DE102021126818A1 - Detection device and a detection method for pathogenic substances contained in the air - Google Patents

Abstract

The invention relates to a method and a detection device (100, 200) for detecting pathogenic substances contained in the air, in particular viruses, and its use. The method comprises: passing a flow of air through an intake duct (116, 216), creating an electric field within a collector section (120, 220) of the intake duct (116, 216), wherein within the collector section (120, 220) any pathogenic substances present are electrostatically captureable, rinsing the collector section (120, 220) with a liquid rinsing medium (124, 224) and then transferring the rinsing medium (124, 224) into a detection volume (122, 222) and detecting turbidity and/or coloring of the rinsing medium ( 124, 224) in the detection volume (122, 222) depending on the presence of at least one pathogenic substance and as a result of a biochemical reaction thereof with antibodies.

Description

The invention relates to a detection device, its use and a detection method for the preferably quantitative detection of pathogenic substances contained in the air. “Pathogenic substance” is understood here to mean substances that have an antigen, ie in particular viruses.

The in situ detection of pathogenic substances in the room and breathing air, so-called aerosol particles, has been the subject of research for a long time and has picked up speed again, not least due to the pandemic consequences of the SARS-CoV-2 virus that recently appeared. As a result, there are numerous prior arts that are also more recent. Reference is made to the following documents as examples.

The document CN 11 1662816 A discloses an arrangement that sucks in room air, filters out viruses in an enrichment tank and directs them together with a buffer solution to a microfluidic chip in which a biochemical reaction (LAMP) takes place under temperature control and is detected using optical methods.

From the U.S. 2020/0309703 A1 an aerosol detector is known which is based on fluorescence excitation of harmful aerosol particles, in particular SARS-CoV-2 viruses, by means of UV radiation. The particles are caught and held on a transparent plate by electrostatic force or simply by gravitational force. The plate is backlit by UV LEDs. Fluorescence is observed by viewing the plate or can be detected using a detector not described in detail. An alarm can be triggered when fluorescence radiation is detected.

From the WO 2008/108872 A2 is a detector for detecting different bioactive substances, including influenza type A viruses. Certain antigens are detected by means of an antibody reaction. For this purpose, a sensor element is coated with the antibody ligand. An electrostatic pulse characteristic of the reaction is measured using an electrode (bio pore sensor) or a characteristic fluorescence using a photodetector (optical based sensor).

The U.S. 7,265,669 B2 treats a self-regenerating collector plate for particles to be detected. Viruses, inter alia, are also mentioned as detection particles. With regard to the detection method, it is mentioned that the device comprises an excitation light source and a photodetector for fluorescent light. The detector can be wall or ceiling mounted for indoor air monitoring.

In Scripture U.S. 7,494,769 B2 bioaerosols are again detected by means of fluorescence or phosphorescence measurement. The room air is pumped to a collector. A special feature is a collector with a liquid reservoir in which the aerosols are caught and concentrated.

In the document CN 11 1665356 A is specifically about the detection of Covid-19 viruses. The laboratory analysis method is based on Raman spectroscopy, more precisely surface enhanced Raman spectroscopy (SERS). Fluid samples are analyzed, which can consist of a concentrated aerosol, for example. Silver or gold surfaces functionalized with antibodies are used for the SERS.

The WO 2006/106235 A1 relates to a device and an automated detection method for microbiological material, including viruses, in which an aerosol is drawn in, concentrated to form a sample and fed to an array of test disks which are coated with antibodies in test zones. A reaction causes a discoloration of the test zone, which is automatically read optically and sent to an evaluation system. Apart from an automatic readout, the detection method is reminiscent of the immunostaining known from the rapid tests.

the document CN 11 0118711 B According to the study, the bacterial load in the room air is determined using fluorescence measurements, taking into account various environmental conditions. The device described therein is suitable for outputting a warning signal as a result of the detection.

In the CN 20 7516253 U discloses an apparatus for detecting hepatitis B virus in air. The device draws air into a housing and directs it into a test liquid located there. The liquid is applied to several test strips via a channel system and the test strips can be observed through windows in the housing wall.

Also the writing CN 21 0720420 U deals with the detection of pathogenic substances in the air by means of antibodies coated on a resin with which stuffing boxes are filled.

Another device for detecting bioactive substances in the air is from the reference EP 1 309 720 B1 known. The device includes an inlet, a filter for filtering out dust and larger particles, a fluid conduit with a barrier where a vortex forms to sort particles by size, and a bioreceptor surface where the particles impact and which is fitted with an aptamer to detect specific substances by binding. Here, too, the reaction is recorded optically using fluorescence radiation.

As in the Scriptures before, the US 2019/0242807 A1 a device and a method for the rapid in situ detection of pathogens, in particular viruses, in the ambient air using an aptamer. The device draws in air, cleans it of particles and enriches them in a buffer solution. This is pumped into a detection chamber that has an electrode functionalized with an aptamer. Counter-electrodes are arranged parallel to a large number of detection chambers. Pathogens are detected by a characteristic electronic response to an electric field applied between them.

In the EP 1 882 177 B1 describes the reaction of an airborne particle with a "reporter" which, after the reaction has taken place, is irradiated with light in a detection zone. Fluorescence, phosphorescence etc. are mentioned as a reaction. The reporter is a fluorescent or phosphorescent molecule that can be attached to an antigen.

