A diagnostic device and diagnostic apparatus suitable for oral samples as well as blood or plasma samples

Abstract

The utility model belongs to but is not limited to human health diagnostics technical field, disclose a kind of diagnostic equipment suitable for oral cavity sample and blood or plasma sample;Including by equipment test strip and equipment box, the lower part of equipment box is fixed test strip, and clamps with the upper part of device box, so that test strip is clamped in device middle;The first end of test strip is sequentially provided with sample application gasket, reagent mixing pad, and test strip end is provided with water absorption pad;Test strip reagent mixing pad and water absorption pad are sequentially provided with test line, control line between them;The test line is composed of antibody or antigen, and the control line is composed of antibody for the antigen found in human plasma. The utility model is suitable for oral cavity sample and blood sample for immediate detection (POC) test, and with internal control device, to ensure that the collection mode of oral cavity sample can optimize test result.

Description

Technical Field

[0001] This utility model belongs to, but is not limited to, the field of human health diagnostics technology, and particularly relates to a diagnostic device and immunochromatographic diagnostic apparatus suitable for oral samples and blood or plasma samples. Background Technology

[0002] Point-of-care (POC) diagnostic reagents are crucial products for human health and well-being. Polymerase chain reaction (PCR) and isothermal amplification methods, used to detect pathogen nucleic acids (DNA and / or RNA), are considered the "gold standard" for microbial detection because they significantly amplify the detection signal. However, POC nucleic acid tests typically require sophisticated instruments and complex extraction methods to remove interfering substances from clinical samples, especially whole blood. Hemoglobin (the main protein component of red blood cells) is particularly effective at inhibiting nucleic acid testing. Therefore, POC nucleic acid tests have not been widely adopted due to their cost and complexity.

[0003] Lateral flow immunochromatography (LFA) is the most common point-of-care (POC) assay, which is well-suited for detecting antibodies (such as anti-syphilis IgA antibodies, anti-hepatitis B surface antigen (HBsAg) antibodies, or anti-hepatitis B core antigen (HBcAg) antibodies) or protein antigens (such as HBsAg, SARS-CoV-2 nucleoprotein). It can also be used to detect disease-related host protein biomarkers, such as elevated levels of alanine aminotransferase 1 (ALT1), a biomarker for liver disease.

[0004] The closest prior art is US patent application US20040184954A1, which discloses a lateral flow immunoassay device for real-time detection of liquid samples such as saliva. This device sequentially places a colloidal gold-binding pad, a nitrocellulose membrane test line, and a control line behind the sample pad, and uses the standard lateral chromatography principle to perform colorimetric interpretation.

[0005] However, the device still has two technical problems: First, the design is only suitable for low-viscosity oral fluids, lacks a blood cell-plasma separation layer, cannot directly process whole blood samples, and is difficult to cover the needs of oral samples and blood / plasma testing in a single strip; Second, it only provides a traditional control line and does not integrate a sample sufficiency or albumin loss detection line with human serum albumin as an abundant endogenous marker, which cannot determine the injection volume and matrix quality in real time, and is prone to false negatives or invalid results. Utility Model Content

[0006] To address the problems existing in the prior art, this invention provides a diagnostic device suitable for oral samples and blood or plasma samples; it is suitable for point-of-care (POC) testing of both oral and blood samples, and has a built-in control mechanism to ensure that the oral sample contains sufficient equivalent plasma proteins, thereby obtaining effective test results.

[0007] This invention is implemented as follows: a diagnostic device suitable for oral samples and blood or plasma samples, including a device test strip and a device box, wherein the lower part of the device box fixes the test strip and clamps it with the upper part of the device box, so that the test strip is clamped in the middle of the device. The test strip has a sample application pad and an optional reagent mixing pad at the beginning, and an absorbent pad at the end. A test line and a control line are arranged between the reagent mixing pad and the absorbent pad. The test line is composed of an antibody or an antigen, and the antigen can be replaced by a receptor or a non-antibody binding reagent, such as a nanobody or an aptamer. The control line is composed of an antibody against an antigen found in human plasma.

