Patent Description:
Efficient collection of airborne particles exhaled by a human to facilitate analysis is of high interest in various applications. For instance, enabling detection of particular substances in a human breath may provide the possibility of screening for infectious diseases, such as influenza and severe acute respiratory syndrome coronavirus <NUM> (SARS-CoV-<NUM>). Thus, collection of exhaled airborne particles in an efficient and inexpensive way may allow screening to be performed frequently, allow quick identification of persons carrying disease, and consequently reducing spreading of the disease. Several diseases, such as influenza and SARS-CoV-<NUM>, spread among humans through droplets and aerosols produced during breathing, blowing, talking, coughing, and sneezing. Thus, it would be of interest to provide a collecting device allowing efficient capture of airborne particles exhaled by a human being and facilitating analysis of substances within the captured particles so as to identify whether the person carries a disease or not.

<CIT> discloses an air sampler for sampling air-borne particles comprising several collection chambers/impactors in parallel and has an inlet nozzle and outlet orifice, and permits passage of air at predetermined flow rate.

<CIT> discloses an airborne substance sensing device comprising a cartridge having an introduction plate in which micropores are formed through which a gas including an airborne substance can pass, a transparent collection plate that is disposed so as to oppose the introduction plate and on which the airborne substance can be made to collide and be collected through the collision of the gas having passed through the micropores, a main body in which the introduction plate and collection plate are disposed in parallel and a flow path for guiding the gas including the airborne substance to the micropores is formed.

Further, a sample may need to be prepared before analysis may be performed. For instance, a reagent may need to be added to the collected particles. Thus, in order to facilitate fast and efficient analysis of airborne particles, combining collected particles with a reagent also needs to be performed in an efficient manner.

An objective of the present inventive concept is to provide a collecting device allowing simple and efficient collection of airborne particles exhaled by a human being. A further objective of the present inventive concept is to allow a reagent to be efficiently provided to the collected particles.

These and other objectives of the present inventive concept are at least partly met by the invention as defined in the independent claims.

According to a first aspect, there is provided a collecting device for collection of airborne particles exhaled by a human being, said collecting device comprising: a first layer and a second layer, wherein the first layer and the second layer are arranged to be spaced apart for forming a particle collection chamber between the first and the second layer, wherein the first layer comprises a plurality of inlets configured to extend through the first layer for transporting a flow of air therethrough into the particle collection chamber; wherein ends of the inlets are configured to face a first surface of the second layer for capturing airborne particles in the flow of air entering the particle collection chamber through the ends of the inlets by impaction of airborne particles on the first surface of the second layer; wherein the second layer comprises a plurality of outlets configured to extend through the second layer for transporting the flow of air therethrough out of the particle collection chamber; the collecting device further comprising at least one liquid access port for filling the particle collection chamber with a reagent; and wherein the particle collection chamber comprises at least one side wall extending from the first layer to the second layer for defining flow of the reagent through the particle collection chamber when filling the particle collection chamber, such that a first portion of the particle collection chamber and a second portion of the particle collection chamber are arranged on opposite sides of the at least one side wall.

Thanks to the collecting device, an efficient capturing of airborne particles may be provided in the particle collection chamber. The use of a plurality of inlets may ensure that a high capturing efficiency of airborne particles is achieved in the particle collection chamber, as capturing of airborne particles occur in multiple positions of the particle collection chamber (associated with respective inlets).

Further, thanks to the collecting device, capturing of airborne particles may be performed in a particle capturing chamber which may further be filled with a reagent. Thus, the collected particles need not be transferred from the collecting device in which the particles are collected for purpose of providing a reagent. This implies that a very efficient collection and preparation of a sample may be provided by the collecting device.

Further, thanks to the particle collection chamber comprising at least one side wall, flow of the reagent through the particle collection chamber may be controlled. This implies that the flow of the reagent through the particle collection chamber may be well-defined since at least a first portion and a second portion of the particle collection chamber are separated by the at least one side wall. A well-defined flow of the reagent may ensure that bubbles are not trapped within the particle collection chamber after the particle collection chamber has been filled with the reagent. Rather, air (or any other gas) in the particle collection chamber may be pushed in a controlled manner by the reagent towards opening(s) through which the air can escape the particle collection chamber.

The air being pushed out by the filling of the particle collection chamber by the reagent may escape the particle collection chamber through the inlets and/or outlets. However, the collecting device may further comprise a separate outlet port through which the air (or any other gas) in the particle collection chamber may also or alternatively leave the particle collection chamber when it is filled by the reagent.

Ensuring that there are no bubbles in the particle collection chamber may be very advantageous in relation to analysis of the collected particles to be performed. For instance, the analysis of the collected particles may be performed through a light-based measurement, such as by illuminating the collected particles and/or substance(s) extracted from the collected particles and detecting light after interaction with the collected particles. Light interaction may include absorption, transmission, scattering, and fluorescence. If bubbles would be present in the particle collection chamber, the bubbles may interact with light used for analysis, such as illumination light or light having interacted with a sample, such as fluorescent light or scattered light. The bubbles may thus affect analysis based on light-based measurements.

The particle collection chamber is adapted for allowing reactions to take place therein and may also be adapted for allowing measurements to be performed in relation to the collected particles in the particle collection chamber. Thus, analysis of the collected particles may be performed in the particle collection chamber.

Thanks to the collecting device being further configured to allow measurements to be performed while a sample, prepared by the collected particles reacting with the reagent, is arranged in the particle collection chamber, the collecting device facilitates a fast analysis of a sample being made.

Optical access to the particle collection chamber may be provided by the first and/or the second layer being transparent to wavelengths of light being used in the light-based measurement. Additionally or alternatively, optical access may be provided through the inlets and/or the outlets defining a space (which may possibly be filled by a liquid reagent) through which optical access to the particle collection chamber is provided.

The collecting device may facilitate an easy and intuitive way of collecting samples through self-test by persons, thereby promoting more frequent testing of people. In this regard, the use of the collecting device for screening of people may allow people to be screened several times per week, such as every day, such that viral load peaks may be identified. If testing is done only once a week, the viral load peak may be missed such that the testing fails to detect persons having a stage of a disease in which the person is highly infectious. Hence, very frequent testing may be required in order to identify highly infectious people and prevent spreading of a disease.

The reagent may be a liquid reagent. The collecting device is configured to receive the reagent through the at least one liquid access port. The reagent may then flow into the particle collection chamber in order to completely fill the particle collection chamber.

The at least one side wall extending from the first layer to the second layer implies that reagent may not leak between the first layer and the side wall or the second layer and the side wall so as to flow from the first portion to the second portion of the particle collection chamber. Thus, the at least one side wall firmly controls flow of the reagent for filling the particle collection chamber.

