US20070232952A1 - Method and Device for Collecting and Analyzing Exhaled Breath - Google Patents

Abstract

A method and device for collecting, storing, shipping, preparing and analyzing condensate derived from the exhaled breath of a user. Using the mouthpiece (15) of the device (10), a human subject inhales drawing air through a check valve (30).

Description

TECHNICAL FIELD
• The subject invention relates generally to a method and device for determining medical conditions, and, more particularly to a method and device for condensing, storing, transporting, degassing and analyzing exhaled breath.
BACKGROUND OF THE INVENTION
• Recent medical research indicates that human airway acidity and ammonia levels may be indicative of several events including the onset of asthmatic symptoms. Furthermore, this research indicates that the acidity measurements taken from a condensed sample of exhaled breath can be correlated to the actual conditions inside the airway.
• Many known devices for collecting condensate from a user's breath rely on gravity to form a condensate pool from which a sample for testing may be drawn. These types of devices require that condensate droplets become large enough to overcome water's naturally tendency to stick to the walls of a collecting tube. Then, when the amount of condensate eventually becomes large enough, a risk of loss of collected condensate sample through seepage out of the collection area may arise due to ineffective sealing of the collection area. Even when an adequate condensate sample had been collected, a risk of contamination occurred due to the necessity to transfer the sample from a collecting tube into test tubes or test devices. Moreover, where the collecting tube is not cooled in some way, condensate formation takes an inordinate amount of time. In some cases, the collecting tube is inserted into an ice bucket or may even be separately cooled by refrigeration systems in order to increase the amount and speed of condensate formation. In other cases, use of a Teflon® collecting tube has been tried to make the tube walls more slippery to enhance the speed and amount of condensate collected. All of these arrangements tend to be either expensive, complicated, ineffective, bulky, inefficient or time-consuming to use. In addition, other condensate collecting and testing devices generally do not provide the ability in a single device both to quickly and efficiently collect condensate while also delivering test substances such as gases or liquids into the condensate without contamination. Moreover, such devices are not typically portable and do not lend themselves easily to use by patients in their own homes. Another disadvantage of devices of the prior art is that they usually do not enable patients to collect condensate samples, prepare those collected samples for testing and then also perform certain tests themselves on the samples.
• What is needed is a device and method for condensate collection which solves the problems and shortcoming already described and, in addition, collects a greater amount of condensate from a given amount of exhaled breath in a shorter time than previously possible while also advancing the art by providing a multi-functional valve for use in such a condensate collection device that simultaneously assists in solving several of those problems.
SUMMARY OF THE INVENTION
• The present invention relates to a device and method for collecting condensate from air exhaled by a subject user. The device comprises a mouthpiece, a filter housing, a hollow condensate collecting tube, a movable valve inserted within the collecting tube, a cooling sleeve for placement over the collecting tube, means for moving the valve through the collecting tube and a removable airtight cap. In order to practice the method employing the device, the cooling sleeve is cooled to a temperature lower than that of the collecting tube prior to being slid thereover, air is inhaled by a subject user through the mouthpiece and exhaled through the movable valve into the collecting tube. After the passage of between about two and twenty minutes of breathing, the cooling sleeve is removed from around the collecting tube, the movable valve is advanced through the tube thereby wiping away condensate formed on the interior walls of the tube causing that condensate to collect in a pool around the valve. Thereafter, an airtight cap may be placed over the end of the collecting tube nearest the condensate pool in order to seal the collecting tube prior to storage and/or shipment to a testing location. At the test location, the airtight cap is removed and one or more gasses or liquids is introduced into the condensate through the unique structure of the valve as called for by the particular test to be performed on the condensate. In one embodiment of the device, gas is introduced into the condensate in order to remove carbon dioxide and permit the acidity level of the condensate to be reproducibly measured. Testing may be performed after removing samples of the condensate from the collecting tube or by means of a probe placed into contact with the condensate pool or by insertion of chemicals or chemically impregnated strips.
• It is a primary objective of this invention to provide a simple self-contained and portable device for efficiently collecting, storing and shipping condensate derived from the exhaled breath of a subject wherein the wettable components of such a device may be disposable.
• An additional objective of this invention is to provide a method for collecting condensate derived from the exhaled breath of a subject which is fast, simple, efficient and performable by nonprofessional personnel.
• A further objective of this invention is to provide a device and method in which condensate samples collected from the exhaled breath of a user may be both collected and subjected in situ to various laboratory tests, including ones for measuring pH levels, without the risk of contamination by exposure to influences external to a collecting tube.
• A yet additional objective of this invention is to provide a condensate collecting device which may be made available for use in a patient's home or workplace.
• It is still another objective of this invention to provide a device and multiple methods for removing carbon dioxide from condensate collected from the exhaled breath of a subject preparatory to measuring the acidity of such condensate.
