connecting passage, and connected to the membrane filter 19 through a moving passage to inject a sample into the chemical. A reaction chamber 19 in which a reaction occurs,
It is connected to the reaction chamber through the flow passage and the fluid inlet and the lower portion, and includes a membrane filter 17 of the microchannel portion is injected samples (samples).

The system for controlling the movement of the microfluid uses a smartphone or an embedded system in which an image analysis of the camera and a microfluidic position control program are installed, and the microfluid by the position controller through image processing of the camera and the positional analysis of the microfluid. To control the opening and closing of a plurality of microvalve by driving the pump driving part and the moving pressure roller of the pumping part to precisely control the position of the reaction chamber (reaction chamber position, A, B, C, D), the principle of the microvalve and pump of the pumping part By using the position (A, B, C, D) of the moving pressure roller driven by the pump drive unit to selectively open and close the specific valve (valve 1,2, 3, 4) of the pumping part To control the movement.

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The pump drive unit is connected to a position controller, uses a PDMS actuator consisting of a PDMS micropump and a valve, and drives the roller by the PDMS actuator.

The PDMS actuator uses a linear motor and drives the rollers by the linear motor.

The smartphone or embedded system includes a camera for photographing chemical reaction images of reagents and samples on a microfluidic system including a reaction chamber of a microfluidic device; An image processor which encodes an image of the camera and buffers the image in a storage unit and analyzes the image through vision image processing image processing; A control unit connected to the image processing unit, the image analysis SW controlling an image analysis and a position of the microfluid, and having a position controller controlling a position of the microfluid by driving a pump driver and a roller; A storage unit connected to the control unit and temporarily storing a camera image; A communication unit providing communication of at least one of Bluetooth, Wi-Fi, and LTE / 5G connected to the control unit; A pump driver for driving a moving pressure roller according to the control of the position controller of the controller; And a moving pressure roller controlled to move horizontally by rolling and pressing by the pump driving unit.

By selectively controlling the opening and closing of at least one or multiple micro valves to precisely control the position of the microfluid by driving the pump driving unit and the moving pressure roller by a position controller through image processing of the camera and the position analysis of the microfluid. Control the movement of microfluidics.

The PDMS actuator is used as a PDMS microfluidic actuator, and the step-by-step diagnostic procedure of the PDMS microfluidic actuator is (a) a liquid sample (red solution) into a fluid sample inlet and a membrane filter ( filter, other reagents are pre-injected into the test LOC, (b) all microvalve valves 1,2,3,4 are closed, and the sample solution ( The sample solution is pumped through the membrane filter, the valves are opened sequentially, the reagents are introduced into the detection zone of the reaction chamber, and (c) the yellow washing buffer, washer, by the principle of the microvalve and pump. Buffer 1) (point D in FIG. 3) connected to the buffer), (d) valve 2 open (point C in FIG. 3) linked to the primary antibody as the green reagent, and (e) washing buffer as the orange reagent. Valve 3 is open and (f) It is open valve 4 having the reagents (enzyme substrate, enzyme substrate).

The image analysis SW provides an image processing function of a camera image and an analysis function of microfluid in the image, and uses any one of gray scale, RGB, and YCbCr conversion.

When the gray scale is used, the image analysis SW buffers and stores a camera image, provides image processing and image analysis, converts a region of interest (ROI) to a gray scale, and generates a region of interest (ROI). The histogram [pixel values of each pixel of the x-axis image, number of corresponding pixel values (frequency)] of the image of the region of interest using a threshold obtained from an experiment in which the outline of the After binarizing the region of interest image to 0,1, performing preprocessing of the image of the ROI region through histogram equalization, detecting contours of the detected objects of the region of interest, Texture Features) and Shape Features are extracted to detect the location of the microfluid at the (x, y) coordinates of the ROI region.

The bioanalytical procedure of the reaction chamber may include: (a) injecting a liquid sample (blood-red solution) required for a chemical reaction into a membrane filter; (b) moving the sample to a detection zone coated with a first antibody; (c) first washing the waste with a yellow buffer, a washing buffer; (d) introducing the primary antibody in the detection zone, moving the enzyme-linked secondary antibody, which is a green solution, to the detection zone, the primary antibody such as analytes Reacting with the secondary antibody to which the enzyme is bound; (e) second washing of the unreacted secondary antibody with an orange solution, wash buffer; And (f) introducing an enzyme substrate into the detection zone to generate a signal for analysis.

In order to develop a coronary artery disease diagnosis device capable of microfluidic control, an image processing-based control system for programmable microfluidic position control of the present invention includes: i) localization of a moving pressure roller by a horizontally moving pump driver; The micropumps and valves are operated according to the position of the rollers using a number of microvalve and micropump using the crimping principle. Ii) Camera and image analysis SW for image measurement and analysis when controlling programmable microfluidic devices. It is equipped with a smartphone or embedded system platform having a, and the micro-valve by controlling the position analysis and roller of the microfluid through image processing and analysis, and controls the microfluidic movement so that the microfluid is accurately positioned in the reaction chamber To provide a precise immunodiagnostic platform for diagnosing coronary artery disease. It was a ball.

Microfluidic devices have been published in a number of studies, and have been used to demonstrate high sensitivity for disease diagnosis, and demonstrate excellent performance in automation, reducing test costs, high accuracy, and high-speed mass screening.

In this research, if a platform that operates microfluidic control is developed stably, it is possible to innovatively solve the situation where commercialization was difficult due to stability. Through this, it is possible to commercialize various technologies utilizing the excellent performance of microfluidic devices, and it will serve as a breakthrough to solve the difficulties of technological development in the bio and biochemical fields.

Through this research, it is possible to make programmable high performance microfluidics for disease diagnosis at low cost for one-time use, and to apply AI-based image processing to precision control system using image measurement in future to have high stability.

As such, the low-cost, high-performance disease diagnostic microfluidic device can be used in a variety of ways, such as disease management of patients with chronic diseases, because the general public can check their disease state at home.

In patients with chronic diseases such as blood sugar, heart disease, and hepatitis, it is necessary to continuously monitor the condition of the disease. By continuous monitoring with the microfluidic device for diagnosing the disease, visit the hospital to receive treatment before an emergency occurs. You can also make yourself more aware of your health by becoming aware of your illness.