Both the first and the second portion of the particle collection chamber need not be in direct contact with the at least one side wall. For instance, the particle collection chamber may comprise two parallel side walls, with a spacing therebetween not being part of the particle collection chamber. This implies that a first side wall may form a wall of the first portion and a second side wall may form a wall of the second portion of the particle collection chamber.

Further, the first and second portions of the particle collection chamber need not be completely sealed from each other. Rather, the first and second portions may be connected to each other at an end of the particle collection chamber, which implies that the reagent will be guided to follow a non-straight path through the particle collection chamber when filling the particle collection chamber.

The at least one side wall may further provide support between the first and second layers of the collecting device. This implies that a structural stability of the collecting device is improved by the at least one side wall. Further, the at least one side wall may improve bonding of the first and second layers to each other in manufacturing of the collecting device.

As used herein, capturing of airborne particles by "impaction" should be construed as particles being removed from the flow of air by forcing the flow of air to change direction. Thanks to the flow of air being forced to change direction, momentum of particles having a certain size will cause the particles not to follow the flow of air in its change of direction and instead the particles will be captured on a collection surface. The capturing of airborne particles may involve capturing of aerosols but may also or alternatively involve capturing of larger droplets in the flow of air.

According to an embodiment, the airborne particles may be borne e.g. by aerosols and/or by droplets in the air exhaled by a person. The airborne particles may further comprise substance(s) of interest, such that analysis of the collected particles may include the particles being subject to reactions for exposing the substance(s) of interest to enable detection of substance(s) of interest in a measurement.

Further, thanks to the collecting device comprising a plurality of inlets and a plurality of outlets, the collecting device facilitates breathing through the collecting device without requiring a high supply pressure to be provided by the person breathing through the collecting device. In particular, the use of a plurality of inlets and outlets enables the flow of air to experience a combined cross-section of the respective inlets and outlets that is relatively large such that a large pressure drop may be avoided even though individual inlets and outlets may have small cross-sections. Further, the small cross-sections facilitate particle collection at low flow rates of the flow of air, such as in the order of <NUM> liters per second.

The collecting device allows a human being to breath or blow into the collecting device such that particles comprised in the exhaled air can be conveniently collected without requiring difficult procedures for the person. Compared to sample collection through a nasal or throat swab, or saliva collection, the collecting device provides a particle collection with much less discomfort for the user and may remove the need for a trained professional to be involved in the sample collection.

The flow of air may be received by the collecting device by the human being blowing directly into an apparatus holding the collecting device, such as through a mouthpiece of the apparatus. Hence, the flow of air may be provided directly from exhalation by the human being. However, it should be realized that the flow of air may alternatively be received indirectly from the human being, e.g. by the human being exhaling into a bag and by the flow of air being provided by the bag towards the collecting device.

The first layer and the second layer may be parallel and define planar surfaces on opposite sides of the particle collection chamber. It should further be realized that the particle collection chamber may further be defined by outermost side walls surrounding an outer periphery of the particle collection chamber. The outermost side walls (together with the at least one side wall) may also provide a spacer for defining a distance between the first layer and the second layer.

The inlets and the outlets may extend from the particle collection chamber to an external environment outside the collecting device. Thus, the inlets may extend through at least the first layer and possibly further layers between the particle collection chamber and the external environment. Similarly, the outlets may extend through at least the second layer and possibly further layers between the particle collection chamber and the external environment.

The inlets may further be defined by walls extending from the first layer into the particle collection chamber and towards the second layer. Thus, the ends of the inlets facing the first surface of the second layer need not be flush with the first layer. Rather, the ends of the inlets may arranged close to the second layer, which may facilitate capturing of particles, while the distance between the first and second layers may be larger than the distance between the ends of the inlets and the second layer to allow a larger volume of the particle collection chamber.

At least the first and second layers of the collecting device may be formed from a semiconductor or semiconductor-based material, such as silicon or silicon dioxide. This may facilitate manufacturing of the collecting device, since small dimensions of the collecting device may be advantageously provided by semiconductor manufacturing processes.

According to an embodiment, the particle collection chamber extends in an area of a plane parallel to the first layer and wherein the at least one liquid access port is arranged at or close to a periphery of the area.

This implies that the reagent may enter the particle collection chamber through a periphery of the area or close to the periphery of the area. Then, the particle collection chamber will be filled from a point of entry into the particle collection chamber. This may ensure that the reagent need not flow in all directions for filling the particle collection chamber (as opposed to if the reagent is entered into the particle collection chamber at a central position of the area). Hence, a risk for bubbles being trapped in the particle collection chamber is further reduced.

The at least one liquid access port may be arranged inside the periphery of the area or outside the periphery of the area. Even if the liquid access port is inside the periphery of the area, since the access port is close to the periphery, a risk of bubbles being trapped in the particle collection chamber may be low.

The liquid access port may be directly connected to the particle collection chamber or may be connected to the particle collection chamber via a connecting channel. Thus, the reagent may be received at the at least one liquid access port and may then be guided through the connecting channel before entering the particle collection chamber at the periphery of the area. In fact, in embodiments with a connecting channel connecting the liquid access port to a periphery of the area, the liquid access port may be distanced from the periphery of the area by a long connecting channel.

The liquid access port being connected to the particle collection chamber through a connecting channel implies that the liquid access port may be spaced apart from inlets (or outlets) even though the liquid access port extends through the first layer (or second layer). This implies that a space around the particle collection chamber in which particles carrying an infectious disease may be sealed as soon as the particles have been collected and, yet, the reagent may be provided into the particle collection chamber. Thus, a further sealing of the connecting channel and the liquid access port may be performed when the reagent has been provided.

According to an embodiment, the plurality of inlets and the plurality of outlets are distributed over the area of the particle collection chamber.

The inlets and outlets may function to allow air to escape the particle collection chamber when the particle collection chamber is filled by the reagent. Thanks to the inlets and outlets being distributed over the area, outlet of air is provided in the entire area of the particle collection chamber. This may further ensure that no bubbles are trapped in the particle collection chamber when it is filled by the reagent.

The plurality of inlets and the plurality of outlets may be evenly distributed over the area such that the plurality of inlets and the plurality of outlets are arranged in a regular pattern over an entire area of the particle collection chamber. This may imply that distances between adjacent inlets and between adjacent outlets is equal over the entire area of the particle collection chamber.

By having a plurality of inlets arranged with small distances between adjacent inlets and arranged to be distributed over the area of the particle collection chamber, a large collection efficiency of the collecting device may be provided using a small footprint of the collecting device.

According to an embodiment, the particle collection chamber is configured for guiding propagation of the reagent from the at least one liquid access port through the particle collection chamber along the at least one side wall, wherein the reagent is guided through a channel having a larger length in a main direction of propagation of the reagent than width transverse to the main direction.

