A device for efficient separation and real-time detection of particulate matter

Abstract

This invention discloses a high-efficiency particle separation and real-time detection device, comprising a microfluidic chip encapsulated from top to bottom as a channel layer and a substrate layer. The channel layer includes a spiral separation channel with an inner inlet and an outer outlet. The inner inlet is Y-connected to the sample channel and the sheath fluid channel, and the outer outlet is Y-connected to the upper and lower branch channels. The outlet of the lower branch channel is connected to the inlet of the flow resistance matching channel. The upper branch channel is connected to the focusing channel, which is connected to the detection channel and the inner and outer outlet channels symmetrically arranged on both sides. The outlets of the flow resistance matching channel, the detection channel, and the inner and outer outlet channels are all equipped with collection devices. The cross-sectional area at the connection between the downstream channels of the outer outlet and at the outlet connection of each collection device upstream of the channel varies along the length direction. An optical imaging system is installed at the detection channel and is communicatively connected to an image processing module. This device can simultaneously achieve high-throughput, precise separation of particles and real-time online image detection, shortening the separation and detection time of particles.

Description

Technical Field

[0001] This invention belongs to the field of microfluidic particle manipulation and computer vision technology, and particularly relates to a device for efficient particle separation and real-time detection. Background Technology

[0002] Precise separation and detection of microparticles play a crucial role in biology, chemistry, medicine, and environmental engineering. For example, the separation and detection of cancer cells from whole blood is of great significance for early cancer diagnosis, treatment monitoring, and prognostic assessment. With breakthroughs in microelectromechanical systems (MEMS) technology, microfluidic chip technology has become a primary means of microparticle manipulation. This technology highly integrates sample preparation, reaction, separation, and detection processes into a single chip through precise control of fluids within micrometer-scale channels. Compared to traditional sorting techniques, microfluidic chips offer miniaturized device size, high detection sensitivity, extremely low sample consumption, and excellent system integration capabilities. Detection of separated microparticles is essential for verifying their biological characteristics. With breakthroughs in computer vision technology in image recognition, feature extraction, sample classification, and real-time processing algorithms, this technology can be applied to microfluidic optical imaging detection applications. High-resolution microscopic imaging combined with advanced image processing algorithms enables automated, high-throughput analysis of microparticle morphology, size, quantity, motion trajectory, and even fluorescent labeling signals, significantly improving detection efficiency and reliability.

[0003] Current research focuses on either high-throughput particle separation or high-sensitivity detection. There is a lack of research on truly integrating high-throughput particle separation with high-sensitivity, real-time online optical imaging detection into a single microfluidic platform. Therefore, how to simultaneously integrate high-throughput particle separation and real-time accurate detection within a microfluidic system is a pressing technical challenge that needs to be addressed. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a device for efficient separation and real-time detection of microparticles, aiming to achieve high-throughput, accurate separation and real-time online image detection of microparticles, thereby shortening the separation and detection time of microparticles.

[0005] The technical solution provided by this utility model is as follows:

[0006] This invention provides a device for efficient separation and real-time detection of microparticles, comprising a microfluidic chip with a channel layer and a substrate layer encapsulated from top to bottom. The channel layer includes a spiral separation channel with an inner inlet and an outer outlet. The inner inlet is Y-connected to the sample channel and the sheath fluid channel, and the outer outlet is Y-connected to the upper branch channel and the lower branch channel. The outlet of the lower branch channel is connected to the inlet of the flow resistance matching channel, and the outlet of the upper branch channel is connected to the inlet of the focusing channel. The outlet of the focusing channel is connected to the detection channel and the inlets of the outer outlet channel and the inner outlet channel symmetrically arranged on both sides of it. The outlets of the flow resistance matching channel, the detection channel, the outer outlet channel, and the inner outlet channel are all equipped with collection devices. The cross-sectional area of ​​the connection between the downstream channels of the outer outlet and the connection between the outlets of the upstream channels of each collection device varies along the length direction. An optical imaging system is provided at the detection channel and is connected to an image processing module via a data cable.

