Dual-band fluorescence detection device and use method thereof

Abstract

The invention belongs to the technical field of optical detection, and particularly relates to a dual-band fluorescence detection device and method. The device comprises a light source emission branch, a light source convergence detection branch and a master control unit. The light source emitting branch comprises a light source emitting unit, a dichroscope and a converging lens; and the light source convergence detection branch and the light source emission branch share a dichroscope and a convergence lens, and are provided with a light source receiving and collecting unit. The master control unit controls the light source emitting unit and processes the collected signals. The light source emitting unit comprises an excitation light source, an IR-cut switching mechanism and a receiving lens; the IR-cut switching mechanism is provided with a receiving optical filter I and a receiving optical filter II side by side, and the receiving optical filter I and the receiving optical filter II are customized according to the test paper. The technical scheme has the characteristics of small size, low cost, convenience in use and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical detection, and particularly relates to a dual-band fluorescence detection device and method. Background Art

[0002] In the modern field of analytical detection, fluorescence analyzers are widely used in many aspects such as medical diagnosis, environmental monitoring, and food safety detection due to their advantages of high sensitivity and high selectivity. As the core front-end component of a fluorescence analyzer, the performance of the optoelectronic detection module directly affects the detection effect of the entire analyzer.

[0003] The working principle of the currently common optoelectronic detection module of a fluorescence analyzer is to irradiate a target sample (the sample type includes liquid or test strip) with ultraviolet light. The substance to be measured in the sample has been previously combined with a fluorescent label. Under ultraviolet irradiation, the fluorescent label is excited and emits fluorescence, and then the analysis function is realized by detecting the fluorescence intensity. For example, in clinical disease diagnosis, a specific fluorescent label is used to bind to the disease marker in a human sample, and the fluorescence intensity is detected by a fluorescence analyzer to judge the presence and development degree of the disease; in the detection of environmental pollutants, the specific binding of a fluorescent label to the pollutant is used to analyze the fluorescence intensity to determine the type and content of the pollutant.

[0004] Commonly used fluorescent labels can be excited by ultraviolet light with a wavelength of about 360 nm, and the fluorescence wavelengths emitted by different fluorescent labels after excitation are different. In the composition of the optoelectronic detection module, the optoelectronic sensor is responsible for detecting the fluorescence intensity. To effectively filter out interfering light and ensure the accuracy of detection, a narrowband receiving filter is usually set at the front end of the sensor, allowing only light of a specific wavelength to pass through. However, this design has obvious drawbacks, that is, the compatibility of the instrument is poor, and it can only measure test strips of a certain specific wavelength. This greatly limits the flexibility of the fluorescence analyzer in practical applications. For example, in clinical tests, in the face of multiple different detection items and test strips using different fluorescent labels, multiple different fluorescence analyzers need to be equipped, which not only increases the detection cost but also occupies a large amount of space.

[0005] To improve the instrument compatibility and enable a single machine to measure test strips using different fluorescent labels, the commonly adopted method in the industry is to design a filter switch at the filter, and achieve it by switching filters of different wavelengths. However, this method also has problems, especially in the field of medical instruments. Medical instruments usually have a low production volume. Adding a switching mechanism to the module not only requires adding components such as electromagnets or motors, but also needs to cooperate with complex related mechanical components to form a switch, which will undoubtedly lead to a significant increase in cost. This makes the popularization and promotion of fluorescence analyzers in the medical market face price obstacles and is not conducive to their wide application in primary medical units and areas with limited resources.

[0006] In summary, the existing photoelectric detection modules of fluorescence analyzers have deficiencies in compatibility and cost control, and a new technical solution is urgently needed to solve these problems in order to promote the further development and application of fluorescence analyzers in various fields. Summary of the invention

[0007] The purpose of the present invention is to break through these bottlenecks and propose a dual-band fluorescence detection device and method, which is committed to solving various problems faced by the existing technology in practical applications. The dual-band fluorescence analysis module and method have the remarkable characteristics of small size, low cost and easy use by virtue of innovative design concept and unique technical architecture.

[0008] The above objectives are achieved specifically through the following technical solutions:

[0009] A dual-band fluorescence detection device includes a master control unit, a light source emitting unit, and a light source receiving and collecting unit, a dichroic mirror, and a converging lens arranged in sequence from top to bottom along a through-line. The light source emitting unit is arranged horizontally, perpendicular to the through-line, and emits emission light horizontally; the dichroic mirror is arranged at an angle, and the emission light is refracted by the dichroic mirror at 90 degrees and then goes vertically downward, passes through the converging lens to reach the sample test paper, and generates a fluorescence signal in cooperation with the sample test paper; the fluorescence signal passes through the converging lens and the dichroic mirror in sequence along a straight line and then enters the light source receiving and collecting unit. The light source receiving and collecting unit includes a photoelectric sensor, a receiving lens, and an IR-cut switching mechanism arranged in sequence from top to bottom; receiving filters I and II for different sample test papers are installed side by side on the IR-cut switching mechanism; the fluorescence signal passes through the receiving filter I or the receiving filter II, and then passes through the receiving lens to reach the photoelectric sensor. The master control unit is electrically connected to the light source emitting unit and the light source receiving and collecting unit respectively, and is used to control the operation of the light source emitting unit and process the fluorescence signal collected by the light source receiving and collecting unit.

