Breath collection device

Abstract

The invention disclosed herein provides a breath condensate analysis cartridge suitable for incorporation into a breath device. The cartridge includes a condensation zone having a peripheral region for receiving exhaled breath. An analysis chamber is included in which the condensed breath sample is analyzed. The surface of the condensation zone acts to create a fluid flow path within the peripheral region. A fluid flow path through the peripheral region connects the condensation zone to the analysis chamber. A lip at least partially covers the peripheral region, and the lip cooperates with the condensation zone to form a capillary that controls fluid flow.

Description

[Technical field]

[0001] The invention described herein relates to a microfluidic cartridge, typically of similar size to a conventional credit card and designed for use in medical diagnostics. The cartridge is specifically for the collection of breath condensate and for the immediate analysis of a defined sample volume of breath condensate within the same cartridge, where the sample is in constant contact with one or more surfaces of the cartridge. [Background technology]

[0002] The present invention relates primarily to the collection of exhaled breath from human subjects, but also to the collection of exhaled breath from animal, typically mammalian, subjects. In a first aspect of the invention, a disposable microfluidic cartridge for collecting and analyzing exhaled breath is disclosed. The cartridge is intended for use in conjunction with a larger device that not only provides a flow path to receive and direct the exhaled breath to the cartridge, but also has the processing capabilities to process the data identified by the cartridge. Once used, the cartridge can be replaced with another cartridge to receive other samples.

[0003] It is well known that analysis of exhaled air, and in particular the alveolar portion of exhaled air, can give a good indication of the health status of a subject. In particular, the presence or absence of certain marker compounds for disease, such as hydrogen peroxide, NOx, etc., can make it possible to diagnose or exclude certain medical conditions.

[0004] However, care should be taken to ensure that the sample is obtained correctly, without contamination by inclusion of unwanted parts of the exhaled air, and that the sample is obtained without causing excessive discomfort to a subject who is already in significant respiratory distress.

[0005] Although microfluidic cartridges are known in the field of breath analysis, they have a number of drawbacks. Firstly, the sample size used in the analysis is not always well controlled. This can lead to errors in the results obtained, since the volume estimated in any calculation may not be accurate, or the assumed concentration of the reagent dissolved in the condensed breath may be inaccurate.

[0006] Furthermore, the size of conventional cartridges provides less control over the temperature of the analysis due to the mass of the components and their latent heat capacity being sufficient to affect the analysis temperature. The present invention, in a preferred embodiment of the invention, provides a cartridge the size of a regular credit card, and therefore of lower heat capacity, which can be relatively easily and cost effectively manufactured based on conventional techniques used in the manufacture of credit cards and the like, especially when materials similar to those utilized in the manufacture of credit cards are used.

[0007] Lightweight, disposable, single-use diagnostic strips have been known for many years, a particular and well-known example being the Self-Monitoring Blood Glucose (SMBG) strip.

[0008] Such glucose strips are produced in the billions per year, with a current reasonable accuracy of about 15%. When produced in large quantities, SMBG strips can cost between 2 and 5 cents per strip. This low cost of production is due in part to the volume of production and in part to the manufacturing techniques used. Manufacturing techniques may include screen printing, deposition, laser ablation, and lamination of materials that form the chambers and channels. SMBG strips are not typically made from injection molding, additive, or subtractive processes. The substrates used for SMBG strips are typically flexible / semi-flexible polymers, onto which thin film laminate materials are deposited to construct devices with microfluidic channels and chambers.

[0009] The object of the present invention is therefore to seek to solve the above-mentioned problems of known breath analyzers. Summary of the Invention [Means for solving the problem]

[0010] According to a first aspect of the invention there is provided a breath condensate analysis cartridge suitable for incorporation into a breath device, the cartridge comprising: a condensation zone having a peripheral region and configured to receive exhaled air; an analysis chamber in which the sample is analyzed; Equipped with the surfaces of the condensation zone act to generate fluid flow paths within the peripheral region; the condensation zone is connected by a fluid flow path to the analysis chamber through the peripheral region; The nozzle further includes a lip at least partially covering the peripheral region, the lip cooperating with the condensation zone to form a capillary for controlling fluid flow.

