WO2011018669A2

WO2011018669A2 - A condenser for breath condensate

Info

Publication number: WO2011018669A2
Application number: PCT/GB2010/051345
Authority: WO
Inventors: Peter W. Dettmar; Michael M. Fagan; Alyn Morice; Vicki Strugala
Original assignee: The University Of Hull
Priority date: 2009-08-14
Filing date: 2010-08-13
Publication date: 2011-02-17
Also published as: GB0914248D0; WO2011018669A3

Abstract

A condenser for collecting breath condensate comprises a vessel for holding a condensing medium and a conduit having an inlet at a first end and an exhaust at a second end, in which the first and second ends are outside of the vessel. A collection port is provided outside of the vessel and in fluid communication with the conduit for collecting condensate. A portion of the conduit is housed within the vessel and positioned so as to be submerged in the condensing medium when the condenser is in use and further arranged so that condensate which forms within the conduit can flow along the conduit under gravity to the collection port when the condenser is in use. The vessel has a base which can sit on a support surface such as a table when the condenser is in use.

Description

A CONDENSERFORBREATH CONDENSATE

The present invention relates to a condenser. In particular, the present invention relates to a condenser for collecting a breath condensate from an animal.

Acid reflux in the stomach can manifest itself with the symptom of "heartburn" as stomach acid passes into the oesophagus. However, acid reflux can cause stomach contents to travel much higher than the oesophagus and pass into the lungs and ear. This is known as extra-oesophageal reflux and can occur as a gaseous vapour (unlike liquid with heartburn) passing upwards from the stomach. Extra-oesophageal reflux is often a result of chronic gastrooesophageal reflux disease (GORD). The gas from the stomach can cause chronic cough, a persistence condition which is difficult to diagnose due to the sporadic nature of the symptoms and similarity of symptoms with other diseases. GORD is one of the most common causes of chronic cough.

The treatment of a GORD related chronic cough depends on a correct diagnosis of the condition. One diagnosis technique involves a 24 hour monitoring of oesophageal pH in which an electrode is placed within the oesophagus of a patient to measure the pH levels over a 24 hour period. This type of testing is time consuming, expensive and inconvenient for a patient.

Another way to diagnose GORD is from the identification of pepsin, bile or abnormal pH levels in a condensate of breath collected from a patient around the time of a symptomatic episode of coughing. However, collection of the condensate can be difficult in a clinical setting due to the sporadic nature of the symptoms.

A currently known condenser which is suitable for a patient to use at home includes an elongate cylindrical collection vessel having a valve at one end and which is open at the other end. The valve is arranged to slide along the collection vessel and act as a plunger.

The collection vessel is housed within an aluminium sleeve which is cooled prior to use of the condenser and a thermal jacket which keeps the device cool. During use, breath enters through a central portion of the valve and condenses on the side walls of the collection vessel which is cooled via the aluminium sleeve. After a predetermined period of time of use, the patient stops breathing into the condenser and a cap is fitted to the open end of the collection vessel before the valve is pushed along the collection vessel to collect the condensate at one end of the collection vessel. The collection vessel can then be mailed to a laboratory for analysis.

Because the condensate adheres to the walls of the known condenser a complex arrangement of components is needed to collect the condensate. This leads to an unduly expensive and complicated condenser which incorporates an actuator and a valve having a seal to act as a plunger. Further, in order for this arrangement to work, the surface to volume ratio of the collection vessel i.e. the condensing unit, is reduced. Also, the amount of condensate which has formed cannot be judged until after the collection process has ceased and the valve actuated along the condenser tube. WO-02/082977 discloses a device for collecting condensate from a patient's breath in order to analyse the content of acetic acid and of acetates in the breath. The device includes a mouthpiece, a condenser and a collection vessel. The condenser comprises an inner tube for the breath sample and an outer tube which defines a space in which a cooling material is placed, for example a gel material having a high heat capacity. The present invention seeks to overcome these problems and provide an improved condenser for collecting a breath condensate.

In one aspect, the invention provides a condenser for collecting a condensate of breath, comprising a vessel for holding a condensing medium; a conduit having an inlet at a first end and an exhaust at a second end, in which the first and second ends are outside of the vessel; and a collection port outside of the vessel and in fluid communication with the conduit for collecting condensate, in which a portion of the conduit is housed within the vessel and positioned so as to be submerged in the condensing medium when the condenser is in use and further arranged so that condensate which forms within the conduit can flow along the conduit under gravity to the collection port when the condenser is in use.

The arrangement of the present invention removes the need to have a separate actuating means to gather the condensate which makes for a simpler, less expensive condenser. Further, collecting the condensate in this way allows for a container to be placed outside the vessel such that the amount of condensate can be judged during collection.

The use of a fluid in a condenser allows the condenser to be transported whilst empty and filled with a suitable condensing medium at a given destination. Thus, the condenser can be efficiently transported to a patient's home and setup for use when a coughing episode occurs. This can be important because it allows a patient to use the device to collect relevant residues at or very soon after the occurrence of a coughing episode. This can provide important information concerning the patient's condition at the time of the episode. This advantage flows from the robust and convenient packaging of the device of the invention and the ability to prepare it for use without assistance from a skilled medical practitioner.

The condensing medium can be a fluid. Preferably, the condensing medium is water. The water can be frozen. Preferably, the condensing medium comprises iced water.

