GB2381580A

GB2381580A - Sample collection

Info

Publication number: GB2381580A
Application number: GB0126001A
Authority: GB
Inventors: Antony Glauser; Nicol John Murray; Elaine Marie Mccash
Original assignee: Sentec Ltd
Current assignee: Sentec Ltd
Priority date: 2001-10-30
Filing date: 2001-10-30
Publication date: 2003-05-07
Also published as: GB0126001D0

Abstract

A sample collection device comprises (a) a sample collecting volume, typically in the form of a tube 10, with an interior surface for receiving a gas borne sample and (b) a collection means 40 for collection and concentration of the sample deposited on the interior of the tube 10 at a location suitable for subsequent analysis. The collection means is typically in the form of a slidable plunger 40 which can include at it's end a curved projection to aid the collection of the deposited sample and an optically transmissive prism which is used in conjunction with an electronic module housed within the plunger 40 to analyse the sample which is collected within the tube. The collection volume 10 may include a vortex generating means to assist deposition of the sample onto the interior surface. Utility may be in the collection of mucus droplets in exhaled breath where the subject exhales into the tube 10 at the end remote from the plunger and the pathogen content of the collected sample is analysed.

Description

SAMPLE COLLECTION APPARATUS Field of the invention The present invention relates to sample collection apparatus, in particular, but not exclusively, to sample collection apparatus for collecting biological samples for assay analysis. Moreover, the invention also relates to a method of collecting samples in the sample collection apparatus.

Background to the invention Sample collection apparatus and methods of sample collection using such apparatus are generally known.

Saliva sample collection can be executed using a simple container for receiving the saliva. An appropriate tool, for example a spatula, can be employed for transferring a portion of the sample to a test carrier for subsequent analysis. In the police force, mouth swaps are frequently employed when undertaking DNA testing of suspects to sweep saliva, epithelial and associated cells from the inside of their mouths.

Collection of biological samples for biopsy is often achieved by scraping cells from a skin or mucus membrane surface and then depositing the cells on a test carrier for subsequent examination and/or analysis. Moreover, invasive methods of biological sample collection such as needles are also known. Such sample collection is often time-consuming, potentially painful and is susceptible to infective ingress in sites where samples have been extracted.

Some human body surfaces are not readily accessible for applying the aforesaid known methods and apparatus, for example inside surfaces of lung bronchia where pathogens such as bacteria, moulds and fungi can become established.

The inventors have appreciated that an alternative method and apparatus for the collection of samples is required for rapid collection of samples from body surfaces that are not immediately accessible.

Summary of the invention According to a first aspect of the present invention, there is provided a sample collection apparatus comprising: (a) a sample collection volume bounded by an interior surface for receiving a gaseously-borne sample; (b) A sample collection volume bounded by an interior surface for receiving a liquid sample where the liquid is sprayed into or added dropwise into the sample collector, and (c) collecting means for collecting, in use, at least a portion of the sample deposited on the interior surface and for concentrating the portion at a test location susceptible to subsequent interrogation.

The invention is of advantage in that the apparatus is capable of effectively and conveniently collecting the sample for analysis.

Preferably, the collection volume is provided with vortex generating means for causing, in use, an incoming jet transporting the gaseously-borne sample to form into one or more vortices to assist with deposition of the sample onto said interior surface.

Vortex flow in a fluid carrying a particulate load results in conversion of kinetic energy in the flow to thermal dissipation therein and a subsequent deceleration with a resulting deposition of the particulate load transported within the flow.

Preferably, the collection volume is implemented as a tubular element and the collecting means is implemented as a plunger element arranged to slidably engage within the interior surface of the tubular element. Such an arrangement is of advantage in that the tubular element is convenient for offering to users'mouths and for hand-held support, whereas the plunger element is capable of sealing an end of the tubular element and, when pushed into the tubular element, assisting to spatially concentrate the sample.

More preferably, the plunger element forms a sufficient seal onto the tubular element for collecting the sample into a nng-like mass when the plunger element. in use, is slidably moved within the tubular element.

Preferably, the plunger element includes an end region comprising a projection susceptible to collecting the ring-like mass together when the plunger element is rotated relative to the tubular element. The projection is capable of functioning in a spoon-like manner to scoop up the sample from the tubular element to concentrate it into one spatial location.