[0010] Preferably, the light source emitting unit comprises an excitation light source, an excitation light lens and an excitation light filter which are coaxially arranged in sequence.

[0011] Preferably, the excitation light filter is a multilayer dielectric film filter; let the central wavelength of the excitation light filter be λ 1 , the half-width is Δλ 1 , then in λ 1 ±Δλ 1 The transmittance within the band range is not less than 90%, and the cut-off depth in other bands is greater than OD4.

[0012] Preferably, the receiving filter I and the receiving filter II are multi-layer dielectric film filters. Let the central wavelength of the receiving filter I be λ 2 , the half-width is Δλ 2, then the transmittance within the wavelength range of λ 2 ±Δλ 2 is not less than 85%, and the cut-off depth in other wavelength ranges is greater than OD3. Let the central wavelength of the receiving filter II be λ 3 and the full width at half maximum be Δλ 3 , then the transmittance within the wavelength range of λ 3 ±Δλ 3 is not less than 85%, and the cut-off depth in other wavelength ranges is greater than OD3. Among them, λ 2 and λ 3 correspond to the characteristic wavelengths of the fluorescence signals generated by different sample test strips respectively.

[0013] A method for using a dual-band fluorescence detection device, comprising:

[0014] Device preparation stage: Customize receiving filters according to two known test strips, including receiving filter I and receiving filter II; during the assembly stage of the dual-band fluorescence detection device, install the two receiving filters in the IR-cut switching mechanism to complete the device assembly.

[0015] Sample preparation stage: Prepare the sample to be detected and drop it into any one of the aforementioned known test strips to obtain a sample test strip.

[0016] Detection start stage: Start the master control unit, and switch to the corresponding receiving filter through the IR-cut switching mechanism according to the sample test strip used; place the sample test strip under the converging lens, and the master control unit controls the light source emission unit to start running.

[0017] Excitation and fluorescence generation stage: The excitation light source emits light, which passes through the excitation light lens and the excitation light filter in sequence to generate excitation light within the wavelength range of λ 1 ±Δλ 1 ; the excitation light enters the converging lens after being refracted by 90° through the dichroic mirror, and the converging lens converges the excitation light on the sample test strip to cause the sample test strip to generate fluorescence.

[0018] Fluorescence collection stage: The fluorescence generated by the sample test strip passes through the converging lens and enters the light source receiving and collecting unit through the dichroic mirror; in the light source receiving and collecting unit, the fluorescence passes through the corresponding receiving filter and the receiving lens on the IR-cut switching mechanism in sequence to filter out stray light, allowing only the fluorescence in the set wavelength range to pass through, and finally the fluorescence is collected by the photoelectric sensor.

[0019] Signal acquisition and processing stage: The photoelectric sensor converts the received fluorescence signal into an electrical signal and transmits it to the master control unit; the master control unit performs processing operations on the electrical signal, including amplification, filtering, and analog-to-digital conversion; analyze the processed signal, and obtain fluorescence information about the test sample according to the characteristics of the signal, including intensity, frequency, and waveform.

[0020] Detection end stage: After the detection is completed, turn off the light source emission unit, stop the master control unit from collecting and processing signals, and save the detection data and analysis results.

[0021] Preferably, in the device preparation stage, when customizing the receiving filter, according to the fluorescence emission characteristics of the known test strip, the central wavelength of the receiving filter is matched with the wavelength of the fluorescence emitted by the corresponding sample test strip.

[0022] Preferably, in the detection startup stage, the receiving filter switching instruction corresponding to the sample test strip is selected through the operation interface of the master control unit.

[0023] Preferably, in the signal acquisition and processing stage, when the master control unit processes the electrical signal, a digital filtering algorithm is used to remove noise interference, and the digital filtering algorithm is one or a combination of mean filtering, median filtering, or Kalman filtering.

[0024] Preferably, in the signal acquisition and processing stage, obtaining the fluorescence information about the test sample includes fluorescence intensity, fluorescence lifetime, and fluorescence spectrum.

[0025] Compared with the prior art, the advantages of this technical solution are as follows:

[0026] 1) Improve compatibility: Compared with the poor compatibility of the photoelectric detection module of traditional fluorescence analyzers, which can only measure test strips of a certain specific wavelength, the present invention sets the receiving filter I and the receiving filter II on the IR-cut switching mechanism, which can be adapted to different sample test strips. One device can measure test strips using different fluorescent markers, greatly improving the instrument compatibility. In practical applications, there is no need to equip multiple instruments, effectively solving the compatibility problem and improving the flexibility of detection.

[0027] 2) Reduce costs: Compared with the traditional method of designing a complex filter switch at the filter, adding electromagnets, motors, and related mechanical components, resulting in a significant increase in costs and affecting the popularization and promotion of fluorescence analyzers in the medical market. The dual-band fluorescence detection device of the present invention has a simple structural design. Compared with the traditional complex switching mechanism, it reduces a large number of mechanical components, reduces the hardware cost, and is more conducive to popularization and use in primary medical units and areas with limited resources.

[0028] 3) Convenient to use: The detection device of the present invention is more convenient in operation. The receiving filter switching instruction corresponding to the sample detection test strip can be selected through the operation interface of the master control unit, without complex operation procedures and professional skills. Ordinary operators can quickly get started, improving the detection efficiency.