[0007] Furthermore, the connection between the downstream flow channels of the external outlet includes a first connection between the lower branch flow channel and the flow resistance matching flow channel, and a second connection between the upper branch flow channel and the focusing flow channel. When the cross-sectional area of ​​the first connection and the second connection changes along the length direction, the change direction is that the height gradually decreases along the length direction.

[0008] Furthermore, the outlets of the flow resistance matching channel, the detection channel, the outer outlet channel, and the inner outlet channel are respectively connected to the outlets of the flow resistance matching channel, the outer outlet channel, the detection channel, and the inner outlet channel. The outlet connection points of the upstream channels of each collecting device include connection point one between the outlets of the flow resistance matching channel and the flow resistance matching channel, connection point two between the outlets of the outer outlet channel and the outer outlet channel, connection point three between the outlets of the detection channel and the detection channel, and connection point four between the outlets of the inner outlet channel and the inner outlet channel. When the cross-sectional area of ​​connection point one, connection point two, connection point three, and connection point four changes along the length direction, the direction of change is that the height gradually increases along the length direction.

[0009] Furthermore, when the change direction is such that the height gradually decreases along the length direction, the cross-sections of the first and second connections are both trapezoidal; when the change direction is such that the height gradually increases along the length direction, the cross-sections of connection one, connection two, connection three, and connection four are all trapezoidal, and the angle between the inclined plane of the trapezoid and the horizontal plane is an obtuse angle.

[0010] Furthermore, the collecting device includes a first collector, a second collector, a third collector, and a fourth collector, the inlets of which are respectively connected to the outlet of the flow resistance matching channel, the outlet of the outer outlet channel, the outlet of the detection channel, and the outlet of the inner outlet channel.

[0011] Furthermore, the spiral separation channel includes a front loop located near the inner inlet and a rear loop located near the outer outlet. The length ratio of the front loop to the rear loop is 3:1. The cross-section of the front loop is a rectangular cross-section, and the cross-section of the rear loop is a concave cross-section with a semi-circular arc.

[0012] Furthermore, the focusing channel is an asymmetric sinusoidal channel with a rectangular cross-section. The asymmetric sinusoidal channel has 3.5 cycles and includes several staggered upper and lower semicircular arc channels. The width of the upper semicircular arc channel is smaller than the width of the lower semicircular arc channel.

[0013] Furthermore, the sample flow channel, sheath fluid flow channel, flow resistance matching flow channel, outer outlet flow channel, detection flow channel, and inner outlet flow channel are direct flow channels with rectangular cross-sections.

[0014] Furthermore, the optical imaging system includes a light source, a condenser lens, an objective lens, a reflecting prism, a lens barrel, and a CMOS sensor. The light source and the condenser lens are arranged from top to bottom above the detection channel, and the objective lens and the reflecting prism are arranged from top to bottom below the detection channel. The light source, the condenser lens, the objective lens, and the reflecting prism are aligned on the same vertical line. The lens barrel and the CMOS sensor are arranged sequentially on the horizontal line of the reflecting prism. The CMOS sensor is communicatively connected to the image processor of the image processing module via a data line.

[0015] Furthermore, it also includes a fluid injection mechanism, which includes a sample injector and a sheath fluid injector. The input end of the sample injector is connected to the inlet of the sample channel, and the input end of the sheath fluid injector is connected to the inlet of the sheath fluid channel.

[0016] Beneficial effects

[0017] This invention achieves efficient and precise integrated separation and detection of particles of different sizes through an innovative microfluidic chip design. By combining a helical separation channel with sheath flow technology, efficient inertial sorting based on particle size differences is achieved, ensuring that target particles enter the predetermined branch. The variable cross-section design at the downstream flow channel and the outlet connection of each upstream flow channel significantly optimizes flow field stability, effectively reducing the risk of clogging and improving the sorting and recovery rate. This allows the focusing flow channel structure to further precisely guide particles to the detection area. Combined with an integrated optical imaging system and image processing module, real-time, high-sensitivity observation and quantitative analysis of target particles is achieved, greatly simplifying the operation process.

