A Crop Airborne Disease Spore Detection Device and Method

Abstract

The present invention provides a device and method for detecting airborne disease spores of crops, comprising a light source, a light-transmitting micropore, a composite-field microfluidic chip, a lensless polarization camera, a signal generator, and an image processing unit; the light source generates interference light through the light-transmitting micropore and irradiates the composite-field microfluidic chip, the polarization camera is located below the composite-field microfluidic chip, the signal generator enables an electric field to be generated within the composite-field microfluidic chip, so that different types of disease spores are enriched in different enrichment regions of the composite-field microfluidic chip; the polarization camera captures the polarization-diffraction fingerprint images of the airborne disease spores in the enrichment region of the composite-field microfluidic chip and transmits them to the image processing unit; the image processing unit processes the images and classifies and identifies the disease spores according to the differences in the relative light intensity distribution values of the polarization-diffraction fingerprint images of the airborne disease spores. The present invention has the characteristics of small volume, low price, and easy operation, and improves the efficiency of disease spore detection.

Description

Technical Field

[0001] The present invention belongs to the technical field of separating, enriching, classifying and identifying airborne disease spores, and particularly relates to an airborne disease spore detection device and method for crops. Background Art

[0002] In recent years, with the increasing demand for a better life, the demand for the "vegetable basket" project has been growing day by day. The vegetable industry in China has developed rapidly. The vegetable basket project in China is one of the main supports and an important way to increase farmers' income. Tomatoes and cucumbers are deeply loved by consumers because of their rich taste and nutritional value, and the cultivation areas of tomatoes and cucumbers account for the main part of the protected cultivation area in China. Tomatoes and cucumbers are inevitably exposed to biological stresses during their growth process, and the temperature and humidity conditions in the greenhouse environment are more conducive to the occurrence, prevalence and spread of airborne fungal diseases. Tomato gray mold is caused by Botrytis cinerea. This disease mainly occurs during the flowering and fruiting periods of tomatoes. After the disease occurs, it can damage the flowers, fruits, leaves and stems of tomato plants. It has an early onset time, a long duration, and is likely to cause a large number of rotten fruits in tomatoes. Cucumber downy mildew is caused by Pseudoperonospora cubensis. After the disease occurs, it mainly damages the leaves of cucumber plants, and can also damage the stems and inflorescences of cucumber plants. It can occur from the seedling stage to the growth stage of cucumber plants, especially when the cucumber enters the fruit-harvesting stage, the disease is more severe. After the disease occurs, most of the leaves of cucumber plants can wither and die within one or two weeks, and the cucumber field turns yellow. Cucumber powdery mildew (commonly known as "white disease") is caused by Podosphaera xanthii and Sphaerotheca fuliginea. After cucumber powdery mildew occurs, it mainly damages the leaves of cucumber plants, and also damages the petioles and stems of cucumber plants. It usually occurs more severely in the middle and late growth stages of cucumber plants, and is likely to cause the leaves of cucumber plants to wither and even pull out the plants in advance. These airborne fungal diseases will become increasingly severe with the expansion of cultivation area and the increase in the number of consecutive cropping years. In severe cases, it can cause a reduction in production, with a yield loss of 20-50%, or even a complete crop failure.

[0003] At present, the diagnosis and control of greenhouse crop diseases are mainly based on the experience of producers and the results of conventional laboratory or on-site tests. Laboratory testing techniques mainly include electron microscopy testing techniques, polymerase chain reaction (PCR), molecular biology testing techniques, etc. These testing techniques can accurately determine the types of greenhouse crop diseases, but laboratory testing techniques have the disadvantages of being destructive, time-consuming, and labor-intensive. Conventional on-site testing techniques mainly use spectral detection techniques and image processing techniques to detect known or specific crop diseases. These techniques can achieve the detection of crop diseases through statistical modeling inversion, and based on this, accurate guidance can be provided for timely prediction and treatment of diseases during greenhouse crop cultivation. However, these diagnostic techniques cannot achieve early warning before the epidemic of diseases, but can only detect them when the diseases occur, and by then, the best window period for preventing and controlling crop diseases has been missed.

[0004] Actually, before the occurrence of airborne diseases in greenhouse crops and the large-scale spread of diseases, the first thing that happens is the spread of airborne disease spores with the air current in the air. When the airborne disease spores in the spread come into contact with plant leaves, they will enter the plant tissue through the stomata of the plant leaves and germinate, and then release more airborne disease spores to continue spreading among plants. Therefore, as long as the spread information of airborne disease spores can be obtained in real time from the transmission route, the prediction and reporting of crop airborne diseases can be carried out in a timely manner. However, there are some problems in the efficient separation and enrichment of airborne disease spores in greenhouse crops: for example, the air composition in the greenhouse is complex and there are a large number of particulate impurities, including pollen, droplets, eggs, dust, pathogen spores, etc., with scales ranging from nm to μm. In addition, the volume fraction of airborne disease spore particles in the air is extremely low, generally less than two per hundred thousand. It is very difficult to quickly and accurately separate airborne disease spores from the mixed particles with extremely low proportion and complex composition, and to separate and enrich spores of different sizes and shapes to the detection area.

[0005] With the improvement of technicians on spore traps, there are more and more spore traps sold on the market now, and using spore traps to capture airborne disease spores in the air has become a common method. For example, existing portable spore traps, vehicle-mounted spore traps, and fixed spore traps all first capture airborne disease spores in the air, and then use a microscope for identification, achieving the capture and detection of airborne disease spores spreading in the air to a certain extent. Although various forms of spore traps sold on the market now can capture airborne disease spores in the air, they cannot separate the captured airborne disease spores, so it is impossible to effectively separate the captured airborne disease spores from other impurities, which is not conducive to the timely identification and counting of airborne disease spores.

[0006] In summary, the existing detection of disease spores has the disadvantages of long time consumption, large lag, high equipment cost, difficult operation, and inability to separate and enrich disease spores in the air. Therefore, the detection device and method for airborne disease spores in a greenhouse are still technical problems that need to be solved urgently. Summary of the Invention

[0007] In view of the above technical problems, the present invention provides a detection device and method for airborne disease spores of crops, which is a detection device and method for airborne disease spores based on the relative light intensity distribution value of polarization-diffraction fringes, realizing the classification and recognition of airborne disease spores of crops and improving the detection efficiency of disease spores.

[0008] Note that the recording of these objectives does not prevent the existence of other objectives. One embodiment of the present invention does not need to achieve all the above objectives. Objectives other than the above can be extracted from the descriptions of the specification, drawings, and claims.

[0009] The present invention achieves the above technical objectives through the following technical means.

[0010] The technical means adopted by the present invention are as follows:

[0011] A detection device for airborne disease spores of crops includes a light source, a light-transmitting micropore, a composite-field microfluidic chip, a lensless polarization camera, a signal generator, and an image processing unit, which are arranged in sequence from top to bottom;

[0012] The light source generates interference light through the light-transmitting micropore and irradiates it on the composite-field microfluidic chip. The polarization camera is located below the composite-field microfluidic chip, and the distance between the composite-field microfluidic chip and the polarization camera is much smaller than the distance from the light-transmitting micropore to the composite-field microfluidic chip;

[0013] The signal generator is connected to the composite-field microfluidic chip. The signal generator is used to generate an alternating voltage, and an electric field is generated inside the composite-field microfluidic chip to enrich different types of disease spores in different enrichment regions of the composite-field microfluidic chip;

[0014] The polarization camera captures and images the polarization-diffraction fingerprint images of the airborne disease spores in the enrichment region of the composite-field microfluidic chip and transmits them to the image processing unit;

[0015] The image processing unit is used to process the polarization-diffraction fingerprint images of the airborne disease spores, obtain the relative light intensity distribution values of the polarization-diffraction fingerprint images of the airborne disease spores, and classify and recognize the disease spores according to the differences in the relative light intensity distribution values.