Using water provides a cheap and easily obtained condensing medium which can be cooled in a household refrigeration unit. The temperature of the condensing medium can be lowered after the vessel has been filled. Alternatively, the temperature of the condensing medium can be lowered prior to filling the vessel. Preferably, the temperature of the condensing medium is not more than about 7⁰C during use. More preferably, the temperature of the condensing medium is not more than about 5⁰C during use. Preferably, the temperature of the condensing medium is greater than about -10⁰C during use. More preferably, the temperature of the condensing medium is greater than about -5⁰C during use. For example, the temperature can be between 0⁰C and 4°C. -A-

The condensing medium can be frozen. Alternatively, the condensing medium can be a mixture of frozen condensing medium and liquid condensing medium.

The conduit includes any part of the condenser which directly channels the breath. The portion of conduit housed within the vessel can include a condensing pipe having a first end and a second end. The first and second ends of the condensing pipe can extend to the outside of the vessel. The conduit can include a mouthpiece which can provide a sealed mating with a patient's mouth. The condensing pipe can attach directly to the mouthpiece at the first end of the condensing pipe. The second end of the condensing pipe can form the exhaust. Alternatively, the exhaust can include an exhaust pipe coupled to the condensing pipe. The second end of the condensing pipe can be coupled to the collection port. The exhaust pipe can be coupled to the collection port.

The condenser can have a support for supporting the condenser on a support surface when in use. Examples of a support surface are a table and a kitchen work top. The vessel can include the support. The vessel can include a base. The base can include the support. Preferably, the base of the vessel can sit on a support surface, and can therefore be the support for the condenser.

A portion of conduit which extends between the condensing pipe in the vessel and the first end of the conduit can be inclined with respect to horizontal when the condenser is in normal use so that any liquid entering the first end with the breath will flow back to the first end of the conduit. Having a portion of the conduit inclined with respect to horizontal provides a simple and effective way of preventing contaminants, for example bulk liquid, from flowing into the condensing pipe which may contaminate the condensate or partially block the condensing pipe.

Alternatively, the condensing pipe can be have a portion inclined with respect to horizontal proximate to the point at which it enters the vessel so that any fluid entering the condensing pipe flows back to the inlet and not to the collection port. The inlet pipe can be made from a polymeric material. The polymer can be a homo- polymer or a copolymer. Examples of polymers are polyethylene, polyamide, polyester and polypropylene. Preferably, the inlet pipe is nylon. The inlet pipe can be attached to an aperture in the vessel. The inlet pipe can be coupled directly to the condensing pipe. Preferably, the condensing pipe has a tortuous configuration, so that the pipe is not straight having portions of the pipe conducting the flow of breath in generally opposite directions through the vessel. This makes the condensing pipe more compact so that the spatial efficiency of the device of the invention is maximised, allowing a greater length of condensing pipe to be arranged within the vessel. For example, the condensing pipe might follow a boustrophedon (zig zag, optionally with parallel legs) path within the vessel.

Preferably, the condensing pipe has a generally helical configuration. The helix can have a circular cross-section for ease of manufacture, but other shapes can be used. The use of a helical configuration for the condenser allows the overall dimension of the condenser to be minimised whilst maintaining a high surface to volume ratio which provides for a more effective condenser.

The condensing pipe should preferably follow a path which does not have an upward portion for fluid flow between the start of the condensing pipe at the point at which the conduit enters the vessel and the collection port. This can facilitate the flow of condensate under gravity to the collection port. The helical configuration of the conduit preferably includes at least 0.5 turns about a central axis, more preferably at least about 1 turn, especially at least about 3.5 turns, for example at least about 5.5 turns. There will generally be not more than about 20 turns, especially not more than about 10 turns. Preferably, the spacing of the turns relative to one another is uniform. The spacing between the turns can be in the range of about 1 to 10 mm. Preferably, the spacing between the turns is greater than 2 mm.

The length of the condensing pipe can be at least about 0.5 m, preferably at least about 0.8 m, more preferably at least about 1.1 m. The length of the condensing pipe can be, for example, about 0.7 m. The wall thickness of the condensing pipe can be between 0.5 mm and 5 mm. Preferably, the wall thickness of the condensing pipe will be between 1.5 and 2.0 mm.

The inner bore of the condensing pipe can be between 1 mm and 10 mm. Preferably, the inner bore of the condensing pipe will be between 2 mm and 8 mm. More preferably still, the inner bore of the condensing pipe will be between 3 mm and 5 mm.

When the condensing pipe has a helical shape, it can be preferred for the ratio of the height of the helix to its transverse dimension to be not more than about 2.5, more preferably not more than about 2.0, especially not more than about 1.5, for example not more than about 1.0. The transverse dimension will be the diameter of the helix when it is circular. The transverse dimension will be the length of a side when the helix is square.

The condensing pipe can be made from a metal. Preferably, the condensing pipe is made from a polymeric material. For example, the condensing pipe may be made from polyamide. The condensing pipe can be made using an extrusion process.

A typical range of values of thermal conductivity for the condensing pipe for the invention is preferably greater than about 0.2 W.rrf'.K^"1 and not more than about 0.6 W.rrf'.K^"1 .

Preferably, the condensing pipe has a thermal conductivity of about 0.25 W.rrf'.K^"1 .

The first end and the second end of the condensing pipe can pass through a wall of the vessel. Any aperture the condensing pipe passes through in a vessel wall can be sealed so that the vessel can hold the condensing medium. For example, the vessel wall can be sealed using sealing compounds, adhesives or glands. The first end of the condensing pipe can exit the vessel above the level of the condensing medium when the condenser is in use.