In the future, by manufacturing microfluidic devices for healthcare converged with artificial intelligence image processing, it is possible to construct a new medical system by enabling remote healthcare and continuous monitoring, enabling healthcare and medical fields, and remote monitoring and convergence with artificial intelligence. It can be applied to microfluidic devices that perform various functions by using a micro valve and a micro pump.

By securing artificial intelligence IT technology, electronic convergence technology, and bio technology combined with various fields such as bio, medical, software, image recognition, and semiconductor microprocessing, we secure the foundation for the development of various healthcare products in the future. By developing technologies that are integrated with medical systems, we will launch AI-based bio and healthcare products to provide new growth engines based on the IT industry and bio technology.

1 is a schematic cross-sectional view of a controllable micropump.
2 is a block diagram of an image processing based control system for microfluidic position control according to the present invention.
3 is an image processing base having a membrane filter (blood purification filter), a reaction chamber, a plurality of fine valves and pumps, a fine valve bump structure, and a smartphone or an embedded system having a camera and image analysis SW according to the present invention. A microfluidic position control system configuration diagram.
4A is a conceptual diagram of a programmable microfluidic position control and image analysis platform using an i) smartphone or ii) an embedded system with a camera and image analysis SW.
Figure 4b is a screen showing the results of the verification experiment for controlling the microfluidic position based on the image processing using a smart phone for controlling the position of the microfluid by measuring the RGB change of the reaction chamber (ROI) in real time.
4C is a view illustrating an image processing-based microfluidic position control platform of a smartphone or an embedded system according to an exemplary embodiment of the present invention.
Figure 4d is a view showing (a) the developed PDMS actuator, (b) PMMA-based LOC test device, (c) roller drive frame.
Figure 4e is a diagram showing a step-by-step diagnostic procedure using the PDMS microfluidic actuator of the proposed elastic material.
4F is a photograph showing the Microfluidic operation procedure of the design platform used in the bio analysis procedure.
FIG. 5 illustrates a combination of a primary antibody, a biomarker, a primary washing, a secondary antibody and an enzyme to a primary antibody and a marker in a reaction chamber, and an enzyme by a secondary washing. When the solution is allowed to flow, the enzyme is removed and the color of the solution is changed.
FIG. 6 is a diagram illustrating a multi-step immune response for diagnosis of coronary artery disease using a programmable microfluidic device in a programmed order.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail the configuration and operation of the invention.

In this study, a low-cost polydimethylsiloxane (PDMS) micropump (PDMS micro-pump) and valves (valve 1,2,3,4), a PDMS actuator, and a programmable LOC (lab-on-a) are provided. The enzyme-linked immunosorbent assay (ELISA) platform on a chip allows the PDMS channel to be selectively moved by micro pumps and valves. Controls the opening and closing of a plurality of micro valves (valve 1,2, 3, 4), and selectively according to the position of the moving pressure roller using the principle of the plurality of micro valves (A, B, C, D) of the pumping part and the pump The specific microvalve (valve 1,2, 3, 4) of the pumping part is opened and closed to control the movement of the microfluid.

Precise positioning of the microfluids (reaction chamber position, A, B, C, D) by the position controller of the smartphone or embedded system through the image processing of the camera and the analysis of the position of the microfluid by the smartphone or embedded system To control the opening and closing of each microvalve (valve 1,2,3,4) by driving the pump drive unit and the moving pressure roller to control the same, and according to the position of the moving pressure roller using the principle of the microvalve and pump of the pumping part. Optionally, the specific microvalve (valve 1,2, 3, 4) of the pumping part is opened and closed to control the movement of the microfluid.

Then, the reaction chamber is controlled to chemically react a plurality of reagents. Selective pressurized polydimethylsiloxane (PDMS) structures were fabricated by a simple system that moved a single roller bar. The performance of the micro-pump is controlled by a programmed microprocessor, with a volume of at least 1 μL adjusted. On-chip microvalves are also programmed to flow multiple reagents that automatically handle multi-step ELISA procedures. By applying the proposed platform, 19.40 pg ml ^-1 cardiac troponin T on microfluidic LOC devices by PDMS valves programmed in various stages of enzyme-linked sandwich immunoassay. (cTnT) was detected successfully.

As a result, the developed micro-pumps and microvalves have been successfully applied to run a series of solutions. It can be widely applied to lab-on-a-chip (LOC) based biological analysis.

The purpose of this study is to develop microfluidic devices for diagnosing coronary artery disease by performing image processing to precisely control complex immunodiagnostic reactions using microfluidics.

Microfluidics is a device for performing various biochemical and immunological analyzes by injecting a very small amount of various reagents into a substrate on which a microchannel through which a fluid flows can be made.

Microfluid uses blood, reagents, and the like. Blood is composed of blood cells (hemocytes) and plasma (plasma), and consists of blood cell components that make up about 45% of the total blood volume. Blood cells consist of white blood cells, red blood cells, and platelets.

Microfluidics develops programmable microfluidic control valves and micro pumps to control microfluidic fluids, and images from a smartphone or embedded system camera on the reaction chamber to observe the reaction. To implement a microfluidic control system based on image processing, to develop an image analysis algorithm and program, and to use in immunodiagnosis for the detection of coronary artery disease markers (target biomarkers).

The microfluidic device, which can program a number of microvalve valves, analyzes the position of the microfluid through image measurement and analysis by the camera and image analysis SW of a smartphone or an embedded system, and drives the pump driver and the roller through the position controller. Precisely control the position of the microfluid. This can be used to accurately diagnose coronary artery disease with high reliability.

Research hypothesis

In order to solve the bubble generation and position inaccuracy generated during the control of the microfluidic device, an image processing based microfluidic position control program of a smartphone or an embedded system was used.

In order to develop a coronary artery disease diagnosis device capable of high reliability and precise microfluidic control, the image processing-based control system for microfluidic position control of the present invention includes: i) a microvalve and micro valve using a local compression principle of a roller; A pump is used to operate the micropump and valve according to the position of the horizontally moving moving pressure roller, and ii) a smartphone with a camera and image analysis SW for image measurement and analysis when controlling a programmable microfluidic device. Or an embedded system platform, which analyzes the position of the microfluid through image processing and analysis, and drives the pump drive unit and the roller through the position controller of the smart phone or the embedded system. Control the opening and closing of the Uh, and, ⅲ) it provides precise immunodiagnostic platform for diagnosing coronary artery disease with them.