• It is yet a further objective of this invention to provide a multipurpose valve structure having a unique elliptical shape for use within a tube for collecting condensate from the exhaled breath of a subject which makes the collection of condensate more efficient and also assists in preparing the collected condensate for laboratory testing.
• It is another objective of this invention to provide a device for degassing and/or for adding one or more gasses, liquids or other materials to a sample of condensate collected from the exhaled breath of a subject prior to or while performing laboratory tests on that sample.
• A further objective of this invention is to provide a device in which condensate may be collected, stored and transported in a single unit.
• Still another objective of this invention is to provide a condensate collecting device which makes septuple use of a valve within the device for preventing the admission of air from a condensate collecting tube during inhalation, admitting exhaled air into the condensate collecting tube, making airflow turbulent, swiping condensate off the interior walls of the tube, preventing efflux of condensate, retaining the condensate in a pool within the tube and channeling gasses or liquids into the condensate.
• Yet another objective of this invention is to provide a simple and efficient method for deaerating or degassing collected condensate.
• Still a further objective of this invention is to provide a malleable duckbill valve having an elliptical cross-section for placement within a non-malleable tube having a circular cross-section so that a seal is made in the duckbill valve without a pressure gradient across the valve.
• A yet additional objective of this invention is to provide a one-way malleable duckbill valve for placement within a condensate collecting tube which encourages turbulent airflow as a subject's exhaled breath passes through.
• Another objective of this invention is to provide a hollow duckbill valve permitting a mechanical seal to be obtained between the valve and the nose portion of a probe inserted into the hollow center of the valve.
• Yet a further objective of this invention is to provide a hollow duckbill valve incorporating one or more passageways through which gasses or fluids will flow when the valve is subjected to particular mechanical stresses.
• An additional objective of this invention is to provide a device with built-in protection for passersby against possible release into the atmosphere of microbes from the lungs of the user of the device.
• These and other objects, features and characteristics of the present invention, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a center cross-sectional view of the device of the invention;
• FIG. 2 is a center cross-sectional view of the individual components of the device of the invention in a disassembled state;
• FIG. 3 is a center cross-section view of the duckbill valve of this invention before insertion into a collecting tube along a plane perpendicular to the walls of a collecting tube;
• FIG. 4 is a center cross-sectional view of the duckbill valve of this invention along line A-A ofFIG. 3;
• FIG. 5 is a side view of the duckbill valve of this invention;
• FIG. 6 is a center cross-sectional view of a collecting tube into which a probe has been inserted behind a duckbill valve.
• FIG. 7 is a center cross-sectional view of a collecting tube into which gas has been introduced under pressure to degas/deaerate condensate;
• FIG. 8 is a schematic of equipment used in performing a second method of degassing/deaerating.
DETAILED DESCRIPTION OF THE INVENTION
• The device of the invention is intended to be used to condense the water normally exhaled in breath by a human subject and to gather this water in such a manner and in such volume that tests may be performed on the condensate. These tests include measuring acidity, ammonia concentration, as well as the concentration of other characteristics, chemicals and compounds of biologic interest. It may be used by an unskilled layperson, then sealed for transport to a laboratory where subsequent analysis may be performed. Alternatively, the device may also function as part of a home- or workplace-diagnostic device constructed to accept the device and perform the required measurements automatically. Additionally, it may be used in any setting without additional devices, by adding chemical reagents or test strips to detect chemical features and compounds of interest.
• For a better understanding of the invention, reference is now made toFIG. 1 of the drawings. This figure illustrates a center cross-sectional view ofinvention device10 in a dormant state prior to use.Device10 may be assembled manually from several principal components either before use or on site.Mouthpiece15 may be a generally tubular T-shaped device with three open projections. On one end,mouthpiece15 has a generallyoblong projection20 designed to be comfortably inserted between a subject user's lips. Theopposite end projection25 may be generally tubular in shape, is open to the atmosphere and includes acheck valve30 situated nearby for admitting ambient air from the atmosphere throughprojection25 into a subject user's mouth and lungs and for preventing an outflow of air throughprojection25 during the exhalation process.
• Projection35 is sized so as to be removably insertable into one end ofoptional filter housing40 and to be retained therein by virtue of friction between the walls of the exterior ofprojection35 and the walls of the interior of the end offilter housing40 into which it is inserted. Alternatively,projection35 can be placed in direct intimate contact with the inner or outer surface of collectingtube60, and retained there by virtue of friction. During exhalation by the subject user,check valve30 closes and forces exhaled breath to flow throughprojection35.
• Optional filter housing40 may comprise a tube-like structure open on both ends and having a filter compartment disposed in the approximate middle thereof separating the twoopenings45 and50 of the tube.Opening45 on one end offilter housing40 is sized so as to receiveprojection35 frommouthpiece15.Optional filter housing40 includes anoptional filter assembly55. In the preferred embodiment, the filter compartment and filter are circular and have a diameter of approximately four times the diameter of opening50, although other configurations and relative dimensions may be used. Different pore size of the filter might be chosen to limit passage of particles to sizes of particular interest. As particle size might relate to site of formation or other features relevant to the airway, this optional filtering is a useful feature.Optional filter assembly55 in general functions to remove larger particles from exhaled breath prior to itsentering collecting tube60 and, depending on the filter chosen, also serves to prevent egress of infectious particles in the atmosphere during exhalation. This feature protects passersby from microbes possibly release from the lung of a subject during use of the device. The structure ofmouthpiece15 serves a similar function by substantially reducing the number of salivary droplets which enteroptional filter housing40 or collectingtube60.
