A detection microfluidic chip for blood analysis

Abstract

The utility model discloses a detection micro -fluidic chip for blood analysis, including base, which is provided with micro -fluidic flow channel on it, upper cover board is bonded with the base, which is provided with blood sample inlet, buffer solution sample inlet and outlet pipe on it, the micro -fluidic flow channel includes blood sample inlet flow channel, buffer solution sample inlet flow channel, diffusion area flow channel, observation area flow channel and outlet flow channel that communicate in proper order, blood sample inlet flow channel is linked with blood sample inlet, buffer solution sample inlet flow channel is linked with buffer solution sample inlet, outlet flow channel is linked with outlet pipe, the upper end of base still is provided with injection glue groove, and injection glue groove surrounds and is provided with the outside of micro -fluidic flow channel, the utility model has the advantages of uniform mixing, reduces flow channel block, improves detection sensitivity.

Description

Technical Field

[0001] This utility model relates to the field of biomedical detection technology, specifically a detection microfluidic chip for blood analysis. Background Technology

[0002] In the field of blood testing, traditional testing methods often rely on large-scale instruments and equipment, which not only have problems such as long testing cycles and high equipment costs, but also fail to meet the demand for rapid and convenient testing in point-of-care diagnosis, thus having significant limitations in application scenarios.

[0003] In recent years, microfluidic technology has gradually become a research hotspot in the field of blood testing due to its significant advantages such as small sample requirements, fast analysis speed, and integrability, providing new ideas for solving the shortcomings of traditional detection methods. However, current blood microfluidic chips still have many shortcomings: First, uneven mixing of blood and related reagents directly affects the accuracy of observation results; second, the chip channels are prone to blockage, resulting in a short chip lifespan and increased usage costs; third, some chip structures are poorly designed, resulting in low detection sensitivity, making it difficult to meet the requirements of high-precision detection. Utility Model Content

[0004] The purpose of this invention is to provide a detection microfluidic chip for blood analysis, which has the advantages of uniform mixing, reduced flow channel blockage, and improved detection sensitivity, thus solving the problems in the prior art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: A detection microfluidic chip for blood analysis includes a substrate on which microfluidic channels are disposed; The upper cover plate is bonded to the substrate and is provided with a blood inlet, a buffer inlet and an outlet tube. The microfluidic channel includes a blood sample inlet channel, a buffer sample inlet channel, a diffusion zone channel, an observation zone channel, and an outlet channel connected in sequence. The blood sample inlet channel is connected to the blood sample inlet, the buffer solution inlet channel is connected to the buffer solution inlet, and the outlet channel is connected to the outlet tube; The upper end of the substrate is also provided with a glue injection groove, which is arranged around the outside of the microfluidic channel.

[0006] Preferably, the cross-sectional shape of the glue injection groove is rectangular, trapezoidal, or semi-circular.

[0007] It is worth noting that this setup offers a variety of optional, easy-to-manufacture groove structures that can effectively accommodate sealant. Rectangular grooves are easy to process, while trapezoidal or semi-circular grooves facilitate the filling and encapsulation of the adhesive, forming a more robust sealing structure and enhancing bond strength and airtightness.

[0008] Preferably, the injection groove is filled with sealant, which is epoxy resin or UV-curable adhesive.

[0009] It is worth noting that this solution achieves high-strength and high-airtightness bonding between the substrate and the cover plate through the encapsulation process. The epoxy resin adhesive has high bonding strength and good pressure resistance, while the UV-curable adhesive has a fast curing speed and a simple process. It can effectively prevent fluid leakage and significantly improve the yield and lifespan of the chip.

[0010] Preferably, the substrate and the top cover are bonded by hot pressing, laser welding, ultrasonic welding or adhesive bonding.

[0011] It is worth noting that a variety of mature and reliable bonding processes are provided, allowing the selection of the most suitable bonding method based on the different materials of the substrate and cover plate (such as plastic / glass). This ensures the integrity of the flow channel seal, which is the foundation for realizing the functions of microfluidic chips, and also facilitates large-scale production.

[0012] Preferably, the buffer solution inlet channel has a serpentine or spiral structure.

[0013] It is worth noting that serpentine or spiral flow channels can significantly increase the mixing path and mixing time of the fluid, and utilize effects such as Dean's vortex to promote thorough and uniform mixing of blood and buffer solution, avoiding observation errors caused by uneven mixing, thereby greatly improving the accuracy and consistency of test results.

[0014] Preferably, the width of the observation area channel is greater than the width of its upstream channel.

[0015] It is worth noting that this widened design can effectively reduce the flow rate of the sample liquid in the observation area, providing sufficient time for cells to settle and spread. This is conducive to the monolayer distribution of cells in the observation area, avoiding stacking, which greatly facilitates clear observation and cell counting under the microscope, and improves the convenience and accuracy of detection.

[0016] Preferably, the substrate is made of PDMS, PMMA, PE or COC material.

[0017] It is worth noting that these materials exhibit good biocompatibility, chemical stability, and optical transparency. PDMS has good air permeability and is easy to process, while PMMA, PE, COC, and other plastic materials are low in cost and have good mechanical properties, making them suitable for large-scale injection molding. This helps reduce the unit cost of chips and promotes commercial applications.

