Self-driven micro-fluidic chip for fingertip blood detection

Abstract

The utility model provides a self-driven micro-fluidic chip for fingertip blood detection, which comprises a bottom plate and a cover plate, the bottom plate is connected with the cover plate, a channel is formed between the bottom plate and the cover plate, the channel is divided into a Y-shaped channel, an S-shaped mixing channel, a reaction chamber and a detection area from top to bottom along the length direction, two through holes are formed in the cover plate, one through hole is used for receiving a fingertip blood sample input from the outside, the other through hole is used for fixedly installing a liquid bag of diluent, the Y-shaped channel is communicated with the two through holes and the S-shaped mixing channel, integrates the diluent liquid bag and the puncturing device, and is provided with the self-driven micro-fluidic chip of the S-shaped mixing channel. The fingertip blood sample can be automatically diluted and fully mixed, the operation process is simplified, and the detection precision and convenience are improved.

Description

Technical Field

[0001] The utility model relates to the field of microfluidic chips, and particularly relates to a self-driven microfluidic chip for fingertip blood detection. Background Art

[0002] As an integrated micro-analysis system, the microfluidic chip (Microfluidic Chip) is developing rapidly and widely used in many fields such as biology, chemistry, and medicine. It integrates functions such as sample preparation, reaction, separation, and detection in a tiny chip. By precisely controlling liquids at the micron or nanometer scale, it realizes the miniaturization and automation of complex processes in traditional laboratories. The emergence of this technology has greatly promoted the research and application in the fields of analytical chemistry, bioengineering, clinical medicine, etc. Especially in the rapidly developing Point of Care Testing (POCT) in recent years, the microfluidic chip has become an indispensable tool.

[0003] POCT refers to the immediate testing carried out beside or close to the patient, without the need to send the sample to a central laboratory far from the patient. Due to the ability to quickly provide test results, POCT has shown great advantages in scenarios such as first aid, community health, and home care. In POCT, fingertip blood testing is a typical application, widely used in fields such as blood glucose monitoring, blood lipid analysis, screening for infectious diseases, and blood gas analysis. The advantage of fingertip blood testing is that the sample is easily obtained, non-invasive or minimally invasive, and is particularly suitable for patients who need frequent testing. However, fingertip blood samples are usually very small in volume (usually in the microliter range) and contain various complex components such as red blood cells, white blood cells, platelets, plasma, etc. Therefore, fingertip blood testing poses high challenges in terms of detection precision, sensitivity, etc.

[0004] Traditional POCT methods such as chromatographic test strips, portable analyzers, etc., although meeting the need for rapid testing to a certain extent, still have limitations in terms of accuracy, sensitivity, and versatility. In contrast, the microfluidic chip, by shrinking laboratory-level analysis functions to the chip size, has improved the detection sensitivity and detection repeatability to varying degrees, providing a more efficient and reliable solution for the detection of fingertip blood in POCT.

[0005] Although the application of microfluidic chips in fingertip blood detection shows great potential, there are still some challenges and deficiencies in the existing technology. First of all, most microfluidic chips rely on external drive systems, such as pumps, piezoelectric devices, or electric fields, to drive the liquid to flow in the chip. Although these external drive devices can precisely control the liquid flow, they also bring system complexity, increased cost, and reduced portability.

[0006] Secondly, during the fingertip blood detection process, the volume of the blood sample is small and the components are complex. Direct detection may lead to inaccurate results. This is because components such as blood cells in the untreated fingertip blood sample may interfere with the detection process and affect the final detection results. Therefore, in many detection applications, the fingertip blood sample needs to be appropriately diluted before detection. This dilution process is usually accomplished by adding a diluent to reduce the viscosity of the blood sample and reduce interfering substances. However, the existing dilution processes usually rely on external devices or manual operations, which not only increase the operation steps but also may introduce operation errors and contamination risks.

[0007] In addition, the mixing effect of the fingertip blood sample and the diluent is also a key factor affecting the detection results. Ideal mixing should ensure that the blood sample and the diluent are fully and evenly mixed to ensure the accuracy of the detection. However, many microfluidic chips in the existing technology do not fully consider this point in their designs. The channel designs of many chips are relatively simple, and the mixing effect is poor, resulting in insufficient mixing of the sample and the diluent, thereby affecting the accuracy and consistency of the detection results. Summary of the Invention

[0008] The purpose of the present utility model is to provide a self-driven microfluidic chip for fingertip blood detection, which integrates a diluent liquid sac and a puncturing device, and is designed with an S-shaped mixing channel, capable of automatically diluting and fully mixing the fingertip blood sample, simplifying the operation process, and improving the accuracy and convenience of detection.

