Sequential triggering type liquid storage bag combined with throttle channel for driving liquid path of micro-fluidic fluorescence immunoassay detection card and control method thereof

Abstract

This invention discloses a sequentially triggered liquid reservoir and throttling channel combined driving liquid path and its control method for a microfluidic fluorescence immunoassay cartridge, belonging to the field of microfluidic detection technology. The liquid path includes a cartridge body, a sample inlet, a first liquid reservoir, a second liquid reservoir, a trigger contact, a release port, a throttling channel, a capillary blocking section, a confluence node, a main liquid path, a detection zone, a waste liquid zone, and an anti-backflow structure. In a single external pressure action, the trigger contact sequentially triggers the release of the first and second liquid reservoirs. The two liquid streams enter the confluence node in a predetermined order via the throttling channel and capillary blocking section, and then enter the detection zone via the anti-backflow structure and the main liquid path. This solution achieves multi-stage liquid path driving within the cartridge without requiring a multi-pump, multi-valve structure in the main unit, improving reaction propulsion and detection consistency.

Description

Technical Field

[0001] This invention relates to the field of microfluidic detection technology, and in particular to a sequentially triggered reservoir and throttling channel combined driving fluid circuit and its control method for a microfluidic fluorescence immunoassay cartridge. Background Technology

[0002] Microfluidic fluorescence immunoassay cartridges typically need to complete sample introduction, reagent release, reaction propulsion, background cleaning, detection zone wetting, and waste liquid sealing within a relatively small volume. To accommodate small desktop analyzers or near-patient testing devices, the external host unit of the cartridge is usually not suitable for complex multi-pump, multi-valve, and multi-channel active fluidization systems.

[0003] Existing simplified cartridges mostly use a single liquid to propel the sample through the detection zone at one time, or rely on external pumps and valves to control the entry of multiple liquids into the flow path in a time-sharing manner. The former is difficult to meet the requirements of staged elution, reaction advancement, or background control in fluorescence immunoassay; the latter increases the complexity of the host structure, the difficulty of control, and the potential for failure, which is not conducive to the use of disposable cartridges with small host systems.

[0004] Furthermore, when multiple reservoirs are directly connected to the flow channel, the release sequence of different liquids is easily affected by the external pressure contact position, differences in reservoir deformation, and fluctuations in microchannel resistance. This leads to instability in the time and order in which the liquids arrive at the detection zone, thus affecting the consistency of the reaction and the stability of the detection results. Therefore, a cartridge-based combined drive fluid path is needed that can release multiple reservoirs in a predetermined order under a single external pressure contact, and that limits the sequential arrival of the liquids through a throttling channel and a capillary blocking structure. Summary of the Invention

[0005] The purpose of this invention is to provide a sequentially triggered liquid reservoir and throttling channel combined driving liquid circuit and its control method for a microfluidic fluorescence immunoassay cartridge, in order to solve the problems of unstable formation of multi-stage liquid circuit timing, complex external control structure and unstable release sequence of multiple liquid reservoirs under small host conditions.

[0006] To achieve the above objectives, the present invention provides a sequentially triggered liquid reservoir and throttling channel combined driving liquid path of a microfluidic fluorescence immunoassay cartridge, comprising a cartridge body, wherein the cartridge body is provided with a sample inlet, a first liquid reservoir, a second liquid reservoir, a trigger crimping part, a first release port, a second release port, a first throttling channel, a second throttling channel, a first capillary blocking part, a second capillary blocking part, a confluence node, a main liquid path, a detection zone, a waste liquid zone, and an anti-backflow structure.

[0007] The trigger crimping part has a first crimping interface and a second crimping interface. The first crimping interface forms a first crimping surface for correspondingly triggering the release of the first liquid reservoir, and the second crimping interface forms a second crimping surface for correspondingly triggering the release of the second liquid reservoir. The first liquid reservoir is connected to the confluence node through a first release port, a first throttling channel, and a first capillary blocking part. The second liquid reservoir is connected to the confluence node through a second release port, a second throttling channel, and a second capillary blocking part.