The plunger element advantageously includes at its end region, optical interfacing means for interfacing between optical interrogating means and the sample, thereby enabling the optical interrogating means to interrogate the sample via the optical interfacing means. Use of optical interrogating means is of benefit in that non- contact interrogation of the sample can be achieved, thereby, in the case of contagious pathogens, reducing the risk of spreading disease further.

Preferably, the plunger element comprises a hollow interior region for receiving, in use, the optical interrogating means. Concentric mounting of the interrogating means within the plunger element, and concentric mounting of the plunger element within the tubular element is of benefit in enabling the interrogating means to be brought in close proximity, for example within a few mm, of the sample. Moreover, such concentric mounting also renders the apparatus potentially highly compact.

Preferably, the tubular element and the plunger element are designed to be disposable items whereas the optical interrogating means is designed to be a nondisposable item. Such disposability is of advantage when the tubular element and the plunger element are used to collect samples including pathogens that are potentially contagious; the tubular element and the plunger element can, for example, be disposed of by incineration to circumvent spread of undesirable pathogens. More preferably, the tubular element and the plunger element are designed to be mutually interlocking after sample collection has occurred therein to prevent these elements being reused with associated risk of cross-contamination.

The optical interfacing means preferably comprises a prism for guiding interrogating radiation from the interrogating means to the sample, and for guiding response radiation from the sample back to the interrogating means. Use of a single optical component for bi-directional optical radiation propagation enables the cost and size of the apparatus to be potentially reduced. More preferably, the prism is a dove-type prism; such a prism is susceptible to being used, for example, in evanescent-wave optical interrogation of samples, especially samples subjected to fluorophore tagging.

The interrogating means comprises a source of strobed radiation for providing the interrogating radiation, and a photodetector and associated demodulator for detecting response radiation from the sample and for demodulating the response radiation with respect to the strobe. Such a strobe arrangement can be applied to discriminate ambient quasi-constant optical radiation contributions, for example as a result of light leakage into the apparatus from its ambient environment.

Preferably, for ease and cheapness of manufacture, one or more of the tubular element and the plunger element are fabricated from plastics materials. More preferably, the plastics materials comprise one or more of an acrylate, polyethylene, polypropylene, glass-filled silicone rubber, polyvinyl chloride (PVC), alkylen, polycarbonate, and polytetrafluoroethylene (PTFE) plastics material. Most preferably, the plastics materials are injection moulded.

According to a second aspect of the present invention, there is provided a method of collecting a sample from a user utilizing an apparatus according to the first aspect of the present invention, the method comprising the steps of: (a) exhaling mucus droplet borne air from the user into a collection volume of the apparatus; (b) depositing mucus droplets from the exhaled air onto an interior surface of the collection volume; (c) collecting the droplets together from the surface using collecting means of the apparatus to provide a collected mass of droplets.

Preferably, the method further comprising the step of interrogating the collected mass of droplets after step (c) to determine one or more characteristics thereof. More preferably the collected mass is interrogated optically.

Preferably, in the method, the collected mass is arranged to fluoresce in response to being optically interrogated, and the one or more characteristics determined from the fluorescence.

Preferably, in step (b) of the method, the exhaled air is arranged to flow in vortices to promote deposition of the droplets onto the interior surface.

Any features of the apparatus can be combined in any combination without departing from the scope of the invention.

Description of the diagrams Embodiments of the invention will now be described, by way of example only, with reference to the following diagrams in which: Figure 1 is an illustration of a plastic sample tube of a sample collection apparatus according to the invention; Figures 2a, 2b and 2c are illustrations of a plastic plunger designed to co-operate with the sample tube of Figure 1; Figure 3 is a schematic diagram of an electronic module for use with the sample tube and plunger of Figures 1,2a, 2b and 2c; Figure 4 is a schematic diagram of steps of a method of collecting a sample using the sample tube, the plunger and the module of Figures 1 to 3; and Figure 5 is a diagram illustrating alternative implementations of the sample tube of Figure 1.