[0009] To achieve the above purpose, the present utility model provides the following technical solutions:

[0010] A self-driven microfluidic chip for fingertip blood detection, comprising a bottom plate and a cover plate. The bottom plate and the cover plate are connected, and a channel is formed between the bottom plate and the cover plate. The channel is divided into a Y-shaped channel, an S-shaped mixing channel, a reaction chamber, and a detection area along the length direction from top to bottom. Two through holes are opened on the cover plate. One through hole is used to receive the externally input fingertip blood sample, and the other through hole is used to fixedly install the liquid sac of the diluent. The Y-shaped channel communicates with the two through holes and the S-shaped mixing channel respectively.

[0011] As a preferred embodiment, a plurality of micro-columns are arranged in the S-shaped mixing channel. The micro-columns are arranged on the bottom plate, and there is a gap between the micro-columns and the cover plate.

[0012] As a preferred embodiment, the micro-column includes:

[0013] A body part, the bottom of the body part is arranged on the bottom plate;

[0014] A raised portion, the raised portion is provided at the top of the body portion, and there is a gap between the raised portion and the cover plate.

[0015] As a preferred embodiment, the raised portion is hemispherical.

[0016] As a preferred embodiment, the distance between the central axes of two adjacent micro-columns is 0.05 - 0.1 mm.

[0017] As a preferred embodiment, the body portion is cylindrical, the diameter of the body portion is 20 - 50 μm, and the height of the body portion is 10 - 200 μm.

[0018] As a preferred embodiment, micro-columns are provided in the reaction chamber and / or the detection area.

[0019] As a preferred embodiment, it further includes:

[0020] A puncturing device, the puncturing device has a conical incision, the puncturing device receives the pressing method, and pierces the liquid sac through the conical incision.

[0021] As a preferred embodiment, the width of the reaction chamber decreases sequentially from top to bottom.

[0022] As a preferred embodiment, the distance between the lower surface of the cover plate and the upper surface of the bottom plate is 0.05 - 1 mm.

[0023] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0024] The channel provided between the bottom plate and the cover plate is a capillary channel. Through the precise micro-columns and surface treatment in the capillary channel, the fingertip blood sample can flow autonomously inside the chip. This not only eliminates the dependence on complex devices such as external pumps, but also reduces the equipment cost and operation complexity.

[0025] The dilution liquid sac and the puncturing device are integrated in the chip, realizing the automatic dilution process of the blood sample.

[0026] The present invention will be further described below in conjunction with the drawings and embodiments. Description of the Drawings

[0027] Figure 1 It is a schematic structural diagram of the self-driven microfluidic chip for fingertip blood detection described in the present invention;

[0028] Figure 2 It is a schematic structural diagram of the Y-shaped channel described in the present invention;

[0029] Figure 3 It is a schematic structural diagram of the S-shaped mixing channel described in the present invention;

[0030] Figure 4 This is a cross-sectional view of the self-driven microfluidic chip for fingertip blood detection according to the present utility model.

[0031] In the figure: 100, bottom plate; 200, cover plate; 210, through hole; 300, channel; 310, Y-shaped channel; 320, S-shaped mixing channel; 330, reaction chamber; 340, time-controlled valve; 350, detection area; 410, liquid sac; 420, puncturing device; 421, conical incision; 500, microcolumn; 510, body part; 520, protruding part. Detailed implementation manners

[0032] The following description is used to disclose the present utility model so that those skilled in the art can implement the present utility model. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious variations. The basic principles defined in the following description of the present utility model can be applied to other implementation schemes, variant schemes, improvement schemes, equivalent schemes, and other technical schemes that do not depart from the spirit and scope of the present utility model.