• Collectingtube60 is a straight plastic tube open on both ends with a circular cross-section and may have a length of between approximately 3 inches and 20 inches, preferably about 8.75 inches, and a diameter of approximately ½ inch and at most approximately 2 inches, preferably about 0.875 inches. With tubes smaller than ½ inch in diameter, exhaling becomes difficult for the subject user, while with tubes larger than 2 inches in diameter, condensation efficiency is low. Regardless of the exact dimension used, the diameter of collectingtube60 may be slightly smaller than that of opening50 infilter housing40, or alternatively smaller than that ofprojection35, so as to fit retentively within the corresponding neck offilter housing40 encompassingopening50 or withinprojection35. Alternatively, the diameter of collectingtube60 may be slightly larger than that of opening50, orprojection35, so that the neck offilter housing40 includingopening50, or alternativelyprojection35, may be securely and retentively inserted inside one end of collectingtube60. Collectingtube60 may also be constructed from other materials such as stainless steel, anodized aluminum, Teflon® and various types of plastics, and functions to collect, condense and store vaporized and aerosolized particles from breath exhaled thereinto.
• The exterior of collectingtube60 may incorporate a writable surface for subject users to identify samples with an indelible marker or other suitable writing instrument. Alternatively, a label with named fields for information could be used or bar coding or other scannable data with identifying or destination information could be imprinted on collectingtube60 prior to delivery.
• Duckbill valve65 is inserted into the lower end of collecting tube60 a distance of approximately ½ inch and remains in a closed position when the device is not in use.Duckbill valve65 may be comprised of rubber or rubber-like elastomeric materials, or plastics which approximate or behave as elastomers, and functions to prevent the passage of air from theend75 of collectingtube60 exposed to the atmosphere during the inhaling process described below usingmouthpiece15 and to admit breath from a subject user into collectingtube60 during the exhaling process, also described below. Its structure and function also prevent the condensate collected in collectingtube60 from escaping during and after the breath condensate collection procedure.
• Coolingsleeve70 is a hollow tube sized to slide over collectingtube60 and place the inner walls of coolingsleeve70 into physical contact or at least close physical proximity with collectingtube60 shortly prior to and during practice of the method of this invention. Coolingsleeve70 may be slightly shorter than collectingtube60 and, when in place, should not extend to a greater height than collectingtube60. Coolingsleeve70 may be constructed of a material such as aluminum or any high specific heat, durable, reusable material which does not deteriorate when wet and tends to retain and maintain a low temperature when cooled. In one preferred embodiment, the cooling sleeve might be a container in which chemicals can be mixed that create an endothermic reaction, thus providing substantial cooling.
• When placed in position surrounding collectingtube60 as required for practice of the method of this invention, coolingsleeve70 functions to draw heat from the inner surface of collectingtube60, as will be described below, so as to accelerate the condensing process occurring within the tube. In the preferred embodiment, when properly positioned, collectingtube60 extends on one open end somewhat beyond the corresponding end of coolingsleeve70 and terminates approximately coequally with the end of coolingsleeve70 on the other end. Alternatively, collectingtube60 may extend on the other end beyond the corresponding end of coolingsleeve70 so as to be insertable into opening50 ofoptional filter housing40.
• FIG. 2 provides a center cross-sectional view along a center vertical axis ofdevice10 of all of the principal components ofdevice10 in a disassembled state from the component positioned vertically the lowest,mouthpiece15, to that positioned highest,airtight cap80.Airtight cap80 is provided as part ofdevice10 for secure, retentive placement overopen end75 of collectingtube60 after the method of the invention has been practiced but prior to storage and/or shipment of collectingtube60 to a laboratory for analysis of condensate. Together with normally closedduckbill valve65,airtight cap80 seals the condensate sample within collectingtube60 and prevents any fluid exchange with matter or air outside of collectingtube60.Airtight cap80 may be formed from malleable plastic or another material, but its composition is not critical to practice of the invention so long as it provides a secure seal withopen end75 when placed thereover. Collectingtube60,duckbill valve65 andairtight cap80 together form a disposable assembly which may be prepackaged for a single use ensuring no complicated cleaning or contamination issues arise from use ofdevice10.
• Duckbill valve65 is a critical component ofdevice10. It is uniformly constructed from rubber or a material with resilient, rubber-like properties.FIG. 3 represents a cross-sectional view ofduckbill valve65 taken below valve leaves100, shown inFIGS. 4 and 5 below, prior to its insertion into collectingtube60 along a plane perpendicular to the walls of collectingtube60 wereduckbill valve65 inserted therein. Note that since collectingtube60 has a circular cross-section, as indicated by dotted line85, one would normally expectduckbill valve65 to have a correspondingly circular cross-section. However, its cross-section is uniquely elliptical so that, when forced into a circular shape, such as in the circular bore of collectingtube60, it will deform disproportionately so as to create a complete seal between the valve leaves100 ofduckbill valve65, shown inFIGS. 4 and 5 below. This structure provides a seal even at zero reverse differential pressure and is dissimilar from duckbill valves known in the art that require pressure gradients to assure complete valve closure. This feature is particularly valuable in this invention since it assists in providing a secure and long-lasting seal to keep condensate inside collectingtube60 during long-term storage and/or transport.
