Optical detection device and portable fluorescence immunoassay analyzer

Abstract

The utility model discloses an optical detection device and a portable fluorescence immunoassay analyzer, and the optical detection device comprises a light source assembly which is used for providing an incident light beam; the first optical assembly is used for converting an incident light beam into a measurement light beam; the fluorescence measurement assembly is used for measuring fluorescence emitted by the irradiated test strip; the second optical assembly is used for guiding the measuring light beam to the surface of the test strip and guiding fluorescence emitted by the test strip after irradiation to the fluorescence measuring assembly; the second optical assembly at least comprises a dichroscope and an enoscope which are arranged in sequence, the measuring light beam is reflected by the dichroscope to form a first light beam, the first light beam is reflected by the enoscope to form a second light beam, the measuring light beam, the first light beam and the second light beam are perpendicular to one another, and the second light beam is perpendicular to the surface of the test strip. In the application, the light beam of the exciting light reaching the surface of the test strip, namely the second light beam, is vertical to the surface of the test strip, so that the problem of inaccurate measurement result in an oblique light detection light path in the prior art is solved.

Description

Technical Field

[0001] This invention belongs to the field of in vitro diagnostic technology, specifically relating to an optical detection device and a portable fluorescence immunoassay analyzer. Background Technology

[0002] Traditional fluorescence immunoassay analyzers are typically benchtop devices, which are bulky and not suitable for portable applications. These factors limit their use in emergency testing fields (such as emergency laboratories, ICUs, pediatrics, ambulances, outdoor emergency rescue and relief, and individual soldier care), as well as in areas with poor transportation and underdeveloped economies. Even though there are some commercially available portable products on the market, they still suffer from drawbacks such as low measurement accuracy and poor reliability.

[0003] For example, Figure 1 provides an optical detection device for a common portable fluorescence immunoassay analyzer, consisting of a single ( Figure 1a ) or more ( Figure 1b Symmetrical light sources 01 (e.g., LEDs, LDs) generate excitation light. After passing through lenses 02, excitation filters 03, and lenses 04, the light is obliquely incident at a certain angle θ (e.g., 45°) onto the test strip 09 inside the test card (not shown in the figure). The fluorophore in a specific area of ​​the test strip fluoresces. After passing through lenses 05, emission filters 06, and lenses 07, the fluorescence is received by the photoelectric sensor 08 and converted into an electrical signal for processing.

[0004] However, the inventors of this application discovered during their research that this "oblique-type" detection optical path, irradiated at a specific angle θ, has the characteristics of simple and compact structure and easy miniaturization. Immunoassay analyzers using this as a measurement carrier are indeed easy to control in terms of height and size, facilitating device miniaturization and portability. However, this optical path has two obvious drawbacks: first, changes in the incident angle θ of the excitation light significantly affect the shape and size of the light spot irradiated on the test strip 9, which complicates the adjustment of various optical components; second, it is constrained by structural processing precision and test strip manufacturing processes. Figure 2 The height distance h from the test strip to the optical housing 10 is difficult to control precisely. Even a small change in h, Δh (hereinafter referred to as "distance fluctuation"), will alter the distance between the test strip and the optical lens, thus affecting fluorescence (e.g., Figure 2 The propagation path (dashed line) introduces errors into the measurement.

[0005] Figure 3a This demonstrates an exemplary "oblique" optical path simulated using optical simulation software (see [link]). Figure 2 The process of excitation and illumination of the test strip to generate fluorescence is visualized, showing the path of fluorescence generation, diffusion, and entry into the photoelectric sensor. This is achieved by varying the distance h between the test strip and the optical housing (parameters are shown in [reference]). Figure 2 Alternatively, change the distance float Δh (see parameters). Figure 2 Using software for multiple simulations, the curve of fluorescence intensity received by the photoelectric sensor as a function of distance fluctuation Δh was plotted, as shown below. Figure 3b . Figure 3b In this model, the fluorescence intensity collected at Δh = 0 is normalized and denoted as unit 1. The "normalized relative fluorescence intensity" curve represents the ratio of the fluorescence intensity collected at different Δh locations to the fluorescence intensity at Δh = 0, as Δh changes. The curve shows that within a distance fluctuation range of Δh ≤ ±0.3 mm (i.e., when the Δh fluctuation caused by manufacturing process and assembly is within ±0.3 mm), the maximum deviation of the fluorescence intensity received by the photoelectric sensor is (1.0895 - 0.9182) / 1.0895 ≈ 15.7%; within a distance fluctuation range of Δh ≤ ±0.2 mm, the maximum deviation of the fluorescence intensity is (1.0592 - 0.9537) / 1.0592 ≈ 9.9%. Therefore, the variation in the distance h between the test strip and the optical shell, or the existence of a distance fluctuation Δh, caused by differences in the processing precision of structural components, the manufacturing process of the test strip, and the assembly of the optical path, leads to significant differences in the detection results, seriously affecting the measurement accuracy and reliability of the analyzer.