[0018] In this invention, the sample liquid, compressed by the sheath fluid, forms a narrow flow layer. Particles in the sample liquid are subjected to Dean drag and inertial lift. Larger particles, due to the greater inertial lift, are inertially focused towards the inner wall, while smaller particles, primarily influenced by Dean force, migrate back and forth along the transverse direction of the flow channel with the Dean flow. When the smaller particles reach the vicinity of the outer wall of the flow channel, the two particle sizes separate. Larger particles enter the focusing channel through the upper branch channel, where they are again subjected to Dean drag and inertial lift, resulting in a centered focused arrangement. These centered particles then enter the detection channel, solving problems such as cell adhesion and excessively high flow rates that prevent capture. The optical imaging module continuously captures images of particle motion and transmits them to the image processing and detection module, which uses a self-developed algorithm to identify and count particles in the detection channel. Through these operations, high-throughput, accurate separation, and real-time online image detection of particles can be achieved simultaneously. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a high-efficiency particle separation and real-time detection device according to the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the microchannel chip of this utility model;

[0021] Figure 3 This is a schematic diagram of the concave cross-sectional structure in the spiral separation channel of this utility model;

[0022] Figure 4 This is a schematic diagram of the variable cross-section structure at the connection between the flow channels near the downstream outlet of this utility model;

[0023] Figure 5 This is a schematic diagram of the variable cross-section structure at the upstream channel outlet connection of the collection device of this utility model;

[0024] Figure 6 This is a schematic diagram of the particle separation achieved by the spiral separation channel of this utility model;

[0025] Figure 7 This is a schematic diagram of the focusing channel of this utility model for achieving particle focusing;

[0026] Figure 8 This is a schematic diagram of particle distribution in the detection channel of this utility model.

[0027] Figure reference numerals: 10. Light source; 11. Condensing lens; 12. Sample injector; 13. Sheath fluid injector; 14. Microfluidic chip; 15. Objective lens; 16. Reflecting prism; 17. Lens tube; 18. CMOS sensor; 19. Image processor; 110. First collector; 111. Second collector; 112. Third collector; 113. Fourth collector; 21. Sample channel; 22. Sheath fluid channel; 23. 24. Spiral separation channel; 25. Flow resistance matching channel; 26. Focusing channel; 27. External outlet channel; 28. Detection channel; 29. ​​Internal outlet channel; 20. Sample inlet; 21. Sheath fluid inlet; 22. Lower branch channel; 23. Upper branch channel; 24. Flow resistance matching channel outlet; 25. Focusing channel outlet; 26. External outlet channel outlet; 27. Detection channel outlet; 28. Internal outlet channel outlet. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0029] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] Example 1

[0032] like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a high-efficiency particle separation and real-time detection device, including a microfluidic chip 14 encapsulating a channel layer and a substrate layer from top to bottom. The channel layer includes a spiral separation channel 23 with an inner inlet and an outer outlet. The inner inlet is Y-connected to the sample channel 21 and the sheath fluid channel 22, and the outer outlet is Y-connected to the upper branch channel 232 and the lower branch channel 231. The outlet of the lower branch channel 231 is connected to the inlet of the flow resistance matching channel 24, and the outlet of the upper branch channel 232 is connected to the inlet of the focusing channel 25. The outlet of the focusing channel 25 is connected to the detection channel 27 and the inlets of the outer outlet channel 26 and the inner outlet channel 28, which are symmetrically located on both sides of it. The outlets of the flow resistance matching channel 24, the detection channel 27, the outer outlet channel 26 and the inner outlet channel 28 are all connected to a collection device. The cross-sectional area of ​​the connection between the downstream channels of the outer outlet and the outlet of the upstream channel of each collection device varies along the length direction. An optical imaging system is provided at the detection channel 27 and is connected to the image processing module via a data cable.

[0033] This invention achieves efficient and precise integrated separation and detection of particles of different sizes through innovative microfluidic chip design. By combining a spiral separation channel with sheath flow technology, efficient inertial sorting can be achieved based on particle size differences, ensuring that target particles enter the predetermined branch. The variable cross-section design between the downstream channels of the external outlet and at the outlet connection of the upstream channels of each collection device significantly optimizes the flow field stability, effectively reduces the risk of blockage and improves the sorting and recovery rate. This allows the focusing channel structure to further precisely guide particles to the detection area. Combined with the integrated optical imaging system and image processing module, real-time, high-sensitivity observation and quantitative analysis of target particles are achieved, greatly simplifying the operation process.