• FIG. 4 additionally shows a center cross-sectional view ofduckbill valve65 across the center of bothleaves100 of the valve on a plane parallel to the walls of collectingtube60 along line A-A ofFIG. 3.Leaves100 incorporatemalleable structures105 with which they are attached tosection115 of the body ofduckbill valve65. An opening may be formed along the slit where leaves100 meet each other. The center ofduckbill valve65 is hollow. Due to the elliptical valve shape constrained in a circular structure, leaves100 are biased to a closed position alongmalleable structures105. Thus, when a subject user is inhaling, leaves100 prevent the admission of air intomouthpiece15 through collectingtube60. However, during exhaling, leaves100 open along the slit where they meet and admit air into collectingtube60. The structure ofduckbill valve65 also results in the creation of turbulence during exhalation which helps to improve condensation efficiency along the walls of collectingtube60. For example, shallow breathing through anempty collecting tube60 is not very turbulent. But when shallow breathing is directed throughduckbill valve65, leaves100 open only a little , and leaves100 vibrate, proving that there is turbulent airflow. When heavier breathing at a higher velocity occurs, leaves100 open further, preventing increased resistance from occurring while still encouraging turbulence.
• During exhalation, particles of airway lining fluid are ripped off the airway wall and carried in the humid airstream out of the body. When the ambient temperature declines below the dew point (i.e. upon egress from the mouth), the gas phase water vapor/water molecules attach themselves onto the small aerosolized particles, enlarging the particles and increasing the chance by inertia that they will strike nearby surfaces such as the interior walls of collectingtube60, especially where there is turbulent airflow. Thus, the creation of turbulent airflow byduckbill valve65 is another important feature since it allows fluid particles to impact the inner surface of collectingtube60, encouraging fluid collection.
• Duckbill valve65 incorporates a notched area around its exterior into which is tightly and sealingly fitted a rubberizedTeflon® ring110 having an exterior diameter just slightly greater than that of the minor axis of the ellipse formed by the footprint ofduckbill valve65 when at rest. Therefore, whenring110 is in place, it is biased and makes sealing contact with the interior walls of collectingtube60.Ring110 may also be composed of materials other than Teflon® such as polypropylene, so long as it functions in the same way as does the Teflon® ring described. This ring serves three functions. First, it is a wiper which, as discussed below, removes condensation from the interior walls of collectingtube60 after the subject user has completed exhalation. Second, it maintains the alignment ofduckbill valve65 in an orthogonal orientation to the walls of collectingtube60. Finally, it functions as a valve itself as discussed next.
• The lower part ofduckbill valve65 consists of twogeneral sections115 and120. There are one or morehollow passageways125 running diagonally upward from aninitiation point130 within the interior hollow area ofduckbill valve65 throughlower section120 into the circular notched area formed on the exterior ofduckbill valve65. Note that only onepassageway125 is required for subsequent degassification or deaeration steps, although as many as ten such passageways may be preferred depending on the circumstances. Also, note that such passages are not circumferential around the valve, so that in a slightly different cross section, they would not be seen at all, revealing thatupper section115 is confluent withlower section120 throughout most of the valve structure.
• Lower section120 tends to be stiffer thanupper section115 since there is a greater volume of material inlower section120 and, unlikesection115, it is constrained from movement by direct contact with the walls of collectingtube60. Thus, when gas pressure is introduced throughpassageways125 againstTeflon® ring110,section115 has a tendency to deflect allowing the gas to pass aroundTeflon® ring110 and into the portion of collectingtube60 aboveduckbill valve65. Firstinner ring135 is a bump-like ridge extending around the hollow inner portion ofduckbill valve65 at approximately at its base. Secondinner ring140 is another bump-like ridge extending around the hollow inner portion ofduckbill valve65 at a point displaced slightly aboveinitiation point130 of anypassageway125. The importance of these features will become clear in conjunction with discussion of the degassing of collectingtube60 discussed below in conjunction withFIGS. 6 and 7.
• FIG. 5 shows a side view ofduckbill valve65 along a plane rotated90 degrees around a vertical axis from the view shown inFIG. 4. This represents a side view along the plane represented by the line B-B ofFIG. 3. As is evident, the valve has a bilateral structural symmetry.
• The method of this invention is practiced afterdevice10 has been assembled as described above and shown in the drawings. Although not a required assembly step, coolingsleeve70 may be placed in a freezer for approximately 20 to 30 minutes prior to use since the larger the difference in temperature between the walls of coolingsleeve70 and collectingtube60 the faster and more efficiently condensation will occur and the greater the amount of condensate produced will be. It is required, however, that coolingsleeve70 be somewhat cooler than collectingtube60 prior to beginning to practice the method so that the condensation process will be enhanced. The coolingsleeve70 can be cooled to various temperatures depending on need. When chilled to −20 degrees C. or below, for example, the exhaled fluid and vapors collect as frozen solid material on the inside of the collectingtube60, a feature advantageous for the assays of compounds unstable in liquid phase water, as would be the case with a cooling sleeve chilled to a somewhat higher temperature. Temperatures obtained in a home refrigerator or home freezer are satisfactory for excellent liquid phase fluid collection for most purposes, including assessing pH. Throughout practice of the method until after installation ofairtight cap80, it is preferable to keep collectingtube60 reasonably perpendicular to the ground.