The vessel can have a square cross-section. The vessel can be cylindrical with a rounded cross-section. For example, the rounded cross-section can be circular or oval. The vessel can have a transverse dimension of between about 18 cm and 6 cm. The transverse dimension will be the diameter of the vessel when it is circular. The transverse dimension will be the length of a side when the vessel is square. The transverse dimension will be the length of its shorter side when the vessel is rectangular. Preferably, the vessel has a transverse dimension of between about 15 cm and 9 cm. The vessel can have a ratio of the biggest transverse dimension to the smallest transverse dimension of from about 1 to about 5. Preferably, the vessel has a ratio of the biggest transverse dimension to the smallest transverse dimension of about 1.

It can be preferred for the ratio of the height of the vessel to its transverse dimension to be not more than about 2.5, more preferably not more than about 2.0, especially not more than about 1.5, for example not more than about 1.0. This has the advantage that the condenser has a reduced tendency to be dislodged from its in use position, for example by being knocked, especially so that it is no longer upright. It also means that the vessel has compact dimensions, which can facilitate cooling of the vessel (especially when it contains a quantity of the condensing medium) in a refrigeration device.

The height of the vessel can be at least about 50 mm. The height of the vessel can be at least about 100 mm. The height of the vessel can be not more than about 300 mm. The height of the vessel can be not more than about 200 mm. The height of the vessel can be not more than about 150 mm. Preferably, the height of the vessel is about 110 mm.

Preferably, the vessel is made from a polymer, for example from a polyolefin. Preferably, the vessel is made from a polypropylene. Preferably, the conduit exits the vessel at a higher position than the collection port when the condenser is in use so that any condensate flows out of the collection port under the influence of gravity. The conduit can exit the vessel by means of a sealing gland.

Alternatively, the conduit can exit the vessel through an aperture which is sealed with a sealing agent. The individual components of the conduit can be joined directly or indirectly via a joining member. A joining member can include a first portion for attaching a first segment of conduit and a second portion for attaching a second segment of conduit. The joining member can include a reducing portion which reduces (or increases) the diameter of the conduit. A joining member can include a third portion for attaching a third component such as the container. Seals, glands and adhesives can also be used to join individual components of the conduit.

The collection port can be a joining member. The collection port can include a body having formations for accepting the condensing pipe and the exhaust pipe. Alternatively, the condensing pipe can include the collection port. Preferably, the exhaust pipe includes the collection port.

The vessel can include an opening for filling and emptying the vessel. Preferably, the opening is located toward the top of the vessel when the vessel is in use, for example with its base sitting on a support surface. The vessel does not need an opening at or towards its base for the condensing medium because the condenser will not normally use an arrangement in which the condensing medium flows through the condenser.

The vessel can be provided with a removable lid which can be removed to allow the vessel to be filled. The vessel can be closed by means of a lid which is not then readily removed, and the opening can be provided in the lid, for example by a removable panel for example in the form of a bung or a screw cap.

The use of a vessel having a lid can facilitate assembly of the condenser by allowing the conduit to be fitted into the vessel when the vessel is open, and then closing the vessel by fitting the lid. Fitting the lid to the vessel has the advantage that it can help to minimise risk of loss of the condensing medium from within the vessel when the condenser is in use.

An opening in the lid of the vessel can be sealed with a sealing device which is operable by hand. The sealing device can be one of a screw cap or a bung. Preferably, the vessel has an open side in which the edges of the vessel at the open side include a portion for mating with a push fit lid. The lid can include a handle which can be used to move the condenser. The conduit can include a one-way valve arranged to prevent a flow of air from the outlet to the inlet. The one-way valve can be located at any position between the first and second end of the conduit. Preferably, the one-way valve is located on the outside of the vessel. The one-way valve can be located at the second end of the conduit. The one-way valve may form part of the exhaust pipe. Preferably, the one-way valve is positioned toward the first end of the conduit. The one-way valve can be made from a support frame and a flexible membrane. The flexible support frame can be made from a polymeric material. The membrane can be made from a polymeric material.

The condenser can include a valve unit which can be detachably attached to the condenser and which houses the one-way valve. Preferably, the valve unit can be detachably attached at the first end of the conduit and is arranged so as to provide a mouthpiece for the condenser. Preferably, the valve unit is disposable

Alternatively, the mouthpiece can be a component for mating to the mouth of a patient which can be coupled to the valve unit, inlet pipe or condensing pipe. The mouthpiece can include a screw thread, bayonet fitting or a push fit portion for coupling to the condenser. The mouthpiece can be made from cardboard. Preferably, the mouthpiece is made from a polymeric material. Examples of suitable polymeric materials are provided above.

The valve unit can include a valve housing. The valve housing can be made from a polymeric material. Examples of suitable polymeric materials are provided above. The valve housing can be made from cardboard. Preferably, the valve unit is disposable.

Having a disposable valve unit which includes a mouthpiece and one-way valve allows the valve unit to be cleaned effectively and a new valve unit attached for every use. This is useful for hygiene purposes and for preventing unwanted contaminants in the condensate if a series of condensates are required.

The condenser can include a container which includes a connecting portion for releasably coupling to the collection port. The connecting portion can accept a cap which seals the container when the container is not coupled to the collection port. The connecting portion can include a threaded portion. The connecting portion can include a bayonet fitting. The connecting portion can include a push- fit portion. The exhaust pipe can be partially enveloped by a wall of the vessel on the outside of the vessel. Preferably, the exhaust pipe which is partially enveloped is vertical. The vessel wall can include a recess to partially envelope the exhaust pipe. Preferably, the exhaust pipe is in direct contact with the vessel wall along the length of the exhaust pipe. In this configuration, the exhaust pipe can act as a condensing pipe which increases the efficiency of the condenser by increasing the length of the condensing portion of the conduit.