[0006] In summary, both theoretical analysis and simulation results show that in the "oblique-type" optical path, changes in the incident angle θ and height distance h will cause large differences in the measurement results between analyzers equipped with this optical path, resulting in a large test CV and seriously affecting the performance of the analyzer. Summary of the Invention

[0007] This invention discloses an optical detection device and a portable fluorescence immunoassay analyzer to solve the problem of inaccurate measurement results in the prior art.

[0008] A first aspect of this application provides an optical detection device and a portable fluorescence immunoassay analyzer, comprising:

[0009] A light source assembly for providing an incident light beam;

[0010] A first optical component is used to convert the incident beam into a measurement beam;

[0011] A fluorescence measurement component is used to measure the fluorescence emitted by the test strip after it has been irradiated.

[0012] The second optical component is used to guide the measurement beam to the surface of the test strip and to guide the fluorescence emitted by the test strip after irradiation to the fluorescence measurement component;

[0013] The second optical component includes at least a dichroic mirror and a refracting mirror arranged in sequence. The measuring beam is reflected by the dichroic mirror to form a first beam, and the first beam is reflected by the refracting mirror to form a second beam. The measuring beam, the first beam, and the second beam are perpendicular to each other, and the second beam is perpendicular to the surface of the test strip.

[0014] Optionally, the first optical component includes at least a beam splitter, which is disposed between the light source component and the dichroic mirror. The portion of the incident beam transmitted through the beam splitter forms the measurement beam, and the portion of the incident beam reflected by the beam splitter forms the reference beam.

[0015] The optical detection device further includes a first photoelectric sensor, which is used to measure the reference beam.

[0016] Optionally, the fluorescence measurement component includes a filter, a second focusing lens, and a second photoelectric sensor arranged in sequence, wherein the second photoelectric sensor is used to measure the fluorescence emitted by the test strip after irradiation.

[0017] Optionally, the optical detection device further includes a measurement unit, which is used to collect data measured by the first photoelectric sensor and the second photoelectric sensor.

[0018] Optionally, the measurement unit is configured to perform the following operations:

[0019] By comparing the initial light intensity data of the reference beam with the current light intensity data, the magnitude of the light intensity change can be obtained;

[0020] If the intensity variation of the reference beam does not exceed the threshold, the data measured by the second photoelectric sensor is the fluorescence value.

[0021] If the intensity variation of the reference beam exceeds the threshold, the data measured by the second photoelectric sensor is compensated, and the compensated data is used as the fluorescence measurement value.

[0022] Optionally, the measurement unit is configured to perform the following operations:

[0023] If the intensity change of the reference beam exceeds the threshold, the data measured by the second photoelectric sensor is multiplied by a correction factor and used as the fluorescence measurement value. The correction factor is the ratio of the current intensity data of the reference beam to the initial intensity data.

[0024] Optionally, the light source assembly includes an excitation light source and a collimating lens arranged in sequence. The excitation light source is used to generate excitation light, and the excitation light forms the incident beam after passing through the collimating lens.

[0025] Optionally, the second optical component further includes a first focusing lens disposed between the refracting mirror and the test strip, for focusing the first light beam onto the surface of the test strip.

[0026] Optionally, it also includes an optical housing for mounting the various optical components, the height of which is less than or equal to 13 mm.

[0027] Optionally, the optical housing includes a fixedly connected upper optical path shell, a lower optical path shell, and a refracting mirror mount. The upper optical path shell and the lower optical path shell are provided with mounting positions for mounting the light source assembly, the first optical assembly, the fluorescence measurement assembly, and the dichroic mirror. The refracting mirror mount is provided with a mounting position for mounting the refracting mirror.

[0028] A second aspect of this application provides a portable fluorescence immunoassay analyzer, comprising an upper shell, a lower shell, and an optical detection device provided in any implementation of the first aspect, wherein the optical detection device is mounted on the lower shell.