[0016] In the above solution, the light source is an LED lamp bead assembly;

[0017] The LED lamp bead assembly includes a plurality of LED lamp beads; the wavelength of the LED lamp beads is determined by collecting the original spectral characteristic curve of airborne disease spores, performing principal component analysis on the original spectral curve, selecting the principal components with a cumulative contribution rate greater than 89%, and then obtaining the corresponding characteristic bands. The corresponding characteristic bands are the light source wavelengths suitable for collecting the diffraction fingerprint images of airborne disease spores, that is, the wavelengths of the LED lamp beads.

[0018] In the above solution, the composite field microfluidic chip includes a polydimethylsiloxane sheet;

[0019] The polydimethylsiloxane sheet is provided with a pretreatment channel for the preliminary separation of airborne disease spores, an airborne disease spore secondary separation channel, and an airborne disease spore enrichment area;

[0020] One end of the pretreatment channel is provided with an airborne disease spore inlet, and the other end of the pretreatment channel is provided with a number of airborne disease spore secondary separation channels. The other end of the pretreatment channel is communicated with one end of the airborne disease spore secondary separation channels. The other ends of the airborne disease spore secondary separation channels are provided with a plurality of airborne disease spore enrichment areas communicated therewith, and each airborne disease spore enrichment area is provided with an air flow outlet;

[0021] On both sides of the pretreatment channel, symmetrically arranged sheath flow channels are respectively provided. The sheath flow channels are used to make the spores move forward in a straight line in the pretreatment channel; on both sides of the downstream of the pretreatment channel where the sheath flow channels are located, and on both sides of the airborne disease spore secondary separation channels, electrode structures are respectively provided; the electrode structures are connected to a signal generator, and the signal generator makes the electrode structures generate an electric field to enrich different types of disease spores into different airborne disease spore enrichment areas.

[0022] Further, the axis of the sheath flow channel intersects the axis of the air inlet section of the pretreatment channel at an acute angle;

[0023] The sheath flow channel includes a first sheath flow channel and a second sheath flow channel; the first sheath flow channel and the second sheath flow channel are respectively provided symmetrically on both sides of the pretreatment channel.

[0024] Further, corresponding first electrode structure and fourth electrode structure, second electrode structure and fifth electrode structure, third electrode structure and sixth electrode structure are provided at the downstream of the pretreatment channel where the sheath flow channels are located; the first electrode structure, the second electrode structure, the third electrode structure, the fourth electrode structure, the fifth electrode structure, and the sixth electrode structure are respectively connected to the signal generator to generate an electric field in the pretreatment channel, so that the airborne disease spores are preliminarily separated when passing through the electric field of the pretreatment channel.

[0025] Further, the airborne disease spore secondary separation channel includes a first airborne disease spore secondary separation channel and a second airborne disease spore secondary separation channel;

[0026] One end of the first secondary separation channel for airborne disease spores is communicated with the pretreatment channel, and the other end is provided with a third enrichment area for airborne disease spores and a fourth enrichment area for airborne disease spores. The third enrichment area for airborne disease spores is provided with a third air flow outlet, and the fourth enrichment area for airborne disease spores is provided with a fourth air flow outlet;

[0027] One end of the second secondary separation channel for airborne disease spores is communicated with the pretreatment channel, and the other end is provided with a first enrichment area for airborne disease spores and a second enrichment area for airborne disease spores; the first enrichment area for airborne disease spores is provided with a first air flow outlet, and the second enrichment area for airborne disease spores is provided with a second air flow outlet;

[0028] The first secondary separation channel for airborne disease spores is provided with a seventh electrode structure and a thirteenth electrode structure arranged oppositely, and an eighth electrode structure and a fourteenth electrode structure;

[0029] The second secondary separation channel for airborne disease spores is provided with a ninth electrode structure and a twelfth electrode structure arranged oppositely, and a tenth electrode structure and an eleventh electrode structure;

[0030] The seventh electrode structure, the eighth electrode structure, the ninth electrode structure, the tenth electrode structure, the eleventh electrode structure, the twelfth electrode structure, the thirteenth electrode structure, and the fourteenth electrode structure are respectively connected to a signal generator to generate an electric field in the secondary separation channel for airborne disease spores, so that the airborne disease spores are secondarily separated when passing through the electric field of the secondary separation channel for airborne disease spores and enter different enrichment areas for airborne disease spores respectively.

[0031] A detection method according to the crop airborne disease spore detection device described above, comprising the following steps:

[0032] Step S1: Turn on the micro air pump and the signal generator. The signal generator generates an alternating voltage, and an electric field is generated in the compound field microfluidic chip, so that different types of disease spores in the air are enriched in different enrichment areas of the compound field microfluidic chip;

[0033] Step S2: Turn on the switch of the light source. The light source generates interference light through the light-transmitting micropores and irradiates the compound field microfluidic chip;

[0034] Step S3: The polarization camera images and collects the polarization-diffraction fingerprint images of the airborne disease spores in the enrichment area of the compound field microfluidic chip and transmits them to the image processing unit;

[0035] Step S4: The image processing unit processes the polarization-diffraction fingerprint images of the airborne disease spores to obtain the relative light intensity distribution values of the polarization-diffraction fingerprint images of the airborne disease spores;

[0036] Step S5: Classify and identify the airborne disease spores according to the differences in the relative light intensity distribution values of the polarization-diffraction fingerprint images of the airborne disease spores extracted in Step S4.

[0037] In the said Step S3, the polarization camera collects the diffraction fingerprint images of the airborne disease spores in different enrichment regions of the composite field microfluidic chip at polarization directions of 0°, 45°, 90°, and 135°.

[0038] In the above solution, the relative light intensity distribution value of the polarization-diffraction fingerprint image of the airborne disease spores in Step S4 is obtained through the following steps:

[0039] Extract the characteristics of the relative light intensity distribution of the polarization-diffraction fingerprint image of the airborne disease spores, calculate the peak value AP, valley value AV, and center value C of the relative light intensity distribution of the spore's polarization-diffraction fingerprint image, and calculate the ratio PCR of the peak value to the valley value, the ratio VCR of the peak value to the center value, and the ratio PVR of the valley value to the center value. The calculation formulas are as follows:

[0040]

[0041] In the formula: AP i represents the relative light intensity of the peak of the polarization-diffraction fingerprint spectrum of the airborne disease spores;

[0042] AV j represents the relative light intensity of the valley of the polarization-diffraction fingerprint spectrum of the airborne disease spores;

[0043] C represents the relative light intensity of the central region of the polarization-diffraction fingerprint spectrum of the airborne disease spores;

[0044] i is the number of bright fringes, and j is the number of dark fringes.

[0045] In the above solution, the SVM model is used to classify and identify the airborne disease spores in Step S5. Specifically:

[0046] Use Accuracy, Precision, Recall, and the comprehensive evaluation index F value F1-Score as the evaluation indicators for the classification and identification of the disease spores. The calculation formulas are as follows:

[0047]

[0048] In the formula: TP (True Positive) represents the number of positive samples predicted as positive by the model;

[0049] FP (False Positive) represents the number of negative samples predicted as positive by the model;

[0050] FN (False Negative) represents the number of positive samples predicted as negative by the model;

[0051] TN (True Negative) represents the number of negative samples predicted as negative by the model;

[0052] When the classifier SVM model performs the classification task, the actually predicted number of airborne disease spores is regarded as the number of positive samples, and the sum of the remaining airborne disease spores is the number of negative samples.