[0029] 4) Comprehensive detection information: In the signal acquisition and processing stage, the present invention can not only obtain the fluorescence intensity, but also obtain the fluorescence lifetime and fluorescence spectrum. Compared with the traditional method of only detecting the fluorescence intensity, it can provide more comprehensive fluorescence information about the detection sample, which helps to more accurately analyze the types, contents, and structural characteristics of substances in the sample, improving the accuracy and reliability of the detection.

[0030] 5) Optimized optical performance: The excitation filter, receiving filter I, and receiving filter II of the present invention all adopt multi-layer dielectric film filters, which have high transmittance in a specific wavelength range and high cut-off depth in other wavelength ranges. They can more effectively filter out stray light, ensure the purity of the detection light, and improve the detection accuracy. Similar high-performance filter designs are not mentioned in the background technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a structural schematic diagram of a dual-band fluorescence detection device;

[0032] Figure 2 is a basic flowchart of the usage method of a dual-band fluorescence detection device.

[0033] In the figure:

[0034] 1. Excitation light source; 2. Excitation light lens; 3. Excitation filter; 4. Dichroic mirror; 5. Converging lens; 6. Photoelectric sensor; 7. IR-cut switching mechanism; 8. Receiving filter I; 9. Receiving filter II; 10. Receiving lens; 11. Sample detection test strip. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. It should not be understood that the present invention is limited to the following examples. Without departing from the concept of the present invention, the variations and improvements of the present invention in this field should be included within the protection scope of the claims of the present invention.

[0036] Unless otherwise defined, the technical terms or scientific terms used in this disclosure should have the ordinary meaning understood by those of ordinary skill in the field to which this disclosure belongs. The words used in this disclosure, including "or", "comprising", and the like, mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0037] Example 1

[0038] This embodiment discloses a dual-band fluorescence detection device, which is a preferred embodiment of the present invention, and has a sophisticated structural design and high performance. Figure 1 As shown, it includes a master control unit, a light source emitting unit, and a light source receiving and collecting unit, a dichroic mirror 4 and a converging lens 5 which are arranged in sequence from top to bottom along a through-line.

[0039] The light source emitting unit is arranged horizontally and perpendicular to the through-line. This unique layout lays the foundation for the propagation and processing of light. The light source emitting unit emits the emitted light horizontally. On this basis, the dichroic mirror 4 is tilted, and the emitted light is refracted 90° by the dichroic mirror 4 and then goes vertically downward to the converging lens 5. The converging lens 5 converges the refracted light to provide suitable light conditions for subsequent detection links. The emitted light passes through the converging lens 5 to reach the sample detection test paper 11, and generates a fluorescent signal in cooperation with the sample detection test paper 11.

[0040] The light source receiving and collecting unit and the light source emitting unit share the dichroic mirror 4 and the converging lens 5. This ingenious design not only saves space but also improves the integration of the device. The fluorescent signal passes through the converging lens 5 and the dichroic mirror 4 in a straight line and then enters the light source receiving and collecting unit.

[0041] The light source receiving and collecting unit includes a photoelectric sensor 6, a receiving lens 10 and an IR-cut switching mechanism 7 arranged in sequence from top to bottom. The receiving filter I8 and the receiving filter II9 are installed side by side on the IR-cut switching mechanism 7. The two receiving filters are respectively applied to different sample detection test strips 11 and can be switched according to actual detection requirements to ensure accurate collection of fluorescence signals of different detection samples. The fluorescence signal passes through the receiving filter I8 or the receiving filter II9, and then passes through the receiving lens 10 to reach the photoelectric sensor 6.

[0042] The master control unit is electrically connected to the light source emitting unit and the light source receiving and collecting unit, and can accurately control the operation of the light source emitting unit and determine the parameters such as the light source opening, closing, and emission intensity. At the same time, the master control unit is also responsible for processing the fluorescent signal collected by the light source receiving and collecting unit, analyzing and calculating the signal through internal algorithms and programs, and finally obtaining the detection results.

[0043] Thus, the working principle of this technical solution is as follows: After the device is started, the master control unit controls the light source unit to emit transmitted light. The transmitted light is directed towards the dichroic mirror 4. After being refracted by the dichroic mirror 4 by 90°, it is converged by the converging lens 5 and finally irradiates the test sample. The test sample is excited to generate fluorescence. The fluorescence returns along the original path, passes through the converging lens 5 and the dichroic mirror 4 again, and reaches the light source receiving and collecting unit. The IR-cut switching mechanism 7 switches the corresponding receiving filter according to the type of the sample test strip 11 to screen the fluorescence. The screened fluorescence reaches the photoelectric sensor 6 through the receiving lens 10. The photoelectric sensor 6 converts the fluorescence signal into an electrical signal and transmits it to the master control unit. The master control unit processes and analyzes the electrical signal, thereby completing the fluorescence detection of the test sample.