[0029] Optionally, the lower shell is fixedly provided with a sliding groove that extends below the optical detection device, and the upper shell is provided with an opening corresponding to the sliding groove, through which the detection card enters the sliding groove.

[0030] Optionally, a first sensor, a second sensor, and a third sensor are sequentially arranged along the direction of the slide groove. The first sensor is located near the opening and is used to detect when the detection card is inserted into the slide groove. The second sensor is used to detect when the detection card reaches the scanning position. The third sensor is used to detect when the detection card reaches the incubation position.

[0031] In the optical detection device provided in this application, the excitation light beam reaching the surface of the test strip, i.e., the second beam, is perpendicular to the surface of the test strip, thus solving the problem of inaccurate measurement results in the "oblique-type" detection optical path of the prior art. Furthermore, this application places the excitation light source horizontally and uses a dichroic mirror and a refracting mirror to convert the horizontal incident light beam into a second beam perpendicular to the surface of the test strip through two reflections, thereby achieving both perpendicular incident light onto the test strip and portability. Attached Figure Description

[0032] Figure 1a An optical detection device (single light source) for a common portable fluorescence immunoassay analyzer provided in the prior art;

[0033] Figure 1b An optical detection device (symmetrical light source) for a common portable fluorescence immunoassay analyzer provided by the prior art;

[0034] Figure 2A schematic diagram showing the distance from the test strip to the optical lens in an oblique-type detection optical path provided by the prior art;

[0035] Figure 3a To simulate the process of exciting and irradiating the test strip with an oblique-type detection optical path and generating fluorescence;

[0036] Figure 3b This is a curve showing the change in fluorescence intensity received by the photoelectric sensor as a function of distance fluctuation Δh when using an oblique-type detection optical path.

[0037] Figure 4a A schematic diagram of the optical detection device and excitation light path provided by the present invention;

[0038] Figure 4b A schematic diagram of the optical detection device and fluorescence path provided by the present invention;

[0039] Figure 5 This is a schematic diagram of the inclined reflective right-angle prism provided by the present invention;

[0040] Figure 6 This is a schematic diagram of the excitation light and fluorescence path from another viewing direction provided by the present invention;

[0041] Figure 7a The process by which the optical detection device provided by the present invention excites and irradiates the test strip to generate fluorescence;

[0042] Figure 7b The curve showing the change in fluorescence intensity received by the photoelectric sensor provided by the present invention as a function of distance fluctuation Δh;

[0043] Figure 8a A schematic diagram showing the position of the optical detection device provided by the present invention relative to the test strip;

[0044] Figure 8b for Figure 8a A schematic diagram of the disassembled structure;

[0045] Figure 8c A partial perspective view of the optical detection device provided by the present invention;

[0046] Figure 9 A schematic diagram of a portable immunoassay analyzer equipped with an optical detection device;

[0047] Figure 10a A comparison of the measurement results of the two analyzers provided by this invention;

[0048] Figure 10b The repeatability test results of the optical detection device provided by the present invention;

[0049] Figure 11A flowchart illustrating the process of the compensation method for light source radiation intensity fluctuations provided by this invention.

[0050] Reference numerals: 01-Light source; 02-Lens; 03-Excitation filter; 04-Lens; 05-Lens; 06-Emission filter; 07-Lens; 08-Photoelectric sensor; 09-Test strip; 10-Optical housing; 1-Light source assembly; 2-First optical assembly; 3-Fluorescence measurement assembly; 4-Second optical assembly; 11-Excitation light source; 12-Collimating lens; 21-Beam splitter; 22-First photoelectric sensor; 31-Filter; 32-Second focusing lens; 33-Second photoelectric sensor; 41-Dichroic mirror; 42-Refracting mirror; 43-First focusing lens; 801-Optical path housing; 802-Optical path lower housing; 803-Refracting mirror mount; 804-Circular housing; 805-Processing plate; 901-Upper housing; 902-Lower housing. Detailed Implementation

[0051] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] Fluorescence immunoassay combines the high sensitivity of fluorescence technology with the high specificity of immunology, providing a novel ultra-micro analytical method for immunology, clinical histochemistry, and laboratory diagnostics. Immunochromatography is a detection technique based on antibody-antigen specific immune reactions and lateral chromatography. Its principle involves capillary action causing the analyte to move along a test strip. The analyte undergoes a specific reaction at the test line (T), while the free analyte undergoes an immune reaction at the control line (C). Fluorescence technology involves labeling antigens and antibodies with fluorescent dyes that do not affect their activity, creating fluorescent probes. These probes react with the corresponding antibody-antigen complex, forming an antigen-antibody complex containing the labeled fluorescent dye. By irradiating the complex with a light source and measuring the fluorescence emitted, the concentration of the analyte can be calculated, enabling quantitative analysis.