[0008] By making the trigger stroke between the first pressure port and the first reservoir bladder shorter than the trigger stroke between the second pressure port and the second reservoir bladder, or by making the release threshold of the first reservoir bladder lower than the release threshold of the second reservoir bladder, the first reservoir bladder releases first, followed by the second reservoir bladder, in a single external pressure-touch action. The first throttling channel, the second throttling channel, the first capillary blocking part, and the second capillary blocking part together define the order in which the two liquids arrive at the confluence node and the detection area, thereby forming a staged liquid path program inside the cartridge without increasing the multi-pump, multi-valve structure of the main unit.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: First, by using a stepped or threshold-differentiated triggering structure, a single external pressure action can generate multi-stage liquid reservoir release; Second, by combining a throttling channel and a capillary blocking section to limit the arrival sequence of the two liquids, the consistency of reaction propulsion and cleaning in microfluidic fluorescence immunoassay is improved; Third, by integrating the liquid path timing capability into a disposable cartridge, the number of pumps and valves on the host side and the control complexity can be reduced; Fourth, by setting an anti-backflow structure downstream of the confluence node, the impact of liquid backflow and out-of-order arrival on detection stability can be reduced. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention.

[0011] Figure 2 This is a simplified flow path diagram according to an embodiment of the present invention.

[0012] Figure 3 This is a flowchart of the control method according to an embodiment of the present invention. Detailed Implementation

[0013] The embodiments of the present invention will now be described with reference to the accompanying drawings. These embodiments are used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0014] like Figure 1 and Figure 2 As shown, this embodiment provides a sequentially triggered reservoir and throttling channel combined driving fluid circuit for a microfluidic fluorescence immunoassay cartridge. Wherein, Figure 1Used to indicate the core structural relationship between the reservoir, trigger crimp, release port, throttling channel, capillary blockage, manifold, and main fluid path within the cartridge; Figure 2 This is used to represent the simplified flow path relationship between the sample inlet, the two liquid confluence, the downstream backflow prevention, the detection zone, and the waste liquid zone. The cartridge body 1 is provided with a sample inlet 2, a first liquid reservoir 3, a second liquid reservoir 4, a trigger crimping part 5, a first crimping interface 6, a second crimping interface 7, a first release port 8, a second release port 9, a first throttling channel 10, a second throttling channel 11, a first capillary blocking part 12, a second capillary blocking part 13, a confluence node 14, a main liquid path 15, a detection zone 16, a waste liquid zone 17, and a backflow prevention structure 18.

[0015] Sample inlet 2 is used to receive liquid samples or sample eluent. A first reservoir 3 is connected to a first throttling channel 10 via a first release port 8, and a first capillary blocking section 12 is located downstream of the first throttling channel 10. A second reservoir 4 is connected to a second throttling channel 11 via a second release port 9, and a second capillary blocking section 13 is located downstream of the second throttling channel 11. The downstream ends of both the first capillary blocking section 12 and the second capillary blocking section 13 are connected to a confluence node 14, which is connected to the main liquid path 15 via an anti-backflow structure 18. A detection zone 16 and a waste liquid zone 17 are sequentially located downstream of the main liquid path 15.

[0016] The first reservoir 3 can be pre-encapsulated with sample elution solution, sample propulsion solution, or reaction initiation solution. The second reservoir 4 can be pre-encapsulated with background cleaning solution, enhancement solution, stop solution, or subsequent propulsion solution. By encapsulating different functional liquids in the first reservoir 3 and the second reservoir 4 respectively, the cartridge can form a liquid path sequence in a detection process, first propelling the sample, then performing supplementary propulsion or background treatment.

[0017] The trigger crimping part 5 is used to receive a single crimping action from the host or an external crimping mechanism. The trigger crimping part 5 has a first crimping interface 6 and a second crimping interface 7. The first crimping interface 6 forms a first crimping surface and corresponds to the release triggering path of the first liquid reservoir 3; the second crimping interface 7 forms a second crimping surface and corresponds to the release triggering path of the second liquid reservoir 4. The two differ in structural position, trigger stroke, or trigger threshold.

[0018] In one embodiment, the trigger crimping part 5 is a stepped crimping member, and the first crimping interface 6 and the second crimping interface 7 form a trigger stroke difference in the crimping direction, so that when the trigger crimping part 5 is subjected to a single external crimp, the first crimping interface 6 first triggers the release of the first liquid reservoir 3, and the second crimping interface 7 triggers the release of the second liquid reservoir 4 in the subsequent stroke.

