CN109298179B - Immunochromatography detection system and background recognition method thereof - Google Patents

Abstract

The invention relates to an immune chromatography detection system and a background recognition method thereof. It includes a main control unit, an optical measurement unit, and a background acquisition unit; the main control unit includes a main control CPU, a driving circuit connected to the main control CPU, and a display module, and the optical measurement unit includes an optical detection device and a transmission device connected to the driving circuit. The background collection unit includes a background signal input module connected to the optical detection device, a conditioning filter module connected to the background signal input module, a conditioning amplification module connected to the conditioning filtering module, and the conditioning amplification module is also connected to the main control CPU. The invention improves the detection range and precision of the immunochromatography detection system; at the same time, it greatly reduces the influence caused by the difference in the physical and chemical properties of the samples to be tested clinically; the invention has strong practicability and can be widely used in medical bedside detection, food Safety testing and other fields have effectively solved the shortcomings of immunochromatography instrument performance degradation caused by background baseline problems.

Description

A kind of immunochromatographic detection system and its background recognition method

technical field

The invention relates to an immune chromatography detection system and a background recognition method thereof.

Background technique

The patent (application number: 201810134327.6) proposes a dry-type immunochromatography detector and its detection method, which includes a fluorescence detection mechanism, a motion mechanism, a scanning mechanism, a judgment mechanism, a switch mechanism, an information collection module, and a main control module. The design realizes T and C line judgment and T/C area ratio through software algorithm, and quantitatively detects the sample concentration. The patent (application number: 201711404592.3) proposes a portable fluorescence immunochromatography test strip imaging detection system, including an optical system, a data transmission system and a data processing system. The detection system uses the image segmentation algorithm to segment the high-definition fluorescence test strip image information collected by the microscope into the T line, C line and background area in the test strip image. The patent (application number: 201610835153.7) proposes a quantitative detection and calculation method based on fluorescence immunochromatography technology, which sequentially undergoes LED light source irradiation, optical filter processing, photodetector detection, electrical signal processing, AD conversion processing, and filtering algorithm Processing, baseline fitting, peak-seeking processing, calculation of T/C area ratio, and calculation of concentration, so as to make judgments based on the calculated concentration results. In the background selection, the least squares fitting is used to select the background baseline, and the concentration of the sample to be tested is quantitatively detected.

There are problems or defects in the above technology:

There are varying degrees of differences in the physical and chemical properties of the samples to be tested clinically, resulting in unstable background baselines in the detection area of the immunochromatographic test strips, which affect the accuracy of the detection results. Therefore, accurate selection of background baseline is the prerequisite for quantitative detection. In the existing immunochromatography detection system, the background baseline selection method is as follows: 1. Select the background baseline by baseline fitting; 2. Determine the inflection point of the characteristic curve by the second-order differential method, and use the baseline value corresponding to the inflection point as the background baseline; 3. 1. Take the average through the continuous collection at the starting position of the immune test strip, and use it as the background baseline. The first two methods are offline data processing methods, which need to rely on the computing power of the PC, and it is difficult to realize these functions on the on-site rapid detection equipment; the last method can only weaken the accidental errors in the actual detection. Systematic errors are powerless.

Contents of the invention

The purpose of the present invention is to provide an immunochromatography detection system and its background recognition method, which improves the detection range and accuracy of the immunochromatography detection system; at the same time, greatly reduces the impact caused by the difference in the physical and chemical properties of the clinical samples to be tested .