[0053] Fluorescence immunoassay technology, with its advantages of high detection sensitivity, no environmental pollution, no radioactivity, and simple operation, has been widely used in the field of medical testing. To meet market demands and application requirements, and to address the problems of large detection coefficients, significant inter-analyte variations, high manufacturing costs, and difficult debugging in existing portable analyzers, this invention develops an optical detection device suitable for rapid, point-of-care testing in portable clinical settings.

[0054] Reference Figure 4a and Figure 4bThe schematic diagram shown illustrates an optical detection device provided in this application, comprising: a light source assembly 1 for providing an incident light beam; a first optical assembly 2 for converting the incident light beam into a measurement light beam; a fluorescence measurement assembly 3 for measuring the fluorescence emitted by a test strip after irradiation; and a second optical assembly 4 for guiding the measurement light beam to the surface of the test strip and guiding the fluorescence emitted by the test strip after irradiation to the fluorescence measurement assembly. The second optical assembly 4 includes at least a dichroic mirror 41 and a refracting mirror 42 arranged sequentially. The measurement light beam is reflected by the dichroic mirror 41 to form a first light beam, and the first light beam is reflected by the refracting mirror 42 to form a second light beam. The measurement light beam, the first light beam, and the second light beam are perpendicular to each other, and the second light beam is perpendicular to the surface of the test strip.

[0055] The light source assembly 1 includes at least an excitation light source to generate excitation light.

[0056] The main function of the dichroic mirror 41 is to reflect the excitation light and transmit the fluorescence, thus achieving effective separation of the excitation light and fluorescence. The refracting mirror 42 has a coating on its surface that alters the direction of light beam propagation; this coating is not limited to protective aluminum, silver, or gold reflective films. The refracting mirror 42 can be selected from a slanted reflective right-angle prism, such as... Figure 5 As shown, laser or fluorescence is incident from the outside of the refracting mirror 42 onto the inclined surface and reflected. Alternatively, a plane mirror can be selected. Considering that the inclined plane reflecting right-angle prism has a better reflection effect, this embodiment preferably uses an inclined plane reflecting right-angle prism.

[0057] The light source assembly 1, the first optical assembly 2, and the second optical assembly 4 form an excitation light path, the path of which is as follows: Figure 4a As shown. The second optical component 4 and the fluorescence measurement component form a fluorescence receiving optical path, the path of which is as follows. Figure 4b As shown.

[0058] In the existing "oblique-type" detection optical path, the beam of excitation light reaching the surface of the test strip has an angle with the vertical direction, which is the incident angle θ, causing inconvenience to the measurement. In this embodiment, the beam of excitation light reaching the surface of the test strip, i.e. the second beam, is perpendicular to the surface of the test strip, thus solving this technical problem.

[0059] Furthermore, the optical detection device provided in this embodiment is applied to a portable fluorescence immunoassay analyzer, which requires a sufficiently small size. The height of the optical components directly determines the overall height of the portable analyzer. However, in traditional technologies, the excitation light source is placed vertically, making it difficult to compress its height dimension and miniaturize it, thus hindering its integration into a portable analyzer. To address this technical problem, this embodiment places the excitation light source horizontally and uses a dichroic mirror and a refracting mirror to convert the horizontal incident light beam into a second beam perpendicular to the surface of the test strip through two reflections. This achieves both vertical incident light onto the test strip and portability.

[0060] Reference Figure 4a and Figure 4b The schematic diagram shows that the light source assembly 1 includes an excitation light source 11 and a collimating lens 12 arranged sequentially. The excitation light source 11 generates excitation light, which forms the incident beam after passing through the collimating lens 12. The excitation light source 11 is preferably a light-emitting diode (LED), a laser diode (LD), or the like, and the collimating lens 12 is preferably an aspherical lens to improve the collimation of the collimated beam.

[0061] The first optical component 2 includes at least a beam splitter 21, which is disposed between the light source component 11 and the dichroic mirror 41. The portion of the incident light beam transmitted through the beam splitter 21 forms the measurement beam, and the portion of the incident light beam reflected by the beam splitter 21 forms the reference beam. The optical detection device also includes a first photoelectric sensor 22, which is used to measure the reference beam.