Referring now to Figure 1, there is shown a substantially cylindrical sample tube indicated by 10. The tube 10 comprises a first open end indicated by 20 for receiving a sample. Moreover, the tube 10 comprises a second end 30 for receiving a hollow plunger 40. The tube 10 also includes a substantially cylindrical side tube 50, the side tube 50 having an associated longitudinal central axis substantially orthogonal to that of the sample tube 10. At a region where the tubes 10,50 meet, there is included a mesh or gauze 60. The tube 10 further comprises a peripheral ring 70 around the first end 20 so that this end 20 is substantially devoid of any sharp edges which could injure a user manipulating the tube 10, for example when the user manipulates the tube 10 towards his/her mouth.

The hollow plunger 40 is also of substantially cylindrical form and fabricated to be slidably moveable within the inside of the sample tube 10 as illustrated, the tube 10

and the plunger 40 being a mutually precise fit. Preferably, the plunger 40 is provided with a resiliently deformable sealing ring (not shown) substantially at an end of the plunger 40 offered to the sample tube 10 when in use. The sealing ring is preferably fabricated from a nitrile rubber material, for example proprietary Viton material, silicone or PTFE. Moreover, the sealing ring is advantageously devoid of an lubricating material, for example silicone grease, which could potentially contaminate the collected sample, and thereby alter its response characteristics.

Additionally, vapour emitted from a lubricant may be harmful to the test subject.

In operation, a user retracts the plunger 40 so that its end surface indicated by 80 is substantially at the second end 30 of the tube 10. In such a collecting state, the tube 10 has most of its interior surface, preferable in excess of 80% thereof, exposed to the first end 20. Moreover, in the collecting state, a route for gas flow from the first end 20 via the gauze 60 and through the side tube 50 is provided to ambient.

In the collection state, the user places the first end 20 to his/her mouth so that the ring 70 engages and seals onto the user's lips. The user then exhales forcefully causing air and mucus droplets in the form of a fine mist to be carried from the user's lungs into the tube 10. A region of the tube 10 around the second end 30 forms a low velocity gas region where exhaled air from the user is inclined to deposit its load of mucus droplets. Conversely, user's exhaled air vented through the side tube flows at relatively high velocity. The side tube 50 and the sample tube 10 are of sufficiently large diameter so as not to impede exhalation of air and mucus droplets from the user.

When the user has forcefully exhaled a plurality of times through the tubes 10,50, the user removes the tube 10 from his/her mouth. A sample for analysis is thereby provided on the inside surface of the tube 10, especially in the region of the second end 30. The plunger 40 is then used for collecting the sample from the inside surface of the tube 10 and then depositing the collected sample onto an optical surface for subsequent interrogation and analysis.

The plunger 40 is especially designed to be susceptible to collecting the sample.

Thus, the plunger 40 will now be described with reference to Figures 2a and 2b.

In Figures 2a and 2b, the plunger 40 is substantially cylindrical in form and comprises a central hollow region 90. The plunger 40 is open at its first end and includes a

round flange 120 for abutting onto the second end 30 of the tube 10 when the plunger 40 is fully inserted into the tube 10, thereby limiting an extent to which the plunger 40 can be pushed into the tube 10. The plunger 40 comprises the end surface 80 whose plane is substantially perpendicular to the central longitudinal axis of the plunger 40. At an eccentric region of the surface 80 as shown, there is included an optically transmissive prism 100 extending into the region 90 and a spoon-like projection 110 extending outwardly from the surface 80 remotely from the region 90. The spoon-like projection 110 is susceptible in use to scooping-up material thereonto. The spoon-like projection 110 extends radially at the surface 80 to a peripheral extent of the surface 80. A peripheral edge 115 of the projection 110 is arranged to slidably contact onto the interior surface of the tube 10. An aperture 120, also known as a prism window, is formed in the end surface 80 so that the prism 100 is in optical communication with sample matter collected onto the projection 110.

The projection 110 is preferably curved over towards its edge remote from the peripheral edge 115 as shown to improve performance of the projection 110 to retain material from the interior surface of the tube 10 scooped up onto the projection 110 during operation.

In order to simplify design of an electronic module adapted for insertion into the plunger 40, it is desirable that the prism 100 is mounted eccentrically but away from the peripheral extent of the surface 80. When the prism 100 and its associated prism window 120 are arranged in such a manner, the projection 110 is preferably of a generally"V"-shape form as illustrated in Figure 2c. Such a"V-shape form is especially effective at collecting and retaining a substantial mass of collected sample thereon.