The channel having a larger length than width implies that the reagent may easily fill the width transverse to the main direction as the reagent flows along the length of the channel. This implies that there is a low risk for bubbles being trapped within the particle collection chamber at sides of the channel.

It should be realized that, when referring to the width of the channel, it is referred to a size of the channel in a transverse direction to the main direction in the plane of the particle collection chamber parallel to the first layer.

It should be further realized that the length of the channel may be defined as a path length of a center line of the channel, which may or may not follow a straight path.

According to an embodiment, the particle collection chamber is separated by the at least one side wall into a plurality of separate compartments, such that the first portion and the second portion form a first compartment and a second compartment, respectively.

Thanks to the particle collection chamber having separate compartments, the separate compartments may be separately and simultaneously filled. This implies that an efficient and fast filling of the particle collection chamber with a reagent may be provided with a relatively large total volume of the particle collection chamber. This also implies that an analysis result may be quickly provided through sampling by the collecting device.

The first and second compartments may each receive flow of air from a plurality of inlets configured to extend through the first layer. Thus, the flow of air from exhalation by the human being may be incident on a surface of the first layer so as to simultaneously provide the flow of air through respective inlets to the first and second compartments. This implies that the collection of particles may be easily provided simultaneously in a plurality of compartments of the particle collection chamber.

Each inlet may be associated with a single compartment, such that each compartment may be associated with a set of inlets dedicated to the compartment.

It should be realized that the particle collection chamber may be separated into more than two compartments, such as three, eight or sixteen compartments, or any other suitable number.

According to an embodiment, the collecting device comprises a plurality of liquid access ports, each liquid access port being associated with a unique compartment of the particle collection chamber.

Thus, the compartments of the particle collection chamber may each be supplied through a dedicated liquid access port. This may ensure that reagent is supplied in a well-controlled manner to each compartment for filling all the compartments of the particle collection chamber simultaneously. Also, each of the compartments is individually controlled, such that the compartments may be filled in different manners, if desired, such as by providing different reagents to different compartments.

According to another embodiment, the collecting device comprises a single liquid access port for filling each of the plurality of compartments of the particle collection chamber.

Thus, reagent may be supplied to all of the plurality of compartments through a single liquid access port. Hence, filling of all of the compartments may be performed in a simple manner. The liquid access port may be branched into separate channels, each being connected to a unique compartment.

According to an embodiment, the at least one side wall is configured to define a non-straight path of propagation of the reagent from the at least one liquid access port through the particle collection chamber.

Thus, flow of reagent when filling the particle collection chamber may follow a narrow channel, while the particle collection chamber may have a small footprint in two dimensions of the plane of the particle collection chamber, such as providing a square shape of the outer periphery of the particle collection chamber.

The non-straight path may include both the first portion of the particle collection chamber and the second portion of the particle collection chamber. This may also imply that there is a fluid connection between all parts of the particle collection chamber.

According to an embodiment, the non-straight path is meander-shaped.

This is an efficient manner of arranging the channel along the non-straight path formed by the particle collection chamber in a small area of the outer periphery of the particle collection chamber.

According to an embodiment, the at least one liquid access port has cross-sectional dimensions for allowing the reagent to be passed through the at least one liquid access port into the particle collection chamber by a capillary force.

This implies that reagent may be supplied into the particle collection chamber in a simple manner. The capillary force may draw reagent into the particle collection chamber. Hence, the reagent may simply be provided as droplet(s) on a surface at which the at least one liquid access port provides an opening.

According to an embodiment, the at least one liquid access port is configured to extend through the first layer or the second layer.

Thus, the at least one liquid access port may provide access to the particle collection chamber at a surface of the collecting device which may also provide access to the particle collection chamber via inlets or outlets.

According to an embodiment, the inlets and the outlets have dimensions for allowing the inlets and the outlets to be filled by the reagent from the particle collection chamber by a capillary force, wherein the capillary force further prevents the reagent to escape from the inlets and the outlets.

Thus, the particle collection chamber and the inlets and outlets connected thereto in the collecting will be completely filled by the reagent. This may ensure that any air within a space in the collecting device connected to the particle collection chamber is pushed out of the collecting device when the particle collection chamber is filled by the reagent. Hence, a risk for bubbles being trapped in the particle collection chamber is further reduced.

This may further facilitate high quality light-based measurements of a sample in the particle collection chamber. in particular if optical access is provided through the inlets and/or outlets. By the inlets and outlets being filled with reagent, light will not need to pass and will hence not be affected by an interface between air and the reagent at an entry of the inlet or outlet into the particle collection chamber. Further, an interface between air and reagent may be avoided at an interface to an external environment outside the collecting device, by a layer being placed in contact with the collecting device. Such layer may also function to seal the particle collection chamber.

According to an embodiment, the collecting device further comprises pillars extending from the first layer to the second layer for improving bonding of the first layer to the second layer.

The pillars may provide support between the first and second layers of the collecting device. This implies that a structural stability of the collecting device is improved by the pillars. Further, the pillars may improve bonding of the first and second layers to each other in manufacturing of the collecting device.

According to a second aspect, there is provided a method for collection of airborne particles exhaled by a human being and providing a reagent to the collected particles, said method comprising: receiving a flow of air onto a first layer of a collecting device, wherein the first layer comprises a plurality of inlets extending through the first layer; passing the flow of air through the inlets into a particle collection chamber between the first layer and a second layer of the collecting device spaced apart from the first layer; capturing airborne particles in the flow of air entering the particle collection chamber by impaction of airborne particles on a first surface of the second layer, wherein ends of the inlets are configured to face the first surface of the second layer; passing the flow of air out of the particle collection chamber through outlets extending through the second layer of the collecting device; filling the particle collection chamber with a reagent through at least one liquid access port, wherein the reagent is guided to flow through the particle collection chamber along at least one side wall through a first portion of the particle collection chamber and a second portion of the particle collection chamber on opposite sides of the at least one side wall.

Thanks to the method, an efficient capturing of airborne particles may be provided in the particle collection chamber. Further, thanks to the method, capturing of airborne particles is performed in a particle capturing chamber which is further filled with a reagent. Thus, the collected particles need not be transferred from the collecting device in which the particles are collected for purpose of providing a reagent. This implies that a very efficient collection and preparation of a sample may be provided by the collecting device.

Further, thanks to the reagent being guided to flow along at least one side wall through first and second portions of the particle collection chamber on opposite sides of the at least one side wall, flow of the reagent through the particle collection chamber is controlled. This implies that the flow of the reagent through the particle collection chamber may be well-defined since at least a first portion and a second portion of the particle collection chamber are separated by the at least one side wall. The well-defined flow of the reagent may ensure that bubbles are not trapped within the particle collection chamber after the particle collection chamber has been filled with the reagent.