[0034] Example 2

[0035] This embodiment provides a device for efficient separation and real-time detection of particulate matter, such as... Figure 1 As shown, it includes a microfluidic chip 14, an optical imaging module, and an image processing module; as Figure 2As shown, the microfluidic chip 14 includes a channel layer and a substrate layer arranged sequentially from top to bottom; the microfluidic chip 14 is fabricated by encapsulating the channel layer and the substrate layer from top to bottom; the channel layer includes a sample channel 21, a sheath fluid channel 22, a spiral separation channel 23, a flow resistance matching channel 24, a focusing channel 25, an external outlet channel 26, a detection channel 27, and an internal outlet channel 28; the sample channel 21 has a sample inlet 211 at its inlet, and the outlet of the sample channel 21 intersects with the outlet of the sheath fluid channel 22 in a Y-shape. The fluids converge into the inner inlet of the spiral separation channel 23; the inlet of the sheath fluid channel 22 is provided with a sheath fluid inlet 221, and the fluid velocity in the sheath fluid channel 22 is greater than the flow velocity in the sample channel 21; the outer outlet of the spiral separation channel 23 has two Y-shaped outlet channels, namely a lower branch channel 231 and an upper branch channel 232. The inflow rate into the lower branch channel 231 is greater than the inflow rate into the upper branch channel 232. The outlet of the lower branch channel 231 is connected to the inlet of the flow resistance matching channel 24, and the outlet of the upper branch channel 232 is connected to the focusing channel 24. The inlet of flow channel 25 is connected. Specifically, the upper branch flow channel 232 and the lower branch flow channel 231 are obtuse-angled structures including inclined and horizontal sections. The inclined sections of the upper branch flow channel 232 and the lower branch flow channel 231 are Y-shaped connected to the spiral separation flow channel, respectively. The horizontal sections of the upper branch flow channel 232 and the lower branch flow channel 231 are connected to the focusing flow channel 25 and the flow group matching flow channel 24, respectively. The outlet of the focusing flow channel 25 is connected to the inlet of the detection flow channel 27, and the outlet 251 of the focusing flow channel is connected to the inlet of the outer outlet flow channel 26. The focusing flow channel outlet 251 is connected to the inlet of the inner outlet flow channel 28. The outer outlet flow channel 26 and the inner outlet flow channel 28 are symmetrically arranged on both sides of the detection flow channel 27. The outlets of the flow resistance matching flow channel 24, the detection flow channel 27, the outer outlet flow channel 26 and the inner outlet flow channel 28 are all connected to a collection device. The cross-sectional area of ​​the connection between the downstream flow channels of the outer outlet and the outlet of the upstream flow channel of each collection device varies along the length direction. An optical imaging system is provided at the detection flow channel 27 and is connected to the image processing module through a data cable.

[0036] In this embodiment, the connection between the downstream flow channels of the outer outlet includes a first connection between the lower branch channel 231 and the flow resistance matching channel 24, and a second connection between the upper branch channel 232 and the focusing channel 25. When the cross-sectional area of ​​the first connection and the second connection changes along the length direction, the change direction is that the height gradually decreases along the length direction. Specifically, the highest and lowest heights of the first connection and the second connection are 150 μm and 50 μm, respectively. Figure 4The height of the cross-section at the first connection is reduced by 50 μm from 150 μm to decrease the length of the matching flow resistance channel 24, thereby reducing the size of the microfluidic chip 14. The height of the cross-section at the second connection is also reduced by 50 μm to increase the flow velocity of 15 μm particles entering the focusing channel 25, thus achieving centered focusing. Simultaneously, in the detection channel 27, the shorter channel facilitates particle capture by the camera, reducing particle blurring caused by camera depth of field.