In Scripture U.S. 10,677,773 B2 is generally a miniaturized device for monitoring the ambient air. A virus detector is mentioned as an example. In terms of content, it is essentially about the spatial arrangement of pumps, channels, sensors, power supply, etc. in the device.

The U.S. 7,705,739 B2 discloses an analysis and warning system for a multi-stage detection of various pathogenic substances, including viruses, in the air. The system includes an optical detection module intended for a luminescence measurement.

The font EP 1 158 292 B1 deals with an aerosol particle detector based on an angle-resolved scattered light measurement under the incidence of a laser beam.

Similarly deals with the U.S. 7,053,783 B2 with a scattered light detector, especially for detecting pathogenic particles in the air. Only the pulse height of the scattered light signals is determined, which is assigned to a particle size in each case, with the presence of pathogenic substances being inferred from the occurrence of certain sizes.

From the KR 101625133 B1 an air quality measuring system with networked detectors is known, which should be suitable for detecting different types of air pollution and alerting if certain limit values are exceeded. Among other things, viruses are also mentioned as impurities. The focus of the writing is on networking. The translated excerpts say nothing about the detection.

The object of the present invention is to provide a reliable detection device for the in situ detection of pathogenic substances contained in the air, which is constructed from simple components and opens up various possible applications.

According to a first aspect of the invention, the object is achieved by a detection method according to claim 1.

The method according to the invention for detecting pathogenic substances contained in air, in particular viruses, has: passing an air stream through an intake line connecting an air inlet to an air outlet, generating an electric field within a collector section of the intake line, with any pathogenic substances present within the collector section can be electrostatically captured or enriched, rinsing the collector section with a liquid rinsing medium and then transferring the rinsing medium into a detection volume and detecting turbidity and/or coloration of the rinsing medium in the detection volume depending on the presence of at least one pathogenic substance and as a result of a biochemical Reaction of the same with antibodies.

The antibodies are either contained in the rinsing medium before rinsing or are added to the rinsing medium in the collector section or in the detection volume.

The invention can be used to examine both the air directly exhaled by a subject using a breath measuring device and the room air using a room air monitoring device. After the air to be examined has been fed through an air inlet into an intake line of a corresponding detection device, the pathogenic substance is enriched in a spatially limited section of the intake line, the collector section. The pathogenic substance is bound to carriers in the air, the so-called aerosol particles, hereinafter also referred to as particles, with which they can be transported over long distances. These carriers are mostly water-based drops containing a dipolari have activity. This property is used to temporarily fix the aerosol particles together with the pathogenic substance using an electrostatic field in the collector section, typically on the inside of the wall of the suction line. The particles enriched in this way, depending on the contamination with or without pathogenic substances, are then transported away from the collector section of the suction line into the detection volume using a liquid, the rinsing medium. Depending on the composition of the flushing medium, it can be advantageous to switch off the electric field before flushing or during flushing, in order to be able to more easily detach the electrostatically adhering particles or aerosol particles from the wall during flushing.

A first alternative provides that the rinsing medium already contains antibodies before rinsing. In this case, an immune reaction, or more precisely an antigen-antibody reaction, of the antigens of the pathogenic substance with the antibodies that are kept ready already takes place during the rinsing process.

According to a second alternative, antibodies immobilized on particulate carriers are kept pre-suspended in a liquid in the detection volume. The rinsing medium itself contains neither antibodies nor carriers beforehand. An immune or antigen-antibody reaction of the antigens of the pathogenic substance with the available antibodies therefore only takes place in the detection volume.

All immunologically active proteins, regardless of their production, are understood here as antibodies, ie in particular also monoclonal antibodies.

It is advantageous if, in the case of the first alternative, particulate carriers are suspended in the rinsing medium after transfer to the detection volume, on which the antibodies are immobilized. This is realized in a particularly advantageous manner in that the particulate carriers are kept pre-suspended in a liquid in the detection volume.

In both cases, the particulate carrier is a matter of suspendable particles, in particular latex particles, on which the binding partner (antibody) with an affinity for the analyte (antigen) to be detected can be immobilized. As soon as the rinsing medium reaches the detection volume, it contains these particles, which is why the suspension is also referred to below as "detection liquid" to distinguish it from the rinsing medium. This suspension is known to be used for particle-enhanced nephelometric or turbimetric immunoassays. If the loaded latex particles come into contact with the analyte to be measured, in this case the aerosol particles, agglutinates are formed, which result in a detectable turbidity. In the case of nephelometry, this turbidity is recorded quantitatively using scattered light measurement. The higher the concentration of the analyte, the more numerous and larger the scattering particle agglutinates and the higher the scattered light signal. The principle has been known for a long time and, for example, in EP 0 019 741 B1 described.

According to an advantageous development of the method, the flushing medium is held in a reservoir, from which the collector section is supplied with a specific volume of flushing medium for flushing. This is done, for example, by measuring the flushing medium using a measuring device that provides a defined volume before it is introduced into the collector section of the intake line for flushing.

An advantageous embodiment of the method provides that the flushing medium is returned to the reservoir after detection from the detection volume if no turbidity could be detected. Here, the reservoir and the detection volume form separate volume areas in the detection device and the flushing medium is recovered in a circulatory system and can be reused. This reduces the consumption of the rinsing medium, which is of economic importance in particular for rinsing media in which the antibodies are already pre-dissolved (hereinafter also referred to as antibody solution).