[0053] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0054] In the present invention, the light source generates interference light through the light-transmitting micropores and irradiates the composite-field microfluidic chip. An electric field is generated inside the composite-field microfluidic chip, enabling different types of disease spores to be enriched in different enrichment regions of the composite-field microfluidic chip. The polarization camera images and collects the polarization-diffraction fingerprint images of the airborne disease spores in the enrichment region of the composite-field microfluidic chip, and transmits them to the image processing unit for processing to obtain the relative light intensity distribution values of the polarization-diffraction fingerprint images of the airborne disease spores. The disease spores are classified and identified according to the differences in the relative light intensity distribution values. The crop airborne disease spore detection device of the present invention has the characteristics of small volume, low price, and easy operation, and can perform on-site separation, enrichment, classification, and identification of crop airborne disease spores in the air, which has important significance and practical value for the fields of facility environment disease detection and environmental control.

[0055] The present invention can be widely used in the fields of separating, enriching, classifying, and identifying crop airborne disease spores in greenhouses.

[0056] Note that the description of these effects does not prevent the existence of other effects. One embodiment of the present invention does not necessarily have all the above effects. Other effects beyond the above can be obviously seen and extracted from the descriptions in the specification, drawings, claims, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0058] Figure 1 It is a schematic diagram of the composition of a crop airborne disease spore detection device according to an embodiment of the present invention;

[0059] Figure 2 It is a schematic diagram of the structure of a crop airborne disease spore detection device according to an embodiment of the present invention;

[0060] Figure 3 It is a schematic diagram of the distribution of three LED lamp beads of the LED lamp bead component according to an embodiment of the present invention;

[0061] Figure 4 It is the original spectral data diagram of airborne disease spores according to an embodiment of the present invention;

[0062] Figure 5 It is a schematic diagram of the spectral data of airborne disease spores after smoothing processing according to an embodiment of the present invention;

[0063] Figure 6 It is a diagram of the calculation result of the weight of the principal component comprehensive coefficient of the spectral data of airborne disease spores after smoothing processing according to an embodiment of the present invention;

[0064] Figure 7 It is a schematic diagram of the structure of a composite field microfluidic chip according to an embodiment of the present invention;

[0065] Figure 8 It is a schematic diagram of the connection between a composite field microfluidic chip and a signal generator and a micropump according to an embodiment of the present invention;

[0066] Figure 9 It is a diagram of the extraction result of the diffraction - polarization fingerprint image features of cucumber powdery mildew spores according to an embodiment of the present invention, where Figure 9 (a) is the relative light intensity distribution at 0°, 9(b) is the relative light intensity distribution at 45°, 9(c) is the relative light intensity distribution at 90°, 9(d) is the relative light intensity distribution at 135°;

[0067] Figure 10 It is a diagram of the extraction result of the diffraction - polarization fingerprint image features of tomato gray mold spores according to an embodiment of the present invention, where Figure 10 (a) is the relative light intensity distribution at 0°, 10(b) is the relative light intensity distribution at 45°, 10(c) is the relative light intensity distribution at 90°, 10(d) is the relative light intensity distribution at 135°;

[0068] Figure 11 It is a diagram of the extraction result of the diffraction - polarization fingerprint image features of cucumber downy mildew spores according to an embodiment of the present invention, where Figure 11 (a) is the relative light intensity distribution at 0°, 11(b) is the relative light intensity distribution at 45°, 11(c) is the relative light intensity distribution at 90°, 11(d) is the relative light intensity distribution at 135°;

[0069] Figure 12 It is Figure 10 A diagram for marking the peak value, center value and valley value of (b);

[0070] Figure 13 It is a schematic diagram of the confusion matrix of the SVM classification model according to an embodiment of the present invention;

[0071] Table 1 shows the cumulative contribution rate of the principal components of the spectral data of airborne disease spores after smoothing processing;

[0072] Table 2 shows the statistical results of the relative light intensity distribution of the diffraction-polarization fingerprints of airborne disease spores;

[0073] Table 3 shows the statistical results of the classification of disease spores by the support vector machine (SVM) model;

[0074] Table 4 shows the performance evaluation results of the classification results of disease spores by the support vector machine (SVM) model.

[0075] In the figure: 1. Power supply; 2. LED lamp bead assembly; 3. Through hole; 4. Composite field microfluidic chip; 5. Lensless polarization camera; 6. Image processing component; 7. 435nm LED lamp bead; 8. 475nm LED lamp bead; 9. 720nm LED lamp bead; 10. Polydimethylsiloxane sheet; 11. Glass slide; 12. Airborne disease spore inlet; 13. Pretreatment channel; 14. First sheath flow channel; 15. Second sheath flow channel; 16. First electrode structure; 17. Second electrode structure; 18. Third electrode structure; 19. Fourth electrode structure; 20. Fifth electrode structure; 21. Sixth electrode structure; 22. Seventh electrode structure; 23. Eighth electrode structure; 24. First secondary separation channel for airborne disease spores; 25. Ninth electrode structure; 26. Tenth electrode structure; 27. Second secondary separation channel for airborne disease spores; 28. Eleventh electrode structure; 29. Twelfth electrode structure; 30. Thirteenth electrode structure; 31. Fourteenth electrode structure; 32. First air flow outlet; 33. First enrichment area for airborne disease spores; 34. Second enrichment area for airborne disease spores; 35. Second air flow outlet; 36. Third air flow outlet; 37. Third enrichment area for airborne disease spores; 38. Fourth enrichment area for airborne disease spores; 39. Fourth air flow outlet; 40. First micro air pump; 41. Second micro air pump; 42. Third micro air pump; 43. Fourth micro air pump; 44. Fifth micro air pump; 45. Sixth micro air pump; 46. Seventh micro air pump; 47. First signal generator; 48. Second signal generator; 49. First wave peak value; 50. Second wave peak value; 51. Central value; 52. First wave valley value; 53. Second wave valley value. Detailed implementation manners

[0076] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0077] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "front", "rear", "left", "right", "upper", "lower", "axial", "radial", "vertical", "horizontal", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more, unless otherwise specifically defined.

[0078] In the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0079] As Figure 1-2 shown is a preferred embodiment of the crop airborne disease spore detection device of the present invention. The crop airborne disease spore detection device includes a light source, a light-transmitting micropore 3, a composite field microfluidic chip 4, a lensless polarization camera 5, a signal generator, and an image processing unit 6 arranged in sequence from top to bottom;

[0080] The light source generates interference light through the light-transmitting micropore 3 and irradiates it on the composite field microfluidic chip 4. The polarization camera 5 is located below the composite field microfluidic chip 4, and the distance between the composite field microfluidic chip 4 and the polarization camera 5 is much smaller than the distance from the light-transmitting micropore 3 to the composite field microfluidic chip 4;

[0081] The signal generator is connected to the composite field microfluidic chip 4. The signal generator is used to generate an alternating voltage, and an electric field is generated inside the composite field microfluidic chip 4 to enrich different types of disease spores in different enrichment regions of the composite field microfluidic chip 4;

[0082] The polarization camera 5 captures and images the polarization-diffraction fingerprint images of the airborne disease spores in the enrichment region of the composite field microfluidic chip 4 and transmits them to the image processing unit 6;

[0083] The image processing unit 6 is used to process the polarization-diffraction fingerprint image of airborne disease spores, obtain the relative light intensity distribution value of the polarization-diffraction fingerprint image of airborne disease spores, and classify and identify the disease spores according to the differences in the relative light intensity distribution values.

[0084] Preferably, the light source is the LED lamp bead assembly 2; the LED lamp bead assembly 2 includes a plurality of LED lamp beads; the wavelength of the LED lamp beads is determined by collecting the original spectral characteristic curve of airborne disease spores, performing principal component analysis on the original spectral curve, selecting the principal components with a cumulative contribution rate greater than 89%, and then obtaining the corresponding characteristic bands, and the corresponding characteristic bands are the light source wavelengths suitable for collecting the diffraction fingerprint images of airborne disease spores, that is, the wavelengths of the LED lamp beads.