The condenser can be prepared for use by providing the condenser of the present invention and filling the vessel with water to act as the condensing medium. Preparing the condenser for use can include placing the condenser in a refrigeration unit to lower the temperature of the water. The condenser can be removed from the refrigeration unit when the water is substantially frozen. Alternatively, ice can be mixed with water before filling the condenser.

The device of the invention can be used to collect a breath condensate sample for analysis to determine one or more of pepsin concentration, bile acid concentration, pH and bacteria content. The device can include a collection vessel for the breath condensate. The vessel can include more than one chamber so that the breath condensate is split between the chambers. At least one chamber can contain a quantity of an agent which inhibits degradation of pepsin, for example citric acid. Separate chambers can be provided for respective portions of the breath condensate which are to be used in different assays. The collection vessel can include a closure component which can be used to seal the or each chamber after breath condensate has been collected. The volume of the or each chamber can be at least about 0.5 ml, preferably at least about 1.0 ml, more preferably at least about 2.0 ml. The volume of the or each chamber can be not more than about 5.0 ml, preferably not more than about 3.0 ml, for example not more than about 2.5 ml. In another aspect, the present invention provides a condenser for collecting a condensate of breath, comprising: a vessel for holding a condensing medium; a conduit having an inlet at a first end and an exhaust at a second end, in which the first and second ends are outside of the vessel; and, a collection port in fluid communication with the conduit for collecting the condensate, in which a portion of conduit which extends between the vessel and the first end is inclined with respect to horizontal so that when the condenser is in use any liquid entering the first end with the breath is urged back toward the inlet.

In another aspect, the present invention provides a condenser for collecting a condensate of breath, comprising: a vessel for holding a condensing medium; a conduit having a valve unit at a first end which acts as an inlet, and a second end which acts as an exhaust, in which the first and second ends are outside of the vessel; and, a collection port in fluid communication with the conduit for collecting the condensate, in which the valve unit can be detachably attached to the first end of the conduit and includes a one-way valve and is arranged to provide a mouthpiece for the condenser. In another aspect, the invention provides a method of collecting a condensate of breath using the condenser of the invention, the method comprising the steps of filling the vessel with the condensing medium; coupling a container to the connection port; and breathing into the inlet for a predetermined period of time.

The method can include the step of freezing the condensing medium prior to breathing into the inlet.

In a further aspect, the invention provides a liquid collection device which comprises: a. a housing which has a stepped outer surface defining a first step and a second step,

b. a nozzle at or towards one end of the housing for discharge of liquid, in which the second step on the outer surface of the housing is further from the nozzle than the first step and is wider than the second step,

c. a first collection vessel having an open face which is a snug fit on the first step,

d. a second collection vessel an open face which is bigger than the open face on the first collection vessel and is a snug fit on the second step.

Each of the collection vessels can be an interference fit on its respective step. Optionally, the device includes a first latch feature associated with the first collection vessel and the first step for retaining the first collection vessel on the first step.

Optionally, the first latch comprises a detent on one of the first collection vessel and the first step and a recess on the other of the first collection vessel and the first step in which the detent can be received.

Optionally, the device includes a second latch feature associated with the second collection vessel and the second step for retaining the second collection vessel on the second step.

Optionally, the second latch comprises a detent on one of the second collection vessel and the second step and a recess on the other of the second collection vessel and the second step in which the detent can be received.

When a collection vessel is retained on a step on the nozzle housing by means of a cooperating latch and detent, it will frequently be preferred for the material of at least one of the collection vessel and the outer surface of the housing to be flexible. It might be appropriate for the materials of each of the collection vessel and the outer surface of the housing to be flexible. It might be appropriate for the material of one of the collection vessel and the outer surface of the housing to be flexible and for the material of the other of the collection vessel and the outer surface of the housing to be relatively rigid. The use of a flexible material can facilitate fitting the collection vessel on to the step provided by the outer surface of the housing, in particular when the latch feature for retaining the collection vessel on the step comprises a detent and a recess.

Optionally, the second collection device provides a plurality of chambers for collection of respective portions of the liquid which is discharged into the collection device through the nozzle.

Optionally, the plurality of chambers are provided in the second collection device so that they are arranged symmetrically around the nozzle when the second collection device is fitted on to the second step. When there are two chambers, the chambers can be provided side-by-side, separated by a wall which functions as a flow splitter so that liquid which is discharged from the nozzle for collection in the collection vessel impinges on the top edge of the wall which divides the flow of the liquid between the chambers. When there are more than two chambers, for example at least three chambers or at least four chambers or at least five chambers or at least six chambers or more, the chambers can be arranged radially. The hub which is defined by the intersection of the walls which divide adjacent chambers can be positioned so that liquid which is discharged from the nozzle for collection in the collection vessel is directed on to the hub, which causes the flow of the liquid to be divided between the chambers. The sizes of the first and second steps will be selected so that the first and second collection vessels can be fitted easily on to the respective steps. The second collection vessel contains multiple chambers and therefore is bigger than the first collection vessel. When the second collection vessel contains four chambers, it might for example be approximately square (possibly with rounded corners to facilitate manufacture by moulding). When the second collection vessel contains six chambers, it might for example be square or rectangular or hexagonal.

Optionally, the device includes a sealing device which can be fitted into the second collection vessel through its open face, the sealing device providing a plurality of sealing plugs which can fit into respective ones of the chambers in the second collection vessel so as to prevent transfer of collected liquid between the chambers in the second collection vessel.