When using a detection liquid with particulate carriers, these are advantageously held back by a filter in the detection volume when the flushing medium is returned to the reservoir. This prevents the carriers from getting into the circulation of the flushing medium.

As an alternative to returning the flushing medium to the reservoir, provision can also be made for the flushing medium to be supplied to the collector section directly from the detection volume for flushing. In this case, the detection volume replaces the reservoir. During the subsequent transfer, the rinsing medium is transported back into the detection volume. It is thus conveyed back and forth alternately between the collector section and the reservoir or detection volume. In this way, too, the rinsing medium can be used several times if no turbidity is detected, ie no antigens could be detected. Is, however, a contamination of the sink medium with the pathogenic substance has occurred, all parts of the detection device that have come into contact with the pathogenic substance, i.e. the suction line, the detection volume, the flushing line including the entire flushing medium contained therein, must be replaced.

In this case, any particulate carriers in the detection liquid are advantageously held back by a filter in the detection volume when the flushing medium is supplied to the collector section.

The air flow is preferably passed through the intake line by means of a pump.

According to a second aspect of the invention, the object is achieved by a detection device according to claim 13.

The detection device for the detection of pathogenic substances contained in air, in particular viruses, has: an air inlet, an air outlet, a suction line connecting the air inlet to the air outlet, electrical contacts which are arranged along the suction line in such a way that within a collector section of the suction line a electric field can be generated, a detection volume for receiving a flushing medium from the collector section, a fluidic connection between the collector section and the detection volume and a sensor element, set up to detect turbidity and/or coloration of the flushing medium in the detection volume depending on the presence of at least one pathogen Substance and as a result of a biochemical reaction of the same with antibodies.

The collector section is defined by the arrangement of the electrical contacts. The antibodies are optionally contained in the flushing medium or are added to the flushing medium in the collector section or in the detection volume.

The detection device preferably has a first electronically switchable valve which is set up to selectively open or close the fluidic connection between the collector section and the detection volume.

According to a first alternative, the detection device preferably also has a reservoir for storing the flushing medium and a flushing line fluidically connecting the reservoir to the collector section for introducing the flushing medium into the collector section.

According to an advantageous embodiment of this first alternative, a measuring device that is integrated in the flushing line and provides a defined volume is provided for measuring a specific volume of the flushing medium. As part of the flushing line, the metering device is connected to the reservoir on the one hand and to the collector section on the other hand and ensures that the flushing medium for flushing is metered into the collector section of the intake line.

A return line fluidically connecting the detection volume to the reservoir is also preferably provided. In this embodiment, a filter is particularly preferably provided in the return line or in the detection volume or between the return line and the detection volume, with which particulate carriers are retained in the detection volume when the flushing medium is returned.

According to a second alternative, a filter is advantageously provided in the fluidic connection between the collector section and the detection volume or in the detection volume, with which particulate carriers are retained in the detection volume when the rinsing medium is fed in from the detection volume into the collector section for the purpose of rinsing.

In the case of both alternatives, the filter preferably has a nominal pore size of at most 0.5 μm, particularly preferably at most 0.3 μm and very particularly preferably at most 0.25 μm. The particulate supports, in particular in spherical form, preferably have a diameter of 300 nm to 1500 nm, particularly preferably 400 nm to 800 nm, and are used in concentrations of preferably 0.02% to 1.5%, particularly preferably 0.04%. up to 0.5%, used in the detection medium to be examined.

In the case of the first alternative, the detection device preferably has a second electronically switchable valve which is set up to selectively close or open the return line. The first and the second electronically switchable valve can be combined in a common valve arrangement. The valve arrangement can be formed by several simple valves or, for example, by a 3/2-way valve or 3/3-way valve, with the 3/3-way valve providing a third switching position in which the detection volume can be drawn from both the collector section and the return line is fluidically separated.

Furthermore, the detection device preferably has a pump which is switched on in the intake line or is connected to the intake line in order to generate an air flow in the intake line. Such a pump allows a constant over the duration of the passage of the air flow Achieve volumetric flow and constant flow velocity in the intake line. Volume flow and electric field strength are tailored to the geometry of the collector section, in particular its length and width in the direction of the field, so that the residence time in the collector section is sufficient to capture the majority of the aerosol particles in the breathing air or room air.

Furthermore, the detection device preferably has an electronic controller to which the pump and the valve are electronically connected.

The sensing element is preferably an optical sensing element electronically connected to an electronic controller and having an optical axis aligned with the detection volume. More precisely, a viewing window through which the optical axis of the sensor element runs is arranged in a first wall of the detection volume. The measurement with the sensor element can be carried out using an external light source. However, the detection device preferably has a light source which is electronically connected to the controller and which is aligned with the detection volume. For this purpose, an inlet window, onto which the light source is aligned, is preferably arranged in a second wall of the detection volume. The light source, the sensor element and the controller are set up to determine the light absorbed or scattered in the detection volume contained in the detection medium. In this way, nephelometric or turbimetric quantitative determinations of the content of the antigens involved in the reaction can be carried out with the detection device. The light source is preferably an infrared light source and particularly preferably a light source which emits radiation in the wavelength range from 800 to 1500 nm, preferably 800 nm to 1000 nm. Furthermore, the light source preferably emits in a wavelength range which is 1.5 times to 2.5 times the diameter of the particulate carrier.