[0037] In this embodiment, the outlets of the flow resistance matching channel 24, the detection channel 27, the outer outlet channel 26, and the inner outlet channel 28 are respectively connected to the flow resistance matching channel outlet 241, the outer outlet channel outlet 261, the detection channel outlet 271, and the inner outlet channel outlet 281. The outlet connections of the channels upstream of each collecting device include connection point one between the outlet of the flow resistance matching channel 24 and the flow resistance matching channel outlet 241, connection point two between the outlet of the outer outlet channel 26 and the outer outlet channel outlet 261, connection point three between the outlet of the detection channel 27 and the detection channel outlet 271, and connection point four between the outlet of the inner outlet channel 28 and the inner outlet channel outlet 281. When the cross-sectional area of ​​connection point one, connection point two, connection point three, and connection point four changes along the length direction, the direction of change is a gradual increase in height along the length direction. Specifically, the highest and lowest heights of connection point one, connection point two, connection point three, and connection point four are 150 μm and 50 μm, respectively. Figure 5 The cross-sectional height of connection point 1, connection point 2, connection point 3 and connection point 4 is increased from 50μm to 150μm. The purpose is to increase the flow channel height to reduce the risk of particle blockage of the flow channel.

[0038] In this embodiment, when the change direction is a gradual increase or decrease in height along the length direction, the cross-sections of the first and second connections are both trapezoidal. When the change direction is a gradual increase in height along the length direction, the cross-sections of connection one, connection two, connection three, and connection four are all trapezoidal. The angle between the inclined plane of the trapezoid and the horizontal plane is an obtuse angle, specifically 150°.

[0039] In this embodiment, the collection device includes a first collector 110, a second collector 111, a third collector 112, and a fourth collector 113. The inlets of the first collector 110, the second collector 111, the third collector 112, and the fourth collector 113 are respectively connected to the flow resistance matching channel outlet 241, the outer outlet channel outlet 261, the detection channel outlet 271, and the inner outlet channel outlet 281.

[0040] Specifically, the cross-sectional height of the lower branch channel 231 is higher than that of the flow resistance matching channel 24, and the connection between them adopts a variable cross-sectional height design. The outlet of the flow resistance matching channel 24 is a flow resistance matching channel outlet 241, and the cross-sectional height of the flow resistance matching channel 24 is lower than that of the flow resistance matching channel outlet 241; the connection between them also adopts a variable cross-sectional height design. The outlet of the upper branch channel 232 is connected to the inlet of the focusing channel 25, and the cross-sectional height of the upper branch channel 232 is higher than that of the focusing channel 25; the connection between them also adopts a variable cross-sectional height design. The focusing channel outlet 251 is connected to the inlet of the detection channel 27, and the outlet of the detection channel 27 is connected to the outlet 271 of the detection channel; the cross-sectional height of the detection channel 27 is lower than that of the detected channel outlet 271; the connection between them also adopts a variable cross-sectional height design. Simultaneously, the focusing channel outlet 251 connects to the outer outlet... The inlet of channel 26 is connected to the outlet of the outer outlet channel 26, and the outlet of the outer outlet channel 26 is connected to the outlet of the outer outlet channel 261. The cross-sectional height of the outer outlet channel 26 is lower than that of the outer outlet channel outlet 261. The connection between the two adopts a variable cross-sectional height design. The outlet of the focusing channel 251 is connected to the inlet of the inner outlet channel 28, and the outlet of the inner outlet channel 28 is connected to the outlet of the inner outlet channel 281. The cross-sectional height of the inner outlet channel 28 is lower than that of the inner outlet channel outlet 281. The connection between the two adopts a variable cross-sectional height design.

[0041] In this embodiment, the spiral separation channel 23 includes a front loop located near the inner inlet and a rear loop located near the outer outlet. The length ratio of the front loop to the rear loop is 3:1. The cross-section of the front loop is a rectangular cross-section with a width of 500 μm and a height of 150 μm. The cross-section of the rear loop is a concave cross-section with a semi-circular arc and a height of 80 μm at the lowest point of the concave cross-section.

[0042] In this embodiment, the focusing channel 25 is an asymmetric sinusoidal channel with a rectangular cross-section. The asymmetric sinusoidal channel has 3.5 cycles, including several staggered upper and lower semicircular arc channels. The width of the upper semicircular arc channel is smaller than the width of the lower semicircular arc channel.