• As the first step in the method, referring again for visual reference toFIG. 1, a subject user placesprojection20 ofmouth piece15 between his or her lips and inhales.Duckbill valve65 remains closed due to the bias offlaps100 and air is admitted intomouthpiece15 fromprojection25 throughcheck valve30. The subject user then exhales. The stream of exhaled breath is blocked from egress out ofprojection25 bycheck valve30 and follows the path of least resistance upward throughprojection35 intooptional filter housing40, throughoptional filter assembly55 and intoduckbill valve65 where leaves100 are caused to separate and open due to the air pressure allowing the exhaled breath to enter collectingtube60. When exhalation is complete, leaves100 return to their naturally biased closed position.
• Due to the temperature differential between the exhaled breath and the air inside and the walls of collectingtube60, the temperature of which has been lowered due to the contact or close proximity of collectingtube60 with coolingsleeve70, condensation begins to form on the walls of collectingtube60 as exhaled breath traverses the length of collectingtube60. Due to the force of gravity, some condensate tends to run down the walls of collectingtube60 to form a pool aroundTeflon® ring110 at the base ofduckbill valve65. Most remains in place as tiny droplets on the inner wall of collectingtube60. Meanwhile, the remaining, now dehydrated, exhaled breath is allowed to escape fromopen end75 of collectingtube60 which remains open to the atmosphere. In general, between about two and twenty minutes of breathing will be performed to provide sufficient sample. In preferred embodiments, a set number of breaths, for example ten, will be sufficient.
• While keeping collectingtube60 perpendicular to the ground and the end of collectingtube60 containingduckbill valve65 nearest to the ground, coolingsleeve70 is slid away from collectingtube60. Then, while keeping collectingtube60 reasonably perpendicular to the ground and the end of collectingtube60 containingduckbill valve65 nearest to the ground,optional filter housing40 and collectingtube60 are manually pulled apart and disengaged from each other. Alternatively,projection35 and collectingtube60 are manually pulled apart, if the filter is not employed.
• A piston and rod combination is provided as an accessory todevice10. The piston is designed to fit within collectingtube60 and to be placed into uniform flat contact with the entire bottom surface ofduckbill valve65 after coolingsleeve70 and collectingtube60 are separated. The rod may be attached to the piston in advance or after insertion of the piston into collectingtube60. Pressure is then exerted againstduckbill valve65 by means of the rod and piston combination movingduckbill valve65 vertically upwards through the inside of collectingtube60 towardsopen end75 thereof. Due to the wiper action ofTeflon® ring110, tiny drops of condensate clinging to the walls of collectingtube60 are collected into a small pool building up around and ahead ofTeflon® ring110. The rod and piston combination are removed from collectingtube60 whenduckbill valve65 has been moved to within approximately two inches fromopen end75 of collectingtube60. At this point,airtight cap80 is securely and sealably installed overopen end75 so that collectingtube60 may be stored and/or shipped to another location, such as a laboratory. By movingduckbill valve65 towardsopen end75, the volume of air within collectingtube60 is reduced for storage purposes, and the surface area of the condensate which might come into contact with contaminating air is minimized. Alternatively, the movement ofduckbill valve65 within collectingtube60 can be deferred until after transport. When desired, this piston and rod combination may also serve the additional purpose of providing a degassing mechanism, as discussed below.
• Once sealed collectingtube60 has arrived at a testing location, which may even be at a subject user's home or workplace if diagnostic equipment is stationed there, the collected condensate may be subjected to a variety of treatments depending on the assay desired to be undertaken. Where acidity of the condensate is to be tested or of concern, a degassing or deaeration of the condensate is performed. Degassing or deaerification is a purification process which removes carbon dioxide from the condensate and allows for more accurate and stable measurement of acidity or pH levels. Without this deaeration step, the carbon dioxide in air diffuses in and out of the condensate, changing its pH. This can occur simply as the result of a person breathing over the top of collectingtube60 when it is open. Thus, any gas that does not contain carbon dioxide or another acid may be used for degassing prior to pH measurement including, but not limited to, argon, helium, oxygen or air that has had carbon dioxide removed from it with a carbon dioxide trap. Alternatively, elimination of carbon dioxide could be accomplished chemically by adding an enzyme and substrate that consumes carbon dioxide and a proton (acid) in a one-to-one ratio.
• In order to perform degassing on the condensate in sealed collectingtube60, any one of three methods may be used. First, a probe, which may also serve as the piston discussed previously, may be inserted through the bottom open end of collectingtube60 and advanced until its further progress is blocked by contact withduckbill valve65 whereupon pressure is exerted until the nose portion of the probe is seated withinduckbill valve65.Airtight cap80 should then be removed. Reference is now made toFIG. 6 where a partial cross-sectional view of collectingtube60 is shown in which probe200 has been seated withinduckbill valve65. The nose portion ofprobe200 has a diameter slightly wider than the diameter of firstinner ring135. In order to seatprobe200, the nose portion is pushed into the hollow center ofduckbill valve65 until further forward movement is impeded by contact between the wider shoulder portion ofprobe200 andlower section120 ofduckbill valve65. At this point, firstinner ring135 has been compacted horizontally so as to form a pressure seal around the nose portion ofprobe200 belowpassageway125, while secondinner ring140 has also been compacted horizontally to form another pressure seal around the nose portion ofprobe200 abovepassageway125.