[0062] The beam splitter 21 and the first photoelectric sensor 22 form an excitation source monitoring channel. The beam splitter 21 is typically an optical element with a special coating to achieve precise control and separation of the beam. In low-cost designs, the beam splitter can be a thin lens made of ordinary finely annealed H-K9L glass.

[0063] The fluorescence measurement component 3 includes a filter 31, a second focusing lens 32, and a second photoelectric sensor 33 arranged in sequence. The second photoelectric sensor 33 is used to measure the fluorescence emitted by the test strip after it is irradiated.

[0064] The filter 31 further filters out the excitation light and transmits fluorescence. The first photoelectric sensor 22 and the second photoelectric sensor 33 are preferably photodiodes, but avalanche photodiodes (APDs), silicon photomultiplier tubes (SiPMs, MPPCs), etc., can also be selected. This embodiment does not impose specific limitations.

[0065] The second optical component 4 also includes a first focusing lens 43, which is disposed between the refracting mirror 42 and the test strip, for focusing the first light beam onto the surface of the test strip. The first focusing lens 43 serves to converge the light beam and collect more energy.

[0066] The test strip inside the test card (not shown) is located on the image-side focal plane of the first focusing lens 43. In this way, the excitation light can be well focused onto the test strip after passing through the first focusing lens 43, making full use of the excitation light energy and improving the illumination efficiency.

[0067] Figure 6 The diagram shows the propagation path of the excitation light and fluorescence from another viewpoint, and also illustrates the distance h from the test strip to the optical housing. Due to variations in the precision of structural component manufacturing, test strip production processes, and optical path assembly, this distance is difficult to control precisely, and there will always be a small fluctuation Δh.

[0068] Figure 7a This paper demonstrates the process of an exemplary optical detection device exciting and illuminating a test strip to generate fluorescence, simulated using optical simulation software. The path of fluorescence generation, dispersion, and entry into the photoelectric sensor is visualized. The distance h from the test strip to the optical housing (parameter description see...) is varied. Figure 6 Or change the distance float Δh (see parameter description). Figure 2 The software was used to simulate the process multiple times, and the resulting graphs were plotted. Figure 7b The relationship curve between fluorescence intensity and distance fluctuation Δh. Figure 7b In this model, the fluorescence intensity collected at Δh = 0 is normalized and denoted as unit 1. The "normalized relative fluorescence intensity" curve represents the ratio of the fluorescence intensity collected at different Δh locations to the fluorescence intensity at Δh = 0, as Δh changes. The curve shows that within a distance fluctuation range of Δh ≤ ±0.3 mm (i.e., when the Δh fluctuation caused by manufacturing process and assembly is within ±0.3 mm), the maximum deviation of the fluorescence intensity received by the photoelectric sensor is (1.0147 - 0.9475) / 1.0147 ≈ 6.6%; within a distance fluctuation range of Δh ≤ ±0.2 mm, the maximum deviation is (1.0147 - 0.9663) / 1.0147 ≈ 4.8%. Compared to the "oblique illumination" detection optical path, this significantly reduces the difference in detection results caused by changes in distance h or distance fluctuation Δh, improving the precision and accuracy of the analyzer's measurement results.

[0069] Figures 8a-8cA schematic diagram of an exemplary optical detection device is shown, along with a schematic diagram of the device's position relative to the test strip inside the test card (not shown). In this embodiment, the optical detection device has a height dimension of only H0 = 13 mm, fully realizing the flattening and miniaturization of the optical path system. Optionally, the height of the optical housing used to mount the various optical components is less than or equal to 13 mm.

[0070] Figures 4a-4b All the optical components described herein are assembled and fixed by an optical path housing 801, an optical path lower housing 802, and a refracting lens mount 803. The optical path housing 801, optical path lower housing 802, and refracting lens mount 803 can be injection molded. The injection molding material is not limited to ABS, POM, etc., and to reduce stray light interference, these materials are preferably black, and can be treated with matte paint later. The optical path housing 801, optical path lower housing 802, and refracting lens mount 803 can be installed and fixed together by snaps, clips, or threaded connections. The optical path housing 801 and optical path lower housing 802 are respectively provided with mounting positions for the light source assembly, the first optical assembly, the fluorescence measurement assembly, and the dichroic mirror, and the refracting lens mount is provided with a mounting position for the refracting mirror. The circular housing 804 serves two purposes: firstly, to fix the excitation light source and the collimating lens, and secondly, to dissipate heat from the excitation light source. Preferably, the circular housing 804 is made of brass, but aluminum alloy is also an option. A processing board 805 is placed at the rear end of the optical sensor. The processing board 805 is used to amplify, convert, and filter the photoelectric signals received by the optical sensor.

