Patent Description:
Current methods to monitor inflammation in the airways utilise blood samples, exhaled breath samples, sputum samples, nasal samples and samples obtained during invasive bronchoscopy.

However, various problems are associated with these existing respiratory sampling techniques, and overall there is failure of the prior art when measuring inflammation with non-invasive sampling methods (blood, breath, sputum and nasal methods) when studying lung diseases. The following takes the example of measuring inflammation in asthma in order to illustrate the range of problems with blood, breath, sputum and nasal samples; but these samples are deficient in a range of lung diseases, and not merely asthma.

Blood analysis: blood sampling is from a site too distant from the airways; blood is influenced by many organs through the circulation around the body, and there is considerable dilution in a volume of approximately <NUM>. In modern clinical practice in asthma there is a tendency to use the blood eosinophil count to assess the level of airway inflammation. This is reflected in a minimum level of blood eosinophils being required before selection of asthmatic patients for a monoclonal antibody therapy (anti-interleukin-<NUM> or anti-IL-<NUM>). However, blood eosinophil counts vary greatly during the day with exercise and due to circadian steroid rhythms.

The eosinophil is regarded as an important target for patients with asthma, since it is a pro-inflammatory cell that migrates from the bloodstream into inflamed respiratory and gut sites (<NUM>, <NUM>). Historically, the humble blood eosinophil count has been extensively used in the management of asthma (<NUM>-<NUM>). Recently, there has been renewed interest in using blood eosinophil counts to select asthmatic patients for monoclonal antibody therapy (<NUM>-<NUM>). A mathematical algorithm has been used to predict elevated sputum eosinophils: the eosinophil/lymphocyte and eosinophil/neutrophil index (ELEN) index (<NUM>). Moreover, the blood eosinophil count is favoured by recent American Thoracic Society / European Respiratory Society international guidelines on severe asthma, that suggest that the utility of other biomarkers in identifying asthma phenotypes needs further validation (<NUM>). However, blood eosinophil counts are notoriously variable, with levels increasing during the day (<NUM>) and exercise having the capacity to increase the eosinophil count (<NUM>). A recent study of <NUM>-hour blood eosinophil counts noted increased variability in the blood eosinophil count of patients with moderate asthma (<NUM>).

Breath NO: levels of exhaled nitric oxide (NO, or FENO) are a crude measure of airway inflammation in asthma. However, levels are variable and very non-specific and can be changed by therapy, dietary factors, and the menstrual cycle in women. They do not provide a specific marker for asthma, where we need to study a range of protein, lipid and prostanoid mediators.

Exhaled breath condensate (EBC) analysis is confounded by the influence of condensed water vapour and the oropharynx; A major problem with current non-invasive sampling methods from the respiratory tract, including breath and sputum analysis, is contamination from the mouth (or oropharynx). Exhaled breath has been extensively studied as a non-invasive means to assess airway inflammation, including by measurement of mediators in exhaled breath condensate (EBC) (<NUM>). Richard Effros and colleagues have elegantly highlighted the issues of salivary contamination and dilution in condensed water vapour that occurs during collection of EBC (<NUM>-<NUM>); and this is likely to be a serious obstacle to measuring EBC pH (<NUM>) (<NUM>) and levels of inflammatory mediators that are in breath droplets.

Breath volatile organic compound (VOC) analysis and metabolomics looks to be more promising (<NUM>-<NUM>). However, VOCs do not include proteins such as cytokines, chemokines and antibodies.

Sputum contains dead and dying cells and mediator levels are influenced by bacteria, saliva, proteases, and sticky mucus proteins. Sputum was used to measure eosinophilia by the late Morrow Brown in his original studies from the <NUM> showing the efficacy of oral prednisolone in asthma (<NUM>), although sputum has been of interest to clinicians since before the time of Hippocrates (<NUM>). The clinical application of quantitation of levels of eosinophils in induced sputum was pioneered by the late Freddy Hargreave (<NUM>). As an extension of this work, normalisation of sputum eosinophil counts has been shown by lan Pavord and colleagues (Leicester and Oxford) to be effective in the reduction of asthma exacerbations (<NUM>). In addition, adult asthma phenotypes have been defined by sputum eosinophil and neutrophil percentages (<NUM>) (<NUM>). There are reports that blood eosinophil counts are a poor surrogate for sputum eosinophil counts (<NUM>, <NUM>), while another group found that blood eosinophil counts can be used to predict sputum eosinophil counts (<NUM>, <NUM>). The analysis of fluid-phase mediators derived from sputum samples has a large number of technical problems (<NUM>): these range from degradation by proteases and bacteria, loss of protein secondary structure due to reduction by dithiothreitol (DTT), binding to mucus, contamination with saliva and oropharyngeal contents, and variable leakage of mediators from dead and dying cells. Elegant attempts have been made to validate measurement of fluid phase levels of IL-<NUM> in sputum (<NUM>), and this has highlighted the effects of proteases (<NUM>).

Nasal sampling is from the airways or respiratory tract, but the mucociliary escalator (MCE) takes nasal molecules from the anterior to posterior, from the nares to the pharynx. Hence the nasal MCE is noncontinuous with the MCE up from the lower airways through bronchi and trachea. However, nasosorption is looking preferable to nasal lavage to measure inflammatory mediators, and does inform about airway inflammation from the upper respiratory tract.