• Probe200 includes a hollow, multipath,cylindrical passageway205 including one ormore openings210 which exit the nose portion ofprobe200 at a height equivalent to the location ofinitiation point130 withinvalve65. Specifically, the location ofopenings210 lies between firstinner ring135 and secondinner ring140 insidevalve65. Argon or another carbon dioxide-free gas may be introduced under pressure throughpassageways205 ofprobe200. As shown inFIG. 7, the pressurized gas follows the path indicated by the dotted lines accompanied by arrows. The mechanical pressure seals formed byinner rings135 and140 against the nose portion ofprobe200 are considerably stronger than the seal produced byring110 against the circular notched area formed on the exterior ofduckbill valve65. Due to the positioning of passageway(s)125, they are not subjected to stress andexit duckbill valve65 at a point where the valve is not subjected to mechanical stress. As a result, the pressurized gas introduced throughpassageways205 follows the unstressed portion ofduckbill valve65, orpassageways125.
• As explained above,upper section115 tends to deflect when exposed to pressurized gas thereby creating a passageway for the gas to circumventTeflon® ring110 and escape into and bubble throughcondensate215 pooled in collectingtube60. Carbon dioxide dissolved in condensate diffuses into the bubbles of the carbon dioxide-free gas. After having passed throughcondensate215, the gas, now containing carbon dioxide derived from the condensate is allowed to escape into the atmosphere from collectingtube60 through now uncappedopen end75. Argon, being heavier than air, assists in preventing carbon dioxide from the ambient air from recontaminating the sample.
• An alternative structure forduckbill valve65 could omitring110 andhollow passageways125 andprobe200. In this case, gas pressure applied into collectingtube60 belowvalve65 by a positive pressure manifold would causeleaves100 induckbill valve65 to open admitting the gas into the condensate pool. The pressure of the gas would prevent condensate from seeping back into the open valve as would the closing bias ofleaves100 when the application of gas pressure terminated. One example of such a manifold would accept the lower end of collectingtube60, make an airtight seal with it and hold it in a vertical position while forcing gas into the tube for degassing. The manifold could interface with available gas plumbing or hoses connecting to a source of gas.
• The third method for degassing is shown in schematic form inFIG. 8. Pursuant to that method,airtight cap80 is removed from collectingtube60 which is then inserted into a device enclosing both ends of the tube. A hard vacuum is applied to both ends of the tube and the area of the tube below the duckbill valve is periodically opened to the atmosphere or to a carbon dioxide-free gas source. This procedure draws the carbon dioxide out of the solution in the condensate and allows it to be removed through the vacuum pump.Open end75 of collectingtube60 is placed inmanifold300, while the opposing end of the tube is placed inmanifold305.Vacuum pump310 is attached to openend75 by means ofmanifold300, whilevacuum gauge315 is attached to the opposing end of collectingtube60 by means ofmanifold305. Three-way, two-position solenoid valve320 is connected betweenvacuum pump310 andvacuum gauge315. Anadjustable orifice325 functioning withsolenoid valve320 is used to regulate the surge of air or other gas into the lower chamber of collectingtube60, and afilter330 is connected toadjustable orifice325 in order to ensure that no contaminants are introduced into the system. A human may be used to determine when to vent the lower part of collectingtube60 throughmanifold305 based on readings fromvacuum gauge315. Alternatively, a vacuum transducer coupled to a controller could be substituted for the vacuum gauge to automate the venting of the collecting tube by energizingsolenoid valve320 pursuant to a control algorithm.
• Certain tests might require passing other gases through or adding liquids or solids to the condensate. The same structures and procedures described above may be used to collect, transport, store and otherwise accomplish these tasks. Other tests that might be performed on collected samples include assays for inorganic and organic compounds, including but not limited to amino acids, volatile organic compounds, lipids and lipid oxidation products, armmonia, simple ions such as sodium and chloride, strong and weak acids and bases, surfactant, inflammatory mediators including cytokines and leukotrienes, oxidation and nitration products including hydrogen peroxide and nitrotyrosine, nucleic acids such as DNA and RNA, endotoxin and other microbial products. In addition, it is important to note that the entire cycle of sampling, storage, degassing and much, if not all, of the analysis is done withindevice10. Transfer of fluid to other apparati is not generally required. Furthermore, all wetted parts ofdevice10 can easily be made disposable to minimize contamination, cleaning, and cost. The device is fully portable and can be used even by small children. In an alternative structure, a filter may be positioned on top of collectingtube60 to prevent infectious particles from escaping while allowing larger particles to be trapped in collectingtube60. Finally, the device and method of this invention may be adapted for animal use in veterinarian applications.
• When the collected condensate sample has been prepared for testing as required, either by degassing or by addition of gas, liquid or another substance, a probe may be inserted throughopen end75 to remove a sample of the condensate for testing purposes. Alternatively, the testing can be performed directly within collectingtube60. For example, after degassing, a calibrated pH probe attached to a pH meter can be immersed in the collected sample to determine sample pH. The sample may be removed by contact with the probe or by suction action through the probe. In other embodiments, chemicals can be added, or a chemically impregnated reagent strip can be immersed into the sample for colorimetric determination of pH and other characteristics and substances.
• The foregoing invention has been described in terms of the preferred embodiment. However, it will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed method and system without departing from the scope or spirit of the invention. The specification and examples are exemplary only, while the true scope of the invention is defined by the following claims.