Furthermore, a pressure sensor is advantageously arranged in the intake line or a pressure sensor is directly fluidly connected to the intake line, which pressure sensor is electronically connected to the controller.

A controllable inlet valve is also advantageously provided, which is arranged in the area of the air inlet and which is electronically connected to the controller.

For example, if the detection device is used to analyze a person's breath, then the valve will only open as a controller if a slight positive pressure is detected upstream, as explained below. It has the benefit that air is only sucked in when a subject is also breathing into a mouthpiece connected to the inlet port. This prevents rebreathing and creates the conditions for a defined volume flow through the intake line.

Furthermore, the detection device advantageously has a pressure sensor which is arranged upstream of the inlet valve in the area of the air inlet or is directly fluidly connected to this area and which is electronically connected to the controller.

For example, if the detection device is used to analyze a person's breath, the combination of the inlet valve and an upstream pressure sensor serves to first determine that a person is breathing into a mouthpiece connected to the inlet port. This increases the pressure in front of the inlet valve (inlet pressure). If the pressure sensor determines that a preset value has been exceeded, i.e. a defined overpressure has been reached, the controller opens the inlet valve in order to fluidly connect the mouthpiece to the detection volume. The defined pressure drop between the overpressure regulated in this way in the mouthpiece and the intake volume ensures a regulated volume flow of the exhaled aerosol and thus creates the prerequisite for a reliable, quantitative determination of the aerosol particles contained in a specific volume. If the inlet pressure determined by the pressure sensor falls below the same or a different preset value, the controller then closes the inlet valve in order to separate the mouthpiece from the detection volume and, among other things, to prevent rebreathing.

Accordingly, in this embodiment, the detection device preferably also includes a mouthpiece that can be connected to the air inlet.

The mouthpiece particularly preferably comprises an inlet section, an outlet section and a branching-off connection section, the connection section being set up for fluidic connection with the inlet socket. In terms of flow, the inlet section, outlet section and connection section are designed and dimensioned in such a way that, on the one hand, by exhaling into the inlet section, sufficient overpressure can be built up in the connection section to exceed the value preset by the control system and thus open the inlet valve. On the other hand, it must be ensured that no significantly higher overpressure builds up when you breathe out builds in order not to significantly manipulate the volume flow through the detection medium.

In addition or as an alternative to the pressure sensor upstream of the inlet valve, a switch to be actuated by the subject, for example, can be provided on the detection device, which puts the device on standby and/or starts the measurement.

In the area of the air outlet, the detection device preferably has a filter element that retains the aerosol particles, so that the exhaled air that does not pass through the detection medium is released into the environment as free as possible of any pathogenic substances that may be present.

Furthermore, it has proven to be advantageous if at least one air guiding element is arranged in the intake line, with which the air flow is guided as directly as possible in the direction of the collector section.

The above-mentioned nephelometry can be used as a detection method, in which the quantitative concentration of finely divided, colloidal aerosol particles can be determined via the turbidity. Here, the detection medium is brought into the light beam of the light source, with part of the light being scattered laterally to the incoming beam due to the turbidity. The scattered light emerges from the detection volume of the container through the viewing window and is possibly directed to a photodetector via optical components (lenses, prisms, mirrors). All optical components and the detector are understood as parts of the sensor element. The measurement of the photodetector is directly proportional to the light intensity.

The detection method of turbidimetry also comes into consideration. Here, the scattering-related reduction in the intensity (extinction) of the light beam passing through the detection medium, i.e. the transmission, is measured, with the concentration of the reaction products being directly proportional to the turbidity of the solution.

As mentioned at the beginning, the detection device is preferably used as a test device for detecting pathogenic substances, in particular viruses, contained in the exhaled air of a subject, i.e. as a breath measuring device, or as a monitoring device for detecting pathogenic substances, in particular viruses, contained in the room air, i.e. as a room air monitoring device. The testing device and the monitoring device may each comprise additional specific functional components, such as the mouthpiece in the case of the testing device, or a suction funnel in the case of the monitoring device, or respectively adapted display or data transmission modules. In particular, the monitoring device can have an interface and/or a radio module for a wired or radio-based exchange of data or signals with a server or a stationary or mobile end device or a similar monitoring device. This equipment is also conceivable for the test device, which, however, in the simplest configuration as a mobile test device, also manages with its own optical and/or acoustic display. On the other hand, the monitoring device can also have an additional optical and/or acoustic display in order to immediately alert people in the monitored room.

• 1A eine schematische Darstellung eines ersten Ausführungsbeispiels des erfindungsgemäßen Nachweisgeräts in einem ersten Betriebszustand;
• 1B eine Ausschnittsvergrößerung aus 1A;
• 2A eine schematische Darstellung des ersten Ausführungsbeispiels in einem zweiten Betriebszustand;
• 2B eine Ausschnittsvergrößerung aus 2A;
• 3A eine schematische Darstellung des ersten Ausführungsbeispiels in einem dritten Betriebszustand;
• 3B eine Ausschnittsvergrößerung aus 3A;
• 4 eine schematische Darstellung eines zweiten Ausführungsbeispiels des erfindungsgemäßen Nachweisgeräts in einem ersten Betriebszustand;
• 5 eine schematische Darstellung des zweiten Ausführungsbeispiels in einem zweiten Betriebszustand;
• 6 eine schematische Darstellung des zweiten Ausführungsbeispiels in einem dritten Betriebszustand;
• 7 eine schematische Darstellung des zweiten Ausführungsbeispiels in einem vierten Betriebszustand und
• 8 das zweite Ausführungsbeispiel des Nachweisgeräts in der Verwendung als Raumluftüberwachungsgerät.