Bronchoscopy sampling includes bronchial biopsy, bronchoalveolar lavage (BAL), bronchial brushes, and bronchosorption. Carrying out bronchoscopy to obtain bronchial mucosal biopsies and bronchial brush samples requires a team of specialist staff in an endoscopy suite, and the patient requires sedation and local anaesthesia. Biopsies, BAL, bronchial brushing samples and bronchosorption from the airways are useful samples for analysis: but the procedure is too erroneous for most asthmatics. Bronchoscopy is generally performed in selected patients with lung cancer, tuberculosis (TB) and interstitial lung diseases at specialised centres.

<CIT> discloses a specimen collecting and testing device having a housing containing a test membrane. An elongated handle having a foam member is slidably received in the housing.

Once the foam member obtains a specimen, the device is held vertically with the foam member pointing upwards and the handle with the foam member is drawn through the housing. In so doing, specimen is expelled from the foam member and delivered to a fluid chamber positioned along the test membrane. The device is then positioned horizontally and specimen that collects in the fluid chamber passes through an aperture in the fluid chamber and onto the test membrane located beneath the aperture.

<CIT> discloses an oral fluid collector having a built in means for collection and an integral indicator in the form of a colour change element. The collector operating by total internal reflection or fibre optic means which visually reveals the presence of fluid to the central portion of the collector by the colour change element reacting to wetting.

<CIT> discloses a biological sample collection system comprising a biological sample collecting wand and a buffer container with a buffer solution. The biological sample collecting wand includes a handle and a sample collector detachably coupled to the handle. The sample collector include one or more sample protrusions, one or more sample apertures, or a combination thereof, at least the sample collector to removably insert into the buffer container. <CIT> discloses a testing device which has a sample container open at one end and a sample collector which includes a tube having a first end and a second end, a piston having a first side and a second side and a hole communicating with the first and second sides, either an absorbent pad or a finger pricking mechanism affixed to the piston on the second side of the piston in fluid communication with the hole in the piston, a holding reservoir having a first end and a second end and a venting hole and a lid hingedly coupled to the holding reservoir at the second end for securing a sample of saliva in the holding reservoir.

Aspects of the present invention seek to provide improved airway sampling devices which seek to overcome or ameliorate one or more of the problems associated with the prior art. In particular, embodiments of the present invention aim to provide a non-invasive airway sampling device for sampling airway mucosal lining fluid (MLF), and especially to obtain lower respiratory tract samples (originating from beyond the vocal cords) free from (or with only minimal) salivary and oropharyngeal contamination.

According to the present invention, there is provided an airway sampling device according to claim <NUM>.

Methods are not part of the claimed invention.

An embodiment of the current invention is based on sampling droplets from the vocal cords and lower respiratory tract (the peripheral airways beyond the vocal cords). The embodiment samples mucosal lining fluid (MLF) that is expelled from the lower respiratory tract by forced expiration or coughing. A key feature of an aspect of the embodiment is to minimise salivary contamination of the obtained sample. An important feature of lower airway MLF is that it passes continuously up the respiratory tract through the mucociliary escalator (MCE), and then passages through the vocal cords before being swallowed. Hence MLF from the vocal cords reflect airway events in the peripheral lower respiratory tract. The MLF in the small airways contains molecules and biomarkers that reflect disease in the underlying tissue. The small airway MLF is transmitted by the MCE to larger airways and up to the vocal cords. The inventors of the present invention have appreciated that it is of great benefit to assess respiratory diseases to capture the fluids from the vocal cords and lower airways in a non-invasive and precise manner, obtaining a sample from the lower respiratory tract (the trachea, bronchi and bronchioles) that is free from (or with only minimal) saliva and oropharyngeal contamination.

In order that the present invention may be more readily understood, embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:.

<FIG> is a schematic diagram showing a detail of a small section of the Muco-Ciliary Escalator (MCE) (shown generally at <NUM>) in a human subject <NUM>. The MCE <NUM> transports Mucosal Lining Fluid (MLF) from the small airways up to the larynx and the vocal cords. In particular, ciliary beating carries MLF upwards from small bronchioles to larger bronchi and onwards to the trachea and to the larynx through the vocal cords. The MLF is then normally swallowed (at a rate of approximately <NUM>/day).

The vocal cords (in the larynx) are "the gateway to the lower respiratory tract" and airways. The MLF provides the body with a barrier against infection clearing out the airways carrying with it foreign particles and microorganisms. Due to the MCE, vocal cord MLF (from part of the larynx) reflects large and small airway molecular events. The surface MLF reflects information in the underlying airway wall and peripheral airway. This is relevant to biomarkers for example for vaccination, lung cancer, infection (whether viral, bacterial or fungal), inflammation, asthma/chronic obstructive pulmonary disease (COPD)/lung fibrosis/cystic fibrosis.

Embodiments of the present invention aim to collect pure vocal cord MLF, free (or with only minimal contamination) from saliva. To do so, embodiments of the present invention take advantage of the fact that the cough function of the human body expels MLF from the vocal chords to the oropharynx. By sampling this expelled MLF from a position within the oropharynx, pure vocal cord MLF, uncontaminated (or with only minimal contamination) by saliva, may be obtained, e.g. to allow analysis of biomarkers contained in the MLF.

The cough function is schematically illustrated with reference to <FIG>. Coughing forces air through the vocal cords at high speed (typically, air is expelled in a cough at velocities ranging from around <NUM> to <NUM> miles/hour). Tracheal and vocal cord MLF is expelled from the mouth by coughing, along with saliva from the uvula, tongue and oropharynx.