[0071] Figure 9 A portable immunoassay analyzer equipped with an exemplary optical detection device is shown. This embodiment provides a portable fluorescence immunoassay analyzer, including… Figure 4a An optical detection device provided in any implementation manner. It mainly consists of an upper shell 901, a lower shell 902, an optical detection device, and other related modules. The optical detection device is mounted on the lower shell 902. The lower shell 902 is fixedly provided with a sliding groove extending below the optical detection device. The upper shell is provided with an opening corresponding to the sliding groove, through which the detection card enters the sliding groove. In this art, the test strip is disposed inside the detection card, and the surface of the detection card has at least a sample dispensing hole for sample application and a detection window for detection; the surface of the detection card also has a barcode recording sample information.

[0072] A first sensor, a second sensor, and a third sensor are sequentially arranged along the direction of the slide groove. The first sensor is positioned near the opening and is used to detect when the detection card is inserted into the slide groove. The second sensor is used to detect when the detection card reaches the scanning position. The third sensor is used to detect when the detection card reaches the incubation position. Additionally, the analyzer contains a motor to drive the detection card to slide.

[0073] This embodiment provides the following detection process: The detection card is inserted into the instrument through the opening. After the first sensor at the slide entrance recognizes the card's positioning information, it starts the motor, which drives the card into the instrument. When the card reaches the scanning position, it is scanned, and the card continues to move into the instrument. When it reaches the incubation position, an incubation operation is performed. After incubation, the card continues to move into the instrument while performing fluorescence detection. After detection, the card is withdrawn from the opening. During fluorescence detection, the card's position is controlled by stroke, and fluorescence data is continuously collected during this stroke. Thanks to the optical detection device described in this invention, the analyzer has a compact layout, small size, and is easy to operate handheld and carry.

[0074] Figure 10a and Figure 10b The test results demonstrate some performance indicators of the analyzer equipped with the optical detection device described in this invention. The comparison instrument is our company's Getein1600 automated benchtop fluorescence immunoassay analyzer, which is already on the market. Figure 10a The results of the two analyzers were compared for CRP at eight concentration gradients. Figure 10b The results show the repeatability test results of the optical detection device of the present invention for seven different concentrations of CRP. In the illustrative test process, the reagent card was continuously removed and loaded, and the process was repeated 10 times, recording 70 sets of data. The arithmetic mean Aver, standard deviation SD, and coefficient of variation CV were calculated, where CV = 100% * SD / Aver.

[0075] Data results show that the portable fluorescence immunoassay analyzer equipped with the optical detection device of the present invention, for the same concentration of CRP, has basically consistent measurement results with the automated benchtop analyzer, demonstrating good accuracy. In terms of repeatability testing, the optical detection device of the present invention performed multiple repeated tests, and the CV was less than 1%, demonstrating excellent repeatability indicators: high detection accuracy and small differences in multiple measurement results.

[0076] In addition, this invention also provides a method for compensating for fluctuations in the intensity of light source radiation. It is understood in the art that all fluorescence immunoassay analyzers, regardless of their form, are based on fluorescence labeling technology. For a given fluorescent substance, when the wavelength and intensity of the excitation light are fixed, the thickness of the liquid layer is fixed, and the concentration of the solution is low, the fluorescence intensity and the concentration of the analyte generally have the following relationship:

[0077] F=GΦI0εLc…………(1);

[0078] Where: G is the instrument constant, Φ is the fluorescence quantum efficiency, I0 is the excitation light intensity, ε is the molar absorption coefficient, L is the optical path length, and c is the concentration of the fluorescent substance.

[0079] Most of the time, the radiation intensity of both light-emitting diodes (LEDs) and laser diodes (LDs) changes with temperature and current. According to formula (1), once the excitation light intensity I0 changes, it will inevitably affect the fluorescence intensity F, thus introducing errors into the measurement results of the analyzer. In this case, a reference beam needs to be added for compensation and correction.