The plunger 40 is fabricated as a hollow member so that the plunger 40 is capable of receiving the aforesaid electronic module into the region 90. The electronic module is preferably of solid cylindrical form as illustrated in Figure 3 and indicated generally by 200. Whereas, in use, the sample tube 10 and its associated plunger 40 are designed to be disposable items, the electronic module 200 is arranged to be reusable as it comprises moderately costly component parts therein, for example a laser, which will be described in more detail later. The module 200 is preferably of elongate form comprising a first end 210 and a second end 220. The second end 220 comprises an eccentrically-disposed optical interfacing region 230 disposed so as to align with the aperture 120, namely the prism window, when the module 200 is

inserted into the plunger 40 to interrogate a sample collected onto the spoon-like projection 110.

The tube 10, the plunger 40 and the module 200 are of advantage in that they are capable of being compact in storage on account of their mutually concentric mountability. Moreover, the tube 10 is capable of collecting substantially all of the sample exhaled by the user. Furthermore, the plunger 40 is capable of enabling the electronic module 200 to interrogate the sample without coming into contact with the sample, thereby rendering the module 200 reusable; operational costs are thereby reduced.

The sample tube 10 with its associated side tube 50, and the plunger 40 are preferably manufactured from plastics materials, for example one or more of an acrylate, polyethylene, polypropylene, glass-filled silicone rubber, polyvinyl chloride (PVC), alkylen, polycarbonate, and polytetrafluoroethylene (PTFE) plastics material.

More preferably, at least one of the tube 10 and plunger 40 are injection moulded.

Alternatively, one or more of the sample tube 10 and its associated side tube 50, and the plunger 40 can be fabricated from extruded metal sheet, or even fabricated by die-cast metal techniques.

Most preferably, the sample 10 tube, the side tube 50 and the gauze 60 are moulded as a single component part. Likewise, the plunger 40 with its associated projection 110 and prism 100 are preferably moulded as a single component from a substantially optically transparent plastics material, for example a polycarbonate or acrylic plastics material.

At the end surface 80, the plunger 40 can optionally include a small orifice 250, for example a substantially round orifice having a diameter in a range of 0.1 to 2.5 mm.

The orifice is of advantage for injecting an atomised spray mist, for example a saline mist, into the tube 10 when deployed to collect a sample from the user. Injection of such a mist into the tube 10 prior to the user exhaling the sample for collection in the tube 10 is of benefit in obtaining substantially quantities of mucus droplets from the user. Alternatively, or additionally, a nozzle 260 for directing such a spray mist into the user's mouth and hence lungs can be included a short distance, for example a few mm, behind the peripheral ring 70 as illustrated. The nozzle 260 is of advantage in comparison to the orifice 250 because it reduces a tendency for spray mist droplets to be deposited on the interior of the tube 10 and hence collected into the

sample on the projection 110. For certain types of bioassay, the presence of contaminants, for example saline mist droplets, can interfere with analysis; positioning the nozzle 260 near the first end 20 assists to reduce bioassay errors being introduced. For other bioassays, it is found that addition of a small quantity of liquid, such as saline or a buffer solution is desirable in that it assists the diffusion of the bacteria to be tested towards the surface of the interrogation system. Such liquids can be added to the system either before or after sample collection, as appropriate, using, for example, an aerosol spray or droplets from a pipette.

The sample tube 10 is preferably also provided with a removable end cap (not shown) so that the second end of the tube 10 can be sealed by applying the end cap after the sample is collected in the tube 10. Thus, the cap is capable of rendering the tubes 10,50 and plunger 40 safer to use when collecting sample from infectious individuals, for example where there is a likelihood of tuberculosis (TB) or similar infection. Moreover, especially if the cap is fabricated from an optically opaque material such as black PVC, the cap can inhibit extraneous ambient light reaching the collected sample at the prism window 120 during optical interrogation.

The electronic module 200 can be implemented so that it comprises a split prism so that interrogating radiation output from the module 200 and radiation returned from the sample to the module 200 propagate along a common axis through the prism window 120. Conversely, the module 200 can be implemented so that interrogating radiation from the module 200 propagates through a first portion of the prism 100 to the sample, and reflected optical radiation from the sample propagates through a second portion of the prism 100 back to the module 200, the first and second portions being substantially non-coincident. Preferably, the prism 100 is configured to support evanescent wave propagation at the prism window 120 to enable highly efficient optical interrogation.