[0033] As shown in Figures 1 to 4 , the self-driven microfluidic chip for fingertip blood detection includes a bottom plate 100 and a cover plate 200. The bottom plate 100 and the cover plate 200 are connected, and a channel 300 is formed between the bottom plate 100 and the cover plate 200. The channel 300 is divided into a Y-shaped channel 310, an S-shaped mixing channel 320, a reaction chamber 330, and a detection area 350 along the length direction from top to bottom. Two through holes 210 are opened on the cover plate 200. One through hole 210 is used to receive the external input fingertip blood sample, and the other through hole 210 is used to fixedly install the liquid sac 410 for diluent. The Y-shaped channel 310 communicates with the two through holes 210 and the S-shaped mixing channel 320 respectively.

[0034] The fingertip blood sample and the diluent in the liquid sac 410 enter the S-shaped mixing channel through the Y-shaped channel 310 for mixing, and then pass through the reaction chamber 330 and the detection area 350 in sequence, which can automatically complete the dilution and sufficient mixing of the fingertip blood sample, simplify the operation process, and improve the accuracy and convenience of detection.

[0035] Referring to Figure 1 and Figure 4 , a connecting plate is provided between the edges of the bottom plate 100 and the cover plate 200, and thus a channel 300 is formed between the upper surface of the bottom plate 100 and the lower surface of the cover plate 200. Preferably, the distance between the upper surface of the bottom plate 100 and the lower surface of the cover plate 200 is 0.05 - 1 mm, so that the channel formed by the bottom plate 100 and the cover plate 200 is a capillary channel, and the sample to be tested can move forward self-driven by its own capillary force when traveling in the channel.

[0036] Among them, two through-holes 210 correspond to the uppermost position of the channel 300. The Y-shaped channel 310 has three ports, two of which are respectively connected to the two through-holes 210, and the last port communicates with the inlet end of the S-shaped mixing channel 320. In this way, the fingertip blood sample and the diluent pass through the Y-shaped channel 310, enter the S-shaped mixing channel and are mixed, and the mixed liquid sequentially passes through the reaction chamber 330 and the detection area 350.

[0037] Such as Figure 3 and Figure 4 shown, a plurality of micro-columns 500 are arranged in the S-shaped mixing channel 320. The micro-columns 500 are arranged on the bottom plate 100, and there is a gap between the micro-columns 500 and the cover plate 200.

[0038] In the S-shaped mixing channel 320, the flow of the liquid is usually in a laminar flow state, and the mixing between different layers of the liquid is very limited. The micro-columns 500 can break the parallel streamlines of the fluid, enhance the mixing efficiency of the fingertip blood and the diluent by disturbing the laminar flow, controlling the flow path and simulating the turbulent effect, which not only eliminates the dependence on complex devices such as external pumps, but also reduces the equipment cost and operation complexity. Of course, the self-driven microfluidic chip can also be placed vertically, and the liquid can flow by its own weight.

[0039] Refer to Figure 4 , the micro-column 500 includes:

[0040] A main body part 510, the bottom of the main body part 510 is arranged on the bottom plate 100;

[0041] A convex part 520, the convex part 520 is arranged on the top of the main body part 510, and there is a gap between the convex part 520 and the cover plate 200.

[0042] The surface of the convex part 520 is an arc surface, which reduces the apparent contact angle of the liquid sample on the upper part of the micro-column, thereby enhancing the wettability of the sample. This makes the flow rate of the fingertip blood sample slow down when flowing through the reaction chamber and the detection area, so as to ensure that the sample can fully react with the reaction reagent, and further improves the accuracy of the detection result. The presence of the micro-columns 500 also increases the internal surface area of the chip, allows more reaction reagents to be embedded, increases the detection range of the target substance, and enables the sample to be measured to fully react with the reaction reagent.

[0043] The micro-columns 500 are arranged in a staggered array on the bottom plate 100, so that the flow time of the sample to be measured between the micro-columns is extended, ensuring sufficient mixing and reaction of the reagent and the accuracy of the measurement results. The distance between the central axes of two adjacent micro-columns 500 is 0.05 - 0.1 mm, enabling the sample to be measured to react fully with the reaction reagent while flowing smoothly through the micro-columns.

[0044] The main body part 510 is cylindrical, with a diameter of 20 - 50 μm and a height of 10 - 200 μm. The convex part 520 is hemispherical, with a height of 10 - 100 μm. In addition to cylinders, the micro-columns 500 can also adopt columnar structures of other shapes.

