Detection Method Of Rice Disease Spores Based On Microfluidic And Diffraction Reconstruction Technology

The losses caused by rice fungal diseases are up to billions of dollars every year in the world,so the early detection of rice fungal diseases has become a research hotspot all around the world.At present,satellite remote sensing,spectral detection and other methods are widely used to detect rice fungal diseases,but the above methods are lagging behind.The disease is caused by spore spreading in the air,so the early detection of the disease can be realized by spore capture detector.The main problems of airborne spore detection are:(1)the composition of air is complex,the contradiction between low concentration spores and high concentration impurities significantly increases the difficulty of spore identification;(2)the concentration of spores in air is very low,while the field of view of microscope is very small,the contradiction between low concentration and small field of view significantly increases the randomness and one sidedness of detection,and reduces the sensitivity.Therefore,a method based on microfluidics and diffraction reconstruction is proposed to detect rice disease spores.According to the characteristics of disease spores,based on the principle of microfluidic purification dynamics,the paper uses simulation software to analyze the coupling of multiple physical fields,optimize the structure parameters of microfluidic chip,and select the appropriate materials and processes to make microfluidic chip to achieve the purification of air borne spores.(2)Based on the scalar diffraction theory,the parameters of the diffraction imaging module,such as light source wavelength,micropore diameter,propagation distance and recording distance,are analyzed;the diffraction image formation is simulated;the large field diffraction imaging module is designed according to the above parameters.(3)Microfluidic chip,diffractive imaging module and environmental sensor were combined to construct rice disease spore detection device,which was used to collect the diffractive image and environmental information of disease spores.(4)According to the causes of the noise in diffracted image,the proper filtering algorithm is selected for image denoising pretreatment;the appropriate algorithm for rice disease spore reconstruction is studied and selected;the spore edge in the reconstruction image is marked and its morphological characteristics are extracted for disease spore detection.(5)The purification performance of microfluidic chip,the accuracy of diffraction reconstruction detection algorithm,the function of environmental sensor and the detection accuracy of the whole device were verified by experiments.The experimental results show that compared with the direct collection of rice blast spore samples,the impurities in the purified samples are reduced,and the accuracy of automatic identification is increased by 50%.Comparing the automatic counting results with the manual counting results,the detection error rate of the diffraction reconstruction feature recognition algorithm is less than 10%.The automatic counting results are linearly related to the manual counting results,with good accuracy.The temperature,humidity,wind speed and direction sensor can work normally continuously.Finally,the accuracy of the device is 85% compared with that of the spore catcher.In conclusion,the detection method of rice disease spores based on microfluidic and diffraction reconstruction technology can be used for the detection of rice disease spores.