The tube 10, the plunger 40 and the electronics module 200 are advantageously fabricated to be within preferred size ranges. For example, the sample tube 10 preferably has a diameter in a range of 20 mm to 30 mm. Moreover, the side tube 50 preferably has a diameter in a range of 1 mm to 10 mm, more preferably in a range of 5 mm to 8 mm. Furthermore, the sample tube 10 preferably has a length in a range of 40 mm to 150 mm, more preferably in a range of 50 mm to 80 mm. The prism window 120 preferably has an area in a range of 9 mm2 to 64 mm2.

In order to further describe operation of a sample collection apparatus according to the invention, the apparatus comprising component parts as illustrated in Figures 1 to 3, a method of collecting a sample using the apparatus will now be described with reference to Figure 4.

The method comprises five steps, namely STEPS A to E.

In STEP A, the plunger 40 is retracted so that a majority of the interior surface of the tube 10 is exposed to the first end 20. A user of the apparatus offers the first end 20 of the tube 10 to his/her mouth and inhales from the tube 10 a mist spray for promoting mucus droplet release from the user's lungs ; the mist is preferably provided by the orifice and/or the nozzle 260 ; moreover, the mist is preferably a saline mist for inducing repeated coughing. The user then forcefully exhales, for example by a coughing action, a jet of air and mucus droplets into the tube 10 in a direction indicated by an arrow 300. When the jet enters the tube 10, turbulence occurs resulting in the formation of a vortex 310. On account of the jet being rapidly decelerated and caused to repeatedly circulate over the interior surface of the tube 10, precipitation of the aforesaid droplets, for example a droplet 320, onto the interior surface occurs as illustrated. Airflow from the tube 10 is vented through the side tube 50, the gauze 60 providing an additional degree of droplet deposition by enhancing formation of the aforesaid vortex turbulence within the tube 10.

The user can repeat coughing into the tube 10 several times to provide a more substantial mass of droplets.

Finally, if desired, a sealing cap can be clipped over the first end 20 of the tube 10 to protect personnel handling the apparatus when the droplets include contagious pathogens, for example TB bacteria. The sealing cap can also provide a benefit of excluding ambient light from the interior of the tube 10 during optical interrogation of the collected sample.

In STEP B, the electronic module 200 is introduced in a direction indicated by an arrow 330 into the plunger 40, the module 200 being in a correctly aligned orientation so that the interfacing region 230 and the prism 100 correctly mutually angularly align.

In STEP C, the module 200 and the plunger 40 are then pushed in a direction indicated by an arrow 340 into the tube 10 so that the end face 80 of the plunger 40 sweeps up the droplets deposited onto the interior surface of the tube 10. Thus, a ring 350 of droplet material is formed along a front peripheral region of the plunger 40. The plunger 40 is of advantage in that it is capable of reducing the amount of extraneous illumination reaching the prism window 120, especially is the plunger is fabricated from a substantially non-radiation transmissive filled plastics material, for example black PVC.

In STEP D, the electronic module 200 and the plunger 40 are rotationally locked together, for example by way of mutually co-operating alignment projections and associated corresponding slots. Next, the electronic module 200 is rotated by at least 3600 about its longitudinal axis relative to the tube 10 so that the spoon-like projection 110 collects up the aforesaid ring 350 to provide a final collected sample concentrated at the prism window 120. When the projection 110 has been rotated through an angle of substantially 3600, resiliently deformable projections (not shown) preferably engage into co-operating recesses to rotationally lock the plunger 40 to the tube 10, thereby rendering the tube 10 and the plunger 40 non-reusable. Such non-reusability is important to prevent the spread of undesirable pathogens and also to reduce the risk of erroneous measurements occurring as a consequence of users attempting to reuse the tube 10 and the plunger 40.

In STEP E, the electronic module 200 is then activated to project optical interrogation radiation via the prism 100 and the prism window 120 to the sample collected at the projection 110. The sample returns a portion of the interrogation radiation, by one or more of direct reflection, transmission, scattering and/or fluorescence, which propagates back through the window 120 and the prism 100 to the module 200.