In more detail, <FIG> illustrates an inhalation phase of the cough function (typically triggered by airway irritation), which fills the lungs (generally at <NUM>) with air. In the next stage of the cough function, shown in <FIG>, the glottis is closed, and the abdominal muscles are compressed, to create pressure. In the following stage of the cough function, shown in <FIG> and <FIG> (the latter being a cross-sectional view through the oropharynx, at the position indicated by the arrowhead in <FIG>), the glottis is opened and a cough-cloud <NUM> is emitted. As part of this process, MLF <NUM> is transmitted from the vocal cords to the oropharynx (see <FIG>).

A first embodiment of an airway sampling device <NUM> is shown in <FIG>. The device <NUM> comprises a handle <NUM> to be gripped by a user (facilitated by a locator <NUM> provided on the upper surface of the handle <NUM> for contact with the user's forefinger), a stem <NUM> extending from the handle <NUM> and a sampling head <NUM> provided at the end of the stem distal from the handle <NUM>, and angled relative to the longitudinal axis of the handle <NUM>.

In the present embodiment, the handle <NUM>, stem <NUM> and sampling head <NUM> are provided as an integrally formed, unitary body e.g. by moulding. An integrally formed stem <NUM>, handle <NUM> and sampling head <NUM> is preferred to minimise the chances of any one of those components coming loose and being swallowed. However, in other embodiments, one or more of these parts of the sampling device <NUM> may be formed as separate parts which may then be attached, releasably or non-releasably, to the other parts to assemble the device. Also in the present embodiment, the sampling device <NUM> may be formed for example from plastics materials such as acrylonitrile butadiene styrene (ABS) or polypropylene (PP); however, different materials (either plastics or otherwise) may be used, as appropriate.

As shown in <FIG> (and in cross section in <FIG>), the sampling head <NUM> is provided with a perimeter wall <NUM> which extends generally perpendicularly to the axis of the stem <NUM> to create a protective hood <NUM> having a cavity or recess <NUM> to accommodate a sample collection membrane <NUM> in the form of a patch or small piece of (preferably absorbent and/or adsorbent) sampling material <NUM>, to collect the sample from the subject <NUM>. The perimeter wall <NUM> includes a gutter <NUM> around its upper edge, the purpose of which is explained later.

The sample collection membrane <NUM> of the present embodiment preferably comprises absorbent and/or adsorbent material, and may for example be Synthetic Absorptive Matrix (SAM™) material. More generally, the sample collection membrane <NUM> materials could for example include, without limitation, a variety of synthetic and functionalised polymers in foam, fibrous or solid format. For example, and without limitation: polyurethane, fibrous hydroxylatred polyester (FHPE), polycaprolactone (PCL), nylon, cellulose acetate, cellulose, nitrocellulose, polyethersulfone, polysulfone, polypropylene, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), acrylic copolymer, white blood cell isolation media; also assay membranes for Point-of-Care (POC) diagnostics, lateral flow and flow through assays, blotting; also materials with antibodies and/or aptamers for diagnostic assays; and the like.

The sample collection membrane <NUM> is retained within the hood <NUM> by, but not limited to, adhesive bond, chemical weld, ultrasonic weld, or an overmoulding.

The sample collection membrane <NUM> is provided with an integral perforation <NUM> for its removal, post sample collection, with forceps or tweezers T, e.g. for analysis or retention by a clinician or other user (see <FIG>). To this end, the sample collection membrane <NUM> further includes a notch <NUM> at one end, to allow ready insertion of e.g. tweezers, to facilitate removal.

<FIG> show the sampling device <NUM> in situ according to an airway sampling method. In this condition, the sampling head <NUM> is located at a sampling position according to the present embodiment, which sampling position is above (for example, a few centimetres above) the vocal cords of a subject <NUM>, within the oropharynx and posterior to the uvula of the subject <NUM>. This allows for MLF, uncontaminated (or with only minimal contamination) by saliva, to be adsorbed or absorbed onto the sample collection membrane <NUM> carried by the sampling head <NUM> when the subject is prompted to give a small cough or forced expiration (i.e. a short, sharp breath out).

The sampling device <NUM> of the present embodiment is specifically designed to facilitate the placement of the sampling head <NUM> into the sampling position shown in <FIG>.

Firstly, various features of the sampling device <NUM> are dimensioned, angled and/or shaped to facilitate placement of the sampling head <NUM> into the sampling position shown in <FIG>. In a preferred embodiment, different variants of the sampling device <NUM> are provided, each version being dimensioned, angled and/or shaped for usage with a subject, allowing ready placement by a user of the sampling head at the sampling position, based upon an age grading of the subject. Ultimately, the decision of which sized sampling device <NUM> to use will be determined by a clinician e.g. to account for a subject who is significantly larger or smaller than average for their age. However, the present embodiment seeks to provide, for example, three different sizes, intended for use by subjects coarsely graded according to three different age groups.

<FIG> show dimensions (all in millimetres) and angles according to a currently most preferred embodiment for usage with an adult human subject (aged <NUM> or over); <FIG> show preferred ranges for these dimensions (all in millimetres) and angles; <FIG> show currently preferred dimensions (all in millimetres) and angles for a large-sized sampling device <NUM> intended for an adult subject (aged <NUM> or over); <FIG> show currently preferred dimensions and angles for a medium-sized sampling device <NUM> intended for a subject aged between <NUM> to <NUM>; and <FIG> show currently preferred dimensions and angles for a small-sized sampling device <NUM> intended for a child subject (aged <NUM> to <NUM>).