[0019] In another embodiment, the first reservoir 3 and the second reservoir 4 have different release thresholds. These release thresholds can be determined by the elastic reservoir wall thickness, the strength of the ruptureable sealing membrane, the height of the compressible cavity, the elastic recovery force of the reservoir material, or a combination thereof. When the release threshold of the first reservoir 3 is lower than that of the second reservoir 4, even if the triggering pressing part 5 presses against both reservoirs in a single action, the first reservoir 3 can be released first, followed by the second reservoir 4.

[0020] The first throttling channel 10 and the second throttling channel 11 can have different lengths, widths, heights, number of bends, or cross-sectional areas to create different flow resistances. The first capillary blocking section 12 and the second capillary blocking section 13 can be a sudden expansion cavity, a hydrophobic blocking band, a stepped blocking surface, a necking section, or a combination thereof. By combining the throttling resistance and the capillary opening threshold, even if there are slight fluctuations in the release time of the two reservoirs, the order in which the two liquids arrive at the confluence node 14 and the detection zone 16 can be further defined.

[0021] The manifold 14 allows liquid released from the first reservoir 3 and the second reservoir 4 to enter the same main liquid path 15. An anti-backflow structure 18 is installed on the main liquid path 15 between the manifold 14 and the detection zone 16. The anti-backflow structure 18 can be a one-way valve, a narrow slit blocking section, a stepped backflow blocking section, or a hydrophilic / hydrophobic partition structure, used to prevent the later-released liquid from flowing back to the branch where the earlier-released liquid was located. The detection zone 16 may include at least one of a fluorescence immunoassay zone, an optical reading window, a reference zone, or a quality control zone. The waste liquid zone 17 is used to receive the liquid after detection.

[0022] Figure 1 The structural relationship between the first liquid reservoir 3, the second liquid reservoir 4, the trigger crimping part 5, the first crimping interface 6, the second crimping interface 7, the first release port 8, the second release port 9, the first throttling channel 10, the second throttling channel 11, the first capillary blocking part 12, the second capillary blocking part 13, the confluence node 14, and the main liquid path 15 is shown. Figure 2 The diagram shows a simplified flow path relationship where two liquids enter the confluence node 14 after passing through the first reservoir 3 and the second reservoir 4 via the throttling channel and the capillary blocking section, and then enter the detection zone 16 and the waste liquid zone 17 via the anti-backflow structure 18 and the main liquid path 15.

[0023] like Figure 3As shown, this embodiment also provides a liquid circuit control method, including the following steps: S1, inserting a cartridge; S2, applying a single pressure to the trigger crimping part 5; S3, triggering the release of the first liquid reservoir 3 by the first pressure interface 6; S4, triggering the release of the second liquid reservoir 4 by the second pressure interface 7; S5, using the first throttling channel 10, the second throttling channel 11, the first capillary blocking part 12, and the second capillary blocking part 13 to limit the sequential arrival of liquid; S6, allowing the liquid to enter the detection area 16 through the anti-backflow structure 18 and the main liquid circuit 15.

[0024] The above structure and method integrate a multi-stage liquid path program into a disposable microfluidic fluorescence immunoassay cartridge by combining the differences in trigger stroke, release threshold, throttling resistance, and capillary opening threshold of the reservoir. This allows the host device to achieve sequential release and sequential liquid loading with only a single press-touch action. Equivalent substitutions or modifications made to the above structural forms, materials, dimensions, liquid types, and combinations without departing from the inventive concept should be included within the scope of protection of this invention.

Claims

1. A sequentially triggered liquid reservoir and throttling channel combined driving fluid path of a microfluidic fluorescence immunoassay cartridge, comprising a cartridge body, the cartridge body having a sample inlet, a first liquid reservoir, a second liquid reservoir, a trigger crimping part, a first release port, a second release port, a first throttling channel, a second throttling channel, a first capillary blocking part, a second capillary blocking part, a confluence node, a main fluid path, a detection zone, a waste liquid zone, and an anti-backflow structure; the trigger crimping part has a first crimping interface and a second crimping interface, the first crimping interface forming a first crimping surface for correspondingly triggering the release of the first liquid reservoir, and the second crimping interface forming a second crimping surface for correspondingly triggering the release of the second liquid reservoir; the first liquid reservoir is connected to the confluence node through the first release port, the first throttling channel, and the first capillary blocking part. The second reservoir is connected to the confluence node via the second release port, the second throttling channel, and the second capillary blocking part. The confluence node is connected to the main liquid path via the anti-backflow structure. The downstream of the main liquid path is connected to the detection area and the waste liquid area in sequence. The trigger stroke between the first pressure port and the first reservoir is less than the trigger stroke between the second pressure port and the second reservoir, or the release threshold of the first reservoir is lower than the release threshold of the second reservoir, so that the first reservoir releases before the second reservoir in a single external pressure action. The first throttling channel, the second throttling channel, the first capillary blocking part, and the second capillary blocking part together limit the order in which the liquid released from the first reservoir and the liquid released from the second reservoir reach the confluence node and the detection area.