[0011] Preferably, the condensation zone is circular, more preferably having a diameter of 15.0 to 25.0 mm, even more preferably 20.0 mm.

[0012] The surfaces of the condensation zone are preferably coated or formed with a hydrophilic material that allows the condensing fluid to form a film across the surface.

[0013] The hydrophilicity of the surface of the condensation zone is preferably selected to form an angle with the breath condensate of less than 20.0°, more preferably between 5.0° and 15.0°, allowing the breath condensate to flow freely from the condensation zone and into the detection zone.

[0014] Alternatively, the detection zone includes an air vent and the hydrophilicity of the surface of the condensation zone is optionally selected to form an angle with the breath condensate of between 23.0° and less than 35.0°, or even between 24.0° and 26.0°, allowing the formation of a critical mass of condensate which then flows into the detection zone as a combined mass.

[0015] Preferably, the lip comprises a narrow strip, the first end of which is adjacent or contiguous with the analysis chamber. The width of the strip is preferably between 125 and 400 μm, particularly preferably between 125 and 300 μm.

[0016] The distance of the strip from the condensation zone is preferably 125 to 350 μm, particularly preferably 250 to 300 μm.

[0017] Optionally, a portion of the condensation zone is formed from or coated with a hydrophobic material, which portion is located adjacent the analysis chamber and the peripheral region.

[0018] Conveniently, the overall dimensions of the cartridge are those of a conventional credit card.

[0019] Optionally, the cartridge has a layered structure that helps enable the cartridge to bend and therefore more flexible than conventional cartridges available in the art.

[0020] The invention will now be described with reference to the accompanying drawings which show, by way of example only, two embodiments of a cartridge. [Brief description of the drawings]

[0021] [Figure 1] FIG. 2 shows component parts of a first embodiment of a cartridge. [Diagram 2] FIG. 1 illustrates fluid held near the periphery of the condensation zone. [Figure 3a] FIG. 2 is a diagram showing the fluid flow within the cartridge. [Figure 3b] FIG. 2 is a diagram showing the fluid flow within the cartridge. [Figure 3c] FIG. 2 is a diagram showing the fluid flow within the cartridge. [Figure 4a] FIG. 2 is a side view of the base card. [Figure 4b] FIG. [Figure 4c] FIG. [Figure 5A] FIG. [Figure 5b] FIG. [Figure 6a] FIG. 6 is a perspective view of the base card and cover sheet of FIGS. 4 and 5 assembled together. [Figure 6b] FIG. 6 is a plan view of the assembled base card and cover sheet of FIGS. 4 and 5; [Figure 7a] FIG. [Figure 7b] FIG. [Figure 8a] FIG. 8 is a perspective view of the elements of FIGS. 4 to 7 assembled together. [Figure 8b] FIG. 8 is a plan view of the assembled elements of FIGS. 4 to 7. [Figure 9] 11A-11D are diagrams illustrating the operation of the second embodiment of the cartridge. [Figure 10] 11A-11D are diagrams illustrating the operation of the second embodiment of the cartridge. [Figure 11] 11A-11D are diagrams illustrating the operation of the second embodiment of the cartridge. [Figure 12] 11A-11D are diagrams illustrating the operation of the second embodiment of the cartridge. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The present invention aims to provide a cartridge for use in a device for analysing exhaled breath condensate. The cartridge incorporates a coolable collection zone in which exhaled breath is collected. The collection zone is fluidly connected to one or more analysis areas in which a defined volume of collected breath is typically mixed with reagents and then analysed to identify the presence and / or concentration of a required analyte. The device in which the cartridge is incorporated may be provided with functionality such as identifying when sample has entered the cartridge and when sufficient sample has been collected, a processor to operate on signals from the cartridge as to whether an assay is being performed, and communication means to transmit readings or results to a display onboard the device or to a remote display.

[0023] The cartridge described in this document is designed to fit into a reader device, where the collection zone is in cooling engagement with a heat sink such as a Peltier cooler mounted within the device. All processing is carried out within the cartridge, including cooling of the breath sample, condensation of the breath sample as a film in the condensation zone, sample processing and eventual analysis. The condensation zone has a hydrophilic surface that aids in the transfer of the sample from the collection zone to the detection zone under the influence of gravity, avoiding the formation of droplets.