[0043] In this embodiment, the sample flow channel 21, sheath fluid flow channel 22, flow resistance matching flow channel 24, outer outlet flow channel 26, outer outlet flow channel 27, detection flow channel 27, and inner outlet flow channel 28 are direct flow channels with rectangular cross-sections.

[0044] Specifically, the spiral separation channel 23 includes two loops, with inner and outer radii of 4.45 mm and 10.90 mm respectively, and a spacing of 1.5 mm between each channel; the focusing channel 25 is an asymmetric sinusoidal channel, including 3.5 cycles; the sample channel 21 and sheath fluid channel 22 are 2.0 mm long direct current channels; the outer outlet channel 26, detection channel 27, and inner outlet channel 28 are 3.0 mm long direct current channels; and the flow resistance matching channel 24 is a 7.0 mm long direct current channel; the first 1.5 loops of the spiral separation channel 23 have a rectangular cross-section of 500 μm (width) × 150 μm (height), and the last 0.5 loops have a concave cross-section with a minimum height of 80 μm and a semi-circular arc, such as... Figure 3 As shown; the focusing channel 25 has a cross-sectional height of 50 μm, and the upper and lower semi-circular arc channels are rectangular channels with widths of 200 μm and 300 μm, respectively; the sample channel 21 has a cross-sectional dimension of 160 μm (width) × 150 μm (height), the sheath fluid channel 22 has a cross-sectional dimension of 370 μm (width) × 150 μm (height), the flow resistance matching channel 24 has a cross-sectional dimension of 300 μm (width) × 50 μm (height), the outer outlet channel 26 and the inner outlet channel 28 have a cross-sectional dimension of 450 μm (width) × 50 μm (height), and the detection channel 27 has a cross-sectional dimension of 600 μm (width) × 50 μm (height).

[0045] In this embodiment, a fluid injection mechanism is also included, which includes a sample injector 12 and a sheath fluid injector 13. The input end of the sample injector 12 is connected to the inlet of the sample channel 21, and the flow rate is set to 0.1 mL / min for injecting the sample. The input end of the sheath fluid injector 13 is connected to the inlet of the sheath fluid channel 22, and the flow rate is set to 1.0 mL / min for injecting the sheath fluid.

[0046] In this embodiment, the optical imaging system includes a light source 10, a condenser lens 11, an objective lens 15, a reflecting prism 16, a lens barrel 17, and a CMOS sensor 18. The light source 10 and the condenser lens 11 are arranged from top to bottom above the detection channel 27, and the objective lens 15 and the reflecting prism 16 are arranged from top to bottom below the detection channel 27. The light source 10, the condenser lens 11, the objective lens 15, and the reflecting prism 16 are aligned on the same vertical line. The lens barrel 17 and the CMOS sensor are arranged sequentially on the horizontal line of the reflecting prism 16. The CMOS sensor is communicatively connected to the image processor 19 of the image processing module via a data cable.

[0047] Specifically, the optical imaging module is located at the detection channel 27. The optical imaging module includes a light source 10, a condenser lens 11, an objective lens 15, a reflecting prism 16, a lens barrel 17, and a CMOS sensor 18. The light emitted by the light source 10 is focused by the condenser lens 11 and then irradiates the detection channel 27. The trajectory of the particles irradiated by the light is collected and magnified by the objective lens 15. The reflecting prism 16 deflects the light path by 90° to adapt to the compact space. The lens barrel 17 with a length of 100mm is set to ensure the back focal length distance in order to achieve the set magnification. The magnified real image is projected onto the CMOS sensor 18 for real-time capture of the image of the particles in the microchannel.

[0048] The image processing module includes an image processor 19. The image processor 19 is connected to the CMOS sensor 18 of the optical imaging module via USB3, so that the image obtained by the CMOS sensor 18 is transmitted to the image processor 19. The image processor 19 uses an algorithm developed by Halcon software to identify and analyze the image obtained by the CMOS sensor 18, and completes the detection and counting of the target sample.