[0044] In this technical solution, one of the innovative points of the dual-band fluorescence detection device lies in the introduction of the IR-cut switching mechanism 7. This mechanism is essentially a filter switch of a security monitoring camera. As a general component of the monitoring camera, it is designed to meet the requirements for different wavelengths when the camera takes images during the day and at night, and can flexibly switch between two filters. Nowadays, cameras are widely popular in life and have a huge production and sales volume. This makes the IR-cut switching mechanism 7 not only low-cost, with a price lower than a single digit, but also small in size, facilitating installation and integration. Applying this mechanism in the dual-band fluorescence detection device is a clever move. By paying a very low cost, the switching function of two filters can be achieved, enabling the device to adapt to two different sample test strips 11. This design greatly improves the applicability of the detection device, effectively controls the cost, and makes the device have a higher cost performance and stronger market competitiveness on the premise of ensuring the detection accuracy.

[0045] Embodiment 2

[0046] This embodiment discloses a dual-band fluorescence detection device. As a preferred implementation of the present invention, that is, based on Embodiment 1, its light source emission unit includes an excitation light source 1, an excitation light lens 2, and an excitation light filter 3 arranged coaxially in sequence. The excitation light source 1, as the initial light generating device, is responsible for generating the original light. The excitation light lens 2 preliminarily converges and arranges the light emitted by the excitation light source 1 to ensure that the light can propagate in a relatively concentrated state. The excitation light filter 3 further screens the light, allowing only the excitation light of a specific wavelength to pass through, providing precise light source conditions for subsequent fluorescence excitation.

[0047] Embodiment 3

[0048] This embodiment discloses a dual-band fluorescence detection device. As a preferred implementation of the present invention, that is, based on Embodiment 1 or 2, its excitation light filter 3 is a multi-layer dielectric film filter with excellent optical performance. Let the central wavelength of the excitation light filter 3 be λ1 and the full width at half maximum is Δλ 1 , then within the wavelength range of λ 1 ±Δλ 1 the transmittance is not less than 90%, which can efficiently allow light of a specific wavelength to pass through, providing a sufficient and accurate light source for subsequent fluorescence excitation. In other wavelength bands, its cut-off depth is greater than OD4 (Optical Density is 4), which means that it can block unwanted light to a great extent, effectively reducing the interference of stray light, ensuring the purity and stability of the excitation light, and providing more accurate light source conditions for subsequent fluorescence excitation.

[0049] Among them, the central wavelength λ 1 and the full width at half maximum Δλ 1 of the excitation light filter 3 are mainly set according to the fluorescence characteristics of the sample to be detected and the requirements of detection accuracy.

[0050] Fluorescence characteristics of the sample to be detected: Different samples to be detected will produce fluorescence at specific wavelengths. For example, some biological samples will emit fluorescence of a specific wavelength after being labeled with specific chemical substances. The central wavelength of the excitation light filter 3 needs to match the wavelength at which the sample can be effectively excited to produce fluorescence, so as to ensure that the light emitted by the excitation light source 1 can maximize the excitation of the sample to produce fluorescence signals. The full width at half maximum determines the wavelength range of the excitation light. An appropriate full width at half maximum can ensure that only the target sample is excited, avoiding the generation of unnecessary interference signals by other substances. For example, if the fluorescence excitation wavelength of the sample is concentrated around 500 nm, the central wavelength can be set to 500 nm, and the full width at half maximum is set within a reasonable range that can effectively excite the sample and exclude other interferences.

[0051] Requirements for detection accuracy: If the requirements for detection accuracy are high, a narrower full width at half maximum is required to reduce the interference of stray light and background signals and improve the detection accuracy. The setting of the central wavelength also needs to be more precise to ensure the exact match between the excitation light and the fluorescence excitation wavelength of the sample. On the contrary, in some detection scenarios with relatively low accuracy requirements, the full width at half maximum can be appropriately relaxed, and the setting of the central wavelength does not need to be too strict.

[0052] In addition, the output characteristics of the excitation light source 1 also need to be considered to ensure that the parameters of the excitation light filter 3 can cooperate with the excitation light source 1 to obtain stable and appropriate excitation light.

[0053] Example 4

[0054] This example discloses a dual-band fluorescence detection device. As a preferred implementation of the present invention, that is, based on Example 1, 2 or 3, its receiving filter I 8 and receiving filter II 9 are multi-layer dielectric film filters, which play a key role in fluorescence signal detection.

[0055] For the receiving filter I8, let the central wavelength of the receiving filter I8 be λ 2 and the full width at half maximum be Δλ 2 , then the transmittance within the wavelength range of λ 2 ±Δλ 2 is not less than 85%, and it can effectively transmit the fluorescence signal generated by the corresponding sample test strip 11. In other wavelength bands, its cut-off depth is greater than OD3 (Optical Density is 3), which can block irrelevant light and avoid interfering with the detection.

[0056] Let the central wavelength of the receiving filter II9 be λ 3 and the full width at half maximum be Δλ 3 , then the transmittance within the wavelength range of λ 3 ±Δλ 3 is not less than 85%, and the cut-off depth in other wavelength bands is greater than OD3 (Optical Density is 3).

[0057] Among them, λ 2 and λ 3 correspond to the characteristic wavelengths of the fluorescence signals generated by different sample test strips 11 respectively. The IR-cut switching mechanism 7 can accurately switch the receiving filter according to the type of the actual sample test strip 11 to ensure accurate acquisition of the fluorescence signals of different test samples.