Referring now to <FIG>, a collecting device <NUM> for collection of airborne particles exhaled by a human being is shown in relation to a sample collector <NUM>. It should thus be realized that according to an embodiment, the collecting device <NUM> may be arranged in a sample collector <NUM> which provides an interface for allowing a flow of air from a human being to be provided through the collecting device <NUM>. However, it should be realized that the collecting device <NUM> may be arranged to receive the flow of air in different manners and need not necessarily be mounted in a sample collector <NUM> or any other apparatus.

The sample collector <NUM> may be used for capturing airborne particles, such as aerosols and/or droplets in the flow of air exhaled by the human being. Thanks to capturing airborne particles, analysis of the airborne particles in the exhaled breath may be performed. This may be used for determining whether the human being carries a disease, which is spread through droplets and aerosols produced during normal breathing, talking, coughing, and sneezing. For instance, the capturing of airborne particles using the sample collector <NUM> may be used for screening whether a person is infected by influenza or severe acute respiratory syndrome coronavirus <NUM> (SARS-CoV-<NUM>). Thanks to the sample collector <NUM> capturing a sample based on an exhaled breath, the capturing of a sample from a person may be performed with minimal discomfort to the person.

The sample collector <NUM> may comprise a mouthpiece <NUM> to be inserted into the mouth of the person and through which the person exhales to provide a flow of air <NUM> through the sample collector <NUM>.

The flow of air <NUM> may be guided through the sample collector <NUM> so as to pass the collecting device <NUM>. The collecting device <NUM> is configured to capture airborne particles from the flow of air <NUM> through impaction in a particle collection chamber of the collecting device <NUM>. The collecting device <NUM> may be configured to capture airborne particles with high efficiency and may further allow analysis of the collected airborne particles.

Analysis of the collected airborne particles involves sample preparation by providing a reagent to the particle collection chamber for allowing reactions to take place in the particle collection chamber. The sample collector <NUM> may be configured to provide access to the collecting device <NUM> arranged in the sample collector <NUM> such that a reagent may be provided to the particle collection chamber while the collecting device <NUM> is arranged in the sample collector <NUM>.

The reactions may further be controlled by providing further influence on the particle collection chamber, such as by heating and/or cooling the sample in the particle collection chamber.

Furthermore, analysis of the collected airborne particles may be performed while the collecting device <NUM> is maintained in the sample collector <NUM>. This implies that a risk of spreading of disease by opening of the sample collector <NUM> may be avoided.

Referring now to <FIG>, the collecting device <NUM> according to an embodiment will be further described.

The collecting device <NUM> comprises a first layer <NUM> and a second layer <NUM>. The first layer <NUM> and the second layer <NUM> are arranged to be spaced apart for defining a particle collection chamber <NUM> between the first layer <NUM> and the second layer <NUM>.

The first layer <NUM> and the second layer <NUM> may each be formed from a semiconductor or semiconductor-based material, such as silicon or silicon dioxide. This may facilitate manufacturing of the collecting device <NUM>, since small dimensions of the collecting device may be advantageously provided by semiconductor manufacturing processes.

The first layer <NUM> comprises a first surface <NUM> configured to receive a flow of air, which may be the flow of air <NUM> in the sample collector <NUM> as described above. The first layer <NUM> also comprises a second surface <NUM> facing the second layer <NUM>. The first layer <NUM> further comprises a plurality of inlets <NUM> having a first end <NUM> at the first surface <NUM> of the first layer <NUM> and a second end <NUM> at the second surface <NUM> of the first layer <NUM>.

The second layer <NUM> comprises a first surface <NUM> facing the first layer <NUM> and a second surface <NUM> at which the flow of air may be output from the collecting device <NUM> after having passed the collecting device <NUM>. The second layer <NUM> further comprises a plurality of outlets <NUM> having a first end <NUM> at the first surface <NUM> of the second layer <NUM> and a second end <NUM> at the second surface <NUM> of the second layer <NUM>.

The inlets <NUM> are configured to extend through the first layer <NUM> for transporting the flow of air <NUM> through the first layer <NUM> from the first end <NUM> to the second end <NUM>. The second ends <NUM> of the inlets <NUM> are configured to face the first surface <NUM> of the second layer <NUM>. Thus, when the flow of air <NUM> passes through the inlets <NUM>, the flow of air <NUM> will impinge on the first surface <NUM> of the second layer <NUM> such that airborne particles may be collected on the first surface <NUM> of the second layer <NUM> and, hence, in the particle collection chamber <NUM>, by impaction.

The particle collection chamber <NUM> has first side <NUM> and a second side <NUM>, wherein the first side <NUM> is defined by the second surface <NUM> of the first layer <NUM> and the second side <NUM> is defined by the first surface <NUM> of the second layer <NUM>. The particle collection chamber <NUM> may further be defined by side surfaces formed in a spacer material <NUM> between the first layer <NUM> and the second layer <NUM>.

The spacer <NUM> can either be a glue, double sided-adhesive tape, or in case of silicon/glass layers <NUM>, <NUM>, the spacer <NUM> can be integrated into one of the layer materials to enable anodic, fusion, or laser bonding of the first layer <NUM> and the second layer <NUM>.

In another embodiment, not shown in <FIG>, the inlets <NUM> may be configured to protrude from second surface <NUM> of the first layer <NUM> to extend further into the particle collection chamber <NUM>. This may imply that the second ends <NUM> of the inlets <NUM> are closer to the first surface <NUM> of the second layer <NUM> so as to improve capturing of particles by impaction while ensuring that a volume of the particle collection chamber <NUM> is not too small.

The inlets <NUM> and the outlets <NUM> are arranged in a staggered arrangement. This implies that center axes of inlets <NUM> and outlets <NUM> are not aligned. Hence, the flow of air <NUM> passing through the inlets <NUM> into the particle collection chamber <NUM> will at least slightly change direction through the particle collection chamber <NUM> before the flow of air <NUM> may exit the particle collection chamber <NUM> through the outlets <NUM>.

Thanks to the inlets <NUM> and the outlets <NUM> being staggered, the inlets <NUM> are arranged directly above the first surface <NUM> of the second layer <NUM> wherein capturing of airborne particles occur. The inlets <NUM> are arranged such that there is at least no opening in the first surface <NUM> of the second layer <NUM> corresponding to an outlet <NUM> at a projection of the center axes of the inlets <NUM> onto the first surface <NUM> of the second layer <NUM>. As shown in <FIG>, the inlets <NUM> and the outlets <NUM> are arranged such that the entire inlet <NUM> is projected on an area of the first surface <NUM> wherein no openings corresponding to outlets <NUM> are provided. Thus, airborne particles may be captured at the first surface <NUM> of the second layer <NUM>, while the flow of air <NUM> through the inlets <NUM> changes direction to follow the first surface <NUM> and then escape the particle collection chamber <NUM> through the outlets <NUM>.