[0080] The following describes the compensation and correction methods in detail. (Refer to...) Figure 4a The light beam emitted by the excitation light source 11 is collimated by the collimating lens 12 and then split into two beams by the beam splitter 21. One beam enters the first photoelectric sensor 22, while the other beam is transmitted through to the rear optical assembly (the second optical assembly). The beam entering the first photoelectric sensor 22 is called the reference beam, denoted as I. c The light beam entering the back-end optical components is called the measurement beam, denoted as I. e .

[0081] The analyzer measures the initial time t0: the intensity of the reference beam received by the first photoelectric sensor 22 is I. c0 The intensity of the measurement beam entering the back-end optical components is I. e0 The fluorescence intensity of the substance to be tested received by the second photoelectric sensor 33 is F0 (those skilled in the art should know that fluorescence is diffused in all directions, and it is impossible to completely collect all the diffused fluorescence. The optical detection device described in this invention only collects fluorescence at a certain spatial angle, and the intensity of this part of the fluorescence is recorded as F0). Then, according to formula (1), we should have:

[0082] F0=GΦI e0 εLc…………(2);

[0083] At time t (which could be 1 hour, 8 hours, 1 day, 1 month, or even 1 year) when the analyzer resumes measurement, assuming that the excitation light intensity has changed due to factors such as changes in ambient temperature or aging of the light source, the reference beam intensity at this time is I. ct The intensity of the measured beam is I.et The fluorescence intensity is F t According to formula (1), we should have:

[0084] F t =GΦI et εLc…………(3);

[0085] Comparing equations (2) and (3), it can be found that due to the change in the radiation intensity of the light source itself, the measurement beam I... e The intensity also changed (by I) e0 Become I et Under otherwise constant conditions, fluorescence intensity will also change, introducing errors into the measurement results. However, the difficulty lies in the fact that the intensity of the measurement beam entering the back-end optical components cannot be directly obtained; in this case, a reference beam is needed for compensation and correction.

[0086] Define the rate of change of light intensity k of the light source. Both the reference beam and the measurement beam are generated by the radiation from the light source, and their rate of change of light intensity should be consistent with that of the light source itself. Therefore, it is clear that:

[0087]

[0088] Substituting equation (4) into equation (3), we get

[0089] As can be seen from equation (5), the introduction of a compensation coefficient (or correction coefficient) I ct / I c0 Subsequently, although the radiation intensity of the light source changed, the ratio I before and after the intensity change was used by measuring the light intensity of the reference beam. ct / I c0 This compensates for the intensity changes of the measurement beam caused by fluctuations in the light source itself, thus effectively ensuring the accuracy of the measurement.

[0090] To reduce the frequency of compensation calibration, a threshold (e.g., 1%, 2%, 5%, etc.) can be set for the rate of change of light source radiant intensity, k. When the rate of change of light source radiant intensity k ≤ the threshold, the change in light source intensity is small, and no data compensation or correction is needed. When the rate of change of light source radiant intensity k > the threshold, the change in light source intensity is large, and compensation and correction are required. The corrected measurement data can, to some extent, compensate for the impact of changes in light source radiant intensity on the measurement results. Specific implementation methods are as follows: Figure 11 As shown.

[0091] In one feasible implementation, the optical detection device further includes a measurement unit configured to perform the following operations:

[0092] Step 101: Collect data measured by the first photoelectric sensor and the second photoelectric sensor.

[0093] Step 102: Compare the initial light intensity data of the reference beam with the current light intensity data to obtain the magnitude of the light intensity change.

[0094] In this step, the magnitude of the light intensity change is described using the rate of change of the light source's radiant intensity. The formula for calculating the rate of change of the light source's radiant intensity is as follows: Among them, I c0 To measure the intensity of the reference beam measured by the analyzer at the initial time t0; I ct The intensity of the reference beam measured by the analyzer at the current moment.

[0095] If the change in light intensity does not exceed the threshold, it means that the change in the radiation intensity of the light source is not significant and has little impact on the measurement data. In this case, proceed to step 103. If the change in light intensity exceeds the threshold, the change in the radiation intensity of the light source is significant and the measurement results need to be compensated. In this case, proceed to step 104.

[0096] Step 103: If the intensity change of the reference beam does not exceed the threshold, the data measured by the second photoelectric sensor is the fluorescence measurement value.

[0097] Step 104: If the intensity change of the reference beam exceeds the threshold, the data measured by the second photoelectric sensor is compensated, and the compensated data is used as the fluorescence measurement value.