In a further aspect, the invention provides a liquid collection device which comprises: a. a housing which has a stepped outer surface defining a step,

b. a nozzle at or towards one end of the housing for discharge of liquid, c. a collection vessel having an open face which is a snug fit on the step, and which provides a plurality of chambers for collection of respective portions of the liquid which is discharged into the collection device through the nozzle, d. a sealing device which can be fitted into the collection vessel through its open face, the sealing device providing a plurality of sealing plugs which can fit into respective ones of the chambers in the vessel so as to prevent transfer of collected liquid between the chambers in the vessel.

Optionally, the plurality of chambers are provided in the collection device so that they are arranged symmetrically around the nozzle when the collection device is fitted on to the step on the outer surface of the nozzle housing.

Optionally, the collection vessel provides a flow splitter which is positioned below the nozzle when the collection device is fitted on to the step on the outer surface of the nozzle housing, which splits the flow of liquid which is discharged from the nozzle between the plurality of chambers in the collection device. The flow splitter can be provided by a divider between the chambers. When there are two chambers, the chambers can be provided side-by-side, separated by a wall which functions as the flow splitter. Liquid which is discharged from the nozzle for collection in the collection vessel impinges on the top edge of the wall which divides the flow of the liquid between the chambers. When there are more than two chambers, for example at least three chambers or at least four chambers or at least five chambers or at least six chambers or more, the chambers can be arranged radially. The hub which is defined by the intersection of the walls which divide adjacent chambers can be positioned so that liquid which is discharged from the nozzle for collection in the collection vessel is directed on to the hub, which causes the flow of the liquid to be divided between the chambers. Optionally, a first one of the chambers contains a first reagent and a second one of the chambers does not contain the said first reagent. The first reagent can comprise one material or more than one material. A first chamber can contain a first reagent and a second chamber can contain a second reagent. A reagent that is provided in the multi- chamber collection vessel can be selected for its ability to inhibit degradation of a component of the collected liquid. A reagent that is provided in the multi-chamber collection vessel can react with a component of the collected liquid to modify the component so that its degradation is inhibited or so that it is modified for the purposes of a subsequent process step. Optionally, the device includes a lid for the or each collection vessel by which the vessel can be sealed to prevent loss of collected liquid. When the vessel has a plurality of chambers and a sealing device which provides a plurality of sealing plugs, the lid can be the sealing device or a separate lid can be provided. The lid might have a lip which fits over and around the collection vessel at its open face.

Embodiments of the present invention will now be described by way of example with reference to the following drawings in which:

Figure 1 is a plan view of a device for collecting breath condensate.

Figure 2 is a cross section through the device shown in Figure 1 in the plane A-A as shown on Figure 1.

Figure 3 is a side schematic view of a first embodiment of a collection device which can be used with the condenser.

Figure 4 is a side view of a collection vial which can be used as part of the collection device shown in Figure 3.

Figure 5 is a side schematic view of a second embodiment of a collection device which can be used with the condenser.

Figure 6 is an exploded view of a collection vial assembly which includes the vial which is used as part of the collection device shown in Figure 5.

Figures 1 and 2 show a condenser 1 which includes a vessel 3 for holding a condensing medium (not shown), an inlet pipe 5, a condensing pipe 7, an exhaust pipe 9 and a container 11. The inlet pipe 5, condensing pipe and exhaust pipe 9 collectively form a conduit having a first end 13 at the inlet of the inlet pipe 5 and a second end 17 at the outlet of the exhaust pipe 9. The conduit channels breath from the first end 13 to the second end 17. When in use, the vessel 3 is filled with a condensing medium which is at a temperature which is sufficiently low to cause a breath condensate to form on the inner walls of the condensing pipe 7. Typically, this temperature will be between 0-4 degrees C. Thus, when a patient breathes into the inlet pipe 5 the breath condenses and flows down the condensing pipe 7 into the container 11.

The vessel 3 is an open-topped cylinder having a cylinder wall and a base 27. The condenser 1 sits on the base 27 when the condenser 1 is in use. The vessel 3 is sealed with a lid 19 which sits directly on top of the upper edge of the vessel wall 15. The lid 19 has an integral handle 21 to aid with it removal and installation. The lid 19 helps maintain the temperature of the condensing medium and prevent accidental spillage.

The vessel 3 is approximately 110mm in height and 150mm wide. The vessel 3 is constructed from polypropylene which is translucent and has a thickness and flexibility sufficient to prevent the vessel 3 from cracking when filled with water which is

subsequently frozen.

A portion of the conduit is located inside the vessel 3 in the form of the condensing pipe 7 having a first end and a second end. The condensing pipe 7 includes three and a half turns of pipe about a common axis with the height of the pipe decreasing along its length thereby giving the pipe a helical configuration. A first end of the condensing pipe 7 is coupled to the inlet pipe 5 toward the top of the vessel 3 with respect to the base 27 via a coupling member which adapts the diameter of the conduit from the narrower condensing pipe 7 to the wider inlet pipe 5. The second end of the condensing pipe 7 is coupled to an aperture in the exhaust pipe 9 on the opposite side of the vessel 3 toward the base 27 using an adhesive sealing agent such as a silicone or press fit with a gland.

The helical configuration allows the length of the condensing pipe 7 to be evenly distributed within the vessel 3 with a continuous downward gradient. Further, the length of the pipe which can be accommodated by the vessel 3 can be increased thereby better utilising the available space. When the vessel 3 is filled with a condensing medium such as water there is intimate contact between the condensing medium and the entire length of the condensing pipe 7 which aids making the condenser 1 more effective. In the case of a condenser 1 using a solid or gel-like condensing medium, the thermal coupling between the condensing pipe 7 and condensing medium may be reduced. Further, the even distribution of the pipe throughout the available interior of the vessel 3 helps to ensure that an even temperature is experienced along the length of the condensing pipe and no warmer regions develop which would reduce the efficiency of the device.