2. The sequentially triggered liquid reservoir and throttling channel combined driving fluid circuit according to claim 1, characterized in that, The first reservoir contains pre-packaged sample elution fluid, sample propulsion fluid, or reaction initiation fluid, while the second reservoir contains pre-packaged background cleaning fluid, enhancement fluid, termination fluid, or subsequent propulsion fluid.

3. The sequentially triggered liquid reservoir and throttling channel combined driving fluid circuit according to claim 1, characterized in that, The first and second reservoirs each include an elastic reservoir wall, a ruptureable membrane, a compressible cavity, or a combination thereof, and the two differ in at least one of the following: reservoir wall thickness, rupture pressure, compression height, or elastic recovery force.

4. The sequentially triggered liquid reservoir and throttling channel combined driving fluid circuit according to claim 1, characterized in that, The triggering crimping part is a stepped crimping part. The first crimping interface and the second crimping interface form a trigger stroke difference in the crimping direction, so that when the triggering crimping part is subjected to a single external crimp, the first reservoir is triggered to release first, and then the second reservoir is triggered to release.

5. The sequentially triggered liquid reservoir and throttling channel combined driving fluid circuit according to claim 1, characterized in that, The first and second throttling channels have different lengths, widths, heights, number of bends, or cross-sectional areas to create different fluid flow resistances.

6. The sequentially triggered liquid reservoir and throttling channel combined driving fluid circuit according to claim 1, characterized in that, The first capillary blocking part and the second capillary blocking part respectively include a protruding cavity, a hydrophobic blocking band, a stepped blocking surface, a constricted segment or a combination thereof, and the capillary opening thresholds of the two are different.

7. The sequentially triggered liquid reservoir and throttling channel combined driving fluid circuit according to claim 1, characterized in that, The anti-backflow structure is installed on the main liquid path between the confluence node and the detection area to prevent the liquid released from the second reservoir from flowing back to the first throttling channel or the first reservoir through the confluence node.

8. The sequentially triggered liquid reservoir and throttling channel combined driving fluid circuit according to claim 1, characterized in that, The detection zone includes at least one of a reaction zone, a reading window, a reference zone, or a quality control zone. A liquid suction device is provided in the waste liquid zone, which is used to draw the liquid through the detection zone toward the waste liquid zone and seal the liquid.

9. The sequentially triggered liquid reservoir and throttling channel combined driving fluid circuit according to claim 1, characterized in that, The first reservoir, the trigger crimping part, and the second reservoir are arranged in sequence along the vertical direction. The first throttling channel and the first capillary blocking part are located on the upper branch, and the second throttling channel and the second capillary blocking part are located on the lower branch. The upper branch and the lower branch converge at the confluence node.

10. A method for controlling a liquid circuit using a sequentially triggered reservoir and a throttling channel jointly driven by any one of claims 1 to 9, characterized in that, include: S1, Insert the cartridge: Insert the microfluidic fluorescence immunoassay cartridge into the host or the pressure contact mechanism; S2, Apply a single external pressure contact to the trigger pressure point; S3, The first pressure interface triggers the release of the first reservoir, allowing the liquid in the first reservoir to enter the confluence node through the first release port, the first throttling channel, and the first capillary blocking part, and propel the sample or preceding liquid towards the detection area; S4, The second pressure interface triggers the release of the second reservoir, allowing the liquid in the second reservoir to enter the confluence node through the second release port, the second throttling channel, and the second capillary blocking part; S5, The first throttling channel, the second throttling channel, the first capillary blocking part, and the second capillary blocking part limit the sequential arrival of the two liquid streams; S6 allows the liquid to enter the detection area through the anti-backflow structure and the main liquid path.

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