[0058] Furthermore, the setting of the central wavelength λ 2 and the full width at half maximum Δλ 2 of the receiving filter I8, as well as the central wavelength λ 3 and the full width at half maximum Δλ 3 of the receiving filter II9, is related to the following factors:

[0059] I. The fluorescence characteristics of the sample test strip 11

[0060] Characteristic fluorescence emission wavelength: After different sample test strips 11 react with specific substances, they will generate fluorescence signals at specific wavelengths, which is the key basis for setting the central wavelength of the receiving filter. For example, if the sample test strip 11 is used to detect a specific biomarker, and the fluorescence peak wavelength emitted by this biomarker after excitation is 520nm, then the central wavelength of the receiving filter I8 may be set to about 520nm to ensure maximum transmission of this fluorescence signal.

[0061] Fluorescence spectrum width: The fluorescence signal generated by the sample detection test strip 11 is not a single wavelength but has a certain spectral width, usually measured by the full width at half maximum (FWHM). To collect the fluorescence signal as completely as possible while excluding interference from other wavelengths, the FWHM of the receiving filter should match the FWHM of the fluorescence spectrum of the sample detection test strip 11. If the FWHM of the fluorescence spectrum is 10 nm, then the FWHM of the receiving filter can be set at around 10 nm.

[0062] II. Requirements for Detection Precision and Specificity

[0063] Improving precision: To improve the detection precision, it is necessary to minimize the interference of light of other wavelengths as much as possible. If a high precision requirement for detection is imposed, the central wavelength of the receiving filter should be more accurately aligned with the characteristic fluorescence wavelength of the sample detection test strip 11, and the FWHM should also be set narrower to allow only the target fluorescence signal to pass through and exclude other possible interfering signals.

[0064] Enhancing specificity: In an environment of multi-index detection or the presence of various fluorescence interferences, specific detection needs to be achieved by precisely setting the central wavelength and FWHM of the receiving filter. For example, when detecting multiple biomarkers simultaneously, each biomarker has its unique fluorescence emission wavelength. The central wavelength of the receiving filter needs to be set to the characteristic wavelength of each biomarker respectively, and the FWHM should be set reasonably so that different filters can specifically receive their corresponding fluorescence signals and avoid cross-interference.

[0065] Example 5

[0066] This example discloses a method for using a dual-band fluorescence detection device. As a preferred implementation of the present invention, as Figure 2 shown, it includes:

[0067] Device preparation stage: Customize receiving filters according to two known detection test strips, including receiving filter I 8 and receiving filter II 9; during the assembly stage of the dual-band fluorescence detection device, install the two receiving filters in the IR-cut switching mechanism 7 to complete the device assembly, ensuring that all components are correctly connected and functioning properly. This ensures that the device can accurately collect the fluorescence signals generated by different sample detection test strips 11, improving the pertinence and accuracy of detection. The principle is as follows: Due to differences in the detected substances and chemical reactions, the fluorescence signal characteristics of different sample detection test strips 11 are different, such as wavelength, intensity, etc. The customized receiving filter I 8 and receiving filter II 9 are designed respectively according to the fluorescence signal characteristics of the two sample detection test strips 11, and can efficiently transmit the fluorescence of the corresponding wavelength while blocking other stray light, thereby ensuring the accuracy of detection. Installing the receiving filters in the IR-cut switching mechanism 7 facilitates quick switching according to the type of sample detection test strip 11 and realizes the detection work adapted to different sample detection test strips 11.

[0068] Sample preparation stage: The sample to be detected is pre-treated to meet the detection requirements. Subsequently, the treated sample to be detected is dropped into one of the known test strips to ensure that the sample to be detected fully reacts with the test strip, making the sample to be detected in a suitable state for detection, ensuring the reliability of the detection result, and finally obtaining the sample test strip 11. The principle is as follows: The sample to be detected may have problems such as impurities and inappropriate concentration, which will interfere with the detection process or affect the accuracy of the detection result. Through pre-treatment operations such as dilution, purification, and pH adjustment, these interfering factors can be eliminated, making the sample meet the reaction requirements of the sample test strip 11. When the treated sample to be detected is dropped into the sample test strip 11, the substance to be detected in the sample undergoes a chemical reaction with the reagent on the test strip, generating a fluorescence signal, providing a signal source for subsequent detection.

[0069] Detection start-up stage: The main control unit is turned on. According to the specific type of the sample test strip 11 used, the IR-cut switching mechanism 7 is used to switch the corresponding receiving filter to the working position (such as switching to the receiving filter Ⅰ 8). Then, the sample test strip 11 is placed directly below the converging lens 5 to ensure that the excitation light can accurately irradiate the sample test strip 11. After that, the main control unit controls the light source emission unit to start running. The principle is as follows: The main control unit is the core control component of the device, responsible for coordinating the work of each component. After the main control unit is turned on, it can control the IR-cut switching mechanism 7 to switch the corresponding receiving filter into the optical path according to the type of the sample test strip 11, ensuring that only the fluorescence signal related to the sample test strip 11 can be collected. Placing the sample test strip 11 directly below the converging lens 5 is to ensure that the excitation light can be accurately focused on the sample test strip 11 to excite the sample test strip 11 to generate fluorescence. The main control unit controls the light source emission unit to start, providing the necessary energy for fluorescence excitation.