As shown in <FIG>, the inlets <NUM> may extend perpendicularly in relation to the first layer <NUM>. Further, the outlets <NUM> may extend perpendicularly in relation to the second layer <NUM>. With the first and second layer <NUM>, <NUM> being parallel, this implies that the inlets <NUM> and the outlets <NUM> are parallel, arranged with the central axes displaced in relation to each other. This is a suitable arrangement for ensuring that the inlets <NUM> and outlets <NUM> are staggered and that the flow of air <NUM> is forced to change direction through the collecting device <NUM>.

Thanks to the flow of air <NUM> being forced to change direction, momentum of airborne particles having a certain size will cause the airborne particles not to follow the flow of air <NUM> in its change of direction and instead the particles will be captured on the collection surface formed by the first surface <NUM> of the second layer <NUM>. The capturing of airborne particles may involve capturing of aerosols but may also or alternatively involve capturing of larger droplets in the flow of air.

Collection of particles in the collecting device <NUM> is further illustrated in the enlarged insert A of <FIG>, illustrating that airborne particles will be captured by impaction on the first surface <NUM> of the second layer <NUM>, before the flow of air <NUM> proceeds to outlets <NUM> extending through the second layer <NUM>.

The collecting device <NUM> may further be configured to provide optical access for performing a measurement, based on light, of airborne particles collected in the particle collection chamber <NUM>.

The measurement may be performed based on light that is passed through at least one of the first and second layers <NUM>, <NUM>. Thus, the first layer <NUM> and/or the second layer <NUM> may be transparent or translucent to provide optical access to the particle collection chamber <NUM>. However, according to another embodiment, optical access is provided through the inlets <NUM> and/or the outlets <NUM>.

In addition to the inlets <NUM> and outlets <NUM>, a liquid access port <NUM> providing a reagent inlet is provided in the collecting device <NUM>. The liquid access port <NUM> may extend through the first layer <NUM> as shown in <FIG> but may alternatively extend through the second layer <NUM> instead. The liquid access port <NUM> enables filling of the particle collection chamber <NUM> with a liquid reagent, such as a polymerase chain reaction (PCR) reagent. The filling of the particle collection chamber <NUM> by the reagent will be discussed in further detail below.

The collecting device <NUM> may further be configured to allow a sample in the particle collection chamber <NUM> to be heated and/or cooled, possibly in numerous iterations, in order to prepare the sample for analysis. For instance, thermal energy may be provided to the particle collection chamber <NUM> for thermal lysis to expose RNA of SARS-CoV-<NUM> in the captured particles, converting the RNA to DNA using reverse transcriptase based on the reagent and providing thermal cycling for amplification of the DNA using quantitative PCR.

As mentioned above, analysis of a sample in the particle collection chamber <NUM> may be performed by light-based measurements of the sample. The reagent should therefore be filled into the particle collection chamber <NUM> such that bubbles are not trapped in the particle collection chamber <NUM>, since bubbles may affect light-based measurement results.

Referring now to <FIG>, a particle collection chamber <NUM> according to a first embodiment is shown. The particle collection chamber <NUM> is formed such that trapping of bubbles in the particle collection chamber <NUM> during filling of the particle collection chamber <NUM> with a liquid reagent may be reduced or avoided.

<FIG> shows a top view of the particle collection chamber <NUM> with the first layer <NUM> and the second layer <NUM> being removed from the view, whereas the inlets <NUM> and the outlets <NUM> are illustrated to indicate the relations between the inlets <NUM> and the outlets <NUM> and the particle collection chamber <NUM>. However, lateral walls surrounding the particle collection chamber <NUM> are indicated in <FIG>.

The particle collection chamber <NUM> comprises at least one side wall <NUM> within an area defined by an outer periphery of the particle collection chamber <NUM>. The area of the particle collection chamber <NUM> extends in a plane parallel to the first layer <NUM> and the second layer <NUM>. Thus, the at least one side wall <NUM> provides guidance of flow of the reagent when the particle collection chamber <NUM> is filled. As shown in <FIG>, a plurality of side walls <NUM> may be provided such that the plurality of side walls <NUM> cooperate to provide guidance of the flow of the reagent. For brevity and simplicity, description below will mainly be made in relation to one of the side walls <NUM>, but it should be realized that the description may apply to each of the plurality of side walls <NUM>.

Since the particle collection chamber <NUM> comprises the side wall <NUM>, the particle collection chamber <NUM> also comprises a first portion 248a and a second portion 248b arranged on opposite sides of the side wall <NUM>. The side wall <NUM> extends from the first layer <NUM> to the second layer <NUM> implies that reagent may not leak between the first layer <NUM> and the side wall <NUM> or the second layer <NUM> and the side wall <NUM> so as to flow directly from the first portion 248a to the second portion 248b of the particle collection chamber <NUM>.

Thanks to the side wall <NUM> the flow of the reagent may be guided along a path through the particle collection chamber <NUM>. In particular, the flow of the reagent may be guided to flow along the side wall <NUM> such that the flow of the reagent propagates within a relatively narrow angle in relation to a main direction of the flow. This implies that the reagent may push air (or any other gas) in the particle collection chamber <NUM> in front of a wavefront of the flow of reagent towards opening(s) of the particle collection chamber <NUM> through which the air (or other gas) can escape. Hence, the arrangement of the particle collection chamber <NUM> may ensure that bubbles are not trapped within the particle collection chamber <NUM> when the particle collection chamber <NUM> is filled by the reagent.

The openings through which air may escape the particle collection chamber <NUM> may be formed by the inlets <NUM> and/or outlets <NUM>. However, the collecting device <NUM> may further comprise a separate outlet port through which the air (or other gas) in the particle collection chamber <NUM> may also or alternatively escape the particle collection chamber <NUM> when it is filled by the reagent.

The collecting device <NUM> shown in <FIG> comprises two liquid access ports 260a, 260b. The liquid reagent may be supplied to each of the liquid access ports 260a, 260b. For instance, liquid reagent may be simultaneously supplied to the liquid access ports 260a, 260b. Use of two liquid access ports 260a, 260b enables the particle collection chamber <NUM> to be filled from two ends of the particle collection chamber <NUM> such that the reagent flowing from each end may meet at a center of the particle collection chamber <NUM>. This implies that the filling of the particle collection chamber <NUM> may occur from two directions simultaneously such that a time required for filling the particle collection chamber <NUM> may be reduced by a factor <MAT> compared to a collecting device <NUM> having only a single liquid access port <NUM>.

Each of the liquid access ports 260a, 260b may be arranged at or close to the outer periphery of the particle collection chamber <NUM>. Since the liquid reagent may thus enter the particle collection chamber <NUM> close to the periphery of the particle collection chamber <NUM>, the liquid reagent is limited by the periphery of the particle collection chamber <NUM> from propagating in any direction from the point of entry. Thus, flow of the reagent when filling the particle collection chamber <NUM> can be further controlled and a risk for bubbles being trapped in the particle collection chamber <NUM> is further reduced.