The invention is explained in more detail below with reference to drawings. Show it:

• 1A a schematic representation of a first embodiment of the detection device according to the invention in a first operating state;
• 1B an enlargement of a section 1A ;
• 2A a schematic representation of the first embodiment in a second operating state;
• 2 B an enlargement of a section 2A ;
• 3A a schematic representation of the first embodiment in a third operating state;
• 3B an enlargement of a section 3A ;
• 4 a schematic representation of a second embodiment of the detection device according to the invention in a first operating state;
• 5 a schematic representation of the second embodiment in a second operating state;
• 6 a schematic representation of the second embodiment in a third operating state;
• 7 a schematic representation of the second embodiment in a fourth operating state and
• 8th the second embodiment of the detection device in use as a room air monitoring device.

The first exemplary embodiment of the detection device according to the invention for detecting pathogenic substances contained in air comprises an air inlet 112, an air outlet 114 and a suction line 116 connecting the air inlet 112 to the air outlet 114 1A and 1B the detection device 100 is shown in a first method step of passing an air stream through. Electrical contacts or electrodes 118 and 119 are disposed along a portion 120 of intake manifold 116 . The electrode 118 is shown here as an anode and the electrode 119 as a cathode. An electrical field forms between the electrical contacts 118, 119 within the intake line 116 as soon as the electrical contacts 118, 119 are connected to a voltage source. In 1B 1 is an enlarged section of the intake manifold section 120, also referred to herein as the “collector section”. In the schematic representation, the electrode 118 is connected to the positive pole of a voltage supply, for example a battery, and the electrode 119 is connected to its negative pole. Electrically charged particles or also dipoles (water droplets, aerosol particles) are enriched in the collector section 120 due to the field along the inside 121 of the wall of the intake line 116 in the collector section 120 . In order to effectively capture dipoles in particular, the electric field in the collector section can be deliberately inhomogeneous. The electrical contacts 118, 119 are located outside of the intake line and the wall of the intake line is not electrically conductive, so that, if possible, no charge equalization takes place within the collector section 120.

The detection device 100 also has a detection volume 122 for receiving a flushing medium 124 . The detection volume is followed by a curved tube segment 144 which, together with the detection volume 122, forms a system of communicating tubes and which is filled with the flushing medium 124 to the same level. The collector portion 120 and the detection volume 122 are connected by a fluidic connection 126 formed in part by the intake line 116 itself.

Furthermore, a filter 152 is provided in the fluidic connection 126 , which is set up to retain particulate carriers, which are present in a suspension in the detection volume 122 , in the detection volume 122 so that they cannot get into the collector section 120 .

A sensor element 128 for detecting turbidity and/or a coloration of the flushing medium 124 enclosed in the detection volume 122 is arranged in the region of the detection volume 122 . As discussed above, turbidity occurs as a function of the presence of a pathogenic substance in the flushing medium 124 and as a result of a biochemical reaction thereof with antibodies also present in the flushing medium 124 . The sensor element 128 is preferably electronically connected to an electronic controller (not shown) and has an optical axis which is aligned with the detection volume 122 . The sensor element 128 is preferably located adjacent to a viewing window that is transparent for a specific wavelength in the wall of the detection volume 122, through which it “looks into” the detection volume 122 along the optical axis. The detection device 100 also has a light source 130 which is also electronically connected to the controller and which is aligned with the detection volume 122 . In this context, aligned means that the light emitted by the light source 130 is emitted along an optical axis which passes through the detection volume 122 either directly or after deflection. In the case of an absorption measurement, the optical axes of the sensor element 128 and the light source 130 run parallel within the detection volume 122 . In the case of a scattered light measurement, they preferably run at a specific angle that is not equal to 180°, preferably 90°, to one another. For this purpose, an entrance window that is transparent to the light emitted by the light source 130 is preferably provided in the wall of the detection volume 122 .

A pump 132 is switched on in the intake line 116, in the example shown here near the outlet 114, and generates an air flow, indicated by the arrow 134. Such a pump 132 can be used to generate a uniform volume flow of the air drawn in, which is matched to the electrical field strength within the collector section 120 . In this way, the efficiency of the device in terms of particle collection can be optimized, i.e. the proportion of particles trapped in the collector section 120 to the total particles in the air flow 134 can be maximized.

In the suction line 116 there are two switching valves 136 and 138 upstream of the pump 132. The first switching valve 136 is switched on in the direction of flow along the suction line 116 before the collector section 120, the second switching valve 138 behind it in the suction line 116. in the in 1A In the illustrated method step of passing the air flow 134 through the intake line 116, the switching valves 136 and 138 are switched so that the intake line 116 from the air inlet 112 to the air outlet 114 is continuous.

