The Research Of The Range Automatic Adjustment Method For Image-based Fluorescence Immunochromatographic Strip Detector

The image-based fluorescent immunochromatographic detection technology is a new detection technology which combines the image processing technology with the fluorescence immunochromatography detection technology,and it can realize the quantitative detection of specific compounds and biomolecules.The existing image-based fluorescence immunochromatography strip detector is limited by the accuracy of the image sensor,and the detection range and sensitivity are hard to meet the existing detection needs.In this paper,by studying the mechanism of the detection of the image-based fluorescent immunochromatography and the mechanism of the camera exposure time adjustment,the CMOS image sensor is used to collect the image information of the fluorescent test strip.The mathematical morphology and least square method are used to filter image noise.Setting up an auto adjustment model for exposure time.Then Otsu threshold segmentation algorithm based on image entropy is applied to get the eigenvalues of the detection band and the control band.By calculating the ratio of the two eigenvalues,the test results are obtained,which achieves the function of automatically adjusting the detection range of the image-based fluorescence immunochromatography strip detector.Therefore,the main work of this paper are as follows:(1)Analyze the principle of the image-based fluorescence immunochromatography.Based on the principle,a theoretical model of automatic range regulation of image fluorescence immunochromatographic detector is established.By exploring the mechanism of automatic adjustment of the range,the exposure amount of the sensor is controlled by automatically adjusting the exposure time of the image sensor.Thus,it can adapt to the detection of various concentration strips and achieve the automatic adjustment function of range.(2)According to the theoretical model of automatic range regulation,this paper designs the hardware system of range automatic adjustment image-based immunofluorescence chromatography strip tester.In this paper,from the selection of the excitation light source,the selection of image sensor and the design of light path,a measuring device for automatic adjustment of image-based fluorescent immunochromatographic strip is designed.Furtherore,the hardware driver algorithm of the detector is realized.(3)In this paper,the software algorithm of range automatic adjustment image fluorescence immunochromatographic strip tester is designed.The original image information of the fluorescent test strip is analyzed and the image noise is filtered by mathematical morphology and least square method.Furthermore,iterative segmentation algorithm,Otsu segmentation algorithm and image-based Otsu segmentation algorithm are used to separate fluorescent strips.Regional consistency and regional contrast were used for evaluation.According to the evaluation results,image-based Otsu segmentation algorithm is used for segmentation.The automatic adjustment algorithm of the range is designed.By judging the gray value of fluorescent test strip,the range control function is set up and the exposure time is obtained.(4)Designing experiments to explore the effectiveness of the model.Furthermore,taking the mature products abroad and the photoelectron immunochromatographic strip test instrument made earlier by our research group as a contrast.The performance of the automatic fluorescent image immunoassay strip detector was tested to compare and analyze the expanding effect of the detection range before and after the range adjustment.The experimental results show that the proposed range automatic adjustment method for image-based fluorescence immunochromatographic strip detector can effectively expands the detection range of the detector.It extends the detection range from 1.95-250?g/mL to 0.98-500 ?g/mL,linear goodness of fit R2>0.99,and repeatability less than 3%.It meets the actual testing needs.