CN117825220A - Sensitization aerosol monitor and method - Google Patents

Abstract

The invention belongs to the technical field of optical detection, and particularly relates to a sensitized aerosol monitor and a method. The monitor comprises at least: an airflow path having a monitoring point; a light source directed at the monitoring point; a scattered light detector for detecting scattered light at the monitoring point; and at least one fluorescent channel detector. The monitoring method comprises the following steps: 1) Di, F1i and F2i are obtained; setting D_th, F1_th and K_th; 2) Comparing Di with D_th; 3) Comparing F1i with F1_th; 4) Comparing the ratio of F1i to F2i, if F1i/F2i < K_th, it is determined to be an sensitized aerosol. According to the invention, the sensitized aerosol such as pollen, allergy bacteria and the like and the non-biological aerosol particles are distinguished from the scattered light characteristic and the fluorescence characteristic by the optical detection technology, and the concentration of the sensitized aerosol is detected, so that the allergy index of the air is estimated in real time, early warning is provided for allergic people and susceptible people, and the induction risk of allergic and infectious respiratory diseases is reduced.

Description

Sensitization aerosol monitor and method

Technical Field

The invention belongs to the technical field of optical detection, and particularly relates to a sensitized aerosol monitor and a method.

Background

Respiratory allergic diseases such as allergic rhinitis are one of the most common allergic diseases, and the incidence thereof has been rapidly increased in recent years. Pollen, germs, etc. in the form of aerosols are among the major allergens.

The sensitized air-borne pollen is an outdoor inhalant allergen, and special proteins on pollen walls can cause allergic symptoms such as dermatitis, eye inflammation, rhinitis, tracheitis, asthma, chronic obstructive pulmonary disease and the like to specific individuals by means of wind-borne transmission, and can also cause diseases of digestive systems (gastric cancer, pancreatic cancer and the like) and increase the incidence rate of diseases of nervous systems (the suicide rate of partial crowds is increased). The air-borne pollen sensitization pollution presents a seasonal variation law, and high-concentration pollen is repeatedly inhaled into the susceptible constitution in spring and autumn every year, so that the incidence rate of respiratory diseases caused by various pollen sensitization is gradually increased, and the air-borne pollen sensitization pollution becomes one of global important chronic diseases and seriously threatens public health. There is a strong correlation between pollen concentration and the incidence of allergic disease.

The method is mainly a manual observation sedimentation method, the monitoring data is the number of pollen particles falling on a glass slide in the past day, the number of pollen on a unit area is observed and calculated through a manual microscope, or the detection is carried out through sampling, weighing and microscopic observation of large-flow air (for example, application number 202223168435.6), and the detection device has large volume, long detection time, inconvenient detection and no real-time performance.

The method can be further used for preliminarily judging whether aerosol particles are biological particles or not based on the principle of fluorescence spectrum, the technical field of onsite monitoring and alarming of biological agents at home and abroad is mainly developed for continuous monitoring and technical research of the biological aerosol, a fixed biological aerosol alarming system and a point source type biological source toxin comprehensive detection system are developed, continuous monitoring and onsite rapid detection means of the biological aerosol are basically established, and the detection target is usually biological bacteria warfare agent smaller than 10 mu m. The common pollen has larger particle size than pathogenic bacteria, has a diameter of about 15-30 μm, has lighter mass, is easy to fly and spread with air in aerosol form, and is technically called air-borne pollen.

The existing single aerosol particle monitoring equipment based on light scattering technology detection can only obtain information such as particle count, particle size spectrum distribution and the like; the detection of the bioaerosol by aerosol particle size detection equipment with a fluorescence detection channel is easily interfered by a large amount of other fluorescent substances; if the pollen particles are detected, a microscopic imaging technology is needed, the detection period is long, and the real-time performance is not achieved.

Therefore, the invention provides the small detection equipment for evaluating the allergy index of the air in real time by distinguishing the sensitized aerosol and the non-biological aerosol particles such as pollen, allergy bacteria and the like from the scattered light characteristic and the fluorescence characteristic through the optical detection technology and detecting the concentration of the sensitized aerosol and the non-biological aerosol particles, thereby providing early warning for allergic people and susceptible people and reducing the induction risk of allergic and infectious respiratory diseases.