[0008] Furthermore, an observation window is provided on the upper part of the device box, which can be opened or is equipped with an optional transparent film cover.

[0009] Furthermore, the upper end of the device box is provided with a sampling and buffer solution application port and a spare sample and buffer solution application port; the sampling and buffer solution application port is located above the reagent mixing pad, and the spare sample and buffer solution application port is located above the sample application pad.

[0010] Another objective of this utility model is to provide a multi-source body fluid sample immunochromatographic diagnostic device, including a device test strip and a device box. The lower part of the device box fixes the test strip and clamps it with the upper part of the device box, so that the test strip is clamped in the middle of the device. The test strip has a sample application pad and an optional reagent mixing pad at the beginning, and an absorbent pad at the end. Between the reagent mixing pad and the absorbent pad are a test line, a depletion control line, and a control test line. The test line is composed of antibodies or antigens, the depletion control line is composed of antibodies against antigens found in human plasma or human respiratory epithelial cells, and the control test line is composed of antibodies against exogenous antigens or antigens in human respiratory epithelial cells. This is used to determine the sufficiency of plasma or respiratory epithelial cells (swab samples) and can be used to determine in real time whether the sample volume and matrix quality are sufficient to avoid false negatives or invalid results.

[0011] Furthermore, an observation window is provided on the upper part of the device box, which can be opened or is equipped with an optional transparent film cover.

[0012] Furthermore, a solid opaque structure is provided on the observation window to conceal or hide the exhaustion control line.

[0013] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this utility model are as follows: This invention provides a diagnostic device suitable for oral samples and blood or plasma samples, applicable to point-of-care (POC) testing of both oral and blood samples, and equipped with an internal control device to ensure that the oral sample collection method optimizes the test results.

[0014] The advantages and benefits of this invention lie in its ability to design a single point-of-care (POC) test (or sample preparation device) that alternates between two main clinical sample types (antibodies and antigens of blood-borne biomarkers)—whole blood / plasma or oral fluid (e.g., saliva or gingival crevicular fluid)—while incorporating procedural controls to ensure sufficient plasma-equivalent proteins for valid results, should a significantly varying oral fluid sample type be used. This is particularly useful for point-of-care tests intended for home use or by undertrained healthcare workers, as some individuals may prefer oral fluid samples over finger-prick or venous whole blood samples.

[0015] First, the rigid limiting and snap-fit ​​structure of the sandwich-type upper and lower boxes ensures that the test strip remains flat and warp-free throughout the transportation, operation and reading process, significantly reducing the risk of micro-cracks and signal delays caused by compression, which is common with traditional bare chips or soft-shell packaging. The upper shell also integrates a flip-up observation window and a shielding plate, which is convenient for visual interpretation and also supports connection to a portable reader. The two modes can be seamlessly switched, thus catering to both home self-testing and professional testing scenarios.

[0016] Secondly, the sample application pad and reagent mixing pad are connected in series and the housing provides a dual-path design of "main inlet + backup inlet": the sample and buffer solution are mixed in the optional mixing pad and enter the membrane surface with the dry powder label, which greatly shortens the color development time; when the blood viscosity is abnormal, the sample volume is insufficient, or the test reagent needs to be used separately, the backup inlet can be used for secondary replenishment, avoiding the waste caused by the interruption of flow due to the traditional single inlet tape, and significantly improving the success rate of disposable consumables.

[0017] Finally, the test line, control line, and newly added depletion control line constitute a "triple quality control" system, which can simultaneously provide results on reaction validity, sample volume adequacy, and target detection within the same observation window. If the sample is insufficient, the detection tag will preferentially deposit at the depletion control line and be hidden by the shielding plate to avoid operator misjudgment. This redundant safety mechanism significantly improves the reliability of on-site testing and enhances the ability to identify false negatives. Attached Figure Description