[0045] The arrangement of the micro-columns 500 causes a stronger perturbation effect when the sample flows through the gaps between the micro-columns, which helps to break the laminar flow state and enhance the mixing effect. At the same time, the appropriate spacing and micro-column diameter also ensure that the fluid can flow smoothly through without being blocked or having too much flow resistance due to overly dense micro-columns.

[0046] Reference Figure 1 , micro-columns are provided in the reaction chamber 330 and / or the detection area 350, enabling the fingertip blood sample to flow autonomously inside the chip.

[0047] As Figure 1 shown, the channel 300 is further divided into a time-controlled valve 340, which is located between the reaction chamber 330 and the detection area 350. The time-controlled valve 340 is a programmable valve, and its main function is to achieve the automatic opening and closing of the valve by setting a controller, thereby controlling the on-off, flow rate or pressure of the fluid.

[0048] The reaction chamber 330 is used to accommodate the fingertip blood sample and the diluent as the space for their reaction. The width of the reaction chamber 330 decreases successively from top to bottom. This design enables the sample to be measured to gradually gather during the flow process. When the sample passes through the reaction chamber 330 and enters the detection area 350, the contraction effect of the channel increases the capillary force of the sample, thereby pushing the sample to flow forward continuously. This design not only extends the residence time of the liquid in the detection area, ensuring that the sample can fully contact and react with the reaction reagent in the detection area, thus improving the accuracy of the detection results.

[0049] The detection area 350 is used to interpret the parameter indicators of the blood sample, thereby reflecting the individual's health status, disease state, and potential health risks, etc.

[0050] To ensure that the fingertip blood sample and the diluent can be fully mixed in the S-shaped mixing channel 320, the widths of the reaction chamber 330, the time-controlled valve 340, and the detection area 350 are all designed to be smaller than the width of the S-shaped mixing channel 320. This design increases the residence time of the liquid in the mixing channel by restricting the flow rate of the liquid through these areas, thereby improving the mixing effect. At the same time, within the mixing channel, the flow path of the liquid is extended, which helps the fingertip blood sample and the diluent to reach a fully mixed state before entering the subsequent reaction chamber 330 and detection area 350, thus ensuring the accuracy and reliability of the detection.

[0051] Reference Figure 1 , the lower end of the channel 300 communicates with a waste liquid pool for collecting the treated waste liquid. Of course, the lower ends of the channels 300 of multiple self-driven microfluidic chips communicate with the same waste liquid pool.

[0052] As Figure 1 and Figure 2 shown, the self-driven microfluidic chip for fingertip blood detection further includes:

[0053] A puncturing device 420 having a conical incision 421, the puncturing device 420 receiving the pressing manner and piercing the liquid sac 410 through the conical incision 421.

[0054] The puncturing device 420 pierces the sealing film of the liquid sac 410 through a carefully designed conical incision structure, thereby realizing the automatic release of the diluent after pressing. The core lies in the geometric shape of the conical incision and its angle setting. The angle range of the conical incision is set between 20° - 150°. The angle of the conical incision determines the force distribution during the puncturing process and the rupture mode of the liquid sac sealing film. When the angle is close to 20°, the incision is sharper, and the force required to pierce the film is smaller, which means that the puncturing can be achieved with less force and is suitable for application scenarios that require very fine operations. However, too small an angle may also cause the incision to be too sharp, increasing the risk of uneven tearing of the film during puncturing, which may lead to unstable release of the diluent and affect the detection accuracy. On the other hand, when the angle of the conical incision is close to 150°, the incision is relatively blunter, and the force during puncturing will be greater, but the puncturing process is more stable, suitable for cases where the viscosity of the diluent is higher or the sealing film of the liquid sac is thicker. The larger angle also reduces the excessive damage of the incision to the liquid sac sealing film, thus avoiding the leakage of the diluent.

[0055] Further, the liquid sac 410 is placed in the corresponding through hole 210 or fixed in the through hole 210 by means of bonding or the like. A puncturing device 420 is disposed in a fitting manner above the liquid sac 410. When an external force acts on the puncturing device 420 and presses the liquid sac 410, the conical incision of the puncturing device 420 punctures the liquid sac 410, so that the diluent in the liquid sac 410 enters the S-shaped mixing channel 320 through the Y-shaped channel 310.