Disclosure of Invention

In order to solve the defects in the prior art, the invention provides a sensitization aerosol monitor and a sensitization aerosol monitoring method. The invention can count the number, the particle size spectrum distribution, the mass concentration distribution, the fluorescent particle size spectrum distribution and the fluorescent spectrum distribution of aerosol particles in the air and carry out pattern recognition, and classify the aerosols such as dust, smog, pollen, bacteria and the like, thereby evaluating the aerosol sensitization risk of the air environment and early warning; the sensor can be used as a detection sensor and an effect evaluation sensor of air purification and disinfection equipment such as an air purifier, an air sterilizer, a fresh air system and the like so as to optimize the working mode and achieve the purposes of energy conservation, consumption reduction and synergy; for the susceptible population and allergic constitution population, information can be provided for taking protective measures in advance, so that the induction risk of allergic and infectious respiratory diseases is reduced.

The technical scheme provided by the invention is as follows:

a sensitized aerosol monitor comprising at least:

an airflow path having a monitoring point;

a light source directed at the monitoring point;

a scattered light detector for detecting scattered light at the monitoring point;

and at least one fluorescent channel detector, each fluorescent channel detector having a fluorescent filter, each fluorescent filter having a different transmission wavelength, and each fluorescent filter blocking Mi Sanshe light signals at the monitoring point.

Based on the technical scheme:

the photoelectric detector with the bandpass filter is used for respectively measuring the scattered light and the fluorescence signal, so that whether the particles are biological particles or non-biological particles can be classified; the number of the light pulses recorded by the detector corresponds to the number of particles, so that the concentration of the particles can be measured; the intensity of the light pulse recorded by the detector reflects the intensity of the rice scattering, which can estimate the particle size.

Further, based on the difference in fluorescence spectra of sensitized and non-bioaerosol materials, screening of bioallergic substances can be performed using fluorescence spectra.

According to the sensitization aerosol monitor provided by the technical scheme, the sensitization aerosol such as pollen, allergy bacteria and the like and the non-biological aerosol particles can be distinguished from the scattered light characteristic and the fluorescence characteristic through the optical detection technology, and the concentration of the sensitization aerosol and the non-biological aerosol particles is detected, so that the small detection equipment for evaluating the allergy index of the air in real time provides early warning for allergic people and susceptible people, and reduces the induction risk of allergic and infectious respiratory diseases.

In the above technical solution, the number of the fluorescent channel detectors may be one, two or more than three.

Further, the light source is also provided with a beam converging lens.

Based on the technical scheme, the light beams emitted by the light source can be converged and projected to the aerosol detection area, and the convergence point is positioned on a particle beam shuttle path in the center of the aerosol detection area and irradiates on the particles; a cylindrical lens can be particularly used, so that a linear converging light spot is formed at a converging point, and the width of exciting light rays at the converging point is 10-200um; or spherical or aspherical lenses are used to form round point converging light spots at converging points, and the diameter of the converging point exciting light spots is 10-200um.

Further, the wavelength of the light source is 260-420nm.

In the above technical scheme, the light source can emit light sources such as laser, an LED light source, a xenon lamp, etc., and is used for illuminating aerosol particles to generate mie light scattering, and simultaneously, the light source is used as a fluorescence excitation light source to excite fluorescent substances in the aerosol particles to emit fluorescence. The wavelength of the light source is in ultraviolet and purple light region, and the wavelength is 260-420nm.

Further, the end of the air flow passage is provided with an exhaust fan which is arranged at the end of the air flow passage and used for driving the air flow to flow through the detection area through the air flow passage.

Further, an extinction baffle is arranged on one side, far away from the light source, of the monitoring point and used for absorbing excitation light, so that the excitation light which is not scattered by aerosol particles is prevented from forming stray light in an optical detection area, and the scattering of rice and the collection of fluorescent signals are prevented.

Furthermore, the scattered light detector and the light source are 90 degrees and are used for converting Mi Sanshe optical signals into electric signals, and the detector is a photoelectric detector with small structural dimensions such as a photodiode, an avalanche photodiode, a silicon photomultiplier and the like, so that the miniaturization of equipment is facilitated. The particle size Di of the detected aerosol can be obtained through the intensity of the detected aerosol scattered light pulse signal, wherein i=1, 2 and … … are the serial numbers of detected aerosol pulses, and the concentration and the particle size distribution of aerosol particles in the air are evaluated according to the pulse number acquired in a certain sampling time and the corresponding particle size Di.