As shown in <FIG>, the liquid access port <NUM> may provide an opening at a top or bottom surface of the collecting device <NUM>, which surface may be defined by the first layer <NUM> or the second layer <NUM> or another layer parallel thereto (if there are plural layers between the top/bottom surface of the collecting device <NUM> and the particle collection chamber <NUM>). The liquid access port <NUM> may extend into the particle collection chamber <NUM>, thus extending through either the first layer <NUM> or the second layer <NUM>, such that the reagent is entered into the particle collection chamber <NUM> through the first side <NUM> or the second side <NUM>.

However, as shown in <FIG>, the liquid access ports 260a, 260b may alternatively end outside the outer periphery of the particle collection chamber <NUM> in the plane of the particle collection chamber <NUM>. The collecting device <NUM> further comprises short connecting channels 262a, 262b connecting each of the liquid access ports 260a, 260b into the particle collection chamber <NUM> at the periphery of the particle collection chamber <NUM>. Thus, the short connecting channels 262a, 262b may transport the reagent from the respective liquid access ports 262a, 262b to the particle collection chamber <NUM>.

Thanks to the liquid ports 260a, 260b being at least slightly spaced from the outer periphery of the particle collection chamber <NUM>, the particle collection chamber <NUM> with the inlets <NUM> and outlets <NUM> may be sealed as soon as the particles (which may carry an infectious disease) have been collected. Still, the reagent may be provided into the particle collection chamber <NUM> through the liquid access ports 260a, 260b and the connecting channels 262a, 262b and a further sealing of the connecting channels 262a, 262b and the liquid access ports 260a, 260b may be performed when the reagent has been provided.

As mentioned, the liquid access ports 260a, 260b may be configured to extend through the first layer <NUM> or the second layer <NUM>. The liquid access ports 260a, 260b may be arranged on the same side of the collecting device <NUM> such that the liquid access ports 260a, 260b extend through the same layer, e.g. the first layer <NUM>. However, according to an alternative, the liquid access ports 260a, 260b may be arranged on opposite sides of the collecting device <NUM> such that one liquid access port (e.g., liquid access port 260a) extends through the first layer <NUM> and the other liquid access port (e.g., liquid access port 260b) extends through the second layer <NUM>.

The liquid access ports 260a, 260b may be configured to draw reagent into the liquid access ports 260a, 260b by a capillary force. Thus, the liquid access ports 260a, 260b may have a cross-sectional size, such as a cross-sectional diameter that is sufficiently small for the reagent to be drawn into the particle collection chamber <NUM>. This may typically be achieved by the liquid access ports 260a, 260b having a diameter of an order of millimeters or less.

The collecting device <NUM> comprises a plurality of inlets <NUM> and a plurality of outlets <NUM> for providing the flow of air <NUM> through the collecting device <NUM> for capturing airborne particles. The inlets <NUM> and outlets <NUM> may further function as openings of the particle collection chamber <NUM> through which air in the particle collection chamber <NUM> may escape when the particle collection chamber <NUM> is filled by the reagent.

The plurality of inlets <NUM> and the plurality of outlets <NUM> may be distributed over the area of the particle collection chamber <NUM>. This implies that capturing of particles may occur distributed over the entire area of the particle collection chamber <NUM>, such that a high efficiency of particle collection may be achieved. Further, thanks to the inlets <NUM> and outlets <NUM> being distributed over the area of the particle collection chamber <NUM>, the particle collection chamber <NUM> is provided with openings allowing air to escape from the particle collection chamber <NUM> throughout the area of the particle collection chamber <NUM>. Thus, a risk for bubbles being trapped in the particle collection chamber <NUM> is further reduced.

The inlets <NUM> and the outlets <NUM> may be configured to draw reagent from the particle collection chamber <NUM> into the inlets <NUM> and outlets <NUM> by a capillary force. Thus, the inlets <NUM> and the outlets <NUM> may have a cross-sectional size, such as a cross-sectional diameter that is sufficiently small for the reagent to be drawn into the inlets <NUM> and the outlets <NUM>. The inlets <NUM> and the outlets <NUM> may anyway desirably have a small cross-sectional dimension to allow efficient capturing of particles of a small size, such that the inlets <NUM> and the outlets <NUM> may anyway be so small as to provide a capillary force for drawing the reagent into the inlets <NUM> and the outlets <NUM>. For instance, the inlets <NUM> may have a diameter in a range of <NUM> - <NUM>, such as in a range of <NUM> - <NUM> for providing efficient collection of particles down to a size of <NUM>. Further, the outlets <NUM> may be dimensioned in relation to the inlets <NUM>. For instance, the outlets <NUM> may have a diameter in the range of <NUM> - <NUM>, such as in the range of <NUM> - <NUM>.

Thanks to the small cross-sectional sizes of the inlets <NUM> and the outlets <NUM>, the capillary force may also prevent the reagent from escaping from the inlets <NUM> and the outlets <NUM> at an interface to a top or bottom surface of the collecting device <NUM>, respectively. Since the inlets <NUM> and the outlets <NUM> may open to a large surface of the collecting device <NUM>, the capillary force will keep the reagent inside the inlets <NUM> and the outlets <NUM>, respectively.

As shown in <FIG>, the side walls <NUM> define a channel through the particle collection chamber <NUM> for guiding the flow of reagent when the particle collection chamber <NUM> is filled from the entry of the reagent into the particle collection chamber <NUM>. The flow of reagent may enter the particle collection chamber <NUM> through a connecting channel 262a, 262b such that the flow of reagent propagates along a main direction defined by the connecting channel 262a, 262b when entering the particle collection chamber <NUM>. The channel of the particle collection chamber <NUM> may further guide the flow of reagent along the main direction along the side walls <NUM>. The channel in the particle collection chamber <NUM> preferably has a larger length in the main direction of propagation of the reagent than width transverse to the main direction. This implies that the reagent may easily fill the width transverse to the main direction as the reagent flows along the length of the channel. This implies that there is a low risk for bubbles being trapped within the particle collection chamber <NUM> at sides of the channel.

As further shown in <FIG>, the side walls <NUM> define a non-straight path through the particle collection chamber <NUM>. In particular, the side walls <NUM> define a meander-shaped path through the particle collection chamber <NUM>. Thus, flow of reagent when filling the particle collection chamber <NUM> follows a narrow channel, while the particle collection chamber <NUM> has a small footprint in two dimensions of the plane of the particle collection chamber <NUM>.

The use of a narrow channel having a long length as shown in <FIG> implies that the time required for filling the particle collection chamber <NUM> by the reagent may be relatively long. This implies that the reagent filling time may account for a large proportion of the time required for performing an analysis using the collecting device <NUM>.