[0024] The cartridge has two main zones inside it: a collection zone and a detection zone. The condensation zone of the collection zone is where the breath is condensed, while the detection zone, largely integrated with the collection zone, is where the detection and quantification of analytes takes place. The detection and quantification of analytes can be done by a number of analytical techniques including UV-Vis spectroscopy, fluorescence spectroscopy, surface plasmon resonance, impedance spectroscopy or electroanalytical chemistry. For techniques including electroanalytical chemistry and impedance spectroscopy, it is necessary to have electrodes in the detection zone. These electrodes can be made by a number of techniques including conductive foil adhesion, vapor deposition, thick film printing, etc. These electrodes can be applied directly onto the substrate that constitutes the "base" of the cartridge, or they can be printed onto a second material that is then slotted into the "base" of the cartridge.

[0025] The cartridge is preferably provided in the form and size of a credit card, which offers advantages both from a user standpoint and a manufacturing cost standpoint since it is a familiar and optimal size and shape for most people, and also provides a platform conducive to large scale, low cost manufacturing. Credit cards are ISO / IEC 7810 compliant and, with billions produced annually, have a highly optimized cost structure due to a very developed and mature supply chain.

[0026] Like the SMBG strips described above, the cartridges described in this patent can be made using a printing and lamination process, but unlike the SMBG strips, they are provided in a credit card format. Using such a process allows for the use of softer materials, reducing the tolerances to which the cartridge can be manufactured. Additionally, softer materials provide compressibility and give the layered structure more capacity for the cartridge to flex, allowing the cartridge to fit more easily into the device.

[0027] The cartridge has several functions including collection of breath condensate. The need to condense and collect the breath necessitates a phase change of the sample, which imposes requirements on the cartridge that were not faced in prior art disposables designed for medical diagnostic applications. One such requirement imposed by the application is the need for a large surface area for breath collection. The amount of breath that can be collected per second is proportional to the surface area of ​​the condensation zone. If the cartridge were small, similar in dimensions to SMBG strips, typically 7mm x 20mm, there would not be enough area to collect the patient's breath in a reasonable time. Use of the credit card format of the present invention allows for a circular breath collection zone with a diameter of about 20.0mm, although diameters of 15.0-25.0mm may be contemplated. This provides a large surface area for condensation, but allows for cooling so that the patient's breath can be collected.

[0028] In this invention, sufficient patient breath can be collected within 60 seconds. Prior art breath condensation collectors positioned in the medical and medical research market require the patient to breathe for several minutes to collect a sufficient volume of sample. This is not acceptable for many clinical applications and patient populations. Considering patients with asthma, chronic pulmonary obstructive disease, cystic fibrosis, etc., these types of patients have difficulty even breathing, so the requirement of other breath collection cartridges / devices to have the patient breathe for several minutes is unethical and may affect the results of any downstream assays.

[0029] The cartridge described herein is optimized to reduce stress on the patient as resistance to exhalation is minimized, and the required duration of breathing into the device is reduced due to the large collection area and small required sample volume, thus allowing the patient to quickly provide a breath condensate sample to the cartridge while only taking normal periodic breaths.

[0030] Along with the large condensation surface, the cartridge also provides additional benefits to the patient due to the microfluidic features, channels and chambers incorporated into the device. Conventional breath condensate collection devices collect hundreds of microliters to milliliters of sample. The volume requirement with this prior art device means that no matter how efficient the breath condensation is, it takes a certain amount of time to condense 100 microliters or more of breath condensate. The cartridge described herein has a detection volume of 4 microliters, and this reduction in the actual volume of sample required means that sample collection time is greatly reduced. The volume of the condensation zone relative to the detection zone is about 10:1, which further aids in the rapid collection of sufficient volume.

[0031] In the device described herein, the condensation zone is provided with a hydrophilic surface, further reducing the sample that needs to be condensed. The beneficial effect of the hydrophilic surface is that droplets do not form on the surface of the condensation zone. The problem with this droplet formation is that the droplets usually have a volume of 10 microliters or more. Thus, a hydrophobic surface that promotes droplet formation results in droplets not forming unless the patient provides a volume of about 10 microliters. These droplets then "remain attached" to the surface until their mass is sufficient to overcome the hydrophobic forces and allow the droplets to start flowing. The use of a hydrophilic surface results in a film of condensate forming on the surface rather than within the droplet, which film starts to flow very quickly after the breath is initially condensed.