An important factor in providing an effective condenser 1 is the surface to volume ratio of the condensing pipe 7. Making the condensing pipe 7 narrower increases the surface to volume ratio of the pipe. However, this also increases the flow resistance within the pipe and makes it more difficult to breathe effectively. This may have a negative impact on the performance of the device if the patient is having difficulty breathing due to a cough.

Making the condensing pipe 7 wider decreases the flow resistance and makes passage of air easier. However, the flow surface to volume ratio is reduced and the air tends to travel down the centre of the condensing pipe 7 reducing the cooling effect further. Other factors to consider are the material of the condensing pipe 7 is made from and the thickness of the walls.

A further consideration with the size of the inner bore diameter is the drag of the airflow on the condensate. Having a narrow pipe will increase the drag factor on the condensate which will result in a faster collection of condensate and vice versa for a wider pipe.

The applicants have found that having a condensing pipe 7 with a helical configuration having three and a half turns spread over a height of 65 mm, an inner bore diameter of 9 mm and a wall thickness of 1.5 mm provides a fast fill rate without too much resistance. The condensing pipe 7 is made from polyamide. A typical value of thermal conductivity for polyamide is 0.25 W.rrf'.K^"1.

The vessel wall 15 has a first recess 23 running parallel to the longitudinal axis of the cylinder from top to bottom of the vessel 3 with respect to the base 27. The condensing pipe 7 exits the vessel 3 in the recess toward the top of the vessel 3 and is coupled to the inlet pipe 5 as a result of a moulding step or by press fitting it into place.

The vessel wall 15 has a second elongate recess running parallel to the longitudinal axis of the cylinder from top to bottom which houses the exhaust pipe 9 so as to be flush with the surface of the vessel wall 15. The exhaust pipe 9 forms the second end of the conduit and provides an exhaust for the breath which has been channelled from the inlet 13. The upper end of the exhaust pipe 9 is exposed to the atmosphere through the lid 19.

The portion of the second recess 25 which accommodates the exhaust pipe 9 is similar in size and shape to the outer diameter of the exhaust pipe 9.

At the bottom end of the exhaust pipe 9 is located a collection port. The collection port forms part of the exhaust pipe 9 and provides a means of attaching the container 11 which is located collinearly with and directly below the exhaust pipe 9. The portion of the second recess 25 which houses the container 11 is larger in order for the container 11 to be easily loaded by hand.

The container 11 is a cylindrical vessel which has a tapered portion at a first end and attaches to the collection port via a screw thread arrangement at a second end. The container 11 is of sufficient size to collect and store up to 5ml of condensate. The screw thread on the container 11 is suitable for attaching a cap so that the container 11 can be sealed for transport. Having a separate container 11 for collecting a sample of condensate and one which is arranged to have a cap fitted directly to it allows the container 11 to be small and easily transported.

The container 11 is translucent and includes graduation marks to provide an indication of the amount of condensate in the container 11. Having a translucent container 11 with graduations located on the outside of the vessel allows a clear view of the amount of condensate which has been collected. Thus, the duration of use can be effectively tailored to ensure the correct amount of condensate is collected.

The inlet pipe 5 forms the inlet to the conduit. The inlet pipe 5 also acts as a valve unit and a mouthpiece. The inlet has a pipe having a wider bore than the condensing pipe 7 and has an outside diameter of approximately 3 cm which allows a patient's lips to easily form a seal around the inlet pipe 5. The inlet pipe 5 is a valve unit in that it incorporates a one-way valve not shown. The one-way valve is a pressure responsive valve which includes a flexible membrane with a rigid support on the inlet side. The rigid support is in the form of a frame which lets air pass through from the inlet and deform the membrane, thereby opening the one-way valve. The rigid support prevents the membrane deforming when a net pressure is experienced from the outlet side of the valve.

The inlet pipe 5 is made from cardboard and the support frame and membrane from plastic. The simple construction of the valve unit and the cardboard construction of the inlet pipe 5 allows the valve unit to be inexpensively constructed and therefore disposable after a breath condensate has been collected. This is advantageous from a hygiene point of view as the mouthpiece is not at risk of harbouring harmful bacteria which can accumulate over time or of cross-contamination of germs between patients. An example of such a valve unit is manufactured by Clement Clarke International Ltd.

In another embodiment (not shown) the condensing pipe 7 includes an 'n' bend toward the first end of the condensing pipe 7. Thus, any fluid entering the condensing pipe 7 is prevented from flowing toward the collection port and container 11.

The inlet pipe 5 is inclined with respect to horizontal so that any liquid which enters the inlet from the patient mouth is substantially prevented from entering the condensing pipe 7. The condensing pipe 7 is coupled to the exhaust pipe 9 toward the bottom end of the exhaust pipe 9 on the outside of the vessel 3 within the second recess 25 and directly above the collection portion as described above.

To prepare the condenser 1 for use, a patient attaches a container 11 to the collection port and fills the vessel 3 with a cold condensing medium, for example, iced water. The condenser 1 is then placed on a flat level surface on the base 27 and is ready for use.

Alternatively, the condenser 1 can be filled with room temperature water from a household tap and placed in refrigeration unit. The refrigeration unit can be any suitable device for lowering the temperature of the water such as a refrigerator or freezer. Using a liquid condensing medium allows the condenser 1 to be transported in an empty state. Once the condenser 1 is with a patient, at home or in the work place for example, the condenser 1 can be filled with the condensing medium.