Further, the number of the fluorescent channel detectors is two, namely a first fluorescent channel detector and a second fluorescent channel detector, and each fluorescent channel detector and the light source form 90 degrees. Correspondingly, the number of the fluorescent filters is two, namely a first fluorescent filter and a second fluorescent filter, wherein the transmission wavelength of the first fluorescent filter comprises 420nm-500nm, and the transmission wavelength of the second fluorescent filter comprises 520nm-600nm.

The first fluorescent filter uses a bandpass filter or a long-wave bandpass filter with a wide-spectrum fluorescent wave band, gates part of fluorescent signals, blocks scattered light signals, and the transmission wavelength of the first fluorescent filter comprises 420nm-500nm.

The first fluorescent channel detector is arranged at 90 degrees with the light source irradiation direction, the light signals of aerosol particles are filtered and then transmitted fluorescent signals are irradiated onto the photosensitive elements of the aerosol particles to be converted into electric signals, and the detector is a photoelectric detector with small structural dimensions such as a photodiode, an avalanche photodiode, a silicon photomultiplier and the like, so that the device is convenient to miniaturize. By which the intensity of the fluorescent pulse of the fluorescent channel 1 of size Di in the aerosol sequence is synchronously detected, if the detected aerosol particles detect a fluorescent pulse in the fluorescent channel 1, the electrical signal F1i converted from its fluorescent pulse signal is recorded as F1i, and if no fluorescent pulse is detected f1i=0.

The second fluorescent filter uses a bandpass filter or a long-wave bandpass filter with a wide-spectrum fluorescent wave band, and is used for blocking the scattered light signals by partial fluorescent signals, and the transmission wavelength of the second fluorescent filter comprises 520nm-600nm.

The second fluorescent channel detector is arranged at 90 degrees with the light source irradiation direction, the light signals of aerosol particles are filtered and then transmitted fluorescent signals are irradiated onto the photosensitive elements of the aerosol particles to be converted into electric signals, and the detector is a photoelectric detector with smaller structural dimensions such as a photodiode, an avalanche photodiode, a silicon photomultiplier and the like, so that the device is convenient to miniaturize. By which the intensity of the fluorescent pulse of the fluorescent channel 2 of size Di in the aerosol sequence is synchronously detected, if the detected aerosol particles detect a fluorescent pulse in the fluorescent channel 2, the electrical signal F2i converted from its fluorescent pulse signal is recorded as F2i, and if no fluorescent pulse is detected, f2i=0 is recorded.

Further, the sensitized aerosol monitor further comprises a processor electrically connected to the scatter detectors and each fluorescence channel detector, respectively.

The invention also provides a sensitization aerosol monitoring method, which adopts the sensitization aerosol monitor provided by the invention for monitoring, and specifically comprises the following steps:

1) Obtaining the particle size Di of the ith aerosol to be tested;

acquiring a fluorescence intensity value F1i of the detected aerosol on the first fluorescence channel detector;

acquiring a fluorescence intensity value F2i of the detected aerosol on the second fluorescence channel detector;

setting a particle size threshold D_th of aerosol;

setting a fluorescence intensity threshold value F1_th of the detected aerosol on the first fluorescence channel detector;

setting a ratio threshold K_th of F1i and F2i;

wherein i is a natural number.

2) Comparing Di with D_th, and if Di > D_th, performing the next step;

3) Comparing F1i with F1_th, and if F1i > F1_th, performing the next step;

4) Comparing the ratio of F1i to F2i, if F1i/F2i < K_th, determining the ith tested aerosol as the sensitized aerosol.

Based on the technical scheme, the monitoring of the sensitized aerosol can be realized. Specifically:

according to the quantity of the sensitized aerosol particles recorded in the fixed sampling time, the concentration of sensitized aerosol in the air is obtained, and then the allergic risk grade early warning can be carried out by referring to the concentration grade as exemplified in QX/T324-2016 pollen allergic meteorological index;

the particle size spectrum distribution and the fluorescent particle size spectrum distribution of aerosols of different types are obtained through detection of aerosols of single type;

the particle size threshold D_th can be obtained through calibration, and the calibration method comprises the following steps:

respectively generating common interferent cigarette and A2 dust simulant aerosol, and acquiring the particle size spectrum distribution and fluorescence particle size spectrum distribution by using equipment to be calibrated after the concentration of the aerosol is stable;