In some applications, the time required for performing an analysis may be of importance. For instance, with a test that may be quickly performed, such as within <NUM> minutes or <NUM> minutes from airborne particles being captured, a high throughput of test results may be provided. This implies that tests may be suitable to be performed at a point that is passed by many people for screening people at such a point. For instance, tests may suitably be made at an entrance to an airport, a shop, or a company facility, for screening people for infectious diseases, such as SARS-CoV-<NUM> before admitting people through the entrance. The high throughput of testing may allow such screening to be performed without long queues being formed. Hence, it may be desired that the reagent filling time is very short, such as shorter than <NUM>.

In situations where a short reagent filling time is desired, the particle collection chamber <NUM> may be designed having a large width. However, the risk of trapping bubbles in the particle collection chamber <NUM> may increase with a large width of the channel. Further, a structural stability of the collecting device <NUM> may be lower with a large width of the channel and hence a large distance between side walls of the channel. Thus, the collecting device <NUM> may be provide with pillars within the channel. The pillars may extend from the first layer <NUM> to the second layer <NUM> and may provide structural stability of the collecting device <NUM>. The pillars may also improve bonding of the first layer <NUM> to the second layer <NUM>.

Referring now to <FIG>, a particle collection chamber <NUM> according to a second embodiment is shown. The particle collection chamber <NUM> is formed such that trapping of bubbles in the particle collection chamber <NUM> during filling of the particle collection chamber <NUM> with a liquid reagent may be reduced or avoided. Further, the particle collection chamber <NUM> is formed for facilitating a fast reagent filling time, such as providing a reagent filling time shorter than <NUM>, where the particle collection chamber <NUM> has a size of less than <NUM>µl or less than <NUM>µl.

Like <FIG>, <FIG> shows a top view of the particle collection chamber <NUM> with the first layer and the second layer being removed from the view, whereas the inlets <NUM> and the outlets <NUM> are illustrated to indicate the relations between the inlets <NUM> and the outlets <NUM> and the particle collection chamber <NUM>. However, lateral walls surrounding the particle collection chamber <NUM> are indicated in <FIG>.

The particle collection chamber <NUM> comprises at least one side wall <NUM> within an area defined by an outer periphery of the particle collection chamber <NUM>. Thus, the at least one side wall <NUM> provides guidance of flow of the reagent when the particle collection chamber <NUM> is filled.

In the embodiment shown in <FIG>, the side walls <NUM> completely separate portions of the particle collection chamber <NUM>. Thus, the particle collection chamber <NUM> is separated into a plurality of compartments 348a-<NUM>. Thus, the side wall <NUM> indicated in <FIG> is arranged such that the compartments 348a, 348b are arranged on opposite sides of the side wall <NUM>.

Thanks to the side wall <NUM> the flow of the reagent may be guided along a path through the particle collection chamber <NUM>. In particular, the flow of the reagent may be guided to flow along the side wall <NUM> in each compartment 348a, 348b such that the flow of the reagent propagates along a main direction of a channel defined by the respective compartment 348a, 348b.

Thanks to the particle collection chamber <NUM> being separated into a plurality of compartments 348a-<NUM>, the channel in each compartment 348a-<NUM> can simply be arranged to have a larger length in the main direction of propagation of the reagent than width transverse to the main direction. This implies that the reagent may easily fill the width transverse to the main direction as the reagent flows along the length of the channel. This implies that there is a low risk for bubbles being trapped within the particle collection chamber <NUM> at sides of the channel. Further, thanks to the particle collection chamber <NUM> having a plurality of compartments 348a-<NUM>, the compartments 348a-<NUM> may be simultaneously filled. Each compartment 348a-<NUM> is relatively small such that it may be quickly filled. Since all compartments 348a-<NUM> may be filled simultaneously, the reagent filling time of the particle collection chamber <NUM> may also be very short, such as shorter than <NUM>.

In <FIG>, a plurality of liquid access ports 360a-<NUM> are shown. Each liquid access port 360a-<NUM> is associated with a corresponding unique compartment 348a-<NUM> of the particle collection chamber <NUM>.

Thus, the compartments 348a-<NUM> of the particle collection chamber <NUM> may each be supplied through a dedicated liquid access port 360a-<NUM>. Thus, there is an accurate control of supply of reagent to the respective compartments 348a-<NUM>, since each compartment 348a-<NUM> is individually supplied. The compartments 348a-<NUM> may be filled simultaneously for providing a very fast filling of the entire particle collection chamber <NUM>. Also, the compartments 348a-<NUM> may be filled in different manners such as at different times or by providing different reagents to different compartments 348a-<NUM>.

However, it should be realized that a single liquid access port may alternatively be used, wherein the single liquid access port may branch for feeding reagent into all of the plurality of compartments 348a-<NUM>. Thus, a simple manner of simultaneously filling all of the plurality of compartments 348a-<NUM> may be provided.

According to yet another alternative, plural liquid access ports may be used, wherein each liquid access port feeds reagent into a subset of the compartments 348a-<NUM>, wherein the subset comprises more than one compartment. Thus, filling of each compartment 348a-<NUM> is not individually controlled. However, there is a possibility of different handling for different subsets of the compartments 348a-<NUM>.

Each of the liquid access ports 360a-<NUM> may be arranged at or close to the outer periphery of the particle collection chamber <NUM>. Since the liquid reagent may thus enter the particle collection chamber <NUM> close to the periphery of the particle collection chamber <NUM>, the liquid reagent is limited by the periphery of the particle collection chamber <NUM> from propagating in any direction from the point of entry. The compartments 348a-<NUM> may define narrow channels such that the reagent enters each compartment 348a-<NUM> at a short end of the channel and may propagate along the channel for filling the compartment 348a-<NUM>. Thus, flow of the reagent when filling the particle collection chamber <NUM> can be further controlled and a risk for bubbles being trapped in the particle collection chamber <NUM> is further reduced.

As shown in <FIG>, the liquid access ports 360a-<NUM> may end outside the outer periphery of the particle collection chamber <NUM> in the plane of the particle collection chamber <NUM>. The liquid access ports 360a-<NUM> may be connected by short connecting channels (only channel 362a, <NUM> are shown for better visibility of <FIG>) connecting each of the liquid access ports 360a-<NUM> into the particle collection chamber <NUM> at the periphery of the particle collection chamber <NUM>. Thus, the short connecting channels 362a, <NUM> may transport the reagent from the respective liquid access ports 362a, <NUM> to the particle collection chamber <NUM>.

Like in the embodiment of <FIG>, the particle collection chamber <NUM> with the inlets <NUM> and outlets <NUM> may be sealed as soon as the particles (which may carry an infectious disease) have been collected. Still, the reagent may be provided into the particle collection chamber <NUM> through the liquid access ports 360a-<NUM> and the connecting channels 362a, <NUM>, which may be sealed when the reagent has been provided.