Water provides a cheap, safe and easily disposed of condensing medium which can be readily cooled in most work places and households using standard refrigeration equipment. Further, using a liquid condensing medium allows for intimate contact between the condensing pipe 7 and condensing medium which allows for a more effective thermal coupling between the two. Also, if the condensing medium is iced water it can be stirred during a collection of condensate allowing the condensing pipe 7 to be maintained at a uniform low temperature.

When the condenser 1 has been prepared for use a patient blows through their mouth into the inlet pipe 5. The patient's breath travels through the one-way valve, along the condensing pipe 7, into the exhaust pipe 9 and out of the condenser 1 via the second end of the conduit. The moisture in the breath, which may include pepsin, bile acids or bacterium condenses on the inner wall of the condensing pipe 7. Gravity causes the condensate to fall along the length of the condensing pipe 7 towards the collection port and into the container 11. This process is aided by the flow of breath within the condensing pipe 7.

After exhaling a breath, the one-way valve prevents air being drawn in through the outlet which would result in the condensate being contaminated by moisture from the air. Hence, the patient must breathe in through their nose or break the seal between their lips and the mouthpiece.

The patient carries on breathing through the condenser 1 until a required amount of condensate has been gathered. Typically, this would be about ImI of condensate which would take approximately 5 to 10 minutes to gather. Once sufficient condensate has been gathered, the container 11 can be removed from the collection port and a cap fastened to the container 11 to seal the condensate within. The condensate can then be stored in the fridge or sent straight to a clinic for analysis. After the procedure has been completed, the inlet pipe 5 can be discarded, the condensing medium removed and the condenser 1 washed ready for the next use.

Figure 3 shows a collection device 100 which is fitted to the wall 102 of the vessel of a condenser of the general kind that is described above with reference to Figures 1 and 2. The device is fitted to the conduit 104 which conducts the flow of a breath condensate.

The collection device includes a connector block 106 having a blind bore formed in it in which the end of the conduit 104 is received. The end of the conduit can be sealed in the bore in the block by means of a sealing material such as an adhesive or a mastic.

The blind bore in which the end of the conduit is received communicates with a through bore 108 which is arranged perpendicular to the blind bore. The through bore is arranged vertically when the condenser is in use so that one end 110 can function as a vent, through which gases in the patient's breath can be discharged.

The opposite end 112 of the through bore 108 directs the discharge of condensed liquid from the patient's breath into a collection vessel 114. The through bore has an extension tube 116 which is fastened to the connector block 106. The extension tube part of the collection device defines a nozzle 118 through which condensed liquid is discharged.

The collection vessel 114 is a vial. The vial is sized so that it is an interference fit around the end of the extension tube 116. The external surface of the extension tube is therefore a first step on the housing provided by the connector block 106 and the extension tube 116, over which the collection vessel 114 can be fitted. A latch arrangement, for example comprising detent and a recess, can be incorporated to retain the vial on the end of the tube. The vial is preferably made from a polymeric material which can be deformed elastically to facilitate fitting the vial on to the extension tube.

The vial 114 is tapered towards its closed end 120. This can facilitate removal of liquid from the vial using a suction device such as a syringe, especially when only a small volume of liquid is present in the vial. Figure 4 shows the vial 114 with a closure cap 122 which can be fitted on the open end of the vial, for example by means of a screw thread.

Figure 5 shows the collection device 128 which is similar to that described above with reference to Figure 3. The device is fitted to the wall 102 of the vessel of a condenser of the general kind that is described above with reference to Figures 1 and 2. The device is fitted to the conduit 104 which conducts the flow of a breath condensate.

As described above, the collection device includes a connector block 106 having a blind bore formed in it in which the end of the conduit 104 is received. The end of the conduit can be sealed in the bore in the block by means of a sealing material such as an adhesive or a mastic.

The blind bore in which the end of the conduit is received communicates with a through bore 108 which is arranged perpendicular to the blind bore. The through bore is arranged vertically when the condenser is in use so that one end 110 can function as a vent, through which gases in the patient's breath can be discharged. The opposite end 112 of the through bore 108 directs the discharge of condensed liquid from the patient's breath into a collection vessel 114. The through bore has an extension tube 116 which is fastened to the connector block 106. The extension tube part of the collection device defines a nozzle 118 through which condensed liquid is discharged.

The connector block 106 defines a step 130. The extension tube 116 extends beyond the step 130.

A collection vessel 132 includes first and second vial chambers 134, 136 which are divided by means of a wall 138. The vessel is sized so that it is an interference fit around the end of the second step 130. A latch arrangement, for example comprising detent and a recess, can be incorporated to retain the vessel on the step. The tube is preferably made from a polymeric material which can be deformed elastically to facilitate fitting the vial on to the extension tube. When the collection vessel is fitted to the step, the dividing wall 138 is located under the nozzle so that liquid discharged from the nozzle impinges on the wall and is divided between the first and second vial chambers 134, 136.

Figure 6 shows a sealing device 140 which can be fitted into the collection vessel 132 through its open face. The sealing device provides first and second sealing plugs 142, 144 which can fit into the first and second vial chambers 134, 136. The sealing plugs are an interference fit in the vial chambers so that seals are formed between the external wall surfaces of the plugs and the internal wall surfaces of the vial chambers, which can prevent transfer of collected liquid between the vial chambers in the vessel. A closure cap 146 which can be fitted on the open end of the collection vessel 132, for example by means of a screw thread.