generating aerosol of pollen or spores and bacteria to be classified, and collecting the aerosol with equipment to be calibrated to obtain particle size spectrum distribution and fluorescence particle size spectrum distribution after the concentration of the aerosol is stable;

by analyzing the corresponding spectrum distribution, the thresholds D_th, F1_th and K_th are selected, so that the false selection rate of the interfering object is low, and the passing rate of the object to be identified is high. The specific threshold device is related to the type of interfering substance to be excluded and the type of target substance to be identified. When the target is pollen, spores and bacteria, D_th is usually 0.5 μm to 2.5. Mu.m. F1_th and k_th are different from each other in terms of photoelectric conversion, optical system acquisition efficiency, conversion of hardware circuits, amplification and other system parameters, and different devices of different systems and the same structural system, and are not particularly limited herein.

According to the invention, the sensitized aerosol such as pollen, allergy bacteria and the like and the non-biological aerosol particles are distinguished from the scattered light characteristic and the fluorescence characteristic by the optical detection technology, and the concentration of the sensitized aerosol is detected, so that the allergy index of the air is estimated in real time, early warning is provided for allergic people and susceptible people, and the induction risk of allergic and infectious respiratory diseases is reduced.

Drawings

Fig. 1 is a schematic structural diagram of a sensitized aerosol monitor according to embodiment 1 of the present invention.

Fig. 2 is a schematic structural diagram of a sensitized aerosol monitor according to embodiment 2 of the present invention.

Fig. 3 is a schematic structural diagram of a sensitized aerosol monitor according to embodiment 3 of the present invention.

Fig. 4 is a distribution diagram of particle diameter spectra of aerosol particles in an effect example of the present invention.

Fig. 5 is a distribution diagram of the mixed multichannel data scatter in the effect example of the present invention.

Fig. 6 is a schematic diagram of a threshold boundary set and an aerosol region for sensitization obtained in an effect example of the present invention.

Fig. 7 is a schematic diagram of f1_th and d_th in the effect example of the present invention.

Fig. 8 is a schematic diagram of f1_th and k_th in the effect example of the present invention.

Fig. 9 is a flow chart of a method of monitoring an aerosol for sensitization provided by the present invention.

In fig. 1,2 and 3, the following structures are listed by the reference numerals:

1. the light source, 2, the light beam collecting lens, 3, the air current passageway, 4, extinction baffle, 5, exhaust fan, 6, scatter light detector, 7, first fluorescence light filter, 8, first fluorescence channel detector, 9, second fluorescence light filter, 10, fluorescence channel detector.

Detailed Description

The principles and features of the present invention are described below with examples only to illustrate the present invention and not to limit the scope of the present invention.

Example 1

As shown in fig. 1, the sensitized aerosol monitor includes: an airflow path 3 having a monitoring point; a light source 1 pointing to a monitoring point; a scattered light detector 6 for detecting scattered light at the monitoring point; the two fluorescence channel detectors are a first fluorescence channel detector 8 and a second fluorescence channel detector 10, respectively. Correspondingly, the number of the fluorescent filters is two, namely a first fluorescent filter 7 and a second fluorescent filter 9. Each fluorescence filter blocks the Mi Sanshe light signal at the monitoring point. The light source 1 is further provided with a beam converging lens 2. An extinction baffle 4 is arranged on one side of the monitoring point away from the light source 1. The end of the air flow path 3 is provided with an exhaust fan 5. The scattered light detector 6 is at 90 ° to the light source 1. Each fluorescent channel detector is at 90 ° to the light source 1.

Example 2

As shown in fig. 2, the overall structure is referred to embodiment 1, except that the number of fluorescent channel detectors is one, and the simplified structure generally performs detection classification only for aerosol particles of a specific fluorescence band, and the classification accuracy is lowered.

Example 3

As shown in fig. 3, the overall structure is different from that of example 1 in that the number of the fluorescence channel detectors is 3-6, and the added structure can perform more finely divided detection on the fluorescence spectrum of the aerosol, and can perform more detailed classification functionally, such as specific pollen category classification.

Example 4

On the basis of embodiment 1, the sensitized aerosol monitor further comprises a processor electrically connected to the scatter detector 6, the first fluorescence channel detector 8 and the second fluorescence channel detector 10, respectively.

Effect example

The test was carried out by using the sensitized aerosol monitor of example 1, the light source was a semiconductor laser light of 405nm, the transmission wavelength of the first fluorescent filter 7 was 420nm to 500nm, and the transmission wavelength of the second fluorescent filter 9 was 520nm to 600nm.