[0018] Figure 1This is a schematic diagram of the three-dimensional structure of a test strip made of nitrocellulose membrane or similar material provided in an embodiment of this utility model; Figure 2 This is a schematic diagram of a diagnostic device for detecting target substances in oral samples and blood or plasma samples, provided by an embodiment of the present invention; Figure 3 This is a schematic diagram of a three-dimensional structure of a test strip made of nitrocellulose membrane or similar material, provided in an embodiment of this utility model. Figure 4 This is a schematic diagram of another diagnostic device for detecting target substances in oral samples and blood or plasma samples provided by an embodiment of the present invention; Figure 5 This is a schematic diagram of a diagnostic component for detecting target substances in oral samples and blood or plasma samples, provided by an embodiment of the present invention; Figure 6 This is a schematic diagram of another diagnostic component for detecting target substances in oral samples and blood or plasma samples provided by an embodiment of the present invention; Figure 7 This is a schematic diagram showing representative results of the preferred test method for detecting HIV antibodies provided in this embodiment of the utility model; Figure 8 This is a schematic diagram of the C-type dual-pass detection provided in an embodiment of the present invention; In the diagram: 1. Plastic backing; 2. Sample application pad; 3. Reagent mixing pad; 4. Equipment test strip; 5. Absorbent pad; 6. Test line; 7. Control line; 8. Equipment box; 9. Observation window; 10. Sampling and buffer solution loading wells; 11. Spare sample and buffer solution loading wells; 12. Depletion control line; 13. Control line; 14. Solid opaque structure; 15. Lower part of the equipment box. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.

[0020] For point-of-care testing (POC) of any specific biomarker found in plasma (such as hepatitis B surface antigen, hepatitis B surface antibody, hepatitis B core antibody, HIV antibody, and hepatitis C antibody), whole blood / plasma samples may be more sensitive than oral fluid samples. However, it is generally believed that even with lower POC sensitivity, the wider acceptance and use of oral fluid home testing leads to more successful diagnostic tests (total diagnostics). In contrast, even with higher POC sensitivity, whole blood testing has a narrower range of applications. By having a single test that can be used with both whole blood and oral fluid, end-users can always choose the most appropriate test in their specific context, thereby maximizing overall diagnostics.

[0021] This embodiment of the invention provides a diagnostic device consisting of a compact sandwich structure formed by the lower part 15 of the device box and the upper part of the device box holding the test strip 4. Positioning ribs and limiting grooves are provided on the inner wall of the lower part 15 of the device box to ensure precise alignment of the test strip 4 in the head-to-tail direction. The upper part of the device box is snapped into place with the lower part, forming a stable support and ensuring uniform force on the test strip. A sample application pad 2 is located below the sample and buffer solution application port 11, and an absorbent pad 5 is embedded in the end drainage cavity, forming a continuous unidirectional capillary channel.

[0022] Test strip 4 uses a nitrocellulose membrane as a base, and from the first end, the sample application pad 2, reagent mixing pad 3, membrane support area, and absorbent pad 5 are stacked in sequence. Each layer is fixed to the sides with medical double-sided adhesive or ultrasonic heat pressing. The membrane support area can be sprayed with test lines 6 and control lines 7 at predetermined coordinates, or sprayed with test lines 6, depletion control lines 12, and control test lines 13, maintaining equal spacing to ensure clear imaging of the flow sequence and no interference between them.

[0023] The upper housing features two independent flow path interfaces: the sampling and buffer solution loading port 10 directly connects to the reagent mixing pad 3, enabling instant mixing of the sample, buffer solution, and label; the spare sample / buffer solution loading port 11 connects to the sample application pad 2 for adding sample or diluent. Both ports are equipped with a liquid-guiding flare and a leak-proof ring, ensuring accurate placement of droplets into the corresponding pads during multi-angle sample addition, preventing overflow.

[0024] After sample addition, the detergent in reagent mixing pad 3 dissolves with the dry powder detection label, and the suspension moves forward along the membrane-supported area under capillary force: upon reaching test line 6, the detection complex is captured by the target antigen and develops color; continuing to control line 7, the remaining label-antibody is captured by anti-human plasma antibody to generate a second signal; if the sample is insufficient, the "A" label from sample application pad 2 preferentially deposits at depletion control line 12, indicating operation failure. All free liquid is eventually absorbed by absorbent pad 5 to prevent backflow.