In order to achieve the above object, the technical solution of the present invention is: an immunochromatographic detection system, comprising a main control unit, an optical measurement unit, and a background acquisition unit; the main control unit includes a main control CPU and a computer connected to the main control CPU A drive circuit and a display module, the optical measurement unit includes an optical detection device and a transmission device connected to the drive circuit, the background acquisition unit includes a background signal input module connected to the optical detection device, and a background signal input module connected to the background signal The conditioning and filtering module connected to the input module, the conditioning and amplification module connected to the conditioning and filtering module, the conditioning and amplification module is also connected to the main control CPU; the optical detection device includes a light source, a first lens, and a dichroic mirror , cylindrical mirror, optical filter, second lens, photoelectric sensor, the light excited by the light source is focused by the first lens and then totally reflected by the dichroic mirror, and then transformed into a rectangular spot by the cylindrical mirror, and acts on the On the surface of the immunochromatographic test strip to be tested on the transmission device, the optical signal reflected by the surface of the immunochromatographic test strip to be tested passes through a dichroic mirror and an optical filter, and is focused by the second lens to the photoelectric sensor, and converted into an electrical signal . The size of the rectangular light spot is close to the size of the color line of the immunochromatographic test strip to be tested. Fig. 4 shows a schematic diagram of light spots illuminated by the optical mechanism of the present invention on the detection window of the test strip. _Let the spot width be L, the detection zone width be L _T , the control zone width be L _C , and the distance between the detection zone and the control zone _be L _TC . much smaller than L _TC , ie , Reasonable spot shape and size, so that when the optical mechanism scans the test strip, the optical signals of the detection zone and the control zone do not interfere and are conducive to the division of the background area and improve the detection accuracy.

The present invention also provides a background recognition method based on the above-mentioned immunochromatographic detection system, comprising the following steps:

Step S1. When measuring the immunochromatography test strip to be tested, the light source is turned on, and the excitation light of the light source is focused by the first lens and is totally reflected by the dichroic mirror, and then shaped into a rectangular spot by the cylindrical mirror, which acts on the immunochromatography test strip to be tested. strip surface;

Step S2, the main control CPU controls the transmission device to move back and forth, so that the rectangular light spot scans back and forth on the detection window on the surface of the immunochromatography test strip to be tested, and passes the optical signal on the detection window through a dichroic mirror and an optical filter, and is transmitted by the first The second lens focuses on the photoelectric sensor and converts it into an electrical signal;

Step S3, the background signal input module receives the electrical signal transmitted by the photoelectric sensor, transmits it to the conditioning filter module and the conditioning amplification module for real-time processing, and finally transmits it to the main control CPU for A/D conversion;

Step S4, the main control CPU recognizes the background area according to the signal after the A/D conversion, stores the scan length of the background area as a control variable in the main control CPU, and adjusts the stepping distance of the stepping motor of the transmission device, The sampling process starts when the dynamic range of each spot scan is controlled in the theoretical background area, and then the stable background area is found by the method of test strip moving speed, test strip window length and spot position identification, and the determined background area The sampling result is used as the final background baseline, and finally the algorithm calculates the mean value as the baseline value of the background area of the immunochromatographic test strip to be tested.

Compared with the prior art, the present invention has the following beneficial effects: the present invention improves the detection range and precision of the immunochromatographic detection system; at the same time, it greatly reduces the impact caused by the difference in the physical and chemical properties of the clinical samples to be tested; the present invention It has strong practicability and can be widely used in medical bedside detection, food safety detection and other fields, and effectively solves the shortcomings of the performance reduction of the immunochromatography test strips caused by the baseline problem.

Description of drawings

Figure 1 is the optical structure of the immunochromatographic detection system.

Fig. 2 is an area distribution diagram of the immunochromatography optical signal sampling curve.

Fig. 3 is a schematic block diagram of the immunochromatographic detection system of the present invention.

Fig. 4 is a schematic diagram of light spots illuminated by the optical mechanism of the present invention on the detection window of the test strip.

Detailed ways

The technical solution of the present invention will be specifically described below in conjunction with the accompanying drawings.

The invention provides an immunochromatography detection system, which includes a main control unit, an optical measurement unit, and a background collection unit; the main control unit includes a main control CPU, a driving circuit connected to the main control CPU, and a display module. The optical measurement unit includes an optical detection device and a transmission device connected to the drive circuit, the background collection unit includes a background signal input module connected to the optical detection device, a conditioning filter module connected to the background signal input module, A conditioning and amplifying module connected to the conditioning and filtering module, the conditioning and amplifying module is also connected to the main control CPU; the optical detection device includes a light source, a first lens, a dichroic mirror, a cylindrical mirror, and an optical filter , the second lens, the photoelectric sensor, the light excited by the light source is focused by the first lens and then totally reflected by the dichroic mirror, and then transformed into a rectangular spot by the cylindrical mirror, and acts on the to-be-measured spot placed on the transmission device On the surface of the immunochromatography test strip, the optical signal reflected by the surface of the immunochromatography test strip to be tested passes through the dichroic mirror, the filter, and is focused by the second lens to the photoelectric sensor, and converted into an electrical signal. The size of the rectangular light spot is close to the size of the color line of the immunochromatographic test strip to be tested.