[0070] Excitation and fluorescence generation stage: The excitation light source 1 emits light, which passes through the excitation light lens 2 and the excitation light filter 3 in sequence to generate excitation light in the wavelength range of λ 1 ±Δλ 1 ; The excitation light enters the converging lens 5 after being refracted by 90° through the dichroic mirror 4. The converging lens 5 converges the excitation light on the sample test strip 11, causing the sample test strip 11 to generate fluorescence. The principle is as follows: The light emitted by the excitation light source 1 is converged by the excitation light lens 2 to increase the light intensity and concentration. The excitation light filter 3 screens the light, allowing only the excitation light within ± to pass through. The excitation light in this wavelength range can interact with the sample on the sample test strip 11, causing it to generate fluorescence. The excitation light enters the converging lens 5 after being refracted by 90° through the dichroic mirror 4. The converging lens 5 focuses the excitation light on the sample test strip 11, enhancing the excitation effect and making it easier for the sample to generate fluorescence.

[0071] Fluorescence acquisition stage: The fluorescence generated by the sample detection test strip 11 returns along the original path. First, it passes through the converging lens 5, and then enters the light source receiving and collecting unit through the dichroic mirror 4. In this unit, the fluorescence sequentially passes through the corresponding receiving filter and the receiving lens 10 on the IR-cut switching mechanism 7 that has been switched in place. The receiving filter plays a role in filtering out stray light and only allowing the fluorescence in the set wavelength band to pass through. Finally, the photoelectric sensor 6 collects the screened fluorescence. The principle is as follows: The fluorescence generated by the sample detection test strip 11 returns along the original path. First, it passes through the converging lens 5, and the converging lens 5 converges the fluorescence to increase the fluorescence intensity. The fluorescence enters the light source receiving and collecting unit through the dichroic mirror 4. In this unit, the corresponding receiving filter on the IR-cut switching mechanism 7 that has been switched in place only allows the fluorescence in a specific wavelength band to pass through according to the type of the sample detection test strip 11, filtering out other stray light to ensure the purity of the collected fluorescence signal. The receiving lens 10 further converges the fluorescence, and finally the photoelectric sensor 6 converts the fluorescence signal into an electrical signal for subsequent processing.

[0072] Signal acquisition and processing stage: The photoelectric sensor 6 converts the received fluorescence signal into an electrical signal and transmits it to the master control unit. The master control unit sequentially performs processing operations such as amplification, filtering, and analog-to-digital conversion on the electrical signal. By analyzing the processed signal and based on the characteristics of the signal such as intensity, frequency, and waveform, fluorescence information about the test sample (including fluorescence intensity, fluorescence lifetime, and fluorescence spectrum) is obtained, and then the test result is derived. The principle is as follows: The photoelectric sensor 6 converts the received fluorescence signal into an electrical signal. Since the electrical signal may be interfered during transmission and the signal intensity is weak, the master control unit sequentially amplifies the electrical signal to enhance the signal intensity, filters to remove noise interference, and performs analog-to-digital conversion to convert the analog signal into a digital signal for computer processing. By analyzing the processed signal and based on the characteristics of the signal such as intensity, frequency, and waveform, it is compared with the known standard signal to obtain the fluorescence information about the test sample, and then the test result is derived.

[0073] Detection end stage: After the detection is completed, first, the light source emission unit is turned off to stop the emission of the excitation light. Then, the master control unit stops the signal acquisition and subsequent processing operations. Finally, the data and analysis results generated by this detection are properly saved for subsequent reference and research. The principle is as follows: Turning off the light source emission unit stops the emission of the excitation light to avoid energy waste and excessive device wear. Stopping the signal acquisition and processing operations of the master control unit puts the device in the standby state. Properly saving the detection data and analysis results, these data and results are important records of the test sample and can be used for subsequent research, comparison, quality control, etc.

[0074] Embodiment 6

[0075] The present embodiment discloses a method for using a dual-band fluorescence detection device. As a preferred implementation of the present invention, that is, based on Embodiment 5, in the device preparation stage, in the customization of the receiving filter, in-depth study of the fluorescence emission characteristics of the known test strip is a key step. Through a professional spectral analysis instrument, the peak wavelength of the fluorescence emitted by each sample test strip 11 is accurately measured, and based on this, the central wavelength of the receiving filter is determined. In addition, the fluorescence wavelength and the emission spectrum of the sample test strip 11 are determined by the luminescent material. Under the condition of knowing the luminescent material of the test strip, the corresponding filter central wavelength and transmittance can be selected according to the spectral characteristics of the luminescent material, without the need for a professional spectral analysis instrument for detection. Matching the central wavelengths of the receiving filter I 8 and the receiving filter II 9 with the peak wavelengths of the fluorescence emitted by the two sample test strips 11 respectively is based on the optical filtering principle. The receiving filter is made by using advanced technologies such as multi-layer dielectric films. When the fluorescence signal irradiates on the filter, only the fluorescence with a wavelength close to the central wavelength can pass through smoothly, while the light of other wavelengths will be reflected or absorbed. In this way, the receiving filter can efficiently transmit the fluorescence generated by the corresponding sample test strip 11, while effectively blocking other stray light, greatly improving the detection accuracy. Install the filter in the IR-cut switching mechanism 7. By using its fast switching characteristic, the filter in the optical path can be quickly adjusted according to the type of the sample test strip 11, realizing the efficient detection of different samples.