According to the present embodiment, the width of the sampling head <NUM> (this width being the dimension labelled in <FIG>) is selected to maximise sampling material size (and hence maximising sample capture), without causing undue discomfort for a patient or subject <NUM>. In particular, the width X of the sampling head <NUM> is designed so as to comfortably clear the corresponding distance X' between the tonsils of the subject <NUM> (see <FIG>) and especially to avoid and/or minimise interreference with the tonsils of a subject during the sample collection process, especially for a subject suffering from a viral or bacterial infection causing the tonsils to swell. In the present embodiment, the width ranges from <NUM> to <NUM> and, as an illustrative example only, may preferably be <NUM> for an adult/large sized device, <NUM> for an intermediate aged/medium sized device and <NUM> for a child/small sized device. A head width of <NUM> or more is advantageous, as it maximises sample capture and allows for a good-sized sample collection membrane <NUM> to be located within the protective hood <NUM> of the sampling head <NUM>. A head width of <NUM> or less is also desirable, to avoid discomfort for the subject, and especially to avoid and/or minimise interreference with the tonsils of a subject during the sample collection process, especially for a subject suffering from a viral or bacterial infection causing the tonsils to swell.

Next, and referring to <FIG> and <FIG>, respectively, the open angle Θ of the sampling head <NUM>, along with the overall vertical depth Z of the sampling device <NUM> (measured from the uppermost point of the sampling device handle <NUM> to the lower-most point (the tip) of the downwardly-angled sampling head <NUM>), are designed to maximise the sampling material sampling area (i.e. to maximise the exposure to expelled MLF), without significantly restricting airflow. Here, the "open angle" of the head <NUM> means the angle Θ of the sampling head <NUM>, and more specifically the plane of the opening of the recess <NUM> within the hood <NUM> (which plane also preferably corresponds to the plane of the sample collection membrane <NUM>) relative to horizontal, when the sampling device <NUM> is positioned in situ in the sampling position shown in <FIG>, with the sampling head <NUM> located at the desired sampling position (i.e. above the vocal cords within the oropharynx, posterior to the uvula). In the present embodiment, the preferred range of open angle Θ° of the sampling head <NUM> is <NUM>° to <NUM>°, with a most preferred angle of <NUM>°, regardless of the age of the subject.

Here, and as explained with reference to <FIG>, an open angle of at least <NUM>° relative to horizontal is preferred, to avoid significantly restricting the airflow of the subject (and hence to avoid reducing the volume of the airborne sample). On the other hand, an open angle of <NUM>° or less relative to horizontal is preferred, to avoid reducing the amount of airborne sample landing on the sample collection membrane, either as a result of sample escaping around the back of the sampling head <NUM>, without coming into contact with the sample collection membrane <NUM>, or simply impinging upon the protective hood <NUM> of the sampling device <NUM>. As shown in <FIG>, the preferred angling and length of the sampling head <NUM> maximise airflow and the amount of sample impacting on the sample collection membrane <NUM>.

The overall depth Z of the sampling device <NUM> is preferably varied according to the age of the subject; purely as an illustration, for a sampling device <NUM> intended for use with an adult (aged <NUM> or over), the depth Z may for example be <NUM>; for a sampling device <NUM> intended for use with an intermediate-aged subject adult (aged <NUM> to <NUM>), the depth Z may for example be <NUM> or <NUM>; for a sampling device <NUM> intended for use with a child (aged <NUM> to <NUM>), the depth Z may for example be <NUM>.

The following table <NUM> recites currently preferred optimal values for the head width X, depth Z and sampling head angle Θ. It is however to be appreciated that the following preferred optimal values, as well as all of the foregoing described angles and dimensions, are strictly non-limiting and illustrative only, and that other angles and dimensions may be used as appropriate.

Next, and also with reference to <FIG>, the outside surface <NUM> of the sampling head <NUM> is smooth and radiused so as to readily deflect the uvula <NUM> of the subject <NUM> towards the rear of the oropharynx, allowing the sampling head <NUM> to adopt the optimal sampling position shown in <FIG>, centrally above the airway of the subject. For example, and simply as an illustration, a mid-point of the outside surface of the sampling head <NUM> may present the angles such as shown in <FIG> (<NUM>° and <NUM>° relative to horizontal when in the sampling position, respectively) to facilitate deflection of the uvula. However these angles are merely illustrative and other angles nay be used, as appropriate.

The sampling head <NUM> is further configured to minimise and/or eliminate sample collection membrane contamination e.g. from saliva or from lymph fluid from the tonsils. Firstly, and as explained above, the sampling head <NUM> is provided with a wrap-around hood <NUM> which encloses the sample collection membrane <NUM> on all sides (other than at the opening to the recess within the hood <NUM>), and hence enables the sampling head <NUM> to push past the tonsils, to upwardly deflect the uvula, and potentially to also contact the back of a subject's throat, without any (or with only minimal) fluid contamination of the sample collection membrane <NUM>. To prevent direct surface contact contamination from these areas the outer surface of the hood <NUM> is designed to be perpendicular to these landmarks, as shown in <FIG>, during placement, sample capture, and removal of the sampling device <NUM> from the subject's airway.

As a further measure, and as noted above, the hood <NUM> is provided with an integral gutter <NUM>. When the sampling device <NUM> is inverted for sample processing, there is a risk that fluids such as saliva or lymph fluid could flow over the peripheral edge of the sampling head <NUM>, potentially contaminating the sample collection membrane <NUM>. The integral gutter <NUM> avoids or ameliorates this risk by capturing these fluids, and allowing them to safely drain away as indicated by the pointed arrows in <FIG>. Flow is gravity fed and dependent on fluid viscosity, and allows fluid to drain off safely outside of the sampling area of the sampling device <NUM>.