[0025] The observation window 9 is located in the center of the top of the equipment box and can be flipped up or covered with a transparent film for visual inspection or reading instrument inspection. A solid opaque structure 14 is added to the observation window 9 to cover the exhaust control line 12 as needed, exposing only the test line 6 and the control test line 3. The entire inspection process is completed within 5-30 minutes. The complete set of structures is precisely positioned and the flow path is stable, ensuring batch-to-batch consistency and reliable results.

[0026] like Figure 1 As shown, this utility model embodiment provides a diagnostic device suitable for oral samples and blood or plasma samples, including a device test strip and a device box. The lower part of the device box fixes the test strip and clamps it with the upper part of the device box, so that the test strip is clamped in the middle of the device. The test strip has a sample application pad and an optional reagent mixing pad at the beginning, and an absorbent pad at the end. A test line and a control line are arranged between the reagent mixing pad and the absorbent pad. The test line is composed of antibodies or antigens, and the control line is composed of antibodies against antigens found in human plasma.

[0027] A plastic backing 1 for assembling different components of the test strip is provided on the equipment test strip 4; One end of the device test strip 4 is provided with a sample application pad 2 and a reagent mixing pad 3. The sample application pad 2 optionally contains reagents and / or filter materials for selectively retaining red blood cells and / or white blood cells from whole blood or other samples, and optionally contains a detection label (e.g., colloidal gold labeled with human albumin) for manual detection control reagents. The reagent mixing pad 3 optionally contains detergents or other additives that are incorporated into the test sample as it flows along the device. Detection labels(s) are optionally added here instead of in the sample application pad 2.

[0028] An absorbent pad 5 is placed at the other end of the test strip 4 to ensure that the buffer solution and sample flow completely along the test strip and to prevent backflow after the test is completed.

[0029] Test line 6 consists of an antibody (or antigen) or other analyte of interest, such as a receptor, a non-antibody binding agent, like a nanobody or aptamer; it is applied to the device test strip to provide the results of a diagnostic test. For example, an anti-XYZ antibody is used in a test to detect the XYZ antigen.

[0030] Control line 7, consisting of antibodies against antigens found in human plasma (such as anti-human serum albumin), is applied to the device test strip to provide a control result indicating the presence of sufficient plasma or whole blood, or an equivalent plasma volume from a saliva, oral, or nasal swab sample, in the test sample. Note that the flow direction of the analytical sample and reagents is indicated by arrows.

[0031] Control line 7 can serve as a control line composed of antibodies against a certain antigen found in human plasma. Anti-human serum albumin is applied to the test strip of the device to provide a control result indicating that there is sufficient plasma or whole blood or an equivalent volume of plasma in a saliva, oral or nasal swab sample in the test sample.

[0032] like Figure 2 As shown, the top of the device box 8 provides a secure assembly for the safe and correct operation of the test strips. The upper part of the device box typically contains the following components: a viewing window 9 (openable, or with an optional transparent film cover) to allow for visual or instrumental analysis and control of test results. The test line 6 and control line 7 are visible through this window.

[0033] The device housing 8 has sampling and buffer loading wells 10 and spare sample and buffer loading wells 11 at corresponding positions on the sample application pad 2 and reagent mixing pad 3. Sampling and buffer loading wells 10 allow for direct addition of samples and / or buffers to the reagent mixing pad portion of the device. Spare sample and buffer loading wells 11 allow for direct addition of samples and / or buffers to the sample pad portion of the device (note that in some examples only one sample / buffer loading well may be required). Note that the flow direction of the analytical samples and reagents is indicated by arrows.

[0034] like Figure 3 As shown, this utility model embodiment provides a diagnostic device suitable for oral samples and blood or plasma samples, including a device test strip and a device box. The lower part of the device box fixes the test strip and clamps it with the upper part of the device box, so that the test strip is clamped in the middle of the device. The test strip has a sample application pad and a reagent mixing pad arranged sequentially at the beginning, and an absorbent pad arranged at the end. Between the reagent mixing pad and the absorbent pad, there is a test line, a depletion control line, and a control test line arranged sequentially. The test line is composed of antibodies or antigens, the depletion control line is composed of antibodies against antigens found in human plasma, and the control test line is composed of antibodies against foreign antigens.