In the 2A and 2 B 1 shows the first exemplary embodiment of the detection device 100 in a second stage of the method, in which the connection between the air inlet 112 and the collector section 120 is interrupted by the valve 136 . At the same time, the valve 136 connects a second inlet 140 to the detection volume 122. A second pump 142 is switched on in the connecting line between the second inlet 140 and the valve 136; As a result, the flushing medium 124 is conveyed out of the curved pipe segment 144 in the direction of the detection volume 122 and also rises up into the intake line 116 up to the collector section 120 . This process is referred to as purging the collector section 120 . Before, during or after flushing, the electrical field applied via the electrical contacts 118, 120 within the collector section 120 is switched off so that the collected particles or aerosol particles 110 can be easily detached from the inside 121 of the suction line 116. This state is in 2 B shown schematically.

After the rinsing process has ended, the pump 142 is switched off again so that the rinsing medium 124 is transferred back into the detection volume 122 . This stage is in the 3A and 3B sketched. If particles or aerosol particles 110 containing a pathogenic substance could be collected, the latter reacts with the antibodies in the flushing medium. The reaction product can be stored in the detection volume 122, as in 3B shown, are detected by means of the arrangement of light source 130 and sensor element 128 as turbidity and/or coloration of the flushing medium 124 in the last method step, for example in a scattered light measurement method nephelometrically or in a turbimetric method determining the attenuation. If necessary, additional particulate carriers on which the antibodies are immobilized are used to increase the turbidity.

4 shows a second embodiment of the detection device 200 according to the invention in a schematic representation. The detection device 200 comprises an air inlet 212, an air outlet 214 and an intake line 216 connecting the air inlet 212 to the air outlet 214. In 4 1, the detection device 200 is shown in a first operating state in which an air flow 234 is directed through the intake line 216. FIG. For this purpose, a pump 232 is again switched on in the intake line, which generates the air flow 234 with an ideally uniform volume flow. Guide elements 235 are located in the intake line and serve the purpose of directing the air flow 234 in a targeted manner to the location at which the aerosol particles are to be captured.

Electrical contacts or electrodes 218 and 219 are disposed along a portion 220 of intake manifold 216 . The electrode 218 is shown here as an anode and the electrode 219 as a cathode. An electric field forms between the electrical contacts 218, 219 within the intake line 216 as soon as the electrical contacts 218, 219 are connected to a voltage source. An electric field is generated in the collector section 220 of the suction line 216 in the same manner as previously described in connection with the first exemplary embodiment, by means of which particles or aerosol particles 110 can be electrostatically enriched or collected. The electric field strength within the collector section 220 is balanced with the strength of the airflow 234 and the length of the collector section to optimize the efficiency of the device in collecting particles as discussed above.

The detection device 200 also has a detection volume 222 for receiving a flushing medium 224 . The collector section 220 and the detection volume 222 are connected to one another by a fluidic connection 226 .

The detection device 200 also has a reservoir 240 for the flushing medium 224 and a flushing line 242 fluidically connecting the reservoir 240 to the collector section 220 for introducing the flushing medium 224 into the collector section 220 . A metering device 254 providing a defined volume for metering a specific volume of the flushing medium 224 is integrated into the flushing line 242. The volume of the metering device 254 is more precisely enclosed between a first metering valve 256 and a second metering valve 258 in the flushing line 242. If the first metering valve 256 is opened while the second metering valve 258 is closed, the volume is filled with a specific filling quantity of the flushing medium 224.

Then in the in 5 As shown in the process step, the first metering valve 256 is closed and the second metering valve 258 is opened, thereby draining the metered flushing medium 224 into the collector section 220 to initiate the flushing process. The volume of the metering device 254 and the volume of the collector section 220 are preferably matched to one another in such a way that the flow generated during flushing covers the entire surface of the collector section 220 . Before or during purging, the electric field is switched off so that the trapped particles or aerosol particles 110 (with or without pathogenic substance contained therein) more easily detached from the inside 221 of the wall of the suction pipe 216 in the collector section 220 during flushing.

In this example, the detection device has a return line 248 fluidically connecting the detection volume 222 to the reservoir 240 . This is closed during this method step by means of a second electronically switchable valve of a valve arrangement 250. At the same time, a first electronically switchable valve of the valve arrangement 250 blocks the fluidic connection 226 between the collector section 220 and the detection volume 222 in the method stage shown here . In this sense, the terms “first and second electronically switchable valve” used herein are to be understood functionally.

Furthermore, a filter 252 is provided on the side of the detection volume 222 immediately in front of the valve arrangement 250, which is set up to retain particulate carriers (with or without antibodies immobilized thereon) in a suspension 225 in the detection volume 222 in the detection volume 222. so that they can neither get into the collector section 220 nor into the return line 248 .

If the fluidic connection 226 or the first electronically switchable valve of the valve arrangement 250 is opened, this initiates the transfer of the flushing medium from the collector section 220 into the detection volume 222 . The subsequent state is in 6 pictured. The suspension 225 initially held there and the flushing medium are brought together in the detection volume 222 . The mixture then forms the detection liquid 227 in which the reaction products of the antibody-antigen reaction are immobilized on the particulate carriers. Whether the antibody-antigen reaction or the immobilization takes place first depends on whether the rinsing medium contains antibodies from the start or whether they were already immobilized on the particulate carriers in the detection volume 222 . However, the liquid on which the suspension 225 is based is preferably the same flushing medium 224 right from the start. The reason for this can be seen from the steps explained below.