[0085] Preferably, the LED lamp bead assembly 2 is connected to the power supply 1.

[0086] Preferably, the diameter of the light-transmitting micropore 3 is 100 μm.

[0087] The power supply 1 is preferably a power bank, and the power bank provides power for the LED lamp bead assembly 2; the light source emitted by the LED lamp bead assembly 2 generates interference light through the light-transmitting micropore 3 located below it to form a spherical wave, and irradiates the enrichment area of the composite field microfluidic chip 4, and the polarization-diffraction fingerprint image of the airborne disease spores in the enrichment area of the composite field microfluidic chip 4 is imaged and collected by the lensless polarization camera 5; the enrichment area of the composite field microfluidic chip 4 is located directly above the imaging unit of the lensless polarization camera 5, and the enrichment area of the composite field microfluidic chip 4 is next to the imaging unit of the lensless polarization camera 5 and the distance between them is much smaller than the distance from the light-transmitting micropore 3 to the composite field microfluidic chip 4, so that the field of view of the polarization-diffraction fingerprint image of the airborne disease spores imaged and collected by the lensless polarization camera 5 is larger than that of the traditional microscope imaging.

[0088] A detection method according to the crop airborne disease spore detection device described above, comprising the following steps:

[0089] Step S1: Turn on the micro air pump and the signal generator, the signal generator generates an alternating voltage, an electric field is generated in the composite field microfluidic chip 4, and different types of disease spores in the air are enriched into different enrichment areas of the composite field microfluidic chip 4;

[0090] Step S2: Turn on the switch of the light source, and the light source generates interference light through the light-transmitting micropore 3 and irradiates on the composite field microfluidic chip 4;

[0091] Step S3: The polarization camera 5 images and collects the polarization-diffraction fingerprint image of the airborne disease spores in the enrichment area of the composite field microfluidic chip 4, and transmits it to the image processing unit 6;

[0092] Step S4: The image processing unit 6 processes the polarization-diffraction fingerprint image of the airborne disease spores to obtain the relative light intensity distribution value of the polarization-diffraction fingerprint image of the airborne disease spores;

[0093] Step S5: Classify and identify the airborne disease spores according to the differences in the relative light intensity distribution values of the polarization-diffraction fingerprint images of the airborne disease spores extracted in Step S4.

[0094] In the said Step S3, the polarization camera 5 collects the diffraction fingerprint images of the airborne disease spores in different enrichment regions of the compound field microfluidic chip 4 at polarization directions of 0°, 45°, 90°, and 135°.

[0095] The relative light intensity distribution value of the polarization-diffraction fingerprint image of the airborne disease spores in the said Step S4 is obtained through the following steps:

[0096] Extract the peak value, valley value, and central value of the relative light intensity distribution of the polarization-diffraction fingerprint image of the airborne disease spores, and calculate the ratio PCR of the peak value to the valley value, the ratio VCR of the peak value to the central value, and the ratio PVR of the valley value to the central value. The calculation formulas are as follows:

[0097]

[0098] In the formula: AP i represents the relative light intensity of the peak of the polarization-diffraction fingerprint spectrum of the airborne disease spores;

[0099] AV j represents the relative light intensity of the valley of the polarization-diffraction fingerprint spectrum of the airborne disease spores;

[0100] C represents the relative light intensity of the central region of the polarization-diffraction fingerprint spectrum of the airborne disease spores;

[0101] i is the number of bright fringes, and j is the number of dark fringes.

[0102] In the said Step S5, the SVM model is used to classify and identify the airborne disease spores. Specifically:

[0103] Use Accuracy, Precision, Recall, and the comprehensive evaluation index F value F1-Score as the evaluation indexes for the classification and identification of the disease spores. The calculation formulas are as follows:

[0104]

[0105] In the formula: TP represents the number of positive samples predicted as positive by the model;

[0106] FP represents the number of negative samples predicted as positive by the model;

[0107] FN represents the number of positive samples predicted as negative by the model;

[0108] TN represents the number of negative samples predicted as negative by the model;

[0109] When the classifier SVM model performs the classification task, the actually predicted number of airborne disease spores is regarded as the number of positive samples, and the sum of the remaining airborne disease spores is the number of negative samples.

[0110] In an embodiment of the present invention, a hyperspectral device is used to collect the reflection spectral data of tomato gray mold spores, cucumber downy mildew spores, and cucumber powdery mildew spores samples. The hyperspectral device used in the experiment is preferably the HIS-VNIR scanning visible-near infrared hyperspectral imaging system produced by Shanghai Wuling Optoelectronic Technology Co., Ltd. This visible-near infrared hyperspectral imaging system mainly includes a visible-near infrared spectrometer, a dark box, an adjustable light source, a stage, a mobile stage, a displacement controller, and a computer, etc. The original spectral characteristic curves of the tomato gray mold spores, cucumber downy mildew spores, and cucumber powdery mildew spores samples are collected, and the original spectral data of the tomato gray mold spores, cucumber downy mildew spores, and cucumber powdery mildew spores samples are obtained as Figure 4 shown. To eliminate the influence of noise on the original spectral analysis, the Savitzky-Golay (S-G) five-point smoothing is used to process the original spectral data of the airborne disease spore samples. The original spectral data is denoised, averaged, and smoothed, and then the schematic diagram of the spectral data of the airborne disease spores obtained by the smoothing process is as Figure 5 shown. There are 512 bands in the original spectral data of the airborne disease spore samples, and there is a large amount of information redundancy between the bands. It is necessary to perform dimensionality reduction processing on the original spectral data. Selecting a suitable data dimensionality reduction algorithm can improve the modeling efficiency and accuracy of the spectral data. In this embodiment, the method of principal component analysis (PCA, Principal Component Analysis) is used to select the characteristic wavelengths of the original spectral data of the collected airborne disease spore samples to achieve the purpose of dimensionality reduction of the original spectral data. Perform principal component analysis on the spectral data of the smoothed airborne disease spore samples in the SPSS22 software, and a total of 17 principal components are obtained. The cumulative contribution rates of the first 2 principal components obtained are shown in Table 1. The cumulative contribution rate of the first principal component and the second principal component of the airborne disease spore spectral data is 92.271%, indicating that the first two principal components contain 92.271% of the information of the spectral data of the airborne disease spore samples. In this embodiment, the first 2 principal components of the spectral data of the airborne disease spore samples are analyzed and processed, and the linear combination coefficients, variances, and comprehensive score model coefficients of the first 2 principal components are solved respectively. Finally, the comprehensive coefficient weights of the first 2 principal components are obtained, as Figure 6As shown in the figure, there are three peaks in the comprehensive coefficient weights of the first two principal components of the spectral data of airborne disease spore samples in the wavelength range of 390 - 1050 nm, corresponding to the wavelength bands of 435 nm, 720 nm, and 980 nm respectively, and three valleys corresponding to the wavelength bands of 475 nm, 920 nm, and 1025 nm respectively. Considering the original data of the spectral data of airborne disease spore samples and the comprehensive coefficient weights of its first two principal components, in this embodiment, light sources with wavelengths of 435 nm, 475 nm, and 720 nm are selected as the light sources for diffraction - polarization imaging of airborne disease spores. And it is determined that the LED lamp bead assembly 2 selects a combination of LED lamp beads with wavelengths of 435 nm, 475 nm, and 720 nm; the LED lamp bead assembly 2 includes a 435 - nm LED lamp bead 7, a 475 - nm LED lamp bead 8, and a 720 - nm LED lamp bead 9. The light source formed by the combination of the 435 - nm LED lamp bead, the 475 - nm LED lamp bead, and the 720 - nm LED lamp bead has a central angle of 120° with the receiving part, as Figure 3 shown; the light - transmitting micropores 3 are located directly below the central angle of the light sources of the three - band lamp beads and are used to generate interference light.