Advantageously, the interrogated radiation is strobed and the return radiation is demodulated with respect to the strobe. More preferably, the prism window 120 is coated in a biologically active material, for example an antibody or antigen bound to a fluorophore material for rendering the apparatus selectively sensitive to a particular pathogen, for example the tuberculosis bacterium.

When STEP E has been completed, the electronic module 200 can be retracted from the plunger 40 for subsequent reuse. Moreover, the tube 10 and the plunger 40 remain a substantially sealed locked unit for disposal, for example by incineration,

thereby preventing potential further spreading of contagious pathogens such as bacteria and viruses collected in the tube 10.

In the method, push and twist operations in STEPS C and D ensures substantially 100% collection of fluids deposited in the sample tube 10 in STEP A are concentrated at the prism window 120. Moreover, the aforesaid sealing cap reduces the risk of personnel contamination when operating the apparatus, and assists to exclude quasi-constant ambient radiation leakage into the tube 10 during optical interrogation of the collected sample. Furthermore, the sample tube 10 and the plunger 40 are simple components to fabricate, for example by injection moulding of plastics materials as described in the foregoing.

It will be appreciated that modifications can be made to the embodiments described above without departing from the scope of the invention. Features of embodiments can be combined in any combination without departing from the scope of the invention.

For example, the apparatus can include an inflatable sealed bag, for example a plastic bag, attached to the side tube 50 so that exhalation by the user is contained within the bag to further reduce the risk of spreading pathogens when using the apparatus.

Moreover, the sample tube 10 can be modified in shape to enhance sample collection therein. In this respect, alternative configurations for the sample tube 10 wiH now be described with reference to Figure 5.

In a first example (EXAMPLE 1), the sample tube 10 is provided with a septum 400, namely a circular orifice recessed from the peripheral ring 70 by a distance in the order of 5 mm to 15 mm. The septum 400 preferably includes a central aperture 410 having a diameter in the order of 3 mm to 20 mm. In operation, the aperture 410 causes an ejected airflow from a user to transform into spiraling vortices that are efficient at depositing mucus droplets present in the airflow onto the interior walls of the sample tube 10. Moreover, the septum 400 is also effective at providing an endstop that is capable of co-operating with the spoon-like projection 110 to assist with sample collection during STEPS C and D above. If required, the side tube 50 can be omitted and the sample tube 10 can be vented through its second end 30 with the plunger 40 removed during sample collection.

Conveniently, a nozzle is formed integrally in the septum 400, the nozzle being directed towards the first end 20 of the tube 10 and operable to eject saline mist into the user's lungs during STEP A to promote exhalation of mucus droplets from the user. Moreover, the aperture 410 is effective at reducing direct saline mist ingress from the septum nozzle into the tube 10 and hence contributing to the collected sample formed on the projection 110.

In a second example (EXAMPLE 2), the sample tube 10 is provided with a puncturable membrane 420 at its second end 30 as illustrated so that the tube 10 can be offered to a user for sample collection, and then the plunger 40 subsequently inserted in the tube 10 by puncturing the membrane 420. Such an arrangement is of advantage in that a visual check can be performed to ensure satisfactory sample collection has occurred before the plunger 40 is inserted into the tube 10; if the sample is, for some reason, unsatisfactory, the user can discard the tube 10 and repeat the sample collection and repeat sample collection using another tube 10 without having to contaminate a plunger 40.

In a third example (EXAMPLE 3), the sample tube 10 is provided with a direction change to promote the formation of vortices and hence assist with sample collection on the interior surface of the tube 10 as illustrated. In the third example, the tube 10 comprises a substantially straight section for receiving the plunger 40 and a curved region in the vicinity of the peripheral ring 70 susceptible to engagement with the user's lips.

In a yet further example of the sample tube 10 (not shown), a peripheral spiral passage is provided between the peripheral ring 70 and the straight section of the tube 10 so as to form an exhaled jet from the user into a spiraling jet which passes a plurality of times over the interior surface of the tube 10 whilst propagating gradually towards the second end of the tube 10 and/or the side tube 50.