The present invention also provides a background recognition method based on the above-mentioned immunochromatographic detection system, comprising the following steps:

Step S1, when measuring the immunochromatography test strip to be tested, the light source is turned on, the excitation light of the light source is focused by the first lens and is totally reflected by the dichroic mirror, and then shaped into a rectangular spot by the cylindrical mirror, the immunochromatography test strip to be tested surface;

Step S2, the main control CPU controls the transmission device to move back and forth, so that the rectangular light spot scans back and forth on the detection window on the surface of the immunochromatography test strip to be tested, and passes the optical signal on the detection window through a dichroic mirror and an optical filter, and is transmitted by the first The second lens focuses on the photoelectric sensor and converts it into an electrical signal;

Step S3, the background signal input module receives the electrical signal transmitted by the photoelectric sensor, transmits it to the conditioning filter module and the conditioning amplification module for real-time processing, and finally transmits it to the main control CPU for A/D conversion;

Step S4, the main control CPU recognizes the background area according to the signal after the A/D conversion, stores the scan length of the background area as a control variable in the main control CPU, and adjusts the stepping distance of the stepping motor of the transmission device, The sampling process starts when the dynamic range of each spot scanning is controlled in the theoretical (non-optimum) background area, and then finds a stable background area by means of the moving speed of the test strip, the length of the test strip window and the identification of the spot position, and The determined background area sampling results are used as the final background baseline, and finally the algorithm calculates the mean value as the baseline value of the background area of the immunochromatographic test strip to be tested.

The following is the specific implementation process of the present invention.

As shown in FIG. 3 , an immunochromatography detection system of the present invention is mainly composed of an optical measurement module, a background collection module, and a main control module. Figure 1 shows the optical structure of the immunochromatographic detection system. When the test strip is measured, the light source is turned on, the excitation light is focused and then totally reflected by the dichroic mirror, transformed into a rectangular spot by the cylindrical mirror, and acts on the surface of the test strip. Then the main control CPU of the main control module controls the transmission device carrying the test strip to move back and forth, so that the rectangular light spot with a suitable width and length is scanned back and forth on the detection window of the test strip, and the optical signal on the detection window passes through the dichroic mirror And filters, focused by the focusing mirror to the optical sensor, and finally converted into electrical signals. By analyzing the photoelectric signal distribution law of the spot scanning detection area, the dynamic recognition of the background area is realized.

The operating principle of the system of the present invention is as follows:

Since the color lines on the strip to be tested appear in the shape of a rectangular strip, in order to make full use of the front-end optical system to extract the signal quantity of the test strip from the detection window, after the outgoing light of the light source passes through the optical path, the light spot focused on the detection window of the test strip should be It is designed as a rectangular spot, and the size of the rectangular spot is designed according to the size of the detection window of the test strip. When performing detection, the main control CPU controls the transmission device carrying the test strip to move back and forth, so that the rectangular light spot scans back and forth in the window of the test strip, and the scanned photoelectric signal is input into the background through the receiver (photoelectric sensor in Figure 1). Acquisition and conditioning circuit for real-time processing, and finally transmitted to the main control CPU for A/D conversion. As shown in Figure 2, it is the area allocation diagram of the immuno-tomography optical signal sampling curve. Since the reflection coefficient of the upper and lower edge areas of the detection window is different from that of the background area, the received background signal drifts, so it cannot be used as the area for background selection. Similarly, the T-line area and C-line area in the detection window should be excluded, then the remaining area should theoretically become the background area. Firstly, the scanning length of the background area is stored in the CPU as a control variable, and the sampling starts when the dynamic range of each spot scanning is controlled in the theoretical (non-optimal) background area by precisely controlling the stepping distance of the stepping motor Then filter and denoise the sampled data, and then find a stable background area through the method of test strip moving speed, test strip window length and spot position recognition, and use the determined background area sampling results as the final background baseline, and finally The mean value is calculated by the algorithm and used as the baseline value of the background area of the test strip.