Claims

CLAIMS:

1. A condenser for collecting breath condensate, comprising:

a vessel for holding a condensing medium;

a conduit having an inlet at a first end and an exhaust at a second end, in which the first and second ends are outside of the vessel; and,

a collection port outside of the vessel and in fluid communication with the conduit for collecting condensate,

in which a portion of the conduit is housed within the vessel and positioned so as to be submerged in the condensing medium when the condenser is in use and further arranged so that condensate which forms within the conduit can flow along the conduit under gravity to the collection port when the condenser is in use.

2. A condenser as claimed in claim 1 , in which a portion of conduit which extends between the vessel and the first end is inclined with respect to horizontal so that when the condenser is in use any liquid entering the first end with the breath will flow back into the inlet and not enter the portion of conduit contained within the vessel.

3. A condenser as claimed in claim 1 or claim 2, in which at least a portion of conduit within the vessel has a generally tortuous configuration.

4. A condenser as claimed in any one of claims 1 to 3, in which the conduit exits the vessel at a higher position than the collection port when the condenser is in use so that any condensate flows towards the collection port.

5. A condenser as claimed in any preceding claim, in which the vessel includes an opening for filling and emptying the vessel.

6. A condenser as claimed in claim 5, in which the opening is sealed with a sealing device which is operable by hand.

7. A condenser as claimed in any preceding claim, in which the conduit includes a one-way valve arranged to prevent a flow of air from the outlet to the inlet.

8. A condenser as claimed in claim 7, which includes a detachable valve unit which houses the one-way valve.

9. A condenser as claimed in claim 8, in which the valve unit can be detachably attached at the first end of the conduit and is arranged so as to provide a mouthpiece for the condenser.

10. A condenser as claimed in any preceding claim, which includes a container, in which the container includes a connecting portion for releasably coupling to the collection port and for accepting a cap which seals the container when the container is not coupled to the collection port.

11. A condenser as claimed in claim 10, in which the container is translucent and has graduation marks so that the amount of collected condensate can be seen during use.

12. A condenser as claimed in any preceding claim, in which the conduit includes a substantially vertical exhaust pipe on the outside of the vessel which is partially enveloped by a wall of the vessel so as to be cooled by the condensing medium.

13. A condenser as claimed in any preceding claim, which includes a frozen condensing medium within the vessel.

14. A condenser for collecting breath condensate, comprising:

a vessel for holding a condensing medium;

a collection port in fluid communication with the conduit for collecting the condensate, in which a portion of conduit which extends between the vessel and the first end is inclined with respect to horizontal so that when the condenser is in use any liquid entering the first end with the breath is urged back toward the inlet.

15. A condenser for collecting breath condensate, comprising:

a vessel for holding a condensing medium;

a conduit having a valve unit at a first end which acts as an inlet, and a second end which acts as an exhaust, in which the first and second ends are outside of the vessel; and, a collection port in fluid communication with the conduit for collecting the condensate,

in which the valve unit can be detachably attached to the first end of the conduit and includes a one-way valve and is arranged to provide a mouthpiece for the condenser.

16. A method of preparing a condenser for use, comprising:

providing the condenser as claimed in any of claims 1 to 10, and

at least partially filling the vessel with water to act as the condensing medium.

17. A method as claimed in claim 16, which includes the step of placing the condenser in a refrigeration unit to lower the temperature of the water.

18. A method as claimed in claim 17, which includes the step of removing the condenser from the refrigeration unit when the water is substantially frozen.

19. A method of collecting a condensate of breath in the condenser as claimed in any of claims 1 to 12, the method comprising the steps of:

filling the vessel with the condensing medium;

coupling a container to the connection port; and

breathing into the inlet for a predetermined period of time.

20. A method as claimed in claim 19, which includes the step of freezing the condensing medium prior to breathing into the inlet.

21. A liquid collection device which comprises:

a. a housing which has a stepped outer surface defining a first step and a second step,

22. A device as claimed in claim 21, which includes a first latch feature associated with the first collection vessel and the first step for retaining the first collection vessel on the first step.

23. A device as claimed in claim 22, in which the first latch comprises a detent on one of the first collection vessel and the first step and a recess on the other of the first collection vessel and the first step in which the detent can be received.

24. A device as claimed in claim 21, which includes a second latch feature associated with the second collection vessel and the second step for retaining the second collection vessel on the second step.

25. A device as claimed in claim 24, in which the second latch comprises a detent on one of the second collection vessel and the second step and a recess on the other of the second collection vessel and the second step in which the detent can be received.

26. A device as claimed in claim 21, in which the second collection device provides a plurality of chambers for collection of respective portions of the liquid which is discharged into the collection device through the nozzle.

27. A device as claimed in claim 26, in which the plurality of chambers are provided in the second collection device so that they are arranged symmetrically around the nozzle when the second collection device is fitted on to the second step.

28. A device as claimed in claim 26, which includes a sealing device which can be fitted into the second collection vessel through its open face, the sealing device providing a plurality of sealing plugs which can fit into respective ones of the chambers in the second collection vessel so as to prevent transfer of collected liquid between the chambers in the second collection vessel.

29. A liquid collection device which comprises:

a. a housing which has a stepped outer surface defining a step,

30. A device as claimed in claim 29, in which the plurality of chambers are provided in the collection device so that they are arranged symmetrically around the nozzle when the collection device is fitted on to the step on the outer surface of the nozzle housing.

31. A device as claimed in claim 30, in which the collection vessel provides a flow splitter which is positioned below the nozzle when the collection device is fitted on to the step on the outer surface of the nozzle housing, which splits the flow of liquid which is discharged from the nozzle between the plurality of chambers in the collection device.

32. A device as claimed in claim 29, in which a first one of the chambers contains a first reagent and a second one of the chambers does not contain the said first reagent.