[0035] A plastic backing 1 for assembling different components of the test strip is provided on the equipment test strip 4; One end of the device test strip 4 is provided with a sample application pad 2 and a reagent mixing pad 3. The sample application pad 2 optionally contains reagents and / or filter materials for selectively retaining red blood cells and / or white blood cells from whole blood or other samples, and optionally contains a test label (e.g., colloidal gold labeled with a mixture of human albumin and chicken IgY) for detecting control reagents. The reagent mixing pad 3 optionally contains detergents or other additives that are incorporated into the test sample as it flows along the device. The test labels(s) are optionally added here, rather than in the sample application pad 2.

[0036] An absorbent pad 5 is placed at the other end of the test strip 4 to ensure that the buffer solution and sample flow completely along the test strip and to prevent backflow after the test is completed.

[0037] Test line 6 consists of an antibody (or antigen) or other analyte of interest, applied to the device test strip to provide the result of a diagnostic test. For example, an anti-XYZ antibody is used in a test to detect the XYZ antigen. Control line 7 consists of an antibody against an antigen found in human plasma, applied to the device test strip to provide a control result indicating the presence of sufficient plasma or whole blood, or an equivalent amount of plasma from a saliva, oral, or nasal swab sample, in the test sample.

[0038] The depletion control line 12 consists of an antibody against an antigen found in human plasma (such as anti-human albumin), applied to the device test strip to provide a control result indicating the presence of sufficient plasma or whole blood, or an equivalent volume of plasma from a saliva, oral, or nasal swab sample, in the test sample. If the sample volume is insufficient, the colloidal gold albumin + chicken IgY tag from the sample application pad 2 will bind to this depletion test line 12 and will not bind to the control test line 13.

[0039] The control test line 13 can be used as a control line for antibodies against foreign antigens (such as chicken IgY) and applied to the device test strip to provide a control result indicating that there is sufficient plasma or whole blood or an equivalent volume of plasma in the test sample, such as saliva, oral or nasal swab samples.

[0040] like Figure 4 As shown, the top of the device box 8 provides a secure assembly for the safe and correct operation of the test strips. The upper part of the device box typically contains the following components: a viewing window 9 (openable, or with an optional transparent film cover) to allow for visual or instrumental analysis of test results and control. The test lines 6 and control test lines 13 are visible through this window.

[0041] The device box 8 has sampling and buffer loading wells 10 and spare sample and buffer loading wells 11 at corresponding positions on the sample application pad 2 and reagent mixing pad 3. The sampling and buffer loading wells 10 are for adding samples and / or buffer directly to the reagent mixing pad portion of the device. The spare sample and buffer loading wells 11 are for adding samples and / or buffer directly to the sample pad portion of the device (note that in some examples only one sample / buffer loading well may be required).

[0042] A control line consisting of antibodies against foreign antigens (such as chicken IgY) is applied to the device test strip to provide control results, indicating that there is a sufficient volume of plasma or whole blood or an equivalent volume of plasma from saliva, oral, or nasal swab samples in the test sample.

[0043] An optional solid opaque structure 14 may be integrated into the top portion of the device housing or used as a feature applied to the test strip to obscure or conceal the results of the depletion control line 12. Note that the flow direction of the analytical sample and reagents is indicated by arrows.

[0044] The test sample is dripped into the sampling and buffer solution well 10. The test sample flows along the device, and the substance in the reagent mixing pad 3 will be incorporated into it. The sample continues to flow along the device. The results of the diagnostic test provided by the test line and the control results provided by the control line can be seen through the observation window 9 of the device box.

[0045] This embodiment of the integrated sampling-pretreatment device uses an open-pore high-density porous cellulose membrane as its core. It loads IgG or IgM antibodies that specifically recognize human erythrocyte glycoprotein A antigen via a non-covalent binding method (drying treatment). Utilizing the rehydration and multivalent properties of the antibodies, a self-aggregation reaction is initiated within seconds of adding the liquid sample. After being captured, erythrocytes form a through-cell microplastic, and the plasma they carry permeates through the membrane under lateral capillary force, minimizing cell membrane rupture and thus reducing downstream chromatographic channel blockage and background scattering signals from the source.