The usage mode of the present invention:

The principle block diagram of the present invention is shown in Fig. 3 . After inserting the immunochromatography test strip, press the measurement button, the main control CPU receives the command, and starts to control the transmission device to advance a fixed step through the drive circuit, so as to realize accurate positioning and detection in the background area, and transmit the signal to the sensor through the optical mechanism. Background acquisition circuit. After conditioning and filtering, conditioning and amplification, it is input to the CPU for A/D conversion, and the background baseline is finally determined. After the light spot scanning is finished, the CPU will extract the feature quantity according to the light signal changes during the scanning process and display it on the LCD screen.

The above are the preferred embodiments of the present invention, and all changes made according to the technical solution of the present invention, when the functional effect produced does not exceed the scope of the technical solution of the present invention, all belong to the protection scope of the present invention.

Claims (1)

1. An immunochromatography detection system, characterized in that, comprises a main control unit, an optical measurement unit, and a background acquisition unit; the main control unit includes a main control CPU and a drive circuit and a display module connected with the main control CPU, The optical measurement unit includes an optical detection device and a transmission device connected to the driving circuit, and the background collection unit includes a background signal input module connected to the optical detection device, a conditioning filter connected to the background signal input module Module, the conditioning amplification module connected with the conditioning and filtering module, the conditioning amplification module is also connected with the main control CPU; the optical detection device includes a light source, a first lens, a dichroic mirror, a cylindrical mirror, a filter Light sheet, second lens, photoelectric sensor, the light excited by the light source is focused by the first lens and then totally reflected by the dichroic mirror, and then transformed into a rectangular spot by the cylindrical mirror, and acts on the light spot placed on the transmission device The surface of the immunochromatographic test strip to be tested, the optical signal reflected by the surface of the immunochromatographic test strip to be tested is passed through a dichroic mirror and an optical filter, and is focused to a photoelectric sensor by a second lens, and converted into an electrical signal; the size of the rectangular spot The size of the color line is similar to that of the immunochromatographic test strip to be tested; The method for determining the size of the rectangular spot is as follows: let the spot width be L, the detection zone width be L _T , the control zone width be L _C , and the distance between the detection zone and the control zone be L _TC . When designing the spot, make the width L tend to Closer to L _T and L _C , and much smaller than L _TC , namely , so that when the optical mechanism scans the test strip, the optical signals of the detection zone and the control zone do not interfere and are conducive to the division of the background area and improve the detection accuracy; The background recognition method of the immunochromatographic detection system comprises the steps of: Step S1. When measuring the immunochromatography test strip to be tested, the light source is turned on, and the excitation light of the light source is focused by the first lens and is totally reflected by the dichroic mirror, and then shaped into a rectangular spot by the cylindrical mirror, which acts on the immunochromatography test strip to be tested. strip surface; Step S2, the main control CPU controls the transmission device to move back and forth, so that the rectangular light spot scans back and forth on the detection window on the surface of the immunochromatography test strip to be tested, and passes the optical signal on the detection window through a dichroic mirror and an optical filter, and is transmitted by the first The second lens focuses on the photoelectric sensor and converts it into an electrical signal; Step S3, the background signal input module receives the electrical signal transmitted by the photoelectric sensor, transmits it to the conditioning filter module and the conditioning amplification module for real-time processing, and finally transmits it to the main control CPU for A/D conversion; Step S4, the main control CPU recognizes the background area according to the signal after the A/D conversion, stores the scan length of the background area as a control variable in the main control CPU, and adjusts the stepping distance of the stepping motor of the transmission device, The sampling process starts when the dynamic range of each spot scan is controlled in the theoretical background area, and then the stable background area is found by the method of test strip moving speed, test strip window length and spot position identification, and the determined background area The sampling result is used as the final background baseline, and the mean value is calculated by the algorithm at last as the baseline value of the background area of the immunochromatography test strip to be tested; The background area is different, resulting in the drift of the received background signal, which cannot be used as the background selection area, so the upper and lower edge areas of the detection window are excluded, and the T line area and C line area in the detection window are excluded at the same time. The remaining area is the theoretical background area.