[0076] Embodiment 7

[0077] This embodiment discloses a method for using a dual-band fluorescence detection device. As a preferred embodiment of the present invention, considering the differences in detection substances and chemical reactions of different sample test strips 11, the generated fluorescence signals have unique characteristics. The fluorescence emission characteristics are mainly reflected in the fluorescence emission spectrum, which includes information such as the fluorescence emission wavelength range, peak wavelength, and the distribution of fluorescence intensity with wavelength. Among them, the fluorescence emission wavelength is a key indicator. Due to different target substances detected by different sample test strips 11, the fluorescence emission wavelengths generated by their chemical reactions will also be different. Therefore, based on Embodiment 5 or 6, in the detection startup stage, a receiving filter switching instruction corresponding to the sample test strip 11 is selected through the operation interface of the master control unit. That is, the operator selects the corresponding receiving filter switching instruction on the operation interface of the master control unit by clicking on the touch screen or operating the control button according to the specific type of the sample test strip 11 used. After the master control unit receives this instruction, the internal control circuit will quickly respond and transmit the control signal to the IR-cut switching mechanism 7. The IR-cut switching mechanism 7 accurately switches the corresponding receiving filter into the optical path according to the received control signal, ensuring that only the fluorescence signals related to this sample test strip 11 can be collected. Placing the sample test strip 11 directly below the converging lens 5 is to ensure that the excitation light can be accurately focused on the test strip to excite the sample to generate fluorescence. The master control unit controls the light source emission unit to start, providing the necessary energy for fluorescence excitation.

[0078] Embodiment 8

[0079] This embodiment discloses a method for using a dual-band fluorescence detection device. As a preferred embodiment of the present invention, considering that the photoelectric sensor 6 converts the received fluorescence signal into an electrical signal, since the electrical signal may be affected by various factors such as electromagnetic interference and thermal noise during transmission, resulting in noise being mixed into the signal, and the original electrical signal intensity is usually weak, which is not conducive to subsequent analysis and processing. Therefore, the master control unit needs to perform a series of processes on the electrical signal. That is, based on Embodiment 5, 6 or 7, in the signal acquisition and processing stage, when the master control unit processes the electrical signal, a digital filtering algorithm is used to remove noise interference, and the digital filtering algorithm is one or a combination of mean filtering, median filtering or Kalman filtering.

[0080] Mean filtering is a simple linear filtering algorithm. It performs an arithmetic average operation on N consecutive sampling values in the signal, and the obtained average value is used as the filtered output value. For example, when N is set to 5, for the electrical signal values of 5 consecutive sampling points, they are added and then divided by 5, and the result obtained is the signal value after filtering at the current moment. This algorithm can effectively eliminate random noise, especially suitable for suppressing noise in smoothly changing signals, making the signal smoother.

[0081] Median filtering is a non-linear filtering algorithm. It sorts N consecutive sampled values in the signal and then takes the median value as the filtered output. For example, for a sequence of 7 sampled values, after sorting these values from smallest to largest, the 4th value is selected as the filtered result. Median filtering performs well in removing impulse noise, can effectively retain the edges and detailed information of the signal, and will not have an excessive smoothing effect on the edges of the signal like mean filtering does.

[0082] Kalman filtering is an optimal recursive filtering algorithm based on the state space model of a linear system. It uses the state equation and observation equation of the system, combines the estimated value of the previous moment and the observed value of the current moment, and makes an optimal estimate of the current state. Kalman filtering can track the changes of the signal in real time, is suitable for processing dynamically changing signals, has a good filtering effect on time-varying signals containing noise, and can accurately estimate the true value of the signal in a complex environment.

[0083] In practical applications, an appropriate filtering algorithm can be selected according to the characteristics of the electrical signal and the type of noise. If the signal mainly contains random noise and the signal changes relatively smoothly, mean filtering may be used alone; if there is more impulse noise, median filtering can be selected; and for dynamically changing signals, Kalman filtering may be more suitable. Multiple algorithms can also be combined. First, use median filtering to remove impulse noise, then further smooth the signal through mean filtering, and finally use Kalman filtering to perform dynamic tracking and optimization of the signal to achieve the best filtering effect.

[0084] After the filtering process, the master control unit also amplifies the electrical signal to enhance the signal strength for subsequent analog-to-digital conversion and analysis. Analog-to-digital conversion converts the analog signal into a digital signal for easy processing by a computer. By analyzing the processed signal and comparing it with known standard signals based on characteristics such as the strength, frequency, and waveform of the signal, fluorescence information about the test sample can be obtained, and then the test result can be derived.