[0046] Plasma permeating through the filter membrane carries the target low-abundance protein and endogenous high-abundance albumin, then flows into a finely constructed three-line detection zone. The innermost layer contains a small-molecule capture zone with an anti-human albumin affinity peptide, providing the first quality control zone for result interpretation. Subsequent detection lines are immobilized with monoclonal or polyclonal capture antibodies or other binding reagents and signal amplification complexes (gold-labeled / fluorescent microspheres optional), enabling quantitative or qualitative identification of the target through immune sandwich or competitive modes.

[0047] To overcome the random influence of external temperature, humidity, and sample differences on chromatography speed, this system incorporates a dual-validation quality control line at the end of the detection zone. Firstly, the constant binding of the goat anti-mouse secondary antibody to the labeled probe reflects whether chromatography has proceeded throughout the entire process. Secondly, a residual albumin capture band is reserved downstream of the anti-albumin loss zone. When sample processing is insufficient or the protein concentration falls below the threshold, this band immediately develops color, alerting the operator to resample and preventing false negative results from entering the decision-making process.

[0048] The reading process employs an integrated miniature spectral sensor array, utilizing multi-point sampling and time-resolved algorithms to correct for membrane surface non-uniformity, outputting semi-quantitative concentration values ​​after R-logit conversion. The quantitative assessment module incorporates dynamic calibration curves based on multi-source data, automatically switching the judgment window according to the baseline levels of different populations, ensuring consistent and comparable results across diverse application scenarios such as vaccine response monitoring, chronic disease management, and drug efficacy tracking.

[0049] The entire system significantly shortens the manual intervention chain in sample pretreatment during industrial implementation, reduces reliance on dedicated centrifugation, cold chain, and high-precision pipetting equipment, and enables mixed oral and fingertip screening to be implemented in primary healthcare settings, remote mobile clinics, and even home environments. Its working mechanism balances the engineering feasibility and theoretical rigor of high-throughput testing, providing a replicable technological paradigm for the in vitro diagnostics industry under the trends of decentralization and multi-fluid fusion.

[0050] Figure 7 This paper demonstrates a preferred testing method for detecting HIV antibodies. In this example, the test strip uses a double-antigen sandwich format. The HIV antigen is fixed on the test strip, and the same HIV antigen binds to colloidal gold. When any HIV antibody of any antibody isotype (IgG, IgM, IgA, etc.) is present, the antigen on the test strip and the gold-labeled antigen form a cross-link through bivalent binding in the antibody variable region, resulting in a positive line. It should be noted that if the subject has a high antibody level, a positive result may be obtained even if the plasma volume is low. A positive test result combined with a weak control line result can still be considered a valid test result. However, if the control line result is too weak, a negative test result may be considered invalid according to internal or external reference standards.

[0051] It is worth noting that the same method of controlling the amount of plasma equivalent in the sample can be used for testing specifically for oral fluid samples, testing specifically for blood or plasma samples, and testing that can be used for blood or plasma samples. For example, there are currently HIV antibody tests and HCV antibody tests on the market specifically for oral fluid samples. All of these tests can be improved by using the control line method described in the embodiments of this invention to control the amount of plasma equivalent in the oral fluid sample used for testing.

[0052] Current oral liquid antibody tests (such as OraQuick HIV or OraQuick HCV) typically involve collecting liquid directly from the mouth onto absorbent collection filter paper integrated into the test strip device. The device is then placed in a test tube containing buffer solution, and the sample is carried into the test device via capillary action. However, many users, especially those who perform home testing, may feel uncomfortable placing part of the test device in their mouth.

[0053] The experience of widespread use of the COVID-19 lateral rapid antigen test kit by patients worldwide has provided an idea for another solution, namely (1) collecting gingival crevicular fluid using optimized swabs (which can be determined experimentally, for example by comparing the amount of IgG or albumin collected by existing and new swabs), and (2) extracting the swab in a buffer tube and then applying the extracted sample to the test device without adding buffer (the operation is exactly the same as the COVID-19 rapid antigen test kit).