[0049] The frame rate setting method for the CMOS sensor 18 in the optical imaging module is as follows: the flow rate of the particulate suspension output from the flow channel outlet 271 is 0.2 mL / min, and the calculated flow channel cross-sectional area is 3 × 10⁻⁶. -8 m 2 Therefore, the particle's velocity was calculated to be 0.1 m / s. Combining the field of view size and magnification size of the CMOS sensor 18, the effective field of view size was determined to be 960 μm × 600 μm. The particle's time to cross the field of view was calculated to be 0.0096 s. Based on this, the frame rate was set to 105 fps to ensure that the same particle would not appear in more than one frame in continuously captured images.

[0050] The image processing module performs the following image processing steps: First, using a background subtraction unit, the flow channel image without target particles is set as the background image. Once an image containing target particles is captured, the image containing the target particles is subtracted from the background image to separate the moving object from the microchannel background. Next, using an image preprocessing unit, mean filtering is applied to the background-subtracted image to linearly smooth its grayscale values, achieving noise reduction. A pixel-by-pixel multiplication function is used to enhance the target image. Then, an automatic thresholding method is used to capture all moving targets. Finally, using a particle recognition unit, the captured moving targets are filtered out from all moving targets based on particle size and shape, and the target particles are counted.

[0051] The specific steps are as follows:

[0052] Step 1: The sample solution of 6μm and 15μm mixed particles is injected into the sample inlet 211 through the sample injector 12, and the sheath fluid is injected into the sheath fluid inlet 221 through the sheath fluid injector 13.

[0053] Step 2: The sample liquid is injected into the spiral separation channel 23 through the sample flow channel 21. The outlet of the sheath fluid flow channel 22 intersects with the outlet of the sample flow channel 21 and flows into the spiral separation channel 23. Due to the compression of the sheath fluid, the sample liquid forms a narrow flow layer. Under the influence of inertial lift and Dean drag, the particles rapidly migrate towards the inner wall of the flow channel. Because the 15μm particles are larger, they are focused near the inner wall of the flow channel due to the dominant inertial lift. The smaller 6μm particles are subject to weaker inertial lift and are mainly affected by Dean drag, thus migrating towards the outer wall with the Dean drag. When the 6μm particles migrate to the vicinity of the outer wall of the flow channel, the 6μm particles and the 15μm particles are separated. Figure 6 As shown.

[0054] Step 3: The 15μm particles enter the focusing channel 25 through the upper branch channel 232. In the focusing channel 25, they are subjected to Dean drag and inertial lift, resulting in a centered focusing arrangement. The centered particles then enter the detection channel 27. Figure 7 As shown; due to the widening of the flow channel, the particles slow down, resulting in slight dispersion of the focused particles, such as... Figure 8 As shown, however, it has no effect on particle counting; after the optical imaging module captures the image of 15μm particles in the flow, it transmits it to the image processing module for detection and counting, and flows into the third collector 112 through the detection channel outlet 271. 6μm particles enter the flow resistance matching channel 24 through the lower branch channel 231, and flow into the first collector 110 through the flow resistance matching channel outlet 241. At the same time, the waste liquid flowing to the inner outlet channel 28 flows into the second collector 111, and the waste liquid flowing to the outer outlet channel 26 flows into the fourth collector 113.

[0055] The above description is merely a preferred embodiment of this utility model and does not constitute any limitation on this utility model. Any person skilled in the art can make many possible variations and modifications to the technical solution of this utility model, or modify it into equivalent embodiments, without departing from the scope of the technical solution of this utility model. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technology of this utility model without departing from the scope of the technical solution of this utility model shall fall within the protection scope of this technical solution.

Claims

1. A device for high efficiency separation and real-time detection of microparticles, characterized in that, The microfluidic chip includes a top-to-bottom encapsulation channel layer and a substrate layer. The channel layer includes a spiral separation channel with an inner inlet and an outer outlet. The inner inlet is Y-connected to the sample channel and the sheath fluid channel, and the outer outlet is Y-connected to the upper branch channel and the lower branch channel. The outlet of the lower branch channel is connected to the inlet of the flow resistance matching channel. The outlet of the upper branch channel is connected to the inlet of the focusing channel. The outlet of the focusing channel is connected to the detection channel and the inlets of the outer outlet channel and the inner outlet channel symmetrically located on both sides of it. The outlets of the flow resistance matching channel, the detection channel, the outer outlet channel, and the inner outlet channel are all equipped with collection devices. The cross-sectional area of ​​the connection between the downstream channels of the outer outlet and the connection between the outlets of the upstream channels of each collection device varies along the length direction. An optical imaging system is provided at the detection channel and is connected to the image processing module via a data cable.