Year 1: Development of microfluidic control system (fine valves and pumps)

-Development and performance evaluation of micro valve and pump using local compression principle of roller

-Micro pump performance analysis and valve operation according to the roller position

2nd year: Development of microfluidic programming technology

-Microfluidic programming technology using structurally programmed microvalve

-Development of fluid control programmable microfluidic device to perform multi-level immunodiagnosis

* 3rd year: Development of image processing based control platform for microfluidic position control

-Embedded system platform for image measurement, image analysis, microfluidic position control

Positional analysis of microfluidics and programmed microvalve control

The microfluid uses blood, reagents, and the like.

Micro pump is a field of micro fluid transport and control in the field of Bio-Micro Electro Mechanical System (Lab-On-a-Chip) including LOC (Lab-On-a-Chip) that allows a small amount of fluid to flow in a desired direction. Used for

Up to now, in the macro domain, a method of transferring a fluid by forming a pressure gradient using a rotational force of a motor has been widely used, but in a micro-sized lab-on-a-chip system, an actuator of a motor having a relatively large volume is used. Difficult to use To overcome this, a micropump with a simple shape was designed.

Microfluidic devices control a very small amount of fluid, and previous research has driven microfluidic devices by attaching a microvalve and a micro pump to an external system.

However, valves and pumps mounted outside the chip are less accurate in controlling very small amounts of fluid and are difficult to correct when errors occur in fluid control. In order to prevent this, when the microvalve and the pump are integrated in the device, it is difficult to implement at low cost to match the characteristics of the microfluidic device that is used and discarded once to prevent contamination of the sample.

[Necessity]

Cost-effectively made microfluidic LOC devices facilitate sub-micro meter precision microchannels, which are miniaturized for microliter-volume sample compartments. The structure is advantageous for conducting ELISA. Minimal samples and reagents are shorter in reaction. Save time and enable multiple methods.

Microchannels for LOC devices are manufactured using a variety of simple techniques, including microfabrication and laser machining using inexpensive materials such as polymethyl methacrylate (PMMA, polyIJmethacrylate) and PDMS (polydimethylsiloxane). And hot embossing.

Limitations of Disposable ELISA Procedures Use the LOC format and enable rapid bioassays in a resource-limited community.

Microfluidic LOC devices for multiplexed assays facilitate the preparation of critical on-chip samples that accurately control sample and reagent volumes sequentially during the analysis process. Limited in applications involving the need for In order to solve this problem, it is important to operate several reagents and samples sequentially with multichannel LOC platforms controlled by microvalve and micropump. .

Currently, microvalves are operated with mechanical, pneumatic, electro-kinetic or externally applied forces. Valves can be used to control sample movement from one channel to another without interruption, or to use electro-mechanical deformation pressures using expensive membranes. Adjust the flow

Moreover, many micro-pumps that control fluid flow in microfluidic LOC devices already reported in the literature are limited by continuous flow. Continuous flow is usually initiated by the surface tension of the meniscus at the end of the microchannel, and the inlets / outlets of the microchannels to direct the flow. Use the surface tension of the droplets located at.

ELISA is a technique used in research or clinical applications to detect antigens or antibodies in a sample, levels of contaminants in food and the environment, screening for drugs of body fluids abuse in bodily fluids, a technique widely used in research and clinical applications to detect in its use.

However, this includes pipettes, plate readers, 96-well plates, and optical colorimetric detectors with large amounts of samples and reagents. Require expensive equipment.

Time-consuming steps of incubation, blocking and washing limit the suitability of POC analysis.

The present invention provides a new on-chip microvalve (on-) that operates a flow of multiple reagents and samples in a controlled manner inside a multichannel LOC platform with a single channel or multichannel valve. chip microvalve and pump were developed.

The full multichannel LOC platform comprises i) a PDMS actuator consisting of a microvalve and pump to control and regulate the solution, and ii) a thermoplastic-based microfluidic LOC device to perform the ELISA procedure. (thermoplastic-based microfluidic LOC device), i.e. microprocessor, which controls the roller bar using the valving and pumping functions of the PDMS actuator to operate samples and reagents inside the LOC device. It consists of The microvalve and pump of the PDMS actuator are implemented with low cost PDMS patterned by replicamolding technology. Through laser machining of PMMA sheets, thermoplastic LOC devices are followed by hot pressing. After the manufacture of the PDMS actuator and the thermoplastic LOC, various backend processes are executed in the device to integrate the PDMS actuator with the fluidic device. A custom roller bar moving across the PDMS actuator was connected to a driving plate using a linear motor to relatively position the bar on actuator on the PDMS actuator. . As the bar moves over the actuator, it selectively pressurizes and deforms the PDMS valve and pump.

In order to operate a particular sample or reagent, modification of the PDMS valve is blocked or open of the selected channel to operate the particular channel, while PDMS pumps generate a negative pressure that regulates the sample / reagent flow inside the channel.

The exact position of the roller bar on certain valves and pumps is programmed microcontroller, which is connected to the bar via a driving plate and a linear motor. It can be set by). The performance of the pumps and valves was characterized to enable approximately 1 μL of fluid.

If the microliter volume sample is operated correctly, the proposed microvalve- and -pump-based LOC platform is successfully applied 19.40 pg ml ^-1 cardiac by applying the whole procedure of ELISA. Detects troponin T (cTnT).

To solve the limitations of existing ELISA by connecting polystyrene made microplates to microfluidic channels on the LOC through reservoirs at the bottom of the well, several groups were A 96-well microplate is combined with a microfluidic LOC. Using a double-sided tape, the micro-machined 96-well ELISA microplate (micro-machined 96-well ELISA microplate) is bound together with acrylic (LOC) with LOC, and PMMA (reassembled with 96-well microplate) PMMA coreassembled 96-well microplates are used.

These procedures include repeated pipetting, adding reagents for assaying and washing to remove residual reagents to minimize background signals. There is also a need for an expensive microplate analyzer including a fluorescence microplate reader and a charge coupled device camera.

