WO2002001182A1

WO2002001182A1 - Alveolar breath sampling container

Info

Publication number: WO2002001182A1
Application number: PCT/AU2001/000759
Authority: WO
Inventors: Ian Donald Reilly; Fernando Agostinho Peixoto Dias; Phillip James Duncan; Vu Khai Co
Original assignee: Invetech Operations Pty Ltd
Priority date: 2000-06-26
Filing date: 2001-06-26
Publication date: 2002-01-03
Also published as: AUPQ838000A0

Abstract

A breath sampling and handling apparatus comprises an inflatable airtight bag (1) has an air communicating aperture (2) which is fitted with an air transmitting tube (3) for moving air into and out of the bag. The tube comprises a primary air transmitting tube (4) which provides communication between an opening at the outer end thereof and the bag and a co-axial outer ventilating tube (5) which provides communication between the interior and exterior environment ofthe bag. A cap (13) is movable axially on the outer end of the primary tube and is movable from a first position opening said tubes and a second position sealing said tubes. The air transmitting tube includes a bayonet fitting (7) facilitating connection of the apparatus to a measuring instrument in a manner whereby said ventilating tube is sealed and said primary tube is open to said instrument to facilitate extraction of air from the bag.

Description

ALVEOLARBREATHSAMPLING CONTAINER

Introduction to the Invention

This invention relates to sampling containers or bags for receiving and handling a users breath samples. In particular the invention relates to an improved helitosis sample bag adapted to sample alveolar breath. Background to the Invention

Sampling bags for the use in capturing the expelled breath of a patient and the handling thereof, including transport to suitable measuring instrumentation, are well known and generally take the form of small inflatable bags, which are blown into by the user until the bag is full, at which time the bags are sealed and transported for use in conjunction with the suitable measuring instrument. One of the difficulties encountered with prior art breath sampling bags is the ability of the bag to sample alveolar air from the deeper part of a patients lungs. In order to sample such air, it is necessary for the user to expel about 150 ml of the lungs workable volume to clear the larger air passages where no gas exchange occurs. This is either difficult or impossible to reliably effect with the use of prior art breath collecting bags. One object of the present invention is to provide an improved breath sampling bag enabling a patient to breath into the bag whilst effecting a recycling of the patients breath until air is reached at which point the bag can be sealed thereby securing a reliable sample of air which has not been diluted with the more superficial air in the patients larger air passages.

A further problem with currently available air sampling bags involves the interface between the bag and the breath testing instrumentation, which does not allow for the expellation of residual air in the pathway of the instrument, which provides a source of error and contamination in current handling techniques.

Another object of the invention is to provide an air sample bag having features which improve the purity of sample transmission from the bag to a measuring instrument. Statement of Invention

In one aspect the invention provides a breath sampling and handling apparatus comprising an inflatable and airtight bag, said bag having an air communicating aperture fitted with an air transmitting tube for moving air into and out of said bag, said air transmitting tube including a primary air transmitting tube and an air ventilating tube; and a cap movable from a first position opening said tubes to a second position sealing said tubes, wherein said primary air transmitting tube provides a direct line of communication between an opening or orifice at an outer end thereof and said bag, and wherein said air ventilating tube provides a line of communication between the interior and exterior environment of said bag such that the user can continuously breathe into said bag until alveolar air is expelled therein and wherein said cap can be moved to seal said primary and ventilating tubes thereby sealing alveolar air in said bag.

The invention will be described in more detail with reference to the attached drawings which show one particular embodiment and wherein: Figure 1 is a plan view of the sample bag;

Figure 2 is an exploded view of the sample bag;

Figure 3 is a schematic view of the sample bag partly inserted into a measuring instrument;

Figure 4 is a schematic view of the sample bag fully inserted into the measuring instrument; and

Figure 5 is a schematic view of the sample bag partly removed from the measuring instrument. Detailed Description of the Invention