[0032] When in collection mode, the cartridge is preferably held in a vertical plane, and gravity is sufficient to move the sample downward from the collection zone towards the detection zone. The movement of the breath condensate film is not random, rather the sample tends to move towards the edge, and the lip around the periphery of the collection zone, in combination with the wall and the condensation surface of the condensation zone, provides a capillary channel to direct the sample. After initially moving downward under gravity, the sample runs down the edge of the collection zone before entering the capillary chamber, which is the lowest point of the collection zone when the cartridge is in this orientation. This second chamber is called the detection zone / chamber. This chamber is closed around its sides, usually four sides, by a cut laminate with a top cover that provides a lid for the chamber. The detection zone is operatively connected, but open to the collection zone. The chamber is also held in a vertical plane while in collection mode and while the patient is breathing into the device.

[0033] Some breath condensation devices described elsewhere have a collection zone positioned in a vertical plane, but a sensor in a horizontal plane, with the sample dripping from one surface to the other. This configuration has the disadvantage that in order to move as a droplet from one surface to the other: the droplet must have a critical mass in order to form a droplet and to be detached from the surface. Again, the collection and detection zones in the cartridge, which are in the same plane with the form of a credit card, allow the breath condensate film to flow easily from the collection zone to the detection zone. The sample is guided to the detection zone along the walls of the edge of the capillary channel formed at the edge of the condensation zone.

[0034] The detection zone in this embodiment fills from the bottom up because the sample flows down the side of the chamber before subsequently filling from the bottom up. This is different from SMBG strips, where the sample is often encouraged to fill the capillary tube in a uniform manner and fill from the front of the capillary, effectively pushing the front of any trapped air ahead of the liquid sample. SMBG strips often have air vents that allow trapped air to escape. The problem of trapped air is avoided in this embodiment of the credit card device because the liquid sample is directed down the wall towards the bottom of the chamber, filling the chamber from the bottom up, a process that is aided by the vertical positioning of the cartridge during sample collection.

[0035] In this sensing chamber, reagents can be added to the sample. In order to perform electrochemical measurements on the sample, it is advisable to control several parameters, including pH and conductivity, so in the chamber, dry reagents are provided for buffering and addition of electrolytes. Also, to have specificity, it is necessary to have an assay in the chamber designed to measure the analyte or parameter of interest. For analytes such as nitric oxide, pH, hydrogen peroxide, etc., assays designed to give a specific signal are often used.

[0036] As mentioned above, the ability to control fluid volumes is even more important since assays may require the addition of reagents to a sample volume, and therefore additional reagents must subsequently be dispersed to provide a predetermined concentration. For example, in many In Vitro Diagnostic assays (IVDS), optically or electrochemically active materials are added to the sample. The concentrations of these species can affect the final measurements, affecting both the precision and accuracy of the assay. The masses of these materials included in the assay are initially controlled by the manufacturing process, e.g., the controlled deposition of known masses of materials into a chamber or well, but the final concentration in the sample depends on the volume of the sample in which the material disperses and / or dissolves. Differences in sample volume affect the concentration of the added materials in that sample, and variations in volume subsequently affect the accuracy of the assay results.

[0037] Volume control can be achieved using fixed volume chambers, pumps and valves, etc. Some of these macro-world solutions work well for volumes larger than milliliters, but may not be as effective for microliter scale volumes where surface interactions are more important relative to bulk properties. A cartridge that fills under the influence of gravity and where the sample enters a fixed volume chamber is the invention described herein. A microfluidic cartridge has the characteristic that once the chamber is filled to the correct volume, no more liquid enters the chamber, and excess liquid is kept outside the chamber, with very little contact between the sample inside the chamber and the sample outside the chamber. This small contact acts as a choke point, resulting in very little mass or heat exchange between the fluid inside the chamber and the fluid outside the chamber.