Claims

1. A dual-band fluorescence detection device, characterized in that: It comprises a master control unit, a light source emitting unit, and a light source receiving and collecting unit, a dichroic mirror (4) and a converging lens (5) which are arranged in sequence from top to bottom along a through-center straight line; The light source emitting unit is arranged horizontally, perpendicular to the through-line, and emits emission light horizontally; the dichroic mirror (4) is arranged at an angle, and the emission light is refracted by the dichroic mirror (4) by 90 degrees and then goes vertically downward, passes through the converging lens (5) to reach the sample test paper (11), and generates a fluorescence signal in conjunction with the sample test paper (11); the fluorescence signal passes through the converging lens (5) and the dichroic mirror (4) in sequence along a straight line and then enters the light source receiving and collecting unit; The light source receiving and collecting unit comprises a photoelectric sensor (6), a receiving lens (10) and an IR-cut switching mechanism (7) which are arranged in sequence from top to bottom; a receiving filter I (8) and a receiving filter II (9) which are applied to different sample detection test strips (11) are installed side by side on the IR-cut switching mechanism (7); the fluorescent signal passes through the receiving filter I (8) or the receiving filter II (9) respectively, and then passes through the receiving lens (10) to reach the photoelectric sensor (6); The master control unit is electrically connected to the light source emitting unit and the light source receiving and collecting unit respectively, and is used to control the operation of the light source emitting unit and process the fluorescent signal collected by the light source receiving and collecting unit.

2. A dual-band fluorescence detection device as claimed in claim 1, characterized in that: The light source emitting unit comprises an excitation light source (1), an excitation light lens (2) and an excitation light filter (3) which are coaxially arranged in sequence.

3. A dual-band fluorescence detection device as claimed in claim 2, characterized in that: The excitation light filter (3) is a multilayer dielectric film filter; if the central wavelength of the excitation light filter (3) is λ1 and the half-width is Δλ1, the transmittance within the wavelength band of λ1±Δλ1 is not less than 90%, and the cut-off depth in other wavelength bands is greater than OD4.

4. A dual-band fluorescence detection device as claimed in claim 1, characterized in that: The receiving filter I (8) and the receiving filter II (9) are multilayer dielectric film filters; if the central wavelength of the receiving filter I (8) is λ2 and the half-width is Δλ2, the transmittance within the λ2±Δλ2 band is not less than 85%, and the cut-off depth in other bands is greater than OD3; if the central wavelength of the receiving filter II (9) is λ3 and the half-width is Δλ3, the transmittance within the λ3±Δλ3 band is not less than 85%, and the cut-off depth in other bands is greater than OD3; wherein λ2 and λ3 correspond to characteristic wavelengths of fluorescence signals generated by different sample detection test strips (11), respectively.

5. A method for using a dual-band fluorescence detection device, characterized in that: include: Device preparation stage: Customize receiving filters according to two known test strips, including receiving filter I (8) and receiving filter II (9); in the dual-band fluorescence detection device assembly stage, install the two receiving filters in the IR-cut switching mechanism (7) to complete the device assembly; Sample preparation stage: prepare the sample to be tested and drop it into any of the aforementioned known test strips to obtain a sample test strip (11); Detection start-up phase: start the main control unit, and according to the sample test strip (11) used, switch to the corresponding receiving filter through the IR-cut switching mechanism (7); place the sample test strip (11) under the converging lens (5), and the main control unit controls the light source emission unit to start operation; Excitation and fluorescence generation stage: the excitation light source (1) emits light, which passes through the excitation light lens (2) and the excitation light filter (3) in sequence to generate excitation light within the wavelength range of λ1±Δλ1; the excitation light is refracted by 90° through the dichroic mirror (4) and then enters the converging lens (5), and the converging lens (5) converges the excitation light onto the sample test paper (11), causing the sample test paper (11) to generate fluorescence; Fluorescence collection stage: the fluorescence generated by the sample test strip (11) passes through the converging lens (5) and the dichroic mirror (4) and enters the light source receiving and collecting unit; in the light source receiving and collecting unit, the fluorescence passes through the corresponding receiving filter and receiving lens (10) on the IR-cut switching mechanism (7) in turn, and stray light is filtered out, allowing only the fluorescence of the set wavelength band to pass through, and finally the fluorescence is collected by the photoelectric sensor (6); Signal collection and processing stage: the photoelectric sensor (6) converts the received fluorescence signal into an electrical signal and transmits it to the master control unit; The master control unit performs processing operations including amplification, filtering, and analog-to-digital conversion on the electrical signal; analyzes the processed signal and obtains fluorescence information about the test sample based on the signal's characteristics including intensity, frequency, and waveform; End of detection phase: After the detection is completed, turn off the light source emission unit, stop the main control unit from collecting and processing signals, and save the detection data and analysis results.

6. A method for using a dual-band fluorescence detection device as claimed in claim 5, characterized in that: During the device preparation stage, when customizing the receiving filter, the central wavelength of the receiving filter is matched with the wavelength of the fluorescence emitted by the corresponding sample test strip (11) based on the fluorescence emission characteristics of the known test strip.

7. A method for using a dual-band fluorescence detection device as claimed in claim 5, characterized in that: In the detection start-up phase, a receiving filter switching instruction corresponding to the sample detection test paper (11) is selected through the operation interface of the main control unit.

8. The method for using the dual-band fluorescence detection device as claimed in claim 5, characterized in that: In the signal acquisition and processing stage, when the master control unit processes the electrical signal, a digital filtering algorithm is used to remove noise interference. The digital filtering algorithm is one or more combinations of mean filtering, median filtering or Kalman filtering.

9. A method for using a dual-band fluorescence detection device as claimed in claim 5, characterized in that: In the signal acquisition and processing stage, fluorescence information about the detected sample is obtained, including fluorescence intensity, fluorescence lifetime and fluorescence spectrum.

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