[0098] In this step, when the intensity change of the reference beam exceeds the threshold, the data measured by the second photoelectric sensor is multiplied by a correction coefficient and used as the fluorescence measurement value. The correction coefficient is the ratio of the current intensity data of the reference beam to the initial intensity data.

[0099] This invention develops an optical detection module that can be mounted on a portable immunoassay analyzer. The innovative optical path design not only achieves an extremely small size, meeting portability requirements, but also significantly improves the measurement accuracy of the portable immunoassay analyzer. The main advantages of this invention are as follows:

[0100] 1. The unique optical detection device not only meets the requirements of small instrument size and portability, but also solves the problems of low detection accuracy, large repeatability CV, and large differences in measurement results of portable analyzers, thus improving the practicality and accuracy of portable immunoassay analyzers.

[0101] 2. An additional light source intensity monitoring channel was added. By acquiring and monitoring the reference beam in real time, measurement differences caused by variations in light source radiation intensity were compensated for, further improving the accuracy and reliability of the measurement results.

[0102] 3. The optical detection device described in this invention is not only applicable to portable immunoassay analyzers, but can also be well applied in other benchtop, large-scale automated equipment, production lines, and modules or devices designed to improve detection accuracy.

[0103] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. An optical detection device, characterized in that, include: A light source assembly for providing an incident light beam; A first optical component is used to convert the incident beam into a measurement beam; A fluorescence measurement component is used to measure the fluorescence emitted by the test strip after it has been irradiated. The second optical component is used to guide the measurement beam to the surface of the test strip and to guide the fluorescence emitted by the test strip after irradiation to the fluorescence measurement component; The second optical component includes at least a dichroic mirror and a refracting mirror arranged in sequence. The measuring beam is reflected by the dichroic mirror to form a first beam, and the first beam is reflected by the refracting mirror to form a second beam. The measuring beam, the first beam, and the second beam are perpendicular to each other, and the second beam is perpendicular to the surface of the test strip.

2. The optical detection device according to claim 1, characterized in that, The first optical component includes at least a beam splitter, which is disposed between the light source component and the dichroic mirror. The portion of the incident light beam transmitted through the beam splitter forms the measurement beam, and the portion of the incident light beam reflected by the beam splitter forms the reference beam. The optical detection device further includes a first photoelectric sensor, which is used to measure the reference beam.

3. The optical detection device according to claim 2, characterized in that, The fluorescence measurement component includes a filter, a second focusing lens, and a second photoelectric sensor arranged in sequence. The second photoelectric sensor is used to measure the fluorescence emitted by the test strip after it is irradiated.

4. The optical detection device according to claim 1, characterized in that, The light source assembly includes an excitation light source and a collimating lens arranged in sequence. The excitation light source is used to generate excitation light, and the excitation light forms the incident beam after passing through the collimating lens.

5. The optical detection device according to claim 1, characterized in that, The second optical component further includes a first focusing lens, which is disposed between the refracting mirror and the test strip to focus the first light beam onto the surface of the test strip.

6. The optical detection device according to claim 1, characterized in that, It also includes an optical housing for mounting the various optical components, the height of which is less than or equal to 13 mm.

7. An optical detection device according to claim 6, characterized in that, The optical housing includes a fixedly connected upper optical path shell, a lower optical path shell, and a refracting mirror mount. The upper optical path shell and the lower optical path shell are provided with mounting positions for mounting the light source assembly, the first optical assembly, the fluorescence measurement assembly, and the dichroic mirror. The refracting mirror mount is provided with a mounting position for mounting the refracting mirror.

8. A portable fluorescence immunoassay analyzer, characterized in that, It includes an upper shell, a lower shell, and an optical detection device as described in any one of claims 1 to 7, wherein the optical detection device is mounted on the lower shell.

9. A portable fluorescence immunoassay analyzer according to claim 8, characterized in that, The lower shell is fixedly provided with a sliding groove that extends to the bottom of the optical detection device. The upper shell is provided with an opening corresponding to the sliding groove, through which the detection card enters the sliding groove.

10. A portable fluorescence immunoassay analyzer according to claim 9, characterized in that, A first sensor, a second sensor, and a third sensor are sequentially arranged along the direction of the slide groove. The first sensor is located near the opening and is used to detect when the detection card is inserted into the slide groove. The second sensor is used to detect when the detection card reaches the scanning position. The third sensor is used to detect when the detection card reaches the incubation position.

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