[0111] Table 1 Cumulative contribution rate of principal components of the principal component analysis results of the spectral data of airborne disease spores after smoothing processing

[0112]

[0113] Combined with Figure 7-8 shown, the composite - field microfluidic chip 4 includes a polydimethylsiloxane sheet 10 with micro - channels engraved thereon and a glass slide 11.

[0114] The polydimethylsiloxane sheet 10 is provided with a pretreatment channel 13 for the preliminary separation of airborne disease spores, a secondary separation channel for airborne disease spores, and an enrichment area for airborne disease spores;

[0115] One end of the pretreatment channel 13 is provided with an airborne disease spore inlet 12, and the other end of the pretreatment channel 13 is provided with a number of secondary separation channels for airborne disease spores. The other end of the pretreatment channel 13 is communicated with one end of the secondary separation channels for airborne disease spores. The other end of the secondary separation channels for airborne disease spores is provided with a plurality of enrichment areas for airborne disease spores communicated therewith, and each enrichment area for airborne disease spores is provided with an air flow outlet;

[0116] On both sides of the preprocessing channel 13, sheath flow channels are symmetrically arranged. The sheath flow channels are used to make the spores move forward in a straight line within the preprocessing channel 13. On both sides of the preprocessing channel 13 at the downstream of the sheath flow channels, as well as on both sides of the secondary separation channel for airborne disease spores, electrode structures are respectively provided. The electrode structures are connected to a signal generator, and the signal generator enables the electrode structures to generate an electric field, so that different types of disease spores are enriched in different airborne disease spore enrichment regions.

[0117] In this embodiment, the power bank provides a 5V power supply for the LED lamp bead assembly 2. The LED lamp bead assembly 2 is composed of an LED lamp bead with a wavelength of 435nm, an LED lamp bead with a wavelength of 475nm, and an LED lamp bead with a wavelength of 720nm. The light source formed by combining the 435nm LED lamp bead, the 475nm LED lamp bead, and the 720nm LED lamp bead has a central angle of 120° with the receiving part, as Figure 3As shown in the figure; the through hole is located directly below the central included angle of the three-band lamp bead light sources, and is used to generate interference light; the light source emitted by the LED lamp bead assembly 2 generates interference light to form a spherical wave through the through hole 3 located below it, and irradiates the enrichment area of the composite field microfluidic chip 4, and the polarization-diffraction fingerprint image of the airborne disease spores in the enrichment area of the composite field microfluidic chip 4 is imaged and collected by the lensless polarization camera 5; the enrichment area of the composite field microfluidic chip 4 is located directly above the imaging unit of the lensless polarization camera 5, and the enrichment area of the composite field microfluidic chip 4 is next to the imaging unit of the lensless polarization camera 5 and the distance between them is much smaller than the distance from the through hole 3 to the composite field microfluidic chip 4, so that the field of view of the polarization-diffraction fingerprint image of the airborne disease spores collected by the lensless polarization camera 5 is larger than that of the traditional microscope imaging; the airborne disease spore inlet and air flow outlet are punched on the polydimethylsiloxane sheet 10 of the composite field microfluidic chip 4 with a punching needle; the airborne disease spore inlet of the composite field microfluidic chip 4 is connected to the micro air pump through a hose, the sheath flow channel is connected to the micro air pump through a hose, and the air flow outlet is connected to the micro air pump through a hose; the electrode structure of the composite field microfluidic chip 4 is connected to the signal generator; the sheath flow channel of the composite field microfluidic chip 4 ensures that the spores flowing into the composite field microfluidic chip from the airborne disease spore inlet move in a straight line forward in the pretreatment channel for the preliminary separation of airborne disease spores; the enrichment area of the airborne disease spores of the composite field microfluidic chip 4 is used to enrich airborne disease spores of different sizes; the signal generator is used to generate an alternating voltage, and the signal generator provides an alternating voltage for the electrode structure to generate an electric field; when the airborne disease spores pass through the electric field generated by the electrode structure, they are preliminarily separated and enter the secondary separation channel of the airborne disease spores respectively; when the airborne disease spores pass through the electric field generated by the electrode structure in the secondary separation channel, they are secondarily separated and enter the enrichment area of the airborne disease spores respectively; the gas flowing in from the airborne disease spore inlet finally flows out of the composite field microfluidic chip 4 from the air flow outlet; during operation, the lensless polarization camera 5 collects the diffraction fingerprint images of the airborne disease spores in the enrichment area of the composite field microfluidic chip 4 at polarization directions of 0°, 45°, 90°, and 135°; the collected diffraction fingerprint images are processed to obtain the relative light intensity distribution values of the polarization-diffraction image fingerprints of the airborne disease spores, and the disease spores are classified and identified according to the differences in the relative light intensity distribution values.

[0118] In an embodiment of the present invention, preferably, the axis of the sheath flow channel intersects the axis of the intake section of the pretreatment channel 13 at an acute angle; the sheath flow channel includes a sheath flow channel 14 and a sheath flow channel 15; the sheath flow channel 14 and the sheath flow channel 15 are respectively arranged symmetrically on both sides of the pretreatment channel 13.

[0119] The preprocessing channel 13 is provided with a correspondingly arranged first electrode structure 16 and a fourth electrode structure 19, a second electrode structure 17 and a fifth electrode structure 20, and a third electrode structure 18 and a sixth electrode structure 21 at the downstream of the sheath flow channel; the first electrode structure 16, the second electrode structure 17, the third electrode structure 18, the fourth electrode structure 19, the fifth electrode structure 20, and the sixth electrode structure 21 are respectively connected to a signal generator to generate an electric field in the preprocessing channel 13, so that the airborne disease spores are preliminarily separated when passing through the electric field of the preprocessing channel 13.

[0120] The airborne disease spore secondary separation channel includes a first airborne disease spore secondary separation channel 24 and a second airborne disease spore secondary separation channel 27;

[0121] One end of the first airborne disease spore secondary separation channel 24 is communicated with the preprocessing channel 13, and the other end is provided with a third airborne disease spore enrichment area 37 and a fourth airborne disease spore enrichment area 38. The third airborne disease spore enrichment area 37 is provided with a third air flow outlet 36, and the fourth airborne disease spore enrichment area 38 is provided with a fourth air flow outlet 39;

[0122] One end of the second airborne disease spore secondary separation channel 27 is communicated with the preprocessing channel 13, and the other end is provided with a first airborne disease spore enrichment area 33 and a second airborne disease spore enrichment area 34; the first airborne disease spore enrichment area 33 is provided with a first air flow outlet 32, and the second airborne disease spore enrichment area 34 is provided with a second air flow outlet 35;

[0123] The first airborne disease spore secondary separation channel 24 is provided with a relatively arranged seventh electrode structure 22 and a thirteenth electrode structure 30, and an eighth electrode structure 23 and a fourteenth electrode structure 31;

[0124] The second airborne disease spore secondary separation channel 27 is provided with a relatively arranged ninth electrode structure 25 and a twelfth electrode structure 29, and a tenth electrode structure 26 and an eleventh electrode structure 28;

[0125] The seventh electrode structure 22, the eighth electrode structure 23, the ninth electrode structure 25, the tenth electrode structure 26, the eleventh electrode structure 28, the twelfth electrode structure 29, the thirteenth electrode structure 30, and the fourteenth electrode structure 31 are respectively connected to a signal generator to generate an electric field in the airborne disease spore secondary separation channel, so that the airborne disease spores are secondarily separated when passing through the electric field of the airborne disease spore secondary separation channel and enter different airborne disease spore enrichment areas respectively.