However, the proposed method involves enzyme material in the isolated regions of reagents, including washing solutions, enzyme-linked secondary antibodies and LOC in separate regions. Zones of the LOC) can be preloaded, and addition of a sample containing a target antigen is required to perform ELISA.

In addition, reagents preloaded in separate zones are sequentially introduced into the reaction chamber. Program controlled microvalve and pumps, avoid manual fluid handling, post-assay images of cameras in smartphones or cameras in embedded systems in the detection zone Analyzed using smartphone app.

2. Basic principle and operation of the design of micro pump and valve

2.1 Design Principles of PDMS Micro-pumps and Valves

2 (a)-(top left) shows the working principle of a PDMS actuator consisting of the proposed micro-pump and valve. As a working micropump, the long semi-cylindrical cavity of the structure is surrounded by a PDMS elastomer, and a rectangular bumper is directly above the cavity. One end of the pump cavity is connected to a thermoplastic test chip under the actuator via a hole, while the other end is connected to the outside of the pump. Pressing a PDMS bumper with a roller bar causes the bumper to deform the PDMS structure and seal the cavity connected to the test chip. The roller of the PDMS actuator increases the volume of the inner cavity of pump.

Negative pressure is generated and the amount of fluid entering the microfluidic channel and the reaction chamber is cavities as shown in Figure 2 (b)-(lower left). Equal to the volume of cavity. Movement of the roller in the opposite direction reduces the volume of the cavity, and the pump generates positive pressure to extract fluid from the chamber. Therefore, a PDMS bumper with a roller bar moving back-forward allows in / out operation of a sample using a micro-pump.

The upper right (c) and the lower right (d) of FIG. 2 show the structure of a microvalve composed of bump patterns on a microchannel with an elastic material of PDMS. . The micro channel operates as follows. The micro channel is cut off when the bump pattern is blocked, so press the button at the top of the channel selectively. Then, when the roller bar is positioned on the bump structure, when the micro channel having the bump structure is closed, it blocks the influx of fluid through the channel and without bumps. When the microchannel is opened, fluid is introduced.

As a result, the operation of opening and closing the microvalve is controlled by placing a roller on the microchannel in a controlled manner with or without the bumper structure.

2.2. Combined operation of PDMS micro pump and valve

Based on the principle of operation of an elastic PDMS actuator, a programmable microfluidic platform is designed in combination with a PDMS actuator together with a thermoplastic LOC device.

Typically, the manufacture of LOC and PDMS actuators is made according to a variety of back-end processes where the actuator is connected to the chip through the holes on the right.

In the proposed platform of micropumps and microvalve, pumping drive withdrawing and pumping samples and reagents into the microchannel of the LOC By the position of the roller according to the PDMS actuator.

In this procedure, the position of the roller remains fixed and the PDMS actuator coupled with the lab on a chip (LOC) moves back and forth.

For movement, the integrated platform is placed on a movable plate that is connected to a microprocessor-controlled linear motor.

When the roller moves through region A, all micro valves and pump bumpers are pressed by the roller and high fluidic resistivity in the pump cavity ) And microchannels.

The sample then enters the sample inlet through a membrane filter, and the roller position moves to region B.

While the channel valves are still closed until the roller position moves to the end of area A, the sample is caused by the negative pressure generated inside the pump cavity by roller movement. The sample is drawn to the detection zone.

When the roller moves gradually through zone B, all the valves on the channels are sequentially open, and the fluid resistivity of the wet membrane filter is more than that of the open valve. After high, fluidic resistivity decreases across the channel.

Thus, in the case of a moving roller on zone B, the reagents preloaded in the reagent chambers are gradually moved to the detection zone and the reagents are mixed with the sample while the reaction takes place. After a certain reaction time, the roller movement is reversed, the opposite occurs, and finally sample waste is pumped from the detection zone to the waste chamber.

This product is a microfluidic LOC platform, PDMS micro-pump and micro-valve has been researched and developed for the diagnosis of coronary artery disease.

The functionality of the PDMS micro-pump and micro-valve was successfully demonstrated by combining the PDMS actuator into an automated platform. The developed micro-pump can be operated accurately at a minimum volume of 1 μL of fluid. The amount of working fluid can be reduced by optimizing the volume of the pump cavity generating elastic restoring force.

In addition, the implementation of hetero-structured bumpers on PDMS valves and pumps optionally allows fluid channels to provide multi-reagent based immunoassay. (fluidic channel) close and open. As a result, the entire ELISA procedure was used to quantitatively detect cardiac troponin T (cTnT) using the developed platform.

Because PDMS actuators and LOC devices are made simple and inexpensive, the platform can be used in a disposable format.

Thus, all microfluidic operations are handled with minimal human intervention by a programmed microprocessor. The proposed platform can be widely applied for POC analysis.

2 is a block diagram of an image processing based control system for microfluidic position control according to the present invention.

1) Micro valves and micro pumps integrated into programmable microfluidic elements

In this study, we fabricated a microvalve and pump structure using elastic restoring force from low-cost silicon material and integrated it into a microfluidic device made of plastic.

As shown in FIG. 2, the operation principle of the micro pump is that when the portion pressed by the roller moves while the chip moves, a cavity is generated in the pump channel by the elastic restoring force. And as much fluid moves as possible.

In the case of a micro-valve, if the bump structure is made only on the selective part on the silicon valve channel, the silicon material is pressed by the roller 10 and the part with the bump structure is closed. The valve without the bump structure is opened. This allows the valves to be controlled in such a way that only the area with the bump structure is closed when the position of the roller changes.

Using this approach, a programmable micro valve and micro pump can be fabricated by creating a pump channel and a valve channel in a silicon material and creating a bump structure only in selective areas. It is possible.

2) Programmable Microfluidic Device Development

3 is a block diagram of a membrane filter (blood purification filter), a reaction chamber, a plurality of microvalve and micropump, a microvalve bump structure, and an image processing-based microfluidic position control system according to the present invention.

The present invention provides a membrane filter (blood purification filter), a reaction chamber, a plurality of micro valves and micro pumps, a micro valve and a bump structure, and an image processing-based microfluidic position control system provided with a fluid inlet and a moving passage.