The particle size distribution diagram of each aerosol particle was obtained using haze dust, cigarettes, pollen, spores, and bacteria as test subjects, respectively, as shown in fig. 4. It can be seen that the particle size spectrum distribution of different aerosols has certain characteristics, the particle size of cigarette smoke is small, and the particle sizes of pollen and spores are large.

The multi-channel data of each aerosol are respectively obtained through detection of the monitor, and the scattered data of a plurality of aerosols are fused together to simulate the situation of detecting mixed aerosols. The mixed multi-channel data scatter distribution is shown in fig. 5.

Based on the data of fig. 4 and 5, a threshold value d_th=2, f1_th=500, and k_th=0.5 is set. Because the aerosol particles are classified by the method for judging the sensitized aerosol provided by the invention under the data condition, the probability of screening smoke and haze as allergens is only 1.4% and 2.3%,93% of pollen and 81% of spores pass the screening. The method can effectively classify sensitized and non-sensitized aerosols. The threshold boundaries set and the resulting sensitized aerosol regions are shown in figures 6, 7, 8 below.

Therefore, in actual detection, the operation can be performed according to the flow shown in fig. 9. According to the sensitization aerosol monitoring method, the pollen and the isospore can be screened as the allergic source with high probability by calibrating the threshold parameter, and the interference of the smoke and the haze is eliminated, so that the accuracy of a screening structure is ensured.

The foregoing description of the preferred embodiments of the invention is not intended to limit the invention to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims (8)

1. A sensitized aerosol monitor comprising at least:

an airflow path (3) having a monitoring point;

a light source (1) directed at the monitoring point;

a scattered light detector (6) for detecting scattered light at the monitoring point;

and at least one fluorescent channel detector, each fluorescent channel detector having a fluorescent filter, each fluorescent filter having a different transmission wavelength, and each fluorescent filter blocking Mi Sanshe light signals at the monitoring point.

2. The sensitized aerosol monitor according to claim 1, wherein:

the light source (1) is also provided with a light beam collecting lens (2);

and/or the wavelength of the light source (1) is 260-420nm.

3. The sensitized aerosol monitor according to claim 1, wherein:

an exhaust fan (5) is arranged at the tail end of the airflow passage (3);

and/or an extinction baffle (4) is arranged on one side of the monitoring point away from the light source (1).

4. The sensitized aerosol monitor according to claim 1, wherein:

the scattered light detector (6) and the light source (1) are at 90 °;

each of the fluorescent channel detectors and the light source (1) is at 90 °.

5. A sensitized aerosol monitor according to any one of claims 1 to 4, wherein:

the number of the fluorescent channel detectors is two, namely a first fluorescent channel detector (8) and a second fluorescent channel detector (10);

correspondingly, the number of the fluorescent filters is two, namely a first fluorescent filter (7) and a second fluorescent filter (9), the transmission wavelength of the first fluorescent filter (7) comprises 420nm-500nm, and the transmission wavelength of the second fluorescent filter (9) comprises 520nm-600nm.

6. The sensitized aerosol monitor according to claim 5, wherein: the sensitized aerosol monitor further comprises a processor which is electrically connected with the scattered light detector (6) and each fluorescent channel detector respectively.

7. A method of monitoring a sensitized aerosol using the sensitized aerosol monitor according to claim 6, comprising the steps of:

1) Obtaining the particle size Di of the ith aerosol to be tested;

acquiring a fluorescence intensity value F1i of the detected aerosol on the first fluorescence channel detector (8);

acquiring a fluorescence intensity value F2i of the detected aerosol on the second fluorescence channel detector (10);

setting a particle size threshold D_th of aerosol;

setting a fluorescence intensity threshold value F1_th of the detected aerosol on the first fluorescence channel detector (8);

setting a ratio threshold K_th of F1i and F2i;

wherein i is a natural number;

2) Comparing Di with D_th, and if Di > D_th, performing the next step;

3) Comparing F1i with F1_th, and if F1i > F1_th, performing the next step;

4) Comparing the ratio of F1i to F2i, if F1i/F2i < K_th, determining the ith tested aerosol as the sensitized aerosol.

8. The method of claim 6, wherein the method further comprises: the value of D_th is 0.5 μm to 2.5. Mu.m.