A sensor element 228 for detecting turbidity and/or coloration of the flushing medium 224 enclosed in the detection volume 222 as a result of the biochemical reaction is again arranged in the region of the detection volume 222 . The sensor element 228 is again preferably electronically connected to an electronic controller (not shown) and has an optical axis which is aligned with the detection volume 222 . The sensor element 228 is again preferably located adjacent to a viewing window that is transparent for a specific wavelength in the wall of the detection volume 222, through which it “looks into” the detection volume 222 along the optical axis. The detection device 200 also has a light source 230 which is also electronically connected to the controller and which is aligned with the detection volume 222 . In this context, aligned means that the light emitted by the light source is radiated along an optical axis, which passes through the detection volume 222 either directly or after deflection. Furthermore, an entrance window that is transparent to the light emitted by the light source is preferably provided in the wall of the detection volume 222 here as well. As described above in connection with the first exemplary embodiment, depending on the measurement method, the optical axes of the sensor element 228 and the light source can be aligned parallel within the detection volume 222 or at a specific angle that is not equal to 180°.

If the detection showed that no turbidity could be detected in the detection volume 222, the flushing medium 224, preferably the same volume that was previously measured in the measuring device 254, after opening the return line 248 or the second electronically switchable valve of the valve assembly 250 from the detection volume 222 through the return line 248 into the reservoir 240, the filter 252 again retaining the particulate carriers in the detection volume 222. This process is in 7 illustrated.

A further pump 246 is provided in the return line 248 for return, which is preferably set up to deliver a precisely metered volume back into the reservoir 240 . This ensures that the volume and mixing ratios of the suspension 225 and the detection liquid 227 always remain constant. This also explains why the liquid on which the suspension 225 is based is preferably the flushing medium 224 from the start.

The advantage of the circuit with return of the flushing medium 224 to the reservoir 240 explained with reference to the second exemplary embodiment is that any impurities in the flushing medium 224 do not have a high concentration over a long period of time if the volume in the circuit and measured in the measuring device 254 is very small in relation to the volume held in the reservoir 240. Therefore, the volume ratio of reservoir 240 to metering device 254 is preferably 50:1, more preferably 100:1, and most preferably 200:1.

In 8th 1 is a simplified representation of an embodiment of the detection device 200 for the detection of pathogenic substances contained in air in use as a monitoring device 202 for indoor air. The detection device 200, which differs from the embodiment of FIG 4 until 7 itself does not differ, is housed here by way of example in a spherical segment-shaped housing 260 for ceiling mounting. The room air 264 is drawn in through openings 261 , 262 in the housing wall into the interior of the housing and then into the air inlet 212 . The priming process is initiated by the controller by activating the pump 232 . The air sucked in is conducted out of the housing 260 through the air outlet 214 and released back into the environment. The measurement runs as previously described. When using the detection device 200 as a monitoring device 202, measurements can be carried out according to a defined scheme at specific time intervals.

Except in one, like in 8th As shown by way of example, housing 260 for ceiling mounting, the monitoring device for room air can also be accommodated in a housing for wall mounting or in a housing that can be placed anywhere in the room or in a portable housing. As already mentioned, the detection device can be supplied with power by means of batteries, rechargeable batteries (accumulators) or by means of a mains unit and a household power supply connection. All of these power supply elements can be integrated into the housing of the indoor air monitoring device.

Reference List

100

detection device

110

particle

112

air intake

114

air outlet

116

intake line

118

electrical contact, electrode

119

electrical contact, electrode

120

collector section

121

inside

122

detection volume

124

flushing medium

126

fluidic connection

128

sensor element

130

light source

132

pump

134

airflow

136

first switching valve

138

second switching valve

140

second inlet

142

second pump

144

pipe segment

152

filter

200

detection device

202

monitoring device

212

air intake

214

air outlet

216

intake line

218

electrical contact, electrode

219

electrical contact, electrode

220

collector section

221

inside

222

detection volume

224

flushing medium

225

suspension

226

fluidic connection

227

detection liquid

228

sensor element

230

light source

232

pump

234

airflow

235

guiding element

240

reservoir

242

purge line

246

pump

248

return line

250

valve assembly

252

filter

254

measuring device

256

first metering valve

258

second metering valve

260

Housing

261

opening

262

opening

264

indoor air

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• CN 111662816A [0003]
• US 2020/0309703 A1 [0004]
• WO 2008/108872 A2 [0005]
• US7265669B2 [0006]
• US7494769B2 [0007]
• CN 111665356A [0008]
• WO 2006/106235 A1 [0009]
• CN 110118711B [0010]
• CN 207516253 U [0011]
• CN 210720420 U [0012]
• EP 1309720 B1 [0013]
• US 2019/0242807 A1 [0014]
• EP 1882177 B1 [0015]
• US 10677773 B2 [0016]
• US 7705739 B2 [0017]
• EP 1158292 B1 [0018]
• US 7053783 B2 [0019]
• KR 101625133 B1 [0020]
• EP 0019741 B1 [0030]

Claims (27)