In addition to the design of the sampling head <NUM>, the stem <NUM> is designed to be thin to minimise contact with the tongue and mouth of a subject <NUM>, thus minimising the gag reflex. For example, and as illustrated in <FIG>, the stem width may preferably be <NUM>, for a sampling device <NUM> intended for use with an adult. Also, the sampling device <NUM> is preferably flexible, to minimise accidental trauma to the subject under testing.

In summary, the sampling device <NUM> of the present embodiment is designed to position the sample collection membrane in the oropharynx (behind the uvula), protected from saliva and other fluids from the mouth, tongue and uvula. On coughing, the sample collection membrane <NUM> catches (by impingement) tiny droplets of MLF from the vocal cords and originating from the lower airways.

An airway sampling method, using the sampling device <NUM> described above, will now be described with reference to <FIG>.

As a preliminary step <NUM>, the back of the subject's throat is sprayed with lignocaine or other local anaesthetic, to minimise discomfort and to reduce the risk of a gag-reflex.

Next, at step <NUM>, and with the subject's mouth wide open, the sampling head <NUM> of the sampling device <NUM> is inserted into the patient's mouth, taking care to avoid saliva contamination to the sampling material from the tongue. Although not necessary, a tongue depressor may optionally be used during this step, to depress the tongue of the subject for greater visibility of the mouth and throat.

At step <NUM>, the rear surface of the sampling head <NUM> is used to upwardly lift the uvula, as necessary, so that the sampling head <NUM> is positioned centrally over the subject's airway, and in particular over the subject's vocal chords, within the oropharynx and posterior to the uvula.

Next, at step <NUM>, the subject is prompted to cough or give a forcible expiration (i.e. a sharp exhalation). As explained above, this results in MLF expelled from the vocal cords to be collected, uncontaminated (or with only minimal contamination) from saliva and other fluids.

Finally, at step <NUM>, the sampling device is removed from the patient's airway, allowing the sample collection membrane <NUM> to be removed from the sampling head <NUM> e.g. for analysis or storage.

A second embodiment of a sampling device <NUM> according to the present invention is shown in <FIG>, in which the same or similar features are given the same reference numerals, and only the differences from the first embodiment will be described. As explained in the following, the primary distinction is that the second embodiment allows for an integrated sample washing and elution function.

To this end, and unlike the first embodiment, the second embodiment is firstly provided with a washing and elution chamber <NUM> at the far end of the handle. As best shown in <FIG>, the washing and elution chamber <NUM> has a perimeter wall <NUM> upstanding from and surrounding the entire circumference of a bottom wall <NUM>, to define a cavity <NUM> within. Within the perimeter wall <NUM>, a plurality of upstanding columns <NUM> are provided, spaced at regular intervals. In use, and as explained below, the chamber <NUM> is designed to be compressed (i.e. squeezed) by a user, as part of the sample washing and elution function. The <NUM> columns push in a spreading motion against the saturated sample collection membrane (e.g. SAM) to maximise the recovery of the eluted MLF, when the user compresses the chamber <NUM> e.g. with their thumb T, as shown in <FIG>. Accordingly, the chamber <NUM> is preferably formed from a deformable, resilient material (such as thermoplastic vulcanizate, TPV, although other suitable materials may equally be employed). In the present embodiment, the chamber <NUM> is further provided with a peripheral undercut feature <NUM> which locates over an annular flange <NUM> within the handle, holding the chamber <NUM> in place, with the bottom wall <NUM> protruding from the handle <NUM> to define a button, to facilitate squeezing of the chamber <NUM> by a user. The outer surface of the bottom wall <NUM> is provided with a roughened or textured area <NUM> to facilitate a user's steady grip on the bottom wall <NUM> during squeezing of the chamber <NUM>. Preferably, the opening of the chamber <NUM> is closed by a removable protective cover <NUM> (see <FIG>), to prevent/reduce contamination risks prior to and during the sample collection process. The bottom wall <NUM> of the chamber <NUM> is further provided with a generally circular weakened area <NUM> of reduced thickness (see <FIG>), the purpose of which is explained later.

Secondly, the device <NUM> of the present embodiment is provided with a hinge <NUM> connecting the handle <NUM> to the stem <NUM> (see <FIG>), and thus permitting the stem <NUM> and sampling head <NUM> to be rotated relative to the handle <NUM> between the unfolded condition shown in <FIG> or <FIG> (for use in sample collection) and a folded condition as shown in <FIG> (for sample washing and elution, as well as sample storage and, optionally, initial shipping).

As in the first embodiment, the sampling head <NUM> of the present embodiment is configured to carry a sample collection membrane <NUM> such as a piece of absorbent and/or adsorbent sampling material (e.g. SAM™), to collect a sample from a subject's airway. In this embodiment, however, the interior of the sampling head <NUM> is further provided with a series of protrusions <NUM>, arranged in a chevron pattern (see <FIG> and <FIG>), on which the sample collection membrane <NUM> is placed, with its edges located on a peripheral ledge <NUM> of the interior head surrounding the chevron-patterned protrusions (see <FIG>). The sample collection membrane <NUM> may be attached to the peripheral edge of the sampling head <NUM> by, but not limited to, adhesive bond, chemical weld, ultrasonic weld, an overmoulding. Again, the sample collection membrane <NUM> is provided with an integral perforation <NUM> for optional removal with forceps or tweezers T (see <FIG>); <FIG> shows the interior of the sampling head <NUM> with the sample collection membrane <NUM> removed.