Image processing based control system for microfluidic position control of the present invention,

A microfluidic system configured to sequentially move reagents and samples into a LOC platform including a microchannel unit having a fluid inlet port and a moving passage and a pumping unit; And

An image of the microfluid reaching a specific position is photographed with a camera on the microfluidic system having a reaction chamber to set one or more regions of interest (reaction chamber positions, A, B, C, D) at one or more specific positions and In order to control the movement of the fluid so that the fluid is located in the area, it is possible to precisely control the position of the microfluid through image analysis, and to drive the roller using the camera and image analysis SW and the pump drive for the fluid position A system for controlling the movement of the microfluid by controlling the opening and closing of the channel or the multichannel micro valves (valve 1,2, 3, 4),
The microfluidic system
A micro pump (11) having a pump bumper (20) of elastic projections on the path of each channel valve of the plurality of micro valves (valve 1,2, 3, 4); Enzyme substrate supply valve 13, secondary wash valve 14 with valve bumper 1, secondary antibody valve 15 with valve bumper 2, primary wash with valve bumper 3 (19-3) A pumping unit having a valve 16 and having the pump driving unit and the roller;
Using the principle of the microvalve and pump, the specific substrate valves 1,2,3,4 of the pumping part are selectively opened and closed according to the position of the moving pressure roller, and the enzyme substrate supply valve 13, 2 of the pumping part. The reagent is introduced into the primary washing valve 14, the secondary antibody valve 15, and the primary washing valve 16 through a connection passage, and the reagent is introduced through the membrane filter 17 through the moving passage. A reaction chamber 19 in which a reaction occurs,
It is connected to the reaction chamber 19 through the movement passage in the fluid inlet and the lower portion, and includes a membrane filter 17 of the microchannel portion in which samples are injected.

Pumped by the smartphone or embedded system to precisely control the position of the microfluid (position of the reaction chamber, A, B, C, D) by the position controller through image processing of the camera and analysis of the position of the microfluid A plurality of micro valves are controlled by driving a negative pump driving part and a moving pressure roller, and a specific microvalve of the pumping part is selectively selected according to the position of the moving pressure roller by using the principle of the micro valve and the pump of the pumping part. , 2, 3, 4 is opened and closed to control the movement of the microfluid.

The region of interest (ROI) at that particular location may be the reaction chamber 19 of the reagent.

The pump driving unit uses an elastic PDMS actuator having an elastic PDMS micro pump and a valve connected to a position controller, and drives a moving pressure roller by the elastic PDMS actuator.

Elastic PDMS actuators use a linear motor.

The pump drive unit uses a linear motor connected to the position controller, and drives the moving pressure roller by the linear motor.

The microfluidic system

A micro pump (11) having a pump bumper (20) of elastic projections on the path of each of the multi channel valves (1, 2, 3, 4); Enzyme substrate supply valve 13, secondary wash valve 14 with valve bumper 1, secondary antibody valve 15 with valve bumper 2, primary wash with valve bumper 3 (19-3) A pumping unit having a valve 16 and having the pump driving unit and the roller;

Using the principle of microvalve and pump, the specific valves (valve 1,2, 3, 4) of the pumping part are selectively opened and closed according to the position (A, B, C, D) of the moving pressure roller. The reagent substrate is connected to the enzyme substrate supply valve 13, the secondary washing valve 14, the secondary antibody valve 15, and the primary washing valve 16 through a connecting passage, and a membrane filter 19 and a moving passage are provided. Reaction chamber 19 is connected to the sample through the chemical reaction is generated, and

It is connected to the reaction chamber through the fluid passage inlet (sample inlet) and the lower portion, and includes a membrane filter 17 of the micro-channel portion in which samples are injected.

For example, microfluidic devices that can be programmed to perform immunodiagnosis, such as coronary artery disease.

Immunodiagnosis is a method of detecting a target biomarker by reacting various reagents, and requires precise fluid control to react various reagents for a certain time.

For example, if the roller is located in Region A, all valves 1,2,3,4 are closed, allowing samples to come from membrane filters (e.g., blood purification filters) 17, and the rollers When placed in B, the valves alternately open and the solution in the reagent chamber moves in sequence.

3) Image processing based microfluidic position control technology

4A is a conceptual diagram of a programmable microfluidic position control and image analysis platform using an i) smartphone or ii) an embedded system with a camera and image analysis SW.

Figure 4b is a screen showing the results of the verification experiment for controlling the microfluidic position based on image processing using a smart phone to control the position of the microfluid by measuring the RGB change in the reaction chamber (ROI, Region of Interest) in real time.

4C is a view illustrating an image processing-based microfluidic position control platform of a smartphone or an embedded system according to an exemplary embodiment of the present invention.

Smartphone or embedded system for image measurement and analysis for microfluidic position control according to an embodiment of the present invention is a reagent (sample, blood) of a reagent (sample) on a microfluidic system having a reaction chamber of the microfluidic device A camera 71 for photographing a chemical reaction image; An image processor 72 encoding an image of the camera 71 and buffering the image in the storage unit 75 and analyzing the image through vision image processing image processing; It is connected to the image processor 72, and is provided with an image analysis SW for analyzing the position of the microfluid shown in the image analysis and image data, and controls the position of the microfluid, and drives the pump driver 76 and the roller 77 A control unit 73 having a position controller 74 for controlling the position of the microfluid; A storage unit 75 connected to the control unit 73 and temporarily storing a camera image; A communication unit 78 providing communication of at least one of Bluetooth, Wi-Fi, and LTE / 5G connected to the control unit 73; A pump driver 76 for driving the roller 77 according to the control of the position controller 74 of the controller 73; And a moving pressure roller 77 controlled to move the roller by horizontal rotation and pressure by the pump driving unit 76 to move the roller horizontally.

Through the image processing of the camera and the position analysis of the microfluid (position of the reaction chamber, A, B, C, D), the pump driving unit 76 and the moving pressure roller 77 of the pumping unit are driven by the position controller 74. In order to precisely control the position of the microfluid, the movement of the microfluid is controlled by selectively controlling the opening and closing of the at least one or the plurality of microvalve (valve 1,2, 3, 4).