Method for detecting pathogenic substances contained in air, comprising: Passing a flow of air (134, 234) through an intake duct (116, 216), generating an electric field within a collector section (120, 220) of the intake duct (116, 216), within the collector section (120, 220) any pathogenic substances present are electrostatically captureable, Flushing the collector section (120, 220) with a liquid flushing medium (124, 224) and then transferring the flushing medium (124, 224) into a detection volume (122, 222) and Detecting turbidity and/or coloration of the flushing medium (124, 224) in the detection volume (122, 222) as a function of the presence of at least one pathogenic substance and as a result of a biochemical reaction of the same with antibodies. procedure after claim 1 , characterized in that the electric field is switched off before rinsing or during rinsing. procedure after claim 1 or 2 , characterized in that the flushing medium (124, 224) contains antibodies during flushing of the collector section (120, 220). procedure after claim 3 , characterized in that in the rinsing medium (124, 224) after the transfer into the detection volume (122, 222) particulate carriers are suspended on which the antibodies are immobilized. procedure after claim 4 , characterized in that the particulate carriers are kept pre-suspended in a liquid in the detection volume (122, 222). Procedure according to one of Claims 1 or 2 , characterized in that in the detection volume (122, 222) antibodies immobilized on particulate carriers are kept pre-suspended in a liquid. Method according to one of the preceding claims, characterized in that the flushing medium (124, 224) is held in a reservoir (240) from which a specific volume of the flushing medium (124, 224) is supplied to the collector section (120, 220) for flushing . procedure after claim 7 , characterized in that the flushing medium (124, 224) is returned to the reservoir (240) after detection from the detection volume (122, 222) if no turbidity could be detected. procedure after claim 8 in connection with one of the Claims 4 until 6 , characterized in that the particulate carriers are held back by a filter (152, 252) in the detection volume (122, 222) when the flushing medium (124, 224) is returned to the reservoir (240). Procedure according to one of Claims 1 until 6 , characterized in that the flushing medium (124, 224) from the detection volume (122, 222) is supplied to the collector section (120, 220) for flushing. procedure after claim 10 in connection with one of the Claims 4 until 6 , characterized in that the particulate carriers are held back by a filter (152, 252) in the detection volume (122, 222) when the flushing medium (124, 224) is supplied to the collector section (120, 220). Method according to one of the preceding claims, characterized in that the air stream (134, 234) is passed through the intake line (116, 216) by means of a pump (132, 232). Detection device (100, 200) for detecting pathogenic substances contained in the air, in particular viruses, having: an air inlet (112, 212), an air outlet (114, 214), an intake line (116, 216) connecting the air inlet (112, 212) to the air outlet (114, 214), electrical contacts (118, 119, 218, 219) which are arranged along the intake line (116, 216) in such a way that an electric field can be generated within a collector section (120, 220) of the intake line (116, 216), a detection volume (122, 222) for receiving a flushing medium (124, 224) from the collector section (120, 220), a fluidic connection (126, 226) between the collector section (120, 220) and the detection volume (122, 222) and a sensor element (128, 228) set up to detect a turbidity and/or coloration of the flushing medium (124, 224) in the detection volume (122, 222) depending on the presence of at least one pathogenic substance and as a result of a biochemical reaction thereof with antibodies. Detection device (100, 200) after Claim 13 , characterized by a first electronically switchable valve, which is set up, either the fluidic connection (126, 226) between to open or close the collector section (120, 220) and the detection volume (122, 222). Detection device (100, 200) after Claim 13 or 14 , characterized by a reservoir (240) for the flushing medium (124, 224) and a flushing line (242) fluidically connecting the reservoir (240) to the collector section (120, 220) for introducing the flushing medium (124, 224) into the collector section ( 120, 220). Detection device (100, 200) after claim 15 , characterized by a measuring device (254) integrated in the flushing line (242) and providing a defined volume for measuring a specific volume of the flushing medium (124, 224). Detection device (100, 200) according to one of Claims 15 or 16 , characterized by a return line (248) fluidically connecting the detection volume (120, 220) to the reservoir (240). Detection device (100, 200) after Claim 17 , characterized by a filter (252) in the return line (248) or in the detection volume (222) or between the return line (248) and detection volume (222). Detection device (100, 200) according to one of Claims 13 until 18 characterized by a filter (152, 252) in the fluidic connection (126, 226) between the collector section (120, 220) and the detection volume (122, 222) or in the detection volume (122, 222). Detection device (100, 200) according to one of claims 18 or 19 , characterized in that the filter (152, 252) has a nominal pore size of at most 0.5 µm, preferably at most 0.3 µm, particularly preferably at most 0.25 µm. Detection device (100, 200) according to one of claims 17 or 18 , characterized by a second electronically switchable valve which is set up to selectively close or open the return line (248). Detection device (100, 200) according to one of Claims 13 until 21 , characterized by a pump (132, 232) switched into the intake line (116, 216) or connected to the intake line (116, 216) for generating an air flow (134, 234) in the intake line (116, 216). Detection device (100, 200) according to at least one of Claims 14 , 21 or 22 characterized by an electronic controller to which the pump (132, 232) and/or the valve assembly (250) are electronically connected. Detection device (100, 200) according to one of Claims 13 until 23 , characterized in that the sensor element (128, 228) is electronically connected to an electronic controller and has an optical axis aligned with the detection volume (122, 222). Detection device (100, 200) after Claim 24 characterized by a light source (130, 230) electronically connected to the controller and aimed at the detection volume (122, 222). Detection device (100, 200) after Claim 25 , characterized in that the light source (130, 230), the sensor element (128, 228) and the controller for determining the light absorbed or scattered in the detection volume (122, 222) are set up. Use of the detection device (100, 200) according to one of Claims 13 until 26 as a test device for detecting pathogenic substances, in particular viruses, contained in the exhaled air of a subject, or as a monitoring device (202) for detecting pathogenic substances, in particular viruses, contained in the ambient air.

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