As shown in <FIG>, the hinge <NUM> is preferably a snap-fit hinge, in which the stem <NUM> and sampling head <NUM> assemble to the handle <NUM> via a snap-fit. To assemble, the hinge centre <NUM> of the stem <NUM> is pushed between hinge studs <NUM> provided in the handle <NUM>, which causes the handle sides to flex rotate, allowing the stem <NUM> to pass the hinge studs. When the hole <NUM> at the hinge centre of the stem <NUM> and the hinge studs <NUM> in the handle <NUM> are in-line, the pre-loaded force within the flexible sides of the handle <NUM> force the hinge studs to snap-in, captivating the hinge assembly.

Preferably, tapered hinged studs <NUM> are used. Tapered studs offer two advantages - firstly, they significantly improves assembly; secondly, the increased surface area contact gives the hinge greater transverse stability.

In the present embodiment, the hinge centre of the stem <NUM> is designed with a deliberate interference, therefore, once assembled, there is a frictional contact between both components (stem <NUM> and handle <NUM>).

Once assembled, and as shown in <FIG>, there are two positional snap-fits, <NUM>° apart, one in the extended "sampling" position and the other in the housed "washing and elution" position. Movement between these positions is facilitated by the scalloped finger locater curves <NUM> provided in the handle <NUM> (see <FIG>).

As with the first embodiment, the present embodiment may be provided in different sizes, shapes and dimensions for usage with different sized-subjects, preferably based as a guideline on the age of the subject. As with the first embodiment, for example, an adult/large size sampling device <NUM> may be produced for preferred use with a subject aged <NUM> or over - see <FIG> and <FIG>, <FIG> for (merely illustrative) preferred dimensions and angles, with a preferable range of dimensions and angles as shown by <FIG>. Further, a medium sized device <NUM> may preferably be dimensioned and angled as shown in <FIG>, for preferable usage with a subject of intermediate age (age <NUM> to <NUM>) and a small sized device <NUM> may preferably be dimensioned and angled as shown in <FIG>, for preferable usage with a subject of child age (age <NUM> to <NUM>). Here, the benefits of using the angles and dimensions shown is the same as for the first embodiment described above, again all dimensions shown are in millimetres, and again, although preferable, all dimensions and angles shown are illustrative and non-limiting and other sizes and dimensions and angles may be used e.g. for different sized subjects.

<FIG> show various free standing positions of the sampling device <NUM> of the present embodiment. As shown in <FIG>, the sides of the handle <NUM>, stem <NUM> and sampling head <NUM> are designed to allow the sampling head <NUM> to stay motionless when placed on its side, without rolling. <FIG> and <FIG> show the device <NUM> in its unfolded/sampling condition, and placed on a level surface so as to rest on the sampling head <NUM> and sides of handle <NUM>. <FIG> shows the sampling device <NUM> placed on a level surface in an inverted condition, resting on a finger-grip portion of the handle <NUM> and the button provided by the bottom wall <NUM> of the washing and elution chamber <NUM>, e.g. for insertion of a washing and elution buffer as explained below in connection with <FIG>.

<FIG> shows the sampling device <NUM> of the present embodiment in a hand grip position for a user to conduct the sampling process described below in connection with <FIG>.

Operation of the second embodiment of the sampling device, according to a second sampling method, will now be described with reference to the flow chart of <FIG>.

Firstly, in step <NUM>, and aided by the scalloped finger locators <NUM>, a user pinches/pulls the stem <NUM> to open device <NUM> (see <FIG>), and rotates the stem <NUM> and sampling head <NUM> relative to the handle <NUM>, to click it into the fully unfolded sampling position.

In Step <NUM>, to reduce the risk of a gag-reflex, the back of the subject's throat is sprayed with lignocaine or other local anaesthetic. As will be appreciated, the order of steps <NUM> and <NUM> may be reversed, or these steps may be performed simultaneously e.g. by two clinicians working in tandem.

In step <NUM>, with the subject's mouth wide open, the sampling head <NUM> of the device <NUM> is inserted into the subject's mouth (see <FIG>), taking care to avoid saliva contamination from the tongue. Although the device is useable on its own, for greater visibility of the mouth and throat, the device <NUM> may optionally be inserted whilst the subject's tongue is depressed using a suitable tongue depressor.

In step <NUM>, the sampling head <NUM> is used to deflect the subject's uvula, as necessary, until the device <NUM> is position centrally over the subject's airway (see <FIG>, with the stem shown in cross-section and the handle omitted, for clarity) and the sampling head located at the desired sampling position namely over the vocal cords, within the oropharynx and posterior to the uvula of the subject.

In step <NUM>, the subject <NUM> is asked to cough or give a forced expiration (a sharp exhalation), thus allowing a sample of MLF to be collected by the sample collection membrane <NUM> located within the sampling head <NUM> of the device <NUM>, uncontaminated (or with only minimal contamination) by saliva or other fluids.

In step <NUM>, the sampling device <NUM> is entirely removed from the subject's airway.

If the sample is to be stored for future sample preparation, the process proceeds to step <NUM>, in which the protective cover <NUM> is removed from the chamber <NUM>, and the stem <NUM> and sampling head <NUM> are rotated towards the handle <NUM> until the closed condition is adopted, protecting the sample from extraneous contamination; the closed sampling device <NUM>, including its collected sample, may then be frozen.