The liquid access ports 360a-<NUM> may be configured to extend through the first layer <NUM> or the second layer <NUM>. The liquid access ports 360a-<NUM> may be arranged on the same side such that the liquid access ports 360a-<NUM> extend through the same layer, e.g. the first layer <NUM>.

The liquid access ports 360a-<NUM> may be configured to draw reagent into the liquid access ports 360a-<NUM> by a capillary force. Thus, the liquid access ports 360a-<NUM> may have a cross-sectional size, such as a cross-sectional diameter that is sufficiently small for the reagent to be drawn into the particle collection chamber <NUM>.

The inlets <NUM> and outlets <NUM> may function as openings of the particle collection chamber <NUM> through which air in the particle collection chamber <NUM> may escape when the particle collection chamber <NUM> is filled by the reagent. The plurality of inlets <NUM> and the plurality of outlets <NUM> may be distributed over the area of the particle collection chamber <NUM>, which may provide a high efficiency of particle collection and reduce a risk for bubbles being trapped in the particle collection chamber <NUM>.

The inlets <NUM> and the outlets <NUM> may be configured to draw reagent from the particle collection chamber <NUM> into the inlets <NUM> and outlets <NUM> by a capillary force. Thus, the inlets <NUM> and the outlets <NUM> may have a cross-sectional size, such as a cross-sectional diameter that is sufficiently small for the reagent to be drawn into the inlets <NUM> and the outlets <NUM>.

Referring now to <FIG>, a method for collection of airborne particles exhaled by a human being and providing a reagent to the collected particles will be described.

The method comprises receiving <NUM> a flow of air <NUM> from a human being onto a plurality of inlets <NUM>, <NUM> of a collecting device <NUM>. The method further comprises passing <NUM> the flow of air <NUM> through the inlets <NUM>, <NUM> into a particle collection chamber <NUM>, <NUM>.

The plurality of inlets <NUM>, <NUM> may extend through at least a first layer <NUM>. The flow of air <NUM> may thus be received on a surface forming an interface between the collecting device <NUM> and an external environment outside the collecting device <NUM>, e.g. an internal space in a sampling compartment of a sample collector <NUM>. The flow of air <NUM> is passed by the plurality of inlets <NUM>, <NUM> from the external environment outside the collecting device <NUM> into the particle capturing chamber <NUM>, <NUM>. The particle capturing chamber <NUM>, <NUM> may be defined between the first layer <NUM> and a second layer <NUM> of the collecting device <NUM> spaced apart from the first layer <NUM>.

The method further comprises capturing <NUM> airborne particles in the flow of air <NUM> entering the particle collection chamber <NUM>, <NUM> by impaction of airborne particles on a first surface <NUM> of the second layer <NUM>. The method further comprises passing <NUM> the flow of air <NUM> out of the particle collection chamber <NUM>, <NUM> through outlets <NUM>, <NUM> extending through at least the second layer <NUM> of the collecting device <NUM> to an external environment outside the collecting device <NUM>.

The inlets <NUM>, <NUM> and the outlets <NUM>, <NUM> may be staggered such that the center axes of the inlets <NUM>, <NUM> are displaced from the center axes of the outlets <NUM>, <NUM> and the center axes of the inlets <NUM>, <NUM> and the outlets <NUM>, <NUM> are not aligned. Thus, ends <NUM> of the inlets <NUM>, <NUM> are configured to face the first surface <NUM> of the second layer <NUM>, such that particles are captured at the first surface <NUM> between the outlets <NUM>, <NUM>. The method thus causes the flow of air <NUM> to be forced to change direction, such that momentum of particles having a certain size will cause the particles not to follow the flow of air <NUM> in its change of direction and instead the particles will be captured on the first surface <NUM>.

The method further comprises filling <NUM> the particle collection chamber <NUM>, <NUM> with a reagent through at least one liquid access port 260a-260b, 360a-<NUM>, wherein the reagent is guided to flow through the particle collection chamber <NUM>, <NUM> along at least one side wall <NUM>, <NUM> through portions of the particle collection chamber <NUM>, <NUM> on opposite sides of the at least one side wall <NUM>, <NUM>.

Thus, the flow of reagent is controlled within the particle collection chamber <NUM>, <NUM> such that a risk of bubbles being trapped within the particle collection chamber <NUM>, <NUM> during filling of the particle collection chamber <NUM>, <NUM> is reduced. Further, the portions of the particle collection chamber <NUM>, <NUM> may be simultaneously filled for providing a short reagent filling time.

In the above the inventive concept has mainly been described with reference to a limited number of examples. However, as is readily appreciated by a person skilled in the art, other examples than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended claims.

Claim 1:
A collecting device (<NUM>) for collection of airborne particles exhaled by a human being, said collecting device (<NUM>) comprising:
a first layer (<NUM>) and a second layer (<NUM>), wherein the first layer (<NUM>) and the second layer (<NUM>) are arranged to be spaced apart for forming a particle collection chamber (<NUM>; <NUM>) between the first (<NUM>) and the second layer (<NUM>),
wherein the first layer (<NUM>) comprises a plurality of inlets (<NUM>; <NUM>) configured to extend through the first layer (<NUM>) for transporting a flow of air (<NUM>) therethrough into the particle collection chamber (<NUM>; <NUM>);
wherein ends (<NUM>) of the inlets (<NUM>; <NUM>) are configured to face a first surface (<NUM>) of the second layer (<NUM>) for capturing airborne particles in the flow of air (<NUM>) entering the particle collection chamber (<NUM>; <NUM>) through the ends (<NUM>) of the inlets (<NUM>; <NUM>) by impaction of airborne particles on the first surface (<NUM>) of the second layer (<NUM>);
wherein the second layer (<NUM>) comprises a plurality of outlets (<NUM>; <NUM>) configured to extend through the second layer (<NUM>) for transporting the flow of air (<NUM>) therethrough out of the particle collection chamber (<NUM>; <NUM>);
the collecting device (<NUM>) further comprising at least one liquid access port (<NUM>; 260a, 260b; 360a-<NUM>) for filling the particle collection chamber (<NUM>; <NUM>) with a reagent; and
wherein the particle collection chamber (<NUM>; <NUM>) comprises at least one side wall (<NUM>; <NUM>) extending from the first layer (<NUM>) to the second layer (<NUM>) for defining flow of the reagent through the particle collection chamber (<NUM>; <NUM>) when filling the particle collection chamber (<NUM>; <NUM>), such that a first portion (248a; 348a) of the particle collection chamber (<NUM>; <NUM>) and a second portion (248b; 348b) of the particle collection chamber (<NUM>; <NUM>) are arranged on opposite sides of the at least one side wall (<NUM>; <NUM>).