[0038] In one embodiment of the device, a collection zone is provided where the vapor sample, such as exhaled air, condenses and flows down the collection zone as a continuous film under gravity to the detection zone due to the hydrophilic nature of the surface where the condensation occurs. By including a partial lid around the edge of the collection zone, a channel is created through which the moving film of the sample can easily travel. The moving film moves into the chamber of the detection zone and the solution flows down the side of the chamber and "sticks" to the side of the chamber due to surface tension, effectively filling the chamber continuously from the bottom. In a scenario where the fluid continues to flow, it can be expected that the chamber will overflow with the overflow in direct contact with the sample, resulting in an unknown total volume. In the design described here, one or more capillary sinks prevent the overflow from freely contacting the sample in the chamber. Before the chamber is filled, the sink is part of directing the fluid sample into the chamber, but once the chamber is filled, the pressure of the now filled chamber prevents further fluid from entering the chamber. Rather than the fluid overflowing and accumulating directly at the top of the chamber, the overflow is partitioned into the capillary sink, with the additional sample remaining in the capillary overflow sink.

[0039] In addition, the interface between the collection zone and the overflow sink and the sample-containing chamber is 0.2 mm wet contact. 2 The capillary overflow sink is constructed and / or formed of a material having a surface area less than 100 nm, which therefore provides a very small interface between the sample in the chamber and the sample that overflows and is captured in the capillary overflow sink. In situations where reagents are added passively or actively in the sensing chamber, the volume of sample into which the reagent dissolves is controlled by the dimensions of the chamber, while any overflow of an otherwise unknown sample volume only comes into contact with the sample via a small interface, ensuring more precise control of the concentration of material added to the sample in the chamber.

[0040] The interface may have a form such as a structure in the form of a capillary tube or the like. Alternatively or additionally, the surfaces of the collection and detection zones may be formed of a hydrophobic material, except that a hydrophilic strip or channel couples the volume within the chamber to overflow sample outside the chamber. Excess sample may be further encouraged to remain outside the chamber by the capillary structure, which provides a surface area for the sample to adsorb, thereby providing sufficient energy gain to prevent the sample from flowing or attempting to flow back into the detection chamber.

[0041] The invention provides elegant control of the volume of sample initially in the detection chamber and the concentration of any material added passively or actively to the sample in the chamber thereafter. The final sample detection volume is controlled and any excess sample is stored outside the detection chamber. As a result, any material added to the sample in the detection chamber to enhance the analysis can be dissolved and dispersed to give a controlled final concentration.

[0042] The use of a primary chamber with capillary control for the sample coupled to an overflow sink capillary chamber provides control of the sample volume without the need for fluid level sensing, active valving and / or pumping, etc.

[0043] Referring specifically to the drawings, FIG. 1 shows the internal working arrangement of a cartridge according to a first embodiment of the invention. 。

[0044] Overlying this is the analytical layer 12. The analytical layer 12 includes a condensation zone 13 of approximately 20mm diameter that is exposed along most of its surface and that, in use, is fluidly connected to a mouthpiece (not shown) of the device to receive breath from a user which condenses into a fluid in the condensation zone 13. The surface of the condensation zone 13 is formed from or coated with a hydrophilic material that causes the condensed breath to spread as a film over its surface. In a first embodiment, the material is hydrophilic such that the contact angle between the condensed fluid and the material is less than 20.0°, preferably between 5.0 and 15.0°. The membrane structure is mounted on a cartridge such that the analytical area is at the bottom. Ji When retained, it acts to cause the fluid to flow downward along the edge of the condensation zone 13 towards the analysis chamber 15 .

[0045] As previously mentioned, it is important that the volume of fluid in the analysis chamber 15 is the correctly defined volume. Therefore, to ensure that the correct volume is obtained, once the correct volume is reached, further inflow or mixing with fluid leaving the condensation zone 13 is minimised.

[0046] For this purpose, lips 16a, 16b are provided on and parallel to the surface of the condensation zone 13 in the region of its edge 14. The lips 16a, 16b are shown in figure 2. As can be seen from the embodiment of figure 2, the lips 16a, 16b have portions 17a, 17b with a greater width than the narrow strips 19a, 19b, each of which has a second end terminating adjacent to the analysis chamber 15. Thereby, contact with or entry into the fluids in the analysis chamber 15 by fluids not required for the analysis is limited. The analysis chamber 15 is covered by a roof 18, which together with the base and walls of the analysis chamber 15 provides the correct volume required for the fluids in the analysis chamber 15.