On the other hand, if a user wishes to directly wash and elute the sample, the process proceeds to step <NUM>. In this step, the protective cover <NUM> is again removed from the chamber <NUM>, and elution buffer is introduced into the chamber <NUM> e.g. via a pipette P as shown in <FIG>. In the present embodiment, the chamber <NUM> has, merely as an example, a maximum capacity of 500µl, although other sized chambers may of course be employed, as appropriate.

Next, in step <NUM>, the stem <NUM> and sampling head <NUM> are rotated towards the handle <NUM> to bring the device <NUM> into its fully folded condition (see <FIG>). As will be appreciated, the sample collection membrane <NUM> will now be located between the chevron-patterned protrusions of the sampling head <NUM> on one side, and the tops of the protruding columns <NUM> provided within the washing and elution chamber <NUM> on the other side.

Next, in step <NUM>, the user shakes the folded device <NUM>, causing the elution buffer to wash the sampling material <NUM> now located within the chamber (see <FIG>). Here, the washing of the sample collection membrane <NUM> is facilitated by the fact that the elution buffer is able to travel freely around and between the columns <NUM> within the chamber and the chevron-patterned protrusions within the sampling head <NUM>, thus readily exposing both sides of the sampling material of the sample collection membrane <NUM> to the elution buffer and hence maximising MLF capture from the sample collection membrane <NUM>.

Next, in step <NUM>, the user orientates the device <NUM> with the circular weakened area <NUM> located over a suitable collection vessel V (see <FIG>).

Finally, in step <NUM>, the user squeezes the button defined by the bottom wall <NUM> of the chamber <NUM>. The resultant pressure increase within the chamber <NUM> causes the weakened area <NUM> to rupture, ejecting the liquid contents (i.e. the elution buffer containing MLF washed from the sampling material) (see <FIG>) into the collection vessel V, e.g. for analysis or storage.

Hence, the process described above provides a user with a ready and convenient means of sample extraction. However, the sample extraction process of <FIG> is only one example, and other sample extraction processes are possible. Some exemplary alternative sample extraction process are described later. First, some further sampling device embodiments are described, in which like features are given the same reference numerals, and the discussion will focus only on the distinctions from the first and/or second embodiments of the sampling device described above.

A third embodiment of a sampling device <NUM> is shown in <FIG>. The sampling device <NUM> of the present embodiment is very similar to the second embodiment described above, but is additionally provided with a transverse slot or groove <NUM>, located forward (i.e. towards the sampling head end) of the finger locator <NUM> of the handle, into which a generally circular cough shield <NUM> is located (as shown in <FIG> and <FIG>) to form the completed device <NUM> shown in <FIG>. The third embodiment is otherwise the same as the second embodiment.

The cough shield <NUM> is preferably made from a thin sheet of plastics material (e.g. Polyethylene Terephthalate Glycol (PETG) or Polycarbonate (PC)) although other suitable materials (e.g. metals) may be used, as appropriate. In the present embodiment, the cough shield <NUM> offers a user ≅<NUM>° protective coverage from the cough cloud generated by the subject during airway sampling, with the remaining ≅<NUM>° of the cough cloud passing underneath the winged sides of the handle. A slot <NUM> is provided in the cough shield <NUM>, offering sufficient clearance for the sampling head <NUM> to be freely rotated between the folded and unfolded conditions of the sampling device <NUM> (see <FIG>).

As will be appreciated, the first embodiment of a sampling device <NUM> described above may likewise be modified to similarly include a cough shield <NUM>, locating into a slot <NUM> to be provided, according to this modification, in the handle of the device <NUM>.

A fourth embodiment of a sampling device <NUM> is shown in <FIG> and <FIG>. This embodiment modifies the second embodiment described above, to include an illumination module <NUM> within the handle <NUM>, and to configure the stem <NUM> and sampling head <NUM> as a light guide device, beneficially allowing for the interior of a subject's mouth to be illuminated to facilitate the correct positioning of the sampling device <NUM> during the sampling process.

In more detail, and as shown in the various parts of <FIG>, the stem <NUM> and sampling head <NUM> of the present embodiment are formed from a suitable light-transmissive material or materials so as to act as a light guide. For example, the stem <NUM> and sampling head <NUM> of the present embodiment may be formed from optically clear thermoplastic styrene-butadiene copolymers (SBC) or optically clear polycarbonates (PC) which are designed to glow with light from an external light source.

Next, the handle <NUM> of the present device is adapted to include a location groove <NUM> (see <FIG>) for accommodating an illumination module <NUM>. In the present embodiment, the illumination module <NUM> includes a snap hook <NUM> (see <FIG>), and the handle <NUM> further comprises a snaphook hole (not shown) to receive the same, to securely retain the illumination module <NUM> in the handle <NUM> (see <FIG>). In the present embodiment, the snap hook <NUM> may be disengaged from the snaphook hole, allowing the illumination module <NUM> to be removed for insertion into one or more other sampling devices <NUM>; that is, one illumination module <NUM> may be re-used (after appropriate cleansing) and shared amongst a plurality of different illuminated sampling devices <NUM>. The illumination module <NUM> is sealed against liquid and dirt ingress and for example may be constructed with an ABS moulded housing, with the necessary electronics potted in place using e.g. a TPE overmoulding process.

Preferably, the illumination module <NUM> may include a switch <NUM>, which may be actuated by a light activating spigot optionally provided within the handle <NUM>. This arrangement may for example allow for the light to be automatically switched on when the illumination module <NUM> is inserted into the handle <NUM> and switched off when the illumination module <NUM> is removed from the handle <NUM>. Alternatively, the switch <NUM> may allow for the light to be automatically switched on when the sampling device <NUM> is brought into its unfolded (sampling) condition, and switched off when the sampling device <NUM> is in the folded condition. Alternatively, a manual on/off switch may be provided for manual activation by a user.