The pump driver 76 and the roller 77 are driven by the position controller 74 to control the position of the microfluid through the image processing of the camera and the position analysis of the microfluid. By stopping the A, B, C, D position provided to control the movement of the fluid by controlling the opening and closing of the micro-valve (valve 1,2, 3, 4) of a single channel or multi-channel.

For example, when blood is injected into a membrane filter (blood purification filter) using an analytical sample, a camera of a smartphone or an embedded system may vision image an image of a region of interest (ROI) on a reaction chamber. Analyze the image through image processing to analyze the location of microfluids (A, B, C, D),

By the pump driver 76 to precisely control the position of the microfluid by the position controller 74 of the smartphone or embedded system through image processing of the camera of the image analysis SW and analysis of the position of the microfluid in the captured image data. The moving pressure roller 77 is driven to control the opening and closing of each microvalve 1, 2, 3, 4 according to the moving position of the roller.

The image analysis SW provides an image processing function of a camera image and an analysis of microfluid in the image, and uses image processing of any one of gray scale, RGB, and YCbCr conversion.

For example, when using the gray scale, the image analysis SW buffers and stores a camera image, provides image processing and image analysis, and provides a region of interest (ROI) in gray scale ( a histogram (pixel value of each pixel of the x-axis image, y-axis correspondence) of the image of the region of interest using an experimental threshold at which the outline of the ROI is extracted. The number of pixel values (frequency)], binarize the ROI image to 0,1 based on the threshold using the ostu algorithm, and then histogram equalization of the image in the ROI region. Pre-processing, detecting contours of detected objects of the region of interest, extracting texture features and shape features, and microfluids of (x, y) coordinates of the ROI region It detects the position.

Figure 4d is a view showing (a) the developed PDMS actuator, (b) PMMA-based LOC test device, (c) roller drive frame. The roller is fixed in a specific position, and only the white PMMA drive plate under the roller is connected to the linear motor to move back and forth under the roller.

Referring to FIG. 1, the micro pump is composed of a microchannel unit 110, a pumping unit 120, and a moving pressurizing unit 130. The microchannel unit 110 includes a fluid inlet 111 and a movement passage 112, and the pumping unit 120 includes a pumping space 121.

The microchannel unit 110 includes a movement passage 112 of the injected fluid, and the movement passage 112 is connected to a fluid inlet 111 for entering and exiting the fluid.

The fluid injected into the fluid inlet 111 is transferred to the reaction chamber through the movement passage 112. That is, when negative pressure is generated through the pumping portion, the fluid near the fluid inlet 111 is transferred through the movement passage 112. To the reaction chamber

The microchannel part 110 is not connected to the moving passage 112 separately, but the moving passage 112 is integrally connected to the fluid inlet 111 and its lower portion. In this case, the microchannel unit 110 moves from the fluid inlet 111 to the reaction chamber. The fluid to be moved.

The reaction chamber is directly connected to the movement passage 112, and fluid is moved by the positive pressure or the negative pressure of the pumping part 120. That is, a pumping space 121 is formed by pressing the pumping unit 120 with a moving pressure roller, and the volume of the pumping space 121 may be variable, and the volume of the volume is changed by the movement of the moving pressure roller. Variation is made, and the fluid introduced by the volume variation is moved.

Referring to FIG. 1, the moving pressing means 130 is moved by rolling while pressing and moving on the pumping unit 120 selectively using a moving pressure roller. Accordingly, the fluid introduced through the fluid inlet 111 moves in a rolling rotation of the roller, thereby moving the fluid to a desired position.

In addition, in order to precisely control the movement of the moving pressure roller, the pump driving part is used to control the position of the microfluid after being programmed in a programmed smart phone, an embedded system, and a computer, instead of moving it with a human hand. This moves the moving pressure roller precisely.

The microchannel unit 110 and the pumping unit 120 include an elastic material having an elastic component. Elastic material is composed of natural rubber or synthetic rubber, natural rubber is isoprene rubber, synthetic rubber is silicone rubber, urethane rubber, butadiene rubber, styrenebutadiene rubber, acrylonitrile butadiene rubber, chloroprene rubber, ethylene propylene rubber, It may be selected from the group consisting of butyl rubber, chlorosulfonated polyethylene rubber, acrylic rubber, polysulfide rubber, fluorine rubber, epichlorohydrin rubber and the like. An example of silicone rubber is polydimethylsiloxane (PDMS).

In addition, the lower portion of the microchannel unit 110 and the pumping unit 120 is made of a non-deformable material, the upper portion of the pumping unit includes an elastic material having an elastic component.

The lower portion of the microchannel unit 110 and the pumping unit 120 may be made of a non-deformable material, and the upper portion of the pumping unit 122 may be made of an elastic material having an elastic component. This may be formed by coupling the upper part of the pumping part 122 made of an elastic material to the lower part of the pumping part of the non-deformable material.

When the upper portion of the pumping part 122 is compressed by the moving pressure roller, other parts have no shape change, and only the upper part of the pumping part 122 has a shape change and is compressed. The pumping space 121 is provided in the pumping unit 120. When the moving pressure roller is moved in the direction of the right arrow, the fluid introduced therefrom moves.

The elastomeric PDMS actuator is used as a PDMS microfluidic actuator made of elastic material.

Figure 4e is a diagram showing the step-by-step operation procedure using the PDMS microfluidic actuator of the proposed elastic material.

(a) Inject a liquid sample (blood-red solution) into the membrane filter 17 with a sample inlet, and pre-inject other reagents into the test LOC. do. The membrane filter 17 is used as a blood purification filter, and the liquid sample uses blood. (b) All micro valves 1,2,3,4 are closed and the sample solution is pumped through a membrane filter. Thereafter, valves 1,2,3,4 are opened sequentially, and reagents are introduced into the detection zone. (c) Using the principle of microvalve and pump, valve 1 open, chamber connected with yellow reagent (washing buffer), was opened (point D in FIG. 3) (d) connected with green reagent (primary antibody) valve 2 open, chamber opened (point C in FIG. 3) (e) valve 3 open, chamber connected to orange reagent (washing buffer, washing buffer) was opened (point B in FIG. 3). (f) valve 4 open, chamber with blue reagent (enzyme substrate) opened (point A in FIG. 3).