[0047] Preferably, the lip comprises a narrow strip whose second end is adjacent or contiguous with the analysis chamber and has a width preferably between 125 and 400 μm, particularly preferably between 125 and 300 μm.

[0048] As summarized in Figures 3a-3c, fluid condenses in the condensation zone 13. The condensing fluid flows around the edge of the condensation zone 13 into the lower region 20 of the analysis chamber 15. Flow continues until the required amount of fluid has entered the analysis chamber 15. Further fluid is then trapped beneath the structure of the lips 16a, 16b. This containment is aided in an optional embodiment by a hydrophobic region 21 of the condensation zone 13 that separates the lower surfaces of the lips 16a, 16b, which region 21 of the condensation zone 13 is formed of or coated with a hydrophobic material.

[0049] Reference is now made to Figures 4a-8b, which show the assembly of a cartridge according to an embodiment of the invention. The assembled cartridge has a layered structure made up of multiple layers held together by means known in the art. The layered structure provides flexibility and strength to the cartridge, which is important generally, but also in instances where, for example, a cartridge may be used in an agricultural environment, where conditions are not as well controlled as in a medical environment. Figures 4a-4c show a base card 40, which supports the other elements of the cartridge. The base card 40 is generally rectangular and has a number of cutouts and openings that accommodate the operating elements of the cartridge.

[0050] The base card 40 has a generally circular central opening 41, which in the illustrated embodiment has a radius of 10.5 mm. The walls of the opening form part of the rim of the condensation zone. A further opening 42 is shaped to accommodate a detection zone including an analysis region. A 2.0 mm wide channel 43 connects the central opening 41 to the further opening 42 to allow fluid to flow between the collection zone and the detection zone, and in some embodiments to receive a sensor card comprising reagents, electrodes etc. for performing the analysis. A 3.0 mm radius opening 44 allows the base card 40 to be fixed to other elements of the cartridge by known fixing means.

[0051] In use, the base card 40 is secured to the body of the device in which it is incorporated. The device is provided with a flow path, one end of which receives exhaled breath from a user. A second end of the flow path is aligned with the opening 42 to receive the exhaled breath or a component thereof.

[0052] 5A, 5b show a first cover sheet 50 which seats and is secured to surface 45 of base card 40 in use. Like base card 40, first cover sheet 50 has a central opening 51 which, in use, forms the wall of a condenser plate. Central opening 51 has a teardrop shape, but with a generally circular portion whose radius matches that of central opening 41. Channel 55 allows cover sheet 50 to slide with respect to any screws, pins or other fastening means that may be in place, and opening 54 allows cover sheet 50 to be secured in place.

[0053] Figures 7a, 7b and 8a, 8b show the final cover plate 70 secured onto the cover sheet 50. The cover plate 70 is often made of a transparent material, is flat and has openings to allow the fastening means to pass therethrough. In the mouth One side of the cover plate 70 is for the most part covered by, or in some embodiments formed by, a hydrophilic material that causes the exhaled air that impinges and condenses thereon to form a film. The cover plate 70 is secured to the other elements of the cartridge described above with the hydrophilic surface facing the openings 44, 54 and the flow of exhaled air from the user.

[0054] In use, in this embodiment the cover plate 70 functions as a condenser plate and will therefore be operatively connected to the cooling means in the final assembled device, and the portion 71 of the cover plate 70 within the openings 41, 51 will therefore be cooled and act as a heat sink for the exhaled air impinging thereon, causing it to condense into a liquid phase.

[0055] As can be seen from figures 8a, 8b, in the region of the exit from the portion 71 to the detection zone, the material from which the base card 40 is made extends beyond the region of the cover sheet 50 in approximately triangular portions (surfaces) 45, 46. The triangular portions (surfaces) 45, 46 join with the surface of the cover plate 70 and the walls of the openings 41, 51 to form capillary tubes which act to draw excess liquid away from the detection zone and thus provide the correct volume in the detection zone. The distance of the triangular portions from the condensation zone is preferably 125-350 μm, particularly preferably 250-300 μm, so as to provide a good capillary effect.