[0056] The usage method of the self-driven microfluidic chip for fingertip blood detection is as follows:

[0057] After the fingertip blood sample enters the Y-shaped channel 310 through the corresponding through hole 210, the operator punctures the liquid sac 410 by manually pressing the puncturing device 420, so that the diluent is released and mixed with the fingertip blood sample in the Y-shaped channel 310, and then flows through the S-shaped mixing channel 320, the reaction chamber 330, the time control valve 340, and the detection area 350 in sequence, and finally enters the waste liquid pool, and the parameter indexes of the blood sample are detected through the detection area 350. Figure 4 The arrow B in the figure indicates the flow direction of the liquid.

[0058] In summary, the channels provided between the bottom plate 100 and the cover plate 200 are capillary channels. Through the precise micro-columns 500 and surface treatment in the capillary channels, the fingertip blood sample can flow autonomously inside the chip. This not only eliminates the dependence on complex external devices such as pumps, but also reduces the equipment cost and operation complexity. Secondly, the diluent liquid sac 410 and the puncturing device 420 are integrated in the chip, realizing the automatic dilution process of the blood sample. In addition, the S-shaped mixing channel not only prolongs the contact time between the blood sample and the diluent in the channel, but also increases the liquid flow path. Further, micro-columns 500 are introduced into the S-shaped mixing channel, so as to achieve more uniform and thorough mixing and reduce the measurement deviation caused by insufficient mixing.

[0059] The above embodiments are only used to illustrate the technical idea and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The scope of the patent adoption of the present invention cannot be limited only by this embodiment, that is, any equivalent changes or modifications made according to the spirit disclosed by the present invention still fall within the scope of the patent of the present invention.

Claims

1. A self-driven microfluidic chip for fingertip blood detection, characterized in that, It includes a bottom plate (100) and a cover plate (200). The bottom plate (100) and the cover plate (200) are connected, and a channel (300) is formed between the bottom plate (100) and the cover plate (200). The channel (300) is divided into a Y-shaped channel (310), an S-shaped mixing channel (320), a reaction chamber (330), and a detection area (350) along the length direction from top to bottom. Two through holes (210) are provided on the cover plate (200). One through hole (210) is used to receive a fingertip blood sample input externally, and the other through hole (210) is used to fixedly install a liquid capsule (410) for diluent. The Y-shaped channel (310) communicates with the two through holes (210) and the S-shaped mixing channel (320) respectively.

2. The self-driven microfluidic chip for fingertip blood detection according to claim 1, wherein A plurality of micro-columns (500) are arranged in the S-shaped mixing channel (320). The micro-columns (500) are arranged on the bottom plate (100), and there is a gap between the micro-columns (500) and the cover plate (200).

3. The self-driven microfluidic chip for fingertip blood detection according to claim 2, characterized in that The micro-column (500) includes: A body portion (510), the bottom of the body portion (510) is arranged on the bottom plate (100); A convex portion (520), the convex portion (520) is arranged on the top of the body portion (510), and there is a gap between the convex portion (520) and the cover plate (200).

4. The self-driven microfluidic chip for fingertip blood detection according to claim 3, wherein The convex portion (520) is hemispherical.

5. The self-driven microfluidic chip for fingertip blood detection according to claim 2, wherein, The distance between the central axes of two adjacent micro-columns (500) is 0.05 - 0.1 mm.

6. The self-driven microfluidic chip for fingertip blood detection according to claim 3, wherein The body portion (510) is cylindrical, the diameter of the body portion (510) is 20 - 50 μm, and the height of the body portion (510) is 10 - 200 μm.

7. The self-driven microfluidic chip for fingertip blood detection according to claim 2, wherein Micro-columns are arranged in the reaction chamber (330) and / or the detection area (350).

8. The self-driven microfluidic chip for fingertip blood detection according to claim 1, characterized in that, It further includes: A puncturing device (420), the puncturing device (420) has a conical incision (421), the puncturing device (420) receives a pressing manner, and punctures the liquid capsule (410) through the conical incision (421).

9. The self-driven microfluidic chip for fingertip blood detection according to claim 1, characterized in that, The width of the reaction chamber (330) decreases sequentially from top to bottom.

10. The self-driven microfluidic chip for fingertip blood detection according to claim 1, characterized in that, The distance between the lower surface of the cover plate (200) and the upper surface of the bottom plate (100) is 0.05 - 1 mm.

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