[0126] The air-borne disease spore inlet 12, the first air flow outlet 32, the second air flow outlet 35, the third air flow outlet 36, and the fourth air flow outlet 39 of the polydimethylsiloxane sheet of the composite field microfluidic chip 4; the air-borne disease spore inlet 12 of the composite field microfluidic chip 4 is connected to the first micro air pump 40 through a hose, the first sheath flow channel 14 is connected to the second micro air pump 41 through a hose, the second sheath flow channel 15 is connected to the third micro air pump 42 through a hose, the first air flow outlet 32 is connected to the seventh micro air pump 46 through a hose, the second air flow outlet 35 is connected to the sixth micro air pump 45 through a hose, the third air flow outlet 36 is connected to the fifth micro air pump 44 through a hose, and the fourth air flow outlet 39 is connected to the fourth micro air pump 43 through a hose; the first electrode structure 16, the second electrode structure 17, the third electrode structure 18, the fourth electrode structure 19, the fifth electrode structure 20, the sixth electrode structure 21, and the seventh electrode structure 22 of the composite field microfluidic chip 4 are respectively connected to the first signal generator 47, and the seventh electrode structure 22, the eighth electrode structure 23, the ninth electrode structure 25, the tenth electrode structure 26, the eleventh electrode structure 28, the twelfth electrode structure 29, the thirteenth electrode structure 30, and the fourteenth electrode structure 31 are respectively connected to the second signal generator 48.

[0127] The first sheath flow channel 14 and the second sheath flow channel 15 of the composite field microfluidic chip 4 are to ensure that the spores flowing into the composite field microfluidic chip 4 from the air-borne disease spore inlet 12 move in a straight line forward in the pre-treatment channel 13 for the preliminary separation of air-borne disease spores; the first air-borne disease spore enrichment region 33, the second air-borne disease spore enrichment region 34, the third air-borne disease spore enrichment region 37, and the fourth air-borne disease spore enrichment region 38 of the composite field microfluidic chip 4 are respectively used to enrich air-borne disease spores of different sizes.

[0128] The first signal generator 47 and the second signal generator 48 are used to generate alternating voltages. The first signal generator 47 provides an alternating voltage for the first electrode structure 16, the second electrode structure 17, the third electrode structure 18, the fourth electrode structure 19, the fifth electrode structure 20, the sixth electrode structure 21, and the seventh electrode structure 22 to generate an electric field; the second signal generator 48 provides an alternating voltage for the seventh electrode structure 22, the eighth electrode structure 23, the ninth electrode structure 25, the tenth electrode structure 26, the eleventh electrode structure 28, the twelfth electrode structure 29, the thirteenth electrode structure 30, and the fourteenth electrode structure 31 to generate an electric field.

[0129] When the airborne disease spores pass through the electric fields generated by the first electrode structure 16, the second electrode structure 17, the third electrode structure 18, the fourth electrode structure 19, the fifth electrode structure 20, the sixth electrode structure 21, and the seventh electrode structure 22, they are preliminarily separated and enter the secondary separation channel 24 of the airborne disease spores and the secondary separation channel 27 of the airborne disease spores respectively; when the airborne disease spores pass through the electric fields generated by the seventh electrode structure 22, the eighth electrode structure 23, the thirteenth electrode structure 30, and the fourteenth electrode structure 31 in the secondary separation channel 24, they are secondarily separated and enter the third enrichment area 37 of the airborne disease spores and the fourth enrichment area 38 of the airborne disease spores respectively; when the airborne disease spores pass through the electric fields generated by the ninth electrode structure 25, the tenth electrode structure 26, the eleventh electrode structure 28, and the twelfth electrode structure 29 in the secondary separation channel 27, they are secondarily separated and enter the third enrichment area 33 of the airborne disease spores and the fourth enrichment area 34 of the airborne disease spores respectively; the gas flowing in from the airborne disease spore inlet 12 finally flows out of the compound field microfluidic chip 4 from the first gas outlet 32, the second gas outlet 35, the third gas outlet 36, and the fourth gas outlet 39;

[0130] In an embodiment of the present invention, during operation, the lensless polarization camera 5 collects the diffraction fingerprint images of the airborne disease spores in the first enrichment area 33, the second enrichment area 34, the third enrichment area 37, and the fourth enrichment area 38 of the compound field microfluidic chip 4 at the polarization directions of 0°, 45°, 90°, and 135°; the collected diffraction fingerprint images are processed to obtain the relative light intensity distribution values of the polarization-diffraction image fingerprints of the airborne disease spores, and the disease spores are classified and identified according to the differences in the relative light intensity distribution values.

[0131] In this embodiment, the detection method of the crop airborne disease spore detection device includes the following steps:

[0132] Step S1: Turn on the micro air pump and the signal generator. The signal generator generates an alternating voltage, and an electric field is generated in the compound field microfluidic chip 4, so that different types of disease spores in the air are enriched in different enrichment areas of the compound field microfluidic chip 4;

[0133] Step S2: Turn on the switch of the light source. The light source generates interference light through the light-transmitting micropores 3 and irradiates the compound field microfluidic chip 4;

[0134] Step S3: The polarization camera 5 images and collects the polarization-diffraction fingerprint images of the airborne disease spores in the enrichment area of the compound field microfluidic chip 4 and transmits them to the image processing unit 6;

[0135] Step S4: The image processing unit 6 processes the polarization-diffraction fingerprint image of the airborne disease spores, extracts the characteristics of the relative light intensity distribution of the polarization-diffraction fingerprint image of the spores, calculates the peak value AP, valley value AV, and center value C of the relative light intensity distribution of the polarization-diffraction fingerprint image of the spores, and calculates the ratio of the peak value to the valley value, the ratio of the peak value to the center value, and the ratio of the valley value to the center value;

[0136] Extract the main bright fringe, main dark fringe, and center fringe of the polarization images of the diffraction fingerprints of Botrytis cinerea spores, Podosphaera xanthii spores, and Pseudoperonospora cubensis spores at 0°, 45°, 90°, and 135°. Then, calculate these three types of characteristics to obtain three parameters: the ratio of the peak value to the center value (PCR, Peak to Center ratio), the ratio of the valley value to the center value (VCR, Valley to Center ratio), and the ratio of the peak value to the valley value (PVR, Peak to Valley ratio). The calculation methods of the parameters refer to formulas (1)-(3).

[0137] To extract the diffraction-polarization fingerprint image characteristics of airborne disease spores, the diffraction-polarization images of the spores were collected and processed. On this basis, the polarization images of the diffraction fingerprints of airborne disease spores at 0°, 45°, 90°, and 135° were obtained respectively. The present invention extracted the characteristics of a total of 600 diffraction-polarization fingerprint images of airborne disease spores, with 200 diffraction-polarization fingerprint images for each type of airborne disease spore. The two-dimensional relative light intensity distribution diagrams of the diffraction-polarization fingerprint images of the three types of spores are respectively as Figure 9-11 shown.

[0138] Taking the 45° relative light intensity distribution in the extraction results of the diffraction-polarization fingerprint image characteristics of Botrytis cinerea spores as an example, combined with Figure 12 the figure seen, with the first peak value 49, the second peak value 50, the center value 51, the first valley value 52, and the second valley value 5, it can be determined that the number of bright fringes and the number of dark fringes are both two. Therefore, i = 1, 2, j = 1, 2.

[0139] Therefore, the three parameters of the ratio of the peak value to the center value (PCR), the ratio of the valley value to the center value (VCR), and the ratio of the peak value to the valley value (PVR) are calculated as follows:

[0140]

[0141] In the formula: AP i represents the relative light intensity of the peak of the diffraction fingerprint spectrum of the airborne disease spores;

[0142] AV j represents the relative light intensity of the trough of the diffraction fingerprint pattern of airborne disease spores;

[0143] C represents the relative light intensity of the central region of the diffraction fingerprint pattern of airborne disease spores;

[0144] i is the number of bright fringes and j is the number of dark fringes.