[0018] Preferably, the top cover is made of PDMS, PMMA, PE or COC material.

[0019] It is worth noting that choosing materials that are the same as or compatible with the substrate can ensure the success rate and strength of bonding. At the same time, the high transparency and low autofluorescence of these materials (especially PMMA and COC) ensure the excellent optical performance of the observation area, providing the necessary conditions for high-definition microscopic imaging.

[0020] Preferably, the interfaces of the blood inlet, buffer inlet, and outlet tube are national standard Luer connectors.

[0021] It is worth noting that the use of standardized Luer connectors enables the chip to be quickly and reliably connected to commonly used fluid control devices such as syringes, pump tubes, and infusion tubes on the market. This greatly enhances the chip's versatility and ease of use, avoids the risk of fluid leakage and connection detachment, and facilitates integration into automated testing systems.

[0022] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. By designing the diffusion zone flow channel as a serpentine or spiral structure, the fluid path and mixing time are significantly increased. When blood and buffer are injected from the blood inlet and buffer inlet respectively and flow through this area, a strong Dean vortex effect is generated at the bend, thereby achieving passive, efficient and uniform mixing, laying a solid foundation for subsequent accurate observation and solving the problem of uneven mixing. 2. This utility model innovatively sets a glue injection groove around the outside of the flow channel on the substrate. During the bonding process, the sealant is injected into the groove and cured to form a strong sealing ring. This design realizes high strength and high airtightness bonding between the substrate and the top cover plate, fundamentally preventing fluid leakage from the flow channel or dead volume and blockage points caused by poor bonding, which greatly improves the reliability and service life of the chip. 3. The flow channel in the observation area is intentionally designed to be wider than the upstream flow channel. When the mixed sample flows into this area, the flow rate drops sharply, providing sufficient time for blood cells to settle and spread, allowing them to be evenly distributed in a single layer. This effectively avoids cell stacking. This design, combined with the cover plate made of high-transparency materials such as PDMS and PMMA, ensures that clear, non-overlapping cell images can be obtained under the microscope, thereby significantly improving the accuracy and sensitivity of cell morphology recognition and counting, making the detection results more reliable, and solving the problem of low detection sensitivity in existing technologies. Attached Figure Description

[0023] Figure 1 The diagram shown is a three-dimensional structural schematic of this utility model; Figure 2 The diagram shown is a three-dimensional structural schematic of the top cover plate of this utility model. Figure 3 The diagram shown is a three-dimensional structural schematic of the base of this utility model; Figure 4 The diagram shown is a cross-sectional three-dimensional structural schematic of the present invention.

[0024] Figure reference numerals: 1. Substrate; 2. Blood sample inlet channel; 3. Buffer sample inlet channel; 4. Diffusion zone channel; 5. Observation zone channel; 6. Outlet channel; 7. Top cover plate; 8. Blood sample inlet; 9. Buffer sample inlet; 10. Outlet tube; 11. Gel dispensing tank. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] To address the problems of uneven blood-reagent mixing, easy clogging of the flow channel, and low detection sensitivity in existing technologies, the following technical solution is proposed. Please refer to [link / reference needed]. Figures 1-4 ; A detection microfluidic chip for blood analysis includes a substrate 1 on which microfluidic channels are disposed; The upper cover plate 7 is bonded to the substrate 1, and is provided with a blood inlet 8, a buffer inlet 9 and an outlet tube 10. The microfluidic channel includes a blood sample inlet channel 2, a buffer sample inlet channel 3, a diffusion zone channel 4, an observation zone channel 5, and an outlet channel 6 connected in sequence. The blood sample inlet channel 2 is connected to the blood sample inlet 8, the buffer sample inlet channel 3 is connected to the buffer sample inlet 9, and the outlet channel 6 is connected to the outlet tube 10. The upper end of the substrate 1 is also provided with a glue injection groove 11, which is arranged around the outside of the microfluidic channel.

[0027] In this embodiment, the cross-sectional shape of the glue injection groove 11 is rectangular, trapezoidal, or semi-circular.

[0028] In this embodiment, specifically, the glue injection groove 11 is filled with sealant, which is epoxy resin glue or UV-curable glue.

[0029] In this embodiment, the substrate 1 and the upper cover plate 7 are bonded by hot pressing, laser welding, ultrasonic welding or adhesive bonding.

[0030] In this embodiment, specifically, the buffer injection channel 3 has a serpentine or spiral structure.

[0031] In this embodiment, specifically, the width of the observation area channel 5 is greater than the width of its upstream channel.

[0032] In this embodiment, specifically, the substrate 1 is made of PDMS, PMMA, PE or COC material.

[0033] In this embodiment, specifically, the upper cover plate 7 is made of PDMS, PMMA, PE or COC material.

[0034] In this embodiment, specifically, the interfaces of the blood inlet 8, the buffer inlet 9, and the outlet tube 10 are national standard Luer connectors.