Position D in FIG. 3 is the valve 1 open point.

Position C of FIG. 3 is the valve 2 open point.

Position B in FIG. 3 is the valve 3 open point.

Position A in FIG. 3 is the valve 4 open point.

4F is a photograph showing the microfluidic operation procedure of the design platform used in the bio analysis procedure.

The bioanalytical procedure of the reaction chamber of the microfluidic system includes (a) injecting a liquid sample (blood-red solution) required for a chemical reaction into a membrane filter into a sample inlet; (b) moving the sample to a detection zone coated with a first antibody; (c) first washing the waste with a washing buffer (yellow solution); (d) introducing the primary antibody in the detection zone, moving an enzyme-linked secondary antibody (green solution) to the detection zone, such as analytes Reacting the first antibody with a secondary antibody to which an enzyme is bound; (e) second washing of unreacted secondary antibody with wash buffer (orange solution); (f) introducing an enzyme substrate into the detection zone to generate a signal for analysis (sacle bar below all photos is 1 cm).

Referring to FIG. 5, in the reaction chamber, a primary antibody, a biomarker, a primary wash, a secondary antibody and an enzyme are coupled to the primary antibody and the marker, and the enzyme is reacted and reacted by the secondary wash. If you run the solution, you will see that the enzyme is removed and the color of the solution changes.

* Development of image processing based microfluidic position control technology

When moving the microfluid, a problem arises in that the pressure required to move the fluid is changed by the surface tension generated at the interface between the air and the fluid.

In order to solve this problem, in this study, image analysis is provided to provide image processing of vision image processing by measuring an image of a fluid reaching a specific position (position of reaction chamber, A, B, C, D). When the SW arrives at a specific location of the camera (ROI, Region of Interest, Reaction Chamber, A, B, C, D), the 'position controller' of the controller of the smartphone or embedded system is the pump drive (PDMS actuator, or The linear motor) controls the movement of the moving pressure roller to control the movement of the microfluid and to stop at a specific position (FIG. 3, A, B, C, D).

The pump drive uses a PDMS actuator to horizontally move the moving pressure roller, and the PDMS actuator uses a linear motor.

Using image processing techniques to control the microfluid in real time to determine the location of the microfluid, it is possible to precisely control the position of the microfluid and to move the fluid to a specific position by surface tension. It is possible to overcome the problem of changing the required pressure.

The microfluidic device for immunodiagnosis requires a process of sequentially filling the microfluidic fluid of various reagents in the reaction chamber 19. In the process of filling the reaction chamber 19, bubbles are caught and the reaction chamber 19 is filled with the reagent. There is a problem that does not come.

In order to solve this problem, this study recognizes when an error situation occurs that generates bubbles using image recognition algorithm. The bubble trap structure designed to remove bubbles uses bubbles to float upward when the fluid and bubbles are together. In the bubble trap structure, bubbles are piled up and only the fluid is transferred to the channel to remove bubbles. Can be.

When image analysis SW detects bubbles by using vision image processing and image recognition, for example, through image analysis and position controller, the micro fluid is moved back to the bubble trap to remove the bubbles, and then back to the reaction chamber. Move it.

For this study, we will learn the information about various microfluidic situations and define the microfluidic control method based on the learning information.

5) Diagnosis of high precision and high sensitivity coronary artery disease by applying high stability microfluidic control system

Programmable microvalve and micropump have been used to develop precision fluid control microfluidic devices based on imaging.

FIG. 6 is a diagram illustrating a multi-step immune response for diagnosis of coronary artery disease using a programmable microfluidic device developed in this study in a programmed order.

Although the immune response for diagnosing coronary artery disease causes various reagents to be reacted in the correct order and time as shown in FIG. .

However, through the stable system developed in this study, 1) injection of a blood sample into the membrane filter, 2) plasma separation from blood, 3) primary washing, 4) secondary antibody reaction with enzyme, and 5) 2 Car washing process, 6) measuring signal generation by enzymes,

For example, diagnosing coronary artery disease using microfluidics can greatly improve the measurement accuracy because the system's stability and reproducibility can be maximized.

Through this research, programmable high performance microfluidics for disease diagnosis will be manufactured at low cost for one-time use, and precision control system using image measurement will be applied to artificial intelligence based image processing in the future to have high stability.

As such, the low-cost, high-performance disease diagnostic microfluidic device can be used in a variety of ways, such as disease management of patients with chronic diseases, because the general public can check their disease state at home.

In patients with chronic diseases such as blood sugar, heart disease, and hepatitis, it is necessary to continuously monitor the condition of the disease. By continuous monitoring with the microfluidic device for diagnosing the disease, visit the hospital to receive treatment before an emergency occurs. You can also make yourself more aware of your health by becoming aware of your illness.

In the future, by manufacturing microfluidic devices for healthcare converged with artificial intelligence image processing, it is possible to construct a new medical system by enabling remote healthcare and continuous monitoring, enabling healthcare and medical fields, and remote monitoring and convergence with artificial intelligence. It can be applied to microfluidic devices that perform various functions by using a micro valve and a micro pump.

It secures the foundation for the development of various healthcare products in the future by securing artificial intelligence IT technology, electronic convergence technology, and bio technology combined with various fields such as bio, medical, software, image recognition, and semiconductor microprocessing. It will launch AI-based bio and healthcare products through technology development that integrates the medical system to provide new growth engines based on the IT industry and bio technology.

As described above, the present invention has been described with reference to a preferred embodiment of the present invention, but the present invention is within the scope not departing from the spirit and scope of the present invention as set forth in the appended claims by those skilled in the art. It will be understood that various modifications or variations may be made.