Referring firstly to Figures 1 and 2, the invention in one aspect, provides a breath sampling and handling means including an inflatable airtight bag 1 for receiving and sampling a patients breath. The bag 1 has an air communicating aperture 2 through which air can pass into and out of the bag. The air communicating aperture is fitted with an air transmitting tube 3 for moving air into and out of the bag. The air transmitting tube allows simultaneous two way movement of air into and out of the bag by way of a primary air transmitting tube 4 and a co-axially located air ventilating tube 5. The free or second end 6 of the air transmitting tube 3 is formed as a bayonet fitting 7 having a housing 8 fitted with peripheral lugs 9. The bayonet fitting provides a plurality of outlet air holes 10 which communicate with the ventilating tube 5 allowing air from the bag 1 to ventilate to the outside atmosphere. An inner O-ring 14 is provided for sealing the outlet air holes 10 as will become apparent hereinafter. The bayonet fitting 7 further extends to an outwardly projecting tube 11 which terminates in an orifice 12 communicating with the primary air transmitting tube 4 and providing a conduit for air movement into the bag 1 via the primary air transmitting tube. The tube 11 of the bayonet 7 is provided with a removable sliding cap 13. The cap 13 is provided for slidable engagement on the tube 11 and can be moved axially on the tube from a first position opening the outlet air holes 10 to a second position where the cap rim engages the outer surface of the tube 11 sealing the orifice 12 and the outlet air holes 10. The tube 11 is also provided with an outer o-ring 15 proximate to the orifice 12 which is adapted to cooperate with the cap to form a seal of the primary air transmitting tube 4. The user inflates the bag 1 by blowing into the orifice 12 of the air transmitting tube 4, thereby causing air to move into the primary transmitting tube 4, such that once the bag is initially full of the patients breath, continued breathing by the patient causes the current contents of the bag to flow in the ventilating tube 5 and exit the device by way of the outlet holes 10.

In use, a patient takes the breath sampling bag of the invention, holding it lightly with a finger grip around the air transmitting tube region 3. The patient then places the orifice 12 at the bayonet plug end into their mouth, and begins blowing. The patients breath passes through the orifice 12, into the primary transmitting tube 4 and into the bag 1. When the bag is full of the patient's breath, the patient continues to blow and the subsequent air pressure in the bag, causes the initial contents of the bag, to return to the outside environment by way of the ventilating tube 5, which passes air co-axially and simultaneously back down the air transmitting tube 3, to exit to the outside environment via the outlet air holes 10. In the process of applying a continuous stream of air, the patient continues to blow until their lungs are exhausted, thereby ensuring that the circulation of the patient's breath results in alveolar breath, being finally captured in the bag. The patient then squeezes the central part of the air transmitting tube, which takes the form of a santoprene finger grip 20, thereby temporarily closing off both ventilating and primary air transmitting channels, causing a temporary seal to the bag. Whilst squeezing the finger grip 20 the patient places the cap 13 on the tube 11 and pushes the cap 13 forward along the tube 11 (that is, towards the bag), thereby sealing both the ventilating channel and the primary air transmitting channel and accordingly, permanently sealing the patient's breath in the bag. An additional feature of the bag of the invention, includes the presence of desiccant 16 which ensures that vapour in the patient's breath is absorbed and does not interfere with the carbon dioxide reading of the patient's breath.

At this stage, the sample bag is ready for transport and use in conjunction with an air measuring instrument. During transport, the desiccant 16 held in the bag absorbs the water vapour present in the breath sample, without absorbing any of the carbon dioxide. The removal of the water vapour prevents the water condensing in the bag and absorbing or affecting any carbon dioxide quantity in the breath sample. Once the bag is transported to the air measuring instrument, the physician carrying out the test, takes the sample bag and again squeezes the santoprene finger grip 20 around the transmitting tube 3 to effect a temporary sealing of the sample in the bag and then removes the cap 13 exposing the orifice 12 communicating with the primary air transmitting channel. The physician then inserts the bag into the matching fitting on the instrument and turns the bayonet fitting 7 clockwise 90 degrees to lock it in place. Reference should now be made to Figures 3 and 4 which show schematic diagrams detailing the insertion of a sample bag bayonet fitting 7 into an air reading instrument. Figure 3 shows the sample bag being initially introduced by way of pushing the tube 11 into a receiving aperture 17 of the instrument (not shown). The outer o-ring 15 fitted to the end of the tube 11 forms an airtight seal against an inner part 18 of the aperture 17 and the act of pushing the tube 11 into the inner part 18, as is shown in Figure 3, causes any residual air in the inner part to be expelled from the measuring instrument by way of an expellation vent 19. In addition, the act of inserting the sample bag causes the inner o-ring 14 to be pushed against the outlet airholes 10 thereby sealing off the ventilating channel and ensuring that the expellation of the contents of the bag 1 is directed only through the primary air transmitting channel and out of the orifice 12, into a sampling chamber (not shown) of the measuring instrument.