As for the illumination module <NUM>, any suitable illumination device may be employed, but for example these may include e.g.:.

An example of a laser light source is shown in <FIG>, with the light emitting element shown in detail in <FIG>. The latter may include, for example, a suitable power supply <NUM> such as two <NUM> Volt batteries wired in parallel, for example <NUM> mAh Lithium Manganese Silicon Batteries having Dimensions ø6. <NUM>, <NUM> thick (Part number: MS621). Also shown in <FIG> is a low profile, tactile, surface mount switch <NUM> e.g. for automatic activation by a light activating spigot optionally provided within the handle <NUM> as described above. The light emitting element further comprises a laser diode <NUM>, for example a <NUM> laser diode with driver module.

An example of an LED light source is shown in <FIG>, with the light emitting element shown in detail in <FIG>. The latter may include, for example, a suitable power supply <NUM> such as two <NUM> Volt batteries wired in series, for example <NUM> mAh Silver Oxide Batteries having dimensions ø6. <NUM>, <NUM> thick (Part number: SR65). Also shown in <FIG> is a low profile, tactile, surface mount switch <NUM> e.g. for automatic activation by a light activating spigot optionally provided within the handle, as described above. The light emitting element further comprises an LED light source <NUM>, for example a <NUM> ultra bright directional LED.

In the same way that the second embodiment may be modified to include an illumination feature, according to a fifth embodiment of the present invention, the first embodiment of the sampling device <NUM> described above may also be modified as shown in <FIG> to include a light module <NUM> within the handle <NUM>, beneficially allowing for the interior of a subject's mouth to be illuminated to facilitate the correct positioning of the sampling device <NUM> during the sampling process. In this embodiment, as it is provided integrally with the sampling head <NUM> and stem <NUM> of the device <NUM>, the handle <NUM> is also configured as a light guide device. In particular, the integral handle <NUM>, stem <NUM> and sampling head <NUM> of the present embodiment are preferably formed from a suitable light-transmissive material or materials so as to act as a light guide. For example, the handle <NUM>, stem <NUM> and sampling device <NUM> of the present embodiment may be integrally formed from optically clear thermoplastic styrene-butadiene copolymers (SBC) or optically clear polycarbonates (PC) which are designed to glow with light from the illumination module <NUM>.

As the present fifth embodiment (like the first embodiment) does not have a folding function, a light activating spigot is not provided in the handle <NUM>. However, a manual light switch is provided for activation by a user, so as to switch on the illumination device during the sampling process. In other respects, such as the nature of the illumination module, the fifth embodiment may generally be the same as for the fourth embodiment described above, and hence is not re-described here.

It will be appreciated that, according to further embodiments of the present invention, the cough shield feature of the third embodiment may also be combined with the fourth and fifth embodiments having the light guide feature.

The following describes some alternative sample extraction methods, suitable for usage with embodiments of the sampling device having a washing and elution chamber (e.g. the second, third and fourth embodiments described above).

According to a further sample extraction method, as shown in <FIG>, rather than a user squeezing the chamber to cause rupture of the weakened area, a user may instead extract the liquid content (elution buffer containing MLF) by inserting a needle N of a syringe S into the weakened area, and pulling back on the plunger of the syringe to extract the sample. The extracted sample may then be processed as desired e.g. ejected from the syringe into a suitable vessel for direct analysis or transferred into a cryogenic storage container and frozen.

According to a still further sample extraction method, as shown in <FIG>, a centrifuge method may for example be employed. According to this embodiment, after conducting the sample gathering process, introducing elution buffer introduced into the chamber and placing the sampling device into its folded condition, a user places the sampling device into a suitable centrifuge tube T (e.g. a cryogenic <NUM> centrifuge tube), with the tube then being closed by a cap C. The centrifuge tube is then located into a suitable centrifuge, which is then operated to spin the centrifuge tube e.g. to spin-down for <NUM> seconds @ <NUM> rpm. This causes the weakened area to rupture, so that the liquid contents (elution buffer containing sampled MLF) collect at the bottom of the centrifuge tube T. A user then removes the cap from the tube, removes the device, and re-caps the tube e.g. for freezing or analysis.

The foregoing description refers to airway sampling from a human subject. However, this is merely exemplary, and according to further embodiments the present invention may instead be applied to sampling devices for airway sampling performed on non-human subjects e.g. livestock such as cattle or pets such as cats and dogs.

The embodiments above assume that a user e.g. a nurse, doctor or other clinician would take a sample from a subject. However, potentially, a subject may take a sample from themselves, in which case the "user" and the "subject" are the same person.

Claim 1:
An airway sampling device (<NUM>) for taking a sample from a subject's airway, the device comprising a handle (<NUM>) to be gripped by a user when taking the sample and a sampling head (<NUM>) carried by the handle, the sampling head comprising a cavity (<NUM>) with an opening for entry by the sample and a sample collection membrane (<NUM>) located within the cavity for receiving the sample, wherein the sampling head is provided with a wrap-around hood (<NUM>) which encloses the sample collection membrane on all sides, other than at the opening to the cavity within the hood, to enable the sampling head to push past the tonsils of the subject, to deflect the uvula of the subject, and potentially to also contact the back of the subject's throat, without any fluid contamination of the sample collection membrane.