2. The device according to claim 1, wherein, The connection between the downstream channels of the external outlet includes a first connection between the lower branch channel and the flow resistance matching channel, and a second connection between the upper branch channel and the focusing channel. When the cross-sectional area of ​​the first connection and the second connection changes along the length direction, the change direction is that the height gradually decreases along the length direction.

3. The device according to claim 2, wherein the device is a micro-particle high- efficiency separation and real-time detection device. The outlets of the flow resistance matching channel, the detection channel, the outer outlet channel, and the inner outlet channel are respectively connected to the outlets of the flow resistance matching channel, the outer outlet channel, the detection channel, and the inner outlet channel. The outlet connection points of the upstream channels of each collecting device include connection point one between the outlets of the flow resistance matching channel and the outlet of the flow resistance matching channel, connection point two between the outlets of the outer outlet channel and the outlet of the outer outlet channel, connection point three between the outlets of the detection channel and the outlet of the detection channel, and connection point four between the outlets of the inner outlet channel and the outlet of the inner outlet channel. When the cross-sectional area of ​​connection point one, connection point two, connection point three, and connection point four changes along the length direction, the direction of change is that the height gradually increases along the length direction.

4. The device according to claim 3, wherein the device is a micro-particle high- efficiency separation and real-time detection device. When the change direction is such that the height gradually decreases along the length direction, the cross-sections of the first and second connections are both trapezoidal. When the change direction is such that the height gradually increases along the length direction, the cross-sections of the first, second, third, and fourth connections are all trapezoidal, and the angle between the inclined plane of the trapezoid and the horizontal plane is an obtuse angle.

5. The high-efficiency particle separation and real-time detection device according to claim 3, characterized in that, The collection device includes a first collector, a second collector, a third collector, and a fourth collector. The inlets of the first collector, the second collector, the third collector, and the fourth collector are respectively connected to the outlet of the flow resistance matching channel, the outlet of the outer outlet channel, the outlet of the detection channel, and the outlet of the inner outlet channel.

6. The device according to claim 1, wherein The spiral separation channel includes a front loop located near the inner inlet and a rear loop located near the outer outlet. The length ratio of the front loop to the rear loop is 3:

1. The cross-section of the front loop is rectangular, and the cross-section of the rear loop is concave with a semi-circular arc.

7. The device according to claim 1, wherein the device is a micro-particle high- efficiency separation and real-time detection device. The focusing channel is an asymmetric sinusoidal channel with a rectangular cross-section. The asymmetric sinusoidal channel has 3.5 cycles and includes several staggered upper and lower semicircular arc channels. The width of the upper semicircular arc channel is smaller than the width of the lower semicircular arc channel.

8. The device according to claim 1, wherein the device is a particle separation and real-time detection device. The sample flow channel, sheath fluid flow channel, flow resistance matching flow channel, outer outlet flow channel, detection flow channel, and inner outlet flow channel are all direct flow channels with rectangular cross-sections.

9. The device of claim 1, wherein the device is a micro-particle high efficiency separation and real-time detection device. The optical imaging system includes a light source, a condenser lens, an objective lens, a reflecting prism, a lens barrel, and a CMOS sensor. The light source and the condenser lens are positioned above the detection channel from top to bottom, and the objective lens and the reflecting prism are positioned below the detection channel from top to bottom. The light source, the condenser lens, the objective lens, and the reflecting prism are aligned on the same vertical line. The lens barrel and the CMOS sensor are sequentially arranged on the horizontal line of the reflecting prism. The CMOS sensor is communicatively connected to the image processor of the image processing module via a data cable.

10. The device of claim 1, wherein the device is a micro-particle high efficiency separation and real-time detection device. It also includes a fluid injection mechanism, which includes a sample injector and a sheath fluid injector. The input end of the sample injector is connected to the inlet of the sample channel, and the input end of the sheath fluid injector is connected to the inlet of the sheath fluid channel.

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