10: roller 11: pump
12: Fluid 13: enzyme substrate supply valve
14: secondary flush valve 15: secondary antibody valve
16: Primary flush valve 17: Membrane filter
19: reaction chamber 19-3: valve bumper
23: pump bumper 71: camera
72: image processing unit 73: control unit (image analysis SW)
74: position controller 75: storage unit
76: pump drive portion 77: roller

Claims (11)

A microfluidic system that sequentially moves reagents and samples to the LOC platform including a microchannel portion having a fluid inlet and a moving passage and a pumping portion; And
An image of a microfluid reaching a specific location is captured by a camera on a microfluidic system having a reaction chamber to establish a region of interest at one or more specific locations and to control the movement of the fluid so that the fluid is located in the region of interest. And a system for precisely controlling the position of the microfluid through image analysis, a system for controlling the movement of the microfluid by driving a roller using a camera and an image analysis SW, and a pump drive for controlling the position of the fluid.
The microfluidic system
A micro pump (11) having a pump bumper (20) of elastic projections on the path of each channel valve of the plurality of micro valves (valve 1,2, 3, 4); Enzyme substrate supply valve 13, secondary wash valve 14 with valve bumper 1, secondary antibody valve 15 with valve bumper 2, primary wash with valve bumper 3 (19-3) A pumping unit having a valve 16 and having the pump driving unit and the roller;
Using the principle of microvalve and pump, the specific substrate of the pumping section is selectively opened and closed according to the position of the moving pressure roller, so that the enzyme substrate supply valve 13, the secondary washing valve 14, the secondary antibody of the pumping section Reagents are connected to the valve 15 and the primary washing valve 16 through a connection passage, and the reaction chamber 19 is connected to the membrane filter 17 through a moving passage to inject a sample to generate a chemical reaction. ,
And a membrane filter (17) connected to the reaction chamber (19) through a moving passage at a fluid inlet and a lower portion, and into which samples are injected. The method of claim 1,
The system for controlling the movement of the microfluid uses a smartphone or an embedded system in which an image analysis of the camera and a microfluidic position control program are installed.
Through the image processing of the camera and the analysis of the position of the microfluid, the pump controller of the pumping unit and the moving pressure roller are driven to precisely control the reaction chamber positions (A, B, C, D) of the microfluid by the position controller. Controlling the opening and closing of the microvalve, and selectively specifying the pumping part according to the position (A, B, C, D) of the moving pressure roller driven by the pump driving part using the principle of the microvalve and the pump of the pumping part. An image processing-based control system for microfluidic position control to control the movement of the microfluid by allowing the valve to open and close. The method of claim 1,
An image processing based control system for controlling microfluidic position, wherein the region of interest at the particular position is a reaction chamber (19) of the reagent. delete The method of claim 1,
The pump driving unit is connected to the position controller, using an elastic actuator consisting of a micro-pump and valve of the elastic material, and driving the roller by the actuator of the elastic material, image processing based control system for microfluidic position control. The method of claim 5,
The actuator of the elastic material uses a linear motor, and drives the roller by the linear motor, image processing based control system for microfluidic position control. The method of claim 2,
The smartphone or embedded system
A camera for photographing a chemical reaction image of a reagent, a sample (eg, blood) on a microfluidic system including a reaction chamber of the microfluidic device;
An image processor which encodes an image of the camera and buffers the image in a storage unit and analyzes the image through vision image processing image processing;
A control unit connected to the image processing unit, the image analysis SW controlling an image analysis and a position of the microfluid, and having a position controller controlling a position of the microfluid by driving a pump driver and a roller;
A storage unit connected to the control unit and temporarily storing a camera image;
A communication unit providing communication of at least one of Bluetooth, Wi-Fi, and LTE / 5G connected to the control unit;
A pump driver for driving a moving pressure roller according to the control of the position controller of the controller; And
It comprises a moving pressure roller which is controlled to move horizontally by moving the rolling pressure by the pump drive unit,
By controlling the position of the microfluid by the position controller through image processing of the camera and analysis of the position of the microfluid, a moving pressure roller is driven by the pump driving unit to selectively control the opening and closing of at least one or multiple microvalve. Image control based control system for controlling the microfluidic position by controlling the movement of the microfluidic. The method of claim 5,
The elastic actuator is used as an elastic microfluidic actuator (PDMS microfluidic actuator), the step-by-step operation of the elastic microfluidic actuator
(a) A fluid sample is injected into the membrane filter 17, other reagents are pre-injected into the test LOC, and the membrane filter 17 is used as a blood purification filter, and the liquid The sample uses blood,
(b) Close all microvalve valves 1,2,3,4, pump a sample solution through the membrane filter, valves open sequentially, reagents react Into the detection zone of the chamber,
(c) on the principle of microvalve and pump, valve 1 open (point D in FIG. 3) connected with a yellow washing buffer,
(d) valve 2 open (point C in FIG. 3) connected to the primary antibody, the green reagent,
(e) valve 3 is opened in connection with the orange reagent wash buffer,
(f) Image processing based control system for microfluidic position control, which opens valve 4 with an enzyme substrate which is a blue reagent. The method of claim 1,
The image analysis SW provides image processing of a camera image and analysis of microfluids in an image, and uses image processing based on any one of gray scale, RGB, and YCbCr conversion, and image processing-based control for microfluidic position control. system. The method of claim 9,
The image analysis SW is
When the gray scale is used, the camera image is buffered and stored, image processing and image analysis functions are provided, the ROI is converted to gray scale, and the ROI region outline is extracted. A histogram [pixel value of each pixel of the x-axis image, number of corresponding pixel values (frequency) of y-axis] of the image of the region of interest using the threshold value of the image of the region of interest) is obtained, and the region of interest image is 0, After binarization to 1, the image is preprocessed in the ROI region through histogram equalization, detects the contours of the objects of the detected region of interest, and retrieves texture features and shape features. Image processing-based control system for microfluidic position control by extracting the position of the microfluid in the (x, y) coordinates of the ROI region. The method of claim 1,
The bioassay procedure of the reaction chamber
(a) injecting a liquid sample (blood-red solution) required for the chemical reaction into the membrane filter;
(b) moving the sample to a detection zone coated with a primary antibody;
(c) first washing the waste with a wash buffer which is a yellow solution;
(d) introducing the primary antibody in the detection zone, moving an enzyme-linked secondary antibody, which is a green solution, to the detection zone, and transferring the primary antibody as an analytes; Reacting the antibody with a secondary antibody to which the enzyme is bound;
(e) second washing of unreacted secondary antibody with an orange solution, wash buffer; And
(f) Imaging based control system for microfluidic position control comprising introducing an enzyme substrate into a detection zone to generate a signal for analysis.

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