[0145] Step S5: Then, the machine learning realizes the classification and recognition of disease spores based on the characteristics of the polarized-diffraction fingerprint images of disease spores extracted in Step S4. In this embodiment, the SVM model is used to classify and recognize airborne disease spores, and accuracy, precision, recall, and the comprehensive evaluation index F value (F1-Score) are used as the evaluation indexes for the classification and recognition of disease spores. The calculation formulas are as follows:

[0146]

[0147] In the formula: TP (True Positive) represents the number of positive samples predicted as positive by the model;

[0148] FP (False Positive) represents the number of negative samples predicted as positive by the model;

[0149] FN (False Negative) represents the number of positive samples predicted as negative by the model;

[0150] TN (True Negative) represents the number of negative samples predicted as negative by the model.

[0151] When the classifier SVM model performs the classification task, the actually predicted number of airborne disease spores is regarded as the number of positive samples, and the sum of the numbers of other airborne disease spores is regarded as the number of negative samples.

[0152] From Figure 9-11 It can be seen that the diffraction fingerprints of each type of airborne disease spores have their unique relative light intensity distributions in the polarized images at 0°, 45°, 90°, and 135° directions. This is because the polarized images in different angular directions block part of the light source information under the action of the polarizer. The statistical results of the relative light intensity distribution values of the diffraction-polarization fingerprint image characteristics of the three types of airborne disease spores are shown in Table 2.

[0153] Table 2 Statistical results of the relative light intensity distribution of the diffraction-polarization fingerprints of three types of airborne disease spores

[0154]

[0155] Combined with the information of the relative light intensity distribution value of the diffraction-polarization fingerprint of the airborne disease spores extracted, six values of each diffraction fingerprint of the airborne disease spores at one polarization angle are calculated according to the formula. There are 24 values at four polarization angles, and these values are used to form 24 characteristic values of the diffraction fingerprint image of the airborne disease spores. Therefore, in this embodiment, the SVM algorithm is used to classify three types of airborne disease spores according to the 24 characteristic values of the diffraction polarization fingerprint image, and the confusion matrix is used to evaluate the performance of the classifier, and the accuracy, precision, recall rate, and the comprehensive evaluation index F value are used as evaluation indicators to evaluate the classification results. A total of 600 diffraction-polarization fingerprint images of the airborne disease spores of greenhouse crops are collected in the experiment, with 200 diffraction-polarization fingerprint images of the spores of tomato gray mold, cucumber powdery mildew, and cucumber downy mildew respectively. 70% of them are randomly selected as the training set, and the remaining 30% are used as the test set. Figure 13 It is the confusion matrix of the classification results of the SVM classification model for the test set of the diffraction-polarization fingerprint images of the airborne disease spores.

[0156] From Figure 13 It can be seen that the SVM classification model correctly identified 56 diffraction-polarization fingerprint images of tomato gray mold spores, 56 diffraction-polarization fingerprint images of cucumber downy mildew spores, and 58 diffraction-polarization fingerprint images of cucumber powdery mildew spores. Among them, the numbers of tomato gray mold spores misclassified as cucumber downy mildew spores and powdery mildew spores are 3 and 1 respectively, the numbers of cucumber downy mildew spores misclassified as tomato gray mold spores and cucumber powdery mildew spores are 2 and 3 respectively, and the numbers of cucumber powdery mildew spores misclassified as tomato gray mold spores and cucumber downy mildew spores are both 1. The statistical results of the SVM classification model are shown in Table 3.

[0157] Table 3 Statistical Results of the SVM Classification Model

[0158]

[0159] And the accuracy, precision, recall rate, and the comprehensive evaluation index F value of the classification results of the SVM classification model are calculated according to formula (4-(7)), and the results are shown in Table 4.

[0160] Table 4 Performance Indicators of the SVM Classification Model

[0161]

[0162] As can be seen from Table 4, the precision, accuracy, recall rate, and F1-Score of the SVM classification model for the classification of tomato gray mold spores are 96.02%, 94.92%, 93.33%, and 94.12% respectively. The precision, accuracy, recall rate, and F1-Score of the SVM classification model for the classification of cucumber downy mildew spores are 94.94%, 93.22%, 91.67%, and 92.44% respectively. The precision, accuracy, recall rate, and F1-Score of the SVM classification model for the classification of cucumber powdery mildew spores are 96.57%, 93.55%, 96.67%, and 95.08% respectively. The average recognition precision, accuracy, recall rate, and F1-Score of the SVM model for the three airborne disease spores in greenhouse crops are 95.85%, 93.89%, 93.88%, and 93.87% respectively. As a comprehensive evaluation index, F1-Score represents the overall performance of the classifier. When classifying airborne disease spores based on the diffraction-polarization fingerprint image features of airborne disease spores, the F1-Score value of the SVM model reaches 93.87%. Therefore, based on the extraction of the diffraction-polarization fingerprint image features of airborne disease spores in greenhouse crops, the SVM model is used to classify the three common airborne disease spores in greenhouse crops.

[0163] The composite field microfluidic chip 4 of the present invention separates and enriches airborne disease spores transmitted in the air in the greenhouse; the lensless polarization camera 5 collects diffraction fingerprint images at four polarization directions of 0°, 45°, 90°, and 135° under the action of interference light in different enrichment regions of the composite field microfluidic chip 4; the polarization-diffraction fingerprint images are subjected to image analysis and feature extraction of the polarization-diffraction fingerprint images under the image processing component 6 to obtain the characteristic data of the relative light intensity distribution value of the polarization-diffraction fingerprint images of airborne disease spores, and finally the classification and recognition of airborne disease spores are realized based on the characteristic data of the relative light intensity distribution value of the polarization-diffraction fingerprint images of airborne disease spores. The technical solution of the present invention solves the problems of complex air composition, low volume ratio of disease spores, and difficult separation and enrichment; and the problem that the volume of airborne disease spores is small, and it is difficult to collect complete disease spore images in the microfluidic enrichment region due to limited field of view in traditional microscopy. The present invention has the characteristics of small volume and easy operation, and improves the efficiency of disease spore detection.

[0164] It should be understood that although this specification is described according to each embodiment, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0165] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present invention, and they are not intended to limit the protection scope of the present invention. Any equivalent embodiments or modifications made without departing from the technical spirit of the present invention should be included within the protection scope of the present invention.

Claims

1. A spore detection device for airborne diseases of crops, characterized in that, It includes a light source, a light-transmitting micropore (3), a composite-field microfluidic chip (4), a lensless polarization camera (5), a signal generator, and an image processing unit (6) arranged in sequence from top to bottom; The light source generates interference light through the light-transmitting micropore (3) and irradiates it on the composite-field microfluidic chip (4). The polarization camera (5) is located below the composite-field microfluidic chip (4), and the distance between the composite-field microfluidic chip (4) and the polarization camera (5) is much smaller than the distance from the light-transmitting micropore (3) to the composite-field microfluidic chip (4); The signal generator is connected to the composite-field microfluidic chip (4). The signal generator is used to generate an alternating voltage, and an electric field is generated inside the composite-field microfluidic chip (4) to enrich different types of disease spores into different enrichment regions of the composite-field microfluidic chip (4); The polarization camera (5) images and collects the polarization-diffraction fingerprint images of the airborne disease spores in the enrichment region of the composite-field microfluidic chip (4) and transmits them to the image processing unit (6); The image processing unit (6) is used to process the polarization-diffraction fingerprint images of the airborne disease spores to obtain the relative light intensity distribution values of the polarization-diffraction fingerprint images of the airborne disease spores, and classify and identify the disease spores according to the differences in the relative light intensity distribution values; The composite-field microfluidic chip (4) includes a polydimethylsiloxane sheet (10); The polydimethylsiloxane sheet (10) is provided with a pretreatment channel (13) for the preliminary separation of airborne disease spores, a secondary separation channel for airborne disease spores, and an enrichment region for airborne disease spores; One end of the pretreatment channel (13) is provided with an airborne disease spore inlet (12), and the other end of the pretreatment channel (13) is provided with several secondary separation channels for airborne disease spores. The other end of the pretreatment channel (13) is communicated with one end of the secondary separation channel for airborne disease spores. The other end of the secondary separation channel for airborne disease spores is provided with a plurality of enrichment regions for airborne disease spores communicated with it, and each enrichment region for airborne disease spores is provided with an air flow outlet; Symmetrically arranged sheath flow channels are respectively provided on both sides of the pretreatment channel (13). The sheath flow channels are used to make the spores move in a straight line forward in the pretreatment channel (13); on both sides of the pretreatment channel (13) at the downstream of the sheath flow channels and on both sides of the secondary separation channel for airborne disease spores, electrode structures are respectively provided; the electrode structures are connected to the signal generator, and the signal generator makes the electrode structures generate an electric field to enrich different types of disease spores into different enrichment regions for airborne disease spores.