[0056] Preferably, the lip comprises a narrow strip, the first end of which is adjacent or contiguous with the analysis chamber, the width of said strip being preferably between 125 and 400 μm, particularly preferably between 125 and 300 μm.

[0057] 9-12, these show a cartridge 90 operating in accordance with a second embodiment of the invention to provide a required volume of liquid to the analysis zone. The second embodiment operates similarly to the first embodiment of the invention in that the surface of the condenser plate 91 is such that condensed breath air forms a film on the surface. Furthermore, to ensure that an accurate measurement is made, the device is provided with a lip 92, a narrow strip 93 and other formations to ensure that the correct volume of liquid is present in the analysis area.

[0058] The hydrophilic material is selected in a second embodiment to give a higher contact angle to the condensed breath of 23.0 to 35.0°, preferably 24.0 to 26.0°, more preferably 25.0°. A standard class of usable compounds is polyester. This prevents the condensed breath from flowing from the condenser plate 91 to the analysis area 94 first, and accumulates on the plate 91.

[0059] Condensed breath still forms a film on the surface of the hydrophilic material, but once a critical mass has accumulated, this will cause the film to collapse and liquid to flow into the analysis area 94. The instantaneous flow of liquid will reduce the chance of air in the analysis area 94 leaking towards the condenser plate 91, which will block the inflow of liquid as it enters the analysis area 94. Therefore, an air vent 95 is provided, which does not have a sufficient diameter for the flow of liquid therethrough. The air vent 95 comprises a channel with dimensions 3×0.12 mm over a length of 0.2 mm, leading to an outlet area with dimensions 4×0.45 mm and a length of 3 mm. Thus, as liquid enters the analysis area 94, air exits via the air vent, indicated by arrow A in FIG. 11. Thus, the analysis area 94 is completely filled without air pockets, and excess liquid is carried away by the thin strip 93 and lip 92.

Claims

1. 1. A breath condensate analysis cartridge suitable for incorporation into a breath device, comprising: a condensation zone having a peripheral region and configured to receive exhaled air; an analysis chamber in which the sample is analyzed; Equipped with a surface of the condensation zone acts to create a fluid flow path within the peripheral region; the condensation zone is connected to the analysis chamber through the peripheral region by a fluid flow path; a lip at least partially covering the peripheral region, the lip cooperating with the condensation zone to form a capillary for controlling fluid flow; the condensation zone is coated or formed with a hydrophilic material; A cartridge in which a portion of the condensation zone is constructed of or coated with a hydrophobic material, said portion being located adjacent to the analysis chamber and the peripheral area.

2. The cartridge of claim 1 , wherein the condensation zone is circular.

3. The cartridge of claim 2, wherein the condensation zone has a diameter of 15.0 to 25.0 mm.

4. The cartridge of claim 3 , wherein the diameter is 20.0 mm.

5. 5. A cartridge according to any one of claims 1 to 4, wherein the hydrophilicity of the surface of the condensation zone is selected to form an angle with breath condensate of less than 20.0°.

6. The cartridge of claim 5, wherein the angle is between 5.0° and 15.0°.

7. 5. A cartridge according to any one of claims 1 to 4, wherein the analysis chamber includes an air vent and the hydrophilicity of the surface of the condensation zone is selected to form an angle of between 23.0° and 35.0° with breath condensate.

8. The cartridge of claim 7, wherein the angle is selected to be between 24.0° and 26.0°.

9. 9. A cartridge according to claim 1, wherein the lip comprises a narrow strip having a first end adjacent or contiguous with the analysis chamber.

10. A cartridge according to claim 9, wherein the narrow strip has a width of 125 to 400 μm.

11. A cartridge according to claim 10, wherein the narrow strip has a width of 125 to 300 μm.

12. A cartridge according to any one of claims 9 to 11, wherein the distance of the narrow strip from the condensation zone is between 125 and 350 µm.

13. The cartridge of claim 12, wherein the distance is between 250 and 300 μm.

14. 14. A cartridge according to any one of claims 1 to 13, wherein the overall dimensions of the cartridge are those of a conventional credit card in accordance with ISO / IEC 7810.

15. 15. A cartridge according to any one of claims 1 to 14, wherein the cartridge has a layered structure made up of a number of layers held together.

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