Claims (31)

1) A portable device for collecting, sporting, storing and processing condensate from air exhaled thereinto comprising:

a mouthpiece having three projections by means of which air is inhaled and exhaled;

an optional filter housing having two openings separated by a filter assembly the first one of which is interconnected with a first projection of said mouthpiece;

a hollow condensate collecting tube having two open ends and a circular cross-section interconnected at a first open end with the second opening of said filter housing;

movable valve means deformable and sealingly inserted between the interior walls of said collecting tube near the first open end thereof for preventing the admission of air during inhalation; admitting exhaled air into said collecting tube, making airflow therethrough turbulent, swiping condensate off the interior walls of said collecting tube, preventing efflux of condensate, retaining the condensate in a pool and channeling gasses or liquids into the condensate;

hollow removable cooling sleeve means slidably placed over said collecting tube wherein said cooling sleeve means has an interior diameter only slightly greater than the exterior diameter of said collecting tube so that the interior walls of said cooling sleeve means are in at least close physical proximity to the exterior walls of said collecting tube for drawing heat from the inner surface of said collecting tube to accelerate the condensing process; and

advancement means removably insertable into the first open end of said collecting tube behind said valve means for pushing said valve means upwards towards the second open end of said collecting tube.

2) The device ofclaim 1 wherein carbon dioxide is removed from the condensate preparatory to testing the acidity level of the condensate by channeling one or more gases through said valve means into the condensate.

3) The device ofclaim 2 wherein the gas channeled through said valve means is one or more selected from argon, helium, oxygen or air that has had carbon dioxide removed from it with a carbon dioxide trap.