The removal of the bag is shown in Figure 5 and involves the physician turning the bayonet fitting 7 anti-clockwise until it releases. The compressed inner o-ring 14 then assists in pushing the fitting slightly outwards. As the physician pulls the bayonet fitting from the instrument aperture 17, room air is drawn through the expellation vent 19 mixing with the remaining sample breath and flushing it from the port. The physician then holds the bag while squeezing the santoprene finger grip to retain the breath sample and replaces the cap 13. The remaining sample is then sealed in the container and may be used to repeat the test if required.

For the instrument to determine the carbon dioxide value for the test correctly, the pre-sample and post-samples must be fitted to specific ports on the instrument. The instrument ports are colour matched to the sample container and interlocks such that the pre-sample container can only be fitted to the pre- sample port and the post-sample container can only be fitted to the post-sample port. The ports and bags are interlocked by the length and width of the bayonet arms on each sample container matching the length and width of the matching slot in the port. The pre-sample port has wide and short slots, matching the wide and short arms of the pre-sample container bayonet. The post-sample port has narrow and long slots, matching the narrow and long arms of the post- sample container bayonet. The post-sample container cannot be fitted to the pre-sample port because the bayonet arms are too long for the sample port slots. Similarly the pre-sample container cannot be fitted to the post-sample port because the bayonet arms are too wide for the sample port slots. In this manner the bayonet configuration of the bags ensures reliable use and minimises errors. Accordingly the invention provides for the first time a highly improved air sample bag and sampling system that allows the reliable and ready access to a patients alveolar air. The ease with which the sample bag can be used ensures reliable consistent sampling and the features of the bag also improve the cooperation of the bag with a measuring instrument to further ensure the reliable and consistent preparation of results .

The invention as detailed in the current application is by way of preferred embodiment only and the invention is not to be seen as Umiting to any of the specific features detailed in the examples.

Claims

1. A breath sampling and handling apparatus comprising an inflatable and airtight bag, said bag having an air communicating aperture fitted with an air transmitting tube for moving air into and out of said bag, said air transmitting tube including a primary air transmitting tube and an air ventilating tube; and a cap movable from a first position opening said tubes to a second position sealing said tubes, wherein said primary air transmitting tube provides a direct line of communication between an opening or orifice at an outer end thereof and said bag, and wherein said air ventilating tube provides a line of communication between the interior and exterior environment of said bag such that the user can continuously breathe into said bag until alveolar air is expelled therein and wherein said cap can be moved to seal said primary and ventilating tubes thereby sealing alveolar air in said bag.

2. Apparatus according to claim 1 wherein said primary and ventilating tubes are formed co-axially in said air transmitting tube.

3. Apparatus according to claim 2 wherein said air transmitting tube is adapted for fitting to said bag at a first or inner end thereof and said outer end is adapted for receiving said cap.

4. Apparatus according to claim 3 wherein a vent opening adjacent said outer end of said air transmitting tube provides communication between said ventilating tube and said exterior environment, and sealing means are provided to co-operate with said cap to seal said opening of said primary tube and said vent opening when said cap is in said second position.

5. Apparatus according to claim 4 wherein said sealing means comprise an inner o-ring for sealing against said vent opening and an outer o-ring for sealing against said primary air transmitting tube.

6. Apparatus according to claim 5 wherein a bayonet fitting is provided on said air transmitting tube adjacent said outer end thereof, said bayonet fitting incorporating said vent opening in the form of a plurality of outlet air holes spaced around the outside of said primary air transmitting tube, and said bayonet fitting facilitating connection of said apparatus to a measuring instrument.

7. Apparatus according to claim 6 wherein said outer o-ring is an interference fit between a rim of said cap and the outer surface of said primary tube.

8. Apparatus according to claim 7 wherein said cap slides axially on said primary tube between said first and second positions.

9. Apparatus according to claim 8 wherein said air transmitting tube is provided with a compressible finger grip region intermediate said inner and outer ends, said region facilitating temporary compression and sealing of both air transmitting tubes.

10. Apparatus according to claim 9 wherein said air transmitting tube is provided with a desiccant means to minimise water content in said air sample.

11. Apparatus according to claim 10 wherein said o-rings and the configuration of said outer end of said air transmitting tube provide a means of direct co-operation between said air bag and said measuring instrument, said bayonet fitting comprising a housing with peripheral lugs on the outside and said primary tube extending therefrom to receive said cap, said inner o-ring being pressed against said vent opening and said outer o-ring sealing against the bore of a receiving aperture of said measuring instrument when said apparatus is connected to said measuring instrument.