2. The crop airborne disease spore detection device according to claim 1, wherein, The light source is an LED lamp bead assembly (2); The LED lamp bead assembly (2) includes a plurality of LED lamp beads; the wavelength of the LED lamp beads is determined by collecting the original spectral characteristic curve of the airborne disease spores, performing principal component analysis on the original spectral curve, selecting the principal components with a cumulative contribution rate greater than 89%, and then obtaining the corresponding characteristic bands. The corresponding characteristic bands are the light source wavelengths suitable for collecting the diffraction fingerprint images of the airborne disease spores, that is, the wavelengths of the LED lamp beads.

3. The crop airborne disease spore detection device according to claim 1, wherein The axis of the sheath flow channel intersects the axis of the air inlet section of the pretreatment channel (13) at an acute angle; The sheath flow channels include a sheath flow channel (14) and a sheath flow channel (15); the sheath flow channel (14) and the sheath flow channel (15) are respectively arranged symmetrically on both sides of the pretreatment channel (13).

4. The crop airborne disease spore detection device according to claim 1, characterized in that, At the downstream of the pretreatment channel (13) in the sheath flow channels, there are correspondingly arranged a first electrode structure (16) and a fourth electrode structure (19), a second electrode structure (17) and a fifth electrode structure (20), a third electrode structure (18) and a sixth electrode structure (21); the first electrode structure (16), the second electrode structure (17), the third electrode structure (18), the fourth electrode structure (19), the fifth electrode structure (20), and the sixth electrode structure (21) are respectively connected to a signal generator to generate an electric field in the pretreatment channel (13), so that the airborne disease spores are preliminarily separated when passing through the electric field of the pretreatment channel (13).

5. The crop airborne disease spore detection device according to claim 1, wherein, The airborne disease spore secondary separation channels include a first airborne disease spore secondary separation channel (24) and a second airborne disease spore secondary separation channel (27); One end of the first airborne disease spore secondary separation channel (24) is communicated with the pretreatment channel (13), and the other end is provided with a third airborne disease spore enrichment area (37) and a fourth airborne disease spore enrichment area (38). The third airborne disease spore enrichment area (37) is provided with a third air flow outlet (36), and the fourth airborne disease spore enrichment area (38) is provided with a fourth air flow outlet (39); One end of the second airborne disease spore secondary separation channel (27) is communicated with the pretreatment channel (13), and the other end is provided with a first airborne disease spore enrichment area (33) and a second airborne disease spore enrichment area (34); the first airborne disease spore enrichment area (33) is provided with a first air flow outlet (32), and the second airborne disease spore enrichment area (34) is provided with a second air flow outlet (35); The first airborne disease spore secondary separation channel (24) is provided with a relatively arranged seventh electrode structure (22) and a thirteenth electrode structure (30), and an eighth electrode structure (23) and a fourteenth electrode structure (31); The second airborne disease spore secondary separation channel (27) is provided with a relatively arranged ninth electrode structure (25) and a twelfth electrode structure (29), and a tenth electrode structure (26) and an eleventh electrode structure (28); The seventh electrode structure (22), the eighth electrode structure (23), the ninth electrode structure (25), the tenth electrode structure (26), the eleventh electrode structure (28), the twelfth electrode structure (29), the thirteenth electrode structure (30), and the fourteenth electrode structure (31) are respectively connected to a signal generator to generate an electric field in the airborne disease spore secondary separation channels, so that the airborne disease spores are secondarily separated when passing through the electric field of the airborne disease spore secondary separation channels and respectively enter different airborne disease spore enrichment areas.

6. A detection method for the detection device of crop airborne disease spores according to any one of claims 1-5, characterized in that, Including the following steps: Step S1: Turn on the micro air pump and the signal generator. The signal generator generates an alternating voltage, and an electric field is generated inside the composite field microfluidic chip (4), causing different types of disease spores in the air to be enriched in different enrichment regions of the composite field microfluidic chip (4). Step S2: Turn on the switch of the light source. The light source generates interference light through the light-transmitting micropores (3) and irradiates the composite field microfluidic chip (4). Step S3: The polarization camera (5) captures and images the polarization-diffraction fingerprint images of the airborne disease spores in the enrichment regions of the composite field microfluidic chip (4) and transmits them to the image processing unit (6). Step S4: The image processing unit (6) processes the polarization-diffraction fingerprint images of the airborne disease spores to obtain the relative light intensity distribution values of the polarization-diffraction fingerprint images of the airborne disease spores. Step S5: Classification and recognition of the airborne disease spores are realized according to the differences in the relative light intensity distribution values of the polarization-diffraction fingerprint images of the airborne disease spores extracted in Step S4.

7. The detection method of the crop airborne disease spore detection device according to claim 6, characterized in that, In the said Step S3, the polarization camera (5) captures the diffraction fingerprint images of the airborne disease spores in different enrichment regions of the composite field microfluidic chip (4) at polarization directions of 0°, 45°, 90°, and 135°.

8. The detection method of the crop airborne disease spore detection device according to claim 6, characterized in that, The relative light intensity distribution values of the polarization-diffraction fingerprint images of the airborne disease spores in the said Step S4 are obtained through the following steps: Extract the characteristics of the relative light intensity distribution of the polarization-diffraction fingerprint image of airborne disease spores, calculate the peak value AP, valley value AV, and center value C of the relative light intensity distribution of the polarization-diffraction fingerprint image of the spores, and calculate the ratio PCR of the peak value to the valley value, the ratio VCR of the peak value to the center value, and the ratio of the valley value to the center value PVR , and the calculation formulas are as follows: Where: AP i represents the relative light intensity of the peak of the polarization-diffraction fingerprint of airborne disease spores; AV j Represents the relative light intensity of the trough of the polarization-diffraction fingerprint of airborne disease spores; C represents the relative light intensity of the central region of the polarization-diffraction fingerprint spectrum of the airborne disease spores. i is the number of bright fringes, and j is the number of dark fringes.

9. The detection method of the crop airborne disease spore detection device according to claim 6, characterized in that, In the said Step S5, an SVM model is used for classification and recognition of the airborne disease spores. Specifically: Accuracy, Precision, Recall, and the comprehensive evaluation index F value F1-Score are used as the evaluation indexes for the classification and recognition of the disease spores. The calculation formulas are as follows: In the formula: TP represents the number of positive samples predicted as positive by the model; FP represents the number of negative samples predicted as positive by the model; FN represents the number of positive samples predicted as negative by the model; TN represents the number of negative samples predicted as negative by the model; When the classifier SVM model performs the classification task, the actually predicted number of airborne disease spores is regarded as the number of positive samples, and the sum of the remaining numbers of airborne disease spores is regarded as the number of negative samples.

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