4) The device ofclaim 1 further including airtight cap means for providing a removable seal over the second open end of said condensate collecting tube after removal of said advancement means from said collecting tube prior to storage and/or shipment to another location.

5) The device ofclaim 1 wherein a second projection of said mouthpiece includes check valve means for admitting air during inhalation and inhibiting the egress of air during exhalation

6) The device ofclaim 1 wherein said valve means has valve leaves and a generally elliptical cross-section which is deformed into a circular shape upon insertion into said collecting tube.

7) The device ofclaim 6 wherein by deforming said valve means a complete seal is created between the valve leaves.

8) The device ofclaim 7 wherein said valve means is generally hollow and includes an upper section of lesser mass and a lower section of greater mass and wherein the boundary between the upper and lower sections is generally defined and separated by one or more pairs of hollow passageways formed in the body of said valve means each of which passageways extends from near the bottom of the hollow interior of said valve means diagonally upward to the exterior of said valve means exiting into a generally semi-circular notch formed at a point above the bottom of said valve means displaced between approximately one-eighth and one-quarter of the length of said valve means away from the bottom thereof

9) The device ofclaim 8 wherein resilient ring means are seated in the notch in said valve means for maintaining said valve means in an orthogonal orientation with the interior walls of said collecting tube, for wiping the inner walls of said collecting tube as said valve means is pushed upwardly therethrough and for deflecting in reaction to force exerted upon it by a pressurized substance flowing through the hollow passageways within said valve means.

10) The device ofclaim 1 wherein said cooling sleeve means has a lower temperature than said collecting tube.

11) The device ofclaim 10 wherein said cooling sleeve means tends to maintain a low temperature.

12) The device ofclaim 11 wherein said cooling sleeve is comprised of aluminum.

13) The device ofclaim 11 wherein said cooling sleeve is comprised of a material having a high specific heal

14) The device ofclaim 1 wherein said cooling sleeve is between approximately one-quarter and one-half inch shorter than said collecting tube.

15) The device ofclaim 1 further including degassification means for forcing pressurized gas through the condensate.

16) The device ofclaim 15 wherein said degassification means is a physical probe which is inserted into the open bottom end of said collecting tube and extended therethrough until brought into physical contact with the bottom of said valve means.

17) The device ofclaim 15 wherein said degassification means is a single positively pressurized manifold into which the open bottom end of said collecting tube is retainably inserted and through which said collecting tube is maintained in a vertical position.

18) The device ofclaim 15 wherein said degassification means comprises a first manifold into which the open bottom end of said collecting tube is retainably placed and a second manifold into which the open top end of said collecting tube is retainably placed wherein both ends of said collecting tube are subjected to a mechanized vacuum and wherein further said second manifold is periodically opened to atmospheric pressure.

19) The device ofclaim 1 wherein the structure of said mouthpiece substantially reduces the number of salivary droplets which are exhaled by a subject from entering said optional filter housing or said collecting tube.

20-27. (canceled)

28. A device for collecting condensate from breath exhaled thereinto comprising:

mouthpiece means for admitting and directing both inhaled and exhaled breath;

a hollow condensate tube having two open ends connected on one end to said mouthpiece means;

movable valve means sealingly inserted between the interior walls of said tube for preventing the admission of air during inhalation, controlling the admission of exhaled breath into said tube during exhalation and swiping condensate off the interior walls of said tube as it is moved along said tube.

29. The device ofclaim 28 wherein said valve means further makes airflow through said tube turbulent, prevents efflux of condensate, retains condensate in a pool and channels gasses or liquids into the condensate.

30. The device ofclaim 28 further comprising cooling means for cooling said tube and for accelerating the formation of condensate.

31. The device ofclaim 30 wherein said cooling means further comprises a pre-chilled hollow, tubular sleeve placed in close physical proximity to the exterior walls of said tube.

32. The device ofclaim 31 wherein said cooling means is constructed from aluminum or any high specific heat, durable, reusable material which does not deteriorate when wet and tends to retain and maintain a low temperature when cooled.

33. The device ofclaim 31 wherein said cooling means is a container in which chemicals can be mixed that create an endothermic reaction.

34. The device ofclaim 28 further comprising advancement means for causing said valve means to move from one end of said tube to the other.

35. The device ofclaim 34 wherein said advancement means is a rod and piston arrangement.

36. The device ofclaim 28 wherein said tube is constructed from one or more of the group of materials consisting of plastic, stainless steel, anodized aluminum, and Teflon®.

37. The device ofclaim 28 wherein said valve means is constructed from one or more of the group of materials consisting of rubber, rubber-like elastomeric materials, and plastics which behave as elastomers.

38. The device ofclaim 28 wherein the device is disposable.

Images