[0054] This method leverages consumer experience and acceptance of rapid antigen testing for COVID-19 and simplifies the integration of testing blood and oral fluid samples within the same testing device. For example, in Figure 7 In the example shown, the sample that can be added to the sample well at the bottom of the device can be whole blood or plasma sample with an appropriate amount of buffer solution, or it can be an oral swab sample extracted into buffer solution and then added to the same sample well. The control test line ensures that enough plasma equivalent is used to obtain valid test results.

[0055] Figure 7 middle: A: Schematic diagram of a lateral flow test with a detection system (HIV antigen), a loss system, and a control system. B: Example results of high, normal, or low plasma equivalent in samples and positive HIV antibody results. C: The cartridge design obscures exhaustion line results, as well as the example results shown in B but within the cartridge. A low plasma equivalent for an HIV-positive result may be considered valid, but an HIV-negative result will be considered invalid due to insufficient plasma sample. This is particularly advantageous for tests that aim to detect multiple analytes simultaneously in a single testing device, such as combined HIV / syphilis antibody testing. Figure 8 The Chembio dual-pathway syphilis assay shown detects two different analytes (a Treponema pallidum-specific antibody and an antibody against the synthetic RPR). In some side-flow point-of-care testing devices, especially when detecting multiple analytes, the sample is added to a sample well outside the device's end (e.g., ...). Figure 8 The Chembio dual-channel test shown includes a syphilis screening / confirmatory test, or a Chembio dual HIV / syphilis test. It is also conceivable that the test sample could be placed in the middle of the device, with blood / plasma flowing in both directions and reacting in two separate test reaction zones.

[0056] Clearly, due to the location of the sample well, neither the Chembio device nor this bidirectional device can be directly used for oral fluid sampling. However, by using (i) the swab and extraction method for collecting gingival crevicular fluid, and (i) the novel plasma control line method described above, dual detection methods for detecting combinations such as HIV and syphilis, HIV and syphilis and hepatitis B virus, or multiple hepatitis B virus biomarkers (HBsAg, anti-HBsAg, anti-HBcAg) can be designed for blood / plasma or oral fluid samples in the same testing device. Figure 8 A schematic diagram is shown, illustrating a test applicable to blood, plasma, or oral fluid samples, employing the aforementioned design features.

[0057] Example 1: Instantaneous Oral Swab Sample Testing Device The diagnostic device of this embodiment includes a device housing 8 and a test strip 4 installed in the lower part 15 of the device housing. The test strip 4 has a sample application pad 2 and a reagent mixing pad 3 sequentially arranged at its first end, and an absorbent pad 5 arranged at its second end. A test line 6 and a control line 7 are sequentially arranged between the reagent mixing pad 3 and the absorbent pad 5. Monoclonal antibodies for detecting specific viral antigens are fixed on the test line 6, and antibodies that specifically bind to common antigens in human plasma are fixed on the control line 7, used to determine the effectiveness of the detection reaction process. An openable observation window 9 is provided at the top of the device housing 8 for observing the color development of the test line 6 and the control line 7.

[0058] During testing, the operator immerses the oral swab in buffer solution to extract the collected secretions. The extracted buffer solution is then dropped 10 drops through the sampling and buffer loading well onto the reagent mixing pad 3. The sample flows along the device's test strip 4 under capillary action, passing sequentially through the test line 6 and control line 7. If the target antigen is present in the sample, test line 6 and control line 7 both develop color, indicating that the testing process is effective. This embodiment is suitable for rapid oral screening of respiratory viruses and rapid oral screening of antigens or antibodies against infectious pathogens (e.g., viruses, bacteria, or fungi).