Although optical interrogation within the apparatus is described in the foregoing, other methods of sample interrogation can be employed. For example, the prism 100 can be substituted with a quartz and/or lead zirconate titanate (PZT) piezo-electric element capable of supporting surface acoustic wave (SAW) propagation thereon. Such surface acoustic waves are capable of interacting with the collected sample on the projection 110 and thereby providing an indication of one or more characteristics

of the sample. For example, the presence of a specific pathogen in the collected sample causes coagulation of a test reagent included on the piezoelectric element, thereby altering acoustic matching of the piezo-electric element and hence a measurable response.

Claims

1. A sample collection apparatus comprising: (a) a sample collection volume bounded by an interior surface for receiving a gaseously-borne sample ; and (b) collecting means for collecting, in use, at least a portion of the sample deposited on the Interior surface and for concentrating the portion at a test location susceptible to subsequent interrogation.

2. An apparatus according to Claim 1, wherein the collection volume is provided with vortex generating means for causing, in use, an incoming jet transporting the gaseously-borne sample to form into one or more vortices to assist with deposition of the sample onto said interior surface.

3. An apparatus according to Claim 1 or 2, wherein the collection volume is implemented as a tubular element and the collecting means is implemented as a plunger element arranged to slidably engage within the interior surface of the tubular element.

4. An apparatus according to Claim 3, wherein the plunger element forms a sufficient seal onto the tubular element for collecting the sample into a ring-like mass when the plunger element, in use, is slidably moved within the tubular element.

5. An apparatus according to Claim 4, wherein the plunger element includes an end region comprising a projection susceptible to collecting the ring-like mass together when the plunger element is rotated relative to the tubular element.

6. An apparatus according to Claim 3,4 or 5, wherein the plunger element includes at its end region optical interfacing means for interfacing between optical Interrogating means and the sample, thereby enabling the optical interrogating means to interrogate the sample via the optical interfacing means.

7. An apparatus according to Claim 6, wherein the plunger element comprises a hollow interior region for receiving, in use, the optical interrogating means.

8. An apparatus according to Claim 6 or 7, wherein the tubular element and the plunger element are designed to be disposable items whereas the optical interrogating means is designed to be a non-disposable item.

9. An apparatus according the 6,7 or 8, wherein the optical interfacing means comprises a prism for guiding interrogating radiation from the interrogating means to the sample, and for guiding response radiation from the sample back to the interrogating means.

10. An apparatus according to Claim 9, wherein the prism is a dove-type prism.

11. An apparatus according to any one of Claims 6 to 10, wherein the interrogating means comprises a source of strobed radiation for providing the interrogating radiation, and a photodetector and associated demodulator for detecting response radiation from the sample and for demodulating the response radiation with respect to the strobe.

12. An apparatus according to any one of Claims 3 to 11 wherein one or more of the tubular element and the plunger element are fabricated from plastics materials.

13. An apparatus according to Claim 12, wherein the plastics materials comprise one or more of an acrylate, polyethylene, polypropylene, glass-filled silicone rubber, polyvinyl chloride (PVC), alkylen, polycarbonate, and polytetrafluoroethylene (PTFE) plastics material.

14. An apparatus according to Claim 13, wherein the plastics materials are injection moulded.

15. An apparatus for collecting samples substantially as hereinbefore described with reference to one or more of Figures 1 to 5.

16. A method of collecting a sample from a user utilizing an apparatus according to one or more of Claims 1 to 15, the method comprising the steps of: (a) exhaling mucus droplet borne air from the user into a collection volume of the apparatus; (b) depositing mucus droplets from the exhaled air onto an interior surface of the collection volume ; (c) collecting the droplets together from the surface using collecting means of the apparatus to provide a collected mass of droplets.

17. A method according to Claim 16, further comprising the step of interrogating the collected mass of droplets after step (c) to determine one or more characteristics thereof.

18. A method according to Claim 17, wherein the collected mass is interrogated optically.

19. A method according to Claim 18, wherein the collected mass is arranged to fluoresce in response to being optically interrogated, and the one or more characteristics determined from the fluorescence.

20. A method according to Claim 16,17, 18 or 19, wherein in step (b) the exhaled air is arranged to flow in vortices to promote deposition of the droplets onto the interior surface.

21. A method of collecting a sample substantially as hereinbefore described with reference to one or more of Figures 1 to 5.