[0035] Working principle: Blood samples are injected into the blood inlet channel 2 inside the chip through the blood inlet port 8, while buffer solution enters the buffer inlet channel 3 through the buffer inlet port 9. The two are injected at a ratio of 10:0.5-5 and an injection rate of 0.5-20 ml / h. Driven by specific pressure, the two converge towards the diffusion channel 4 at a precisely controlled flow rate. The addition of buffer solution can delay the upward movement of blood and facilitate the flat diffusion of blood in the channel. When blood and buffer solution enter the diffusion channel 4, which has a serpentine or spiral continuous bending structure, strong secondary flow and Dean vortex are generated under the combined action of fluid inertial force and channel geometry, enabling the two liquids to achieve multi-level and high-efficiency mixing. By combining the extended path of the diffusion zone channel with a low flow rate of 0.5-20 ml / h, the mixing time of blood and buffer in the diffusion zone channel 4 is extended from 0.1 seconds in the traditional straight channel to 0.3-0.5 seconds, providing sufficient time for molecular diffusion and ensuring uniform mixing. After thorough mixing, the liquid flow then enters the observation channel 5, which is significantly wider than the upstream channel. Due to the sudden increase in the cross-sectional area of ​​the channel, the fluid velocity decreases significantly. Under the influence of the fluid velocity and their own physical properties, the various types of cells in the blood present a specific arrangement pattern in the observation channel according to a certain pattern. Under the influence of gravity and hydrodynamics, the blood cells gradually settle and form a stable monolayer distribution at the bottom of the observation area, effectively avoiding cell overlap or accumulation, and creating the best conditions for clear observation of cell morphology and accurate counting under the microscope. According to the fluid mechanics continuity equation, as the channel width increases, the flow velocity will decrease from 10-50 mm / s in the diffusion zone to 2-10 mm / s in the observation zone. The flow rate decreases to that of blood cells (such as red blood cells, density 1.09 g / cm³). 3Provide sufficient settling time, according to Stokes' law (settling velocity v=2r). 2 (ρ-ρ0)g / (9η), where r is the cell radius, ρ is the cell density, ρ0 is the buffer density, and η is the viscosity. Red blood cells can settle within 0.5-2 seconds, forming a monolayer distribution at the bottom of the flow channel in the observation area, avoiding cell stacking and obstruction, and providing a clear field of view for microscopic observation. After observation, the waste liquid continues to flow to the outlet channel 6 and is finally discharged from the chip through the outlet pipe 10. Throughout the process, the epoxy resin or UV-cured adhesive filled in the injection tank 11 surrounding the microfluidic channel forms a continuous and reliable sealing barrier, ensuring that the substrate 1 and the top cover plate 7 remain completely sealed under various operating pressures, and completely eliminating fluid leakage or external contamination. The blood inlet 8, buffer inlet 9, and outlet tube 10 all adopt the national standard Luer connector standard to ensure a quick, sealed, and reliable connection with external injection pumps, infusion tubes, and collection devices, which can guarantee the ease of operation and system stability of the entire testing process.

[0036] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0037] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention.

Claims

1. A detection microfluidic chip for blood analysis, characterized in that, Includes a substrate (1) on which microfluidic channels are provided; The upper cover plate (7) is bonded to the substrate (1) and is provided with a blood inlet (8), a buffer inlet (9) and an outlet tube (10). The microfluidic channel includes a blood sample inlet channel (2), a buffer sample inlet channel (3), a diffusion zone channel (4), an observation zone channel (5), and an outlet channel (6) connected in sequence. The blood sample inlet channel (2) is connected to the blood sample inlet (8), the buffer sample inlet channel (3) is connected to the buffer sample inlet (9), and the outlet channel (6) is connected to the outlet tube (10). The upper end of the substrate (1) is also provided with a glue injection groove (11), which is arranged around the outside of the microfluidic channel.

2. The detection microfluidic chip for blood analysis according to claim 1, characterized in that, The cross-sectional shape of the glue injection groove (11) is rectangular, trapezoidal or semi-circular.

3. A detection microfluidic chip for blood analysis according to claim 1 or 2, characterized in that, The injection groove (11) is filled with sealant, which is epoxy resin or UV-curable adhesive.

4. The detection microfluidic chip for blood analysis according to claim 1, characterized in that, The substrate (1) and the top cover plate (7) are bonded by hot pressing, laser welding, ultrasonic welding or adhesive bonding.

5. A detection microfluidic chip for blood analysis according to claim 1, characterized in that, The buffer injection channel (3) has a serpentine or spiral structure.

6. A detection microfluidic chip for blood analysis according to claim 1, characterized in that, The width of the observation channel (5) is greater than the width of its upstream channel.

7. A detection microfluidic chip for blood analysis according to claim 1, characterized in that, The substrate (1) is made of PDMS, PMMA, PE or COC material.

8. A detection microfluidic chip for blood analysis according to claim 1, characterized in that, The top cover (7) is made of PDMS, PMMA, PE or COC material.

9. A detection microfluidic chip for blood analysis according to claim 1, characterized in that, The interfaces of the blood inlet (8), buffer inlet (9) and outlet tube (10) are national standard Luer connectors.

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