[0059] Example 2: Rapid Whole Blood Infection Detection Device The diagnostic device of this embodiment includes a device housing 8 and a device test strip 4 fixed to the lower part 15 of the device housing. The upper part of the device housing 8 has sampling and buffer solution application ports 10 and spare sample and buffer solution application ports 11. The application ports 10 are located above the reagent mixing pad 3, and the application ports 11 are located above the sample application pad 2, facilitating repeat or control testing. The device test strip 4 sequentially includes the sample application pad 2, the reagent mixing pad 3, and the absorbent pad 5. A test line 6, a depletion control line 12, and a control line 13 are sequentially arranged in the middle area. The test line 6 is immobilized with a monoclonal antibody that recognizes bacterial toxins. The depletion control line 12 is immobilized with an antibody that can bind to natural antigens in human plasma to determine whether the sample has sufficiently passed through. The control line 13 is immobilized with an antibody against an external standard antigen to verify the reliability of the detection system.

[0060] In use, a whole blood sample collected from a fingertip is dripped into the sampling and buffer solution loading well 10. The plasma is mixed with the buffer solution via the reagent mixing pad 3 and then migrates along the test strip 4. If the target toxin antigen is detected, the test line 6 will show color. The depletion control line 12 shows color, indicating sufficient sample flow, and the control line 13 shows color, indicating that the system is functioning normally. This device has a compact structure and is suitable for primary healthcare or rapid on-site blood infection monitoring.

[0061] Example 3: Plasma Multiplex Immunoscreening Device The diagnostic device in this embodiment consists of a device housing 8 and a test strip 4 fixed to the lower part 15 of the device housing. The test strip 4 has a sample application pad 2 and a reagent mixing pad 3 sequentially arranged at its first end, and an absorbent pad 5 at its second end. Multiple parallel test lines 6 and a control line 7 are sequentially arranged between the reagent mixing pad 3 and the absorbent pad 5. The test lines 6 are respectively fixed with monoclonal antibodies (or other binding reagents) targeting different disease-related antigens, enabling simultaneous multi-item detection. The control line 7 is used to verify the effectiveness of the reaction system. The upper part of the device housing 8 has an openable observation window 9 covered with a transparent film cover, facilitating visual reading of the color development of the multiple test lines 6 and the control line 7.

[0062] During testing, the plasma sample is mixed with buffer solution and then added to the test strip 4 through the sampling and buffer solution application well 10. If the corresponding target antigen is present when the liquid flows along the capillary direction, the corresponding test line 6 will show color; the control line 7 will remain colored if the test is normal. This device is suitable for blood banks and hospitals to perform rapid multi-indicator screening of plasma, and can complete the simultaneous detection of multiple indicators within minutes, improving testing efficiency and safety.

[0063] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship 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. In addition, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0064] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any modifications, equivalent substitutions and improvements made by those skilled in the art within the technical scope disclosed in this utility model, and within the spirit and principles of this utility model, should be included within the protection scope of this utility model.

Claims

1. A diagnostic device suitable for oral samples as well as blood or plasma samples, characterized in that, The device includes a test strip and a device box. The test strip is fixed to the lower part of the device box and clamps the test strip in conjunction with the upper part of the device box. The test strip has a sample application pad and an optional reagent mixing pad at its first end and an absorbent pad at its second end. A test line and a control line are arranged between the reagent mixing pad and the absorbent pad. The test line is formed by an antibody or an antigen, and the control line is formed by an antibody against an antigen in human plasma.

2. The diagnostic device according to claim 1, characterized in that, The upper part of the equipment box is equipped with an observation window, which can be opened or is covered with a transparent film.

3. The diagnostic device of claim 1, wherein, The upper end of the device box has sampling and buffer solution application ports as well as spare sample and buffer solution application ports. The sampling and buffer solution application ports are located above the reagent mixing pad, and the spare sample and buffer solution application ports are located above the sample application pad.

4. A diagnostic device suitable for oral samples as well as blood or plasma samples, characterized in that, The device includes a test strip and a box. The test strip is fixed to the lower part of the box and clamps the test strip in conjunction with the upper part of the box. The test strip has a sample application pad and a reagent mixing pad at its first end and an absorbent pad at its last end. A test line, a depletion control line and a control test line are arranged between the reagent mixing pad and the absorbent pad.

5. The diagnostic device of claim 4, wherein, The upper part of the equipment box is equipped with an observation window, which can be opened or is covered with a transparent film.

6. The diagnostic device of claim 4, wherein, The observation window has a solid opaque structure located directly above the depletion control line.

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