Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02217883 1997-10-09
W 0~'32-~2 PCT/SE96/00~74
A DEVICE FOR ~ ~U~N1! IN ~x~r-~n AIR
The present invention relates to a device for detecting one
or more components in exhaled air, and particularly for
detecting the presence of pathogenic bacteria Helicobacter
pylori in stomach and intestinal tracts of hllm~n beings.
R~ 701~ND OF THE lNV~N.LlON
Gaseous components can be analyzed in various ways, such as
by gas chromatography, flame photometry and spectrophotome-
try, for instance. These methods, however, require the use
of expensive equipment and are much too advanced in many
cases. Simpler, alternative methods are those in which the
gas is absorbed by a material and the presence or absence of
a gaseous component indicated with the aid of a colour
indicator. Examples in this respect are the blow tubes used
to indicate the presence of alcohol in ~h~l ~tion air. The~e
devices have the drawback of not being constructed for
separate measurements on the absorbent material.
Certain conditions and illnesses can be indicated by analyz-
ing exhalation air. For instance, stomach ulcers are caused
mainly by the pathogenic bacteria Helicobacter pylori. A
method has been described for indicating the presence of this
bacteria and has been applied in clinical research for a
number of years. According to this method, patients are to
swallow an isotope-labelled, preferably radioactive, urea
preparation. ~elicobacter pylori present in the gastric and
intestinal tract will break the urea down to carbon dioxide,
among other materials. This carbon dioxide is then
transported to the lungs through the normal physiology of the
body, where it is exhaled together with the carbon dioxide
that has been formed in r~m~; n; ng body organs. Because the
carbon dioxide that is formed by the bacteria is labelled,
the amount of carbon dioxide exhaled can be measured by
causing the patient to blow the exhalation air through a tube
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and down into a liquid which absorbs carbon dioxide. This
liquid is then ex~mined with the aid of appropriate measuring
instruments, for instance a scintillator counter, to indicate
i~otope labelled components in the exhaled carbon dioxide as
a sign of the presence of ~elicobacter pylori.
The aforesaid method is relatively complicated and time-
consuming. In addition, it requires the use of expensive and
bulky apparatus. Furthermore, no product for carrying out
this method is actually available commercially.
OBJECTS OF ~1~ lNV~ ON
The object of the present invention is to provide apparatus
for use in detecting one or more components in exhalation
air. The apparatus shall be producible at low costs and shall
also satisfy requirem~nts of long-term storability and
reproducibility of test results. Another object is also to
obviate the complex handling of liquids and the use of space-
consuming analysis instruments.
These objects are fulfilled by the present invention, whichrelates to a device which consists of a tubular element,
which may be rigid or soft as a plastic bag and through which
air is conducted. A nozzle is formed on one end of the tube.
The opposite end of the tube is fitted with a plate, which
may either be an airtight plate or a porous membrane. The
plate is attached to the tube in a m~nne~ which will enable
it to be readily ~e,l,oved therefrom. The plate fitting may
either have the form of a screw device or snap-coupling, or
may simply comprise adhesive tape. A dry, absorbent material
has been mounted on or incorporated in the plate. This
absorbent material is adapted solely to absorb a specific
amount of desired gaseous component. A colour indicator in
the absorbent substance indicates when the m~; mllm amount of
gaseous component has been absorbed. When an airtight plate
is used, the outer edge of the plate is perforated so as to
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W 096/32062 PCT/SE96/00474
allow air to pass out and therewith enable air to flow
r through the tube.
The patient blows exhalation air through the nozzle and
causes said air to flow across or through the plate. The
plate can be separated from the tube when the plate becomes
saturated. The plate is then analyzed in an appropriate
measuring in~trument, to indicate the presence or absence of
components in question.
In a preferred embodiment, the present invention is used to
indicate the presence of isotope labelled carbon dioxide in
~hA1~tion air, and in particular to indicate the presence
of radioactive carbon dioxide formed as a conversion product
of the bacteria Helicobacter pylori. To this end, the plate
has mounted thereon or incorporates a c~hon dioxide absorb-
ing material. A patient ~m;n;stered with radioactive
labelled urea is asked to blow through the inventive device.
Carbon dioxide, including radioactively labelled carbon
dioxide, is absorbed on the plate. The plate is then removed
from the device and analyzed with regard to radioactivity in
an appropriate measuring device, to indicate the presence of
the bacterium Helicobacter pylori.
The present invention thus provides a simple device for use
in indicating the presence or absence of ~ori~ nts in
exhalation air.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of an inventive device.
Figure 2a is a view from above of a further embodiment of the
inventive device.
Figure 2b is a side view of the embodiment shown in Figure
2a.
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W 096~2062 PCT/~ Jo~74
DE~ATT~n DESCRIPTION OF ~ E FIG ~ ES
Figure 1 illustrates primarily the embodiment in which a
porous membrane is used and the air shall be caused to flow
through the plate. The device is comprised of a tubular
element 1 provided with a nozzle 2 at one end. An absorbent
plate 3 is fitted detachably to the opposite end. When an
airtight plate is used in this embodiment, the outer edge of
the plate will be perforated with holes 4, so as to enable
air to flow through the device. These perforations are
excluded when a porous membrane is used.
Figures 2a and 2b show two views of one embo~;m~nt of the
device suitable when an airtight plate is used. The reference
signs used in the Figures correspond to those used in Figure
1. The broken line in Figure 2b indicates that the whole of
the upper part of the device including the plate can be
separated from the lower part and introduced into a measuring
instrument. When a porous membrane is used, the device is not
provided with perforations 4.
When using the device, a patient exhales through the nozzle
2. The ~xh~lAtion air then passes through the tubular element
1, and flows through the plate 3, or across the plate 3, and
out through the holes 4. The tube is constructed to ensure
m-~;mllm contact between the air flow and the absorbent plate.
Subsequent to having absorbed a mA~;mllm amount of gaseous
component, as indicated by the colour indicator, the plate
is detached from the tubular element and introduced in a
measuring instrument for indication of a desired component.
Alternatively, the whole of the upper part, including the
plate, is detached from the rem~;n~r of the device and
introduced into the measuring instrument.
The device may be made from any suitable material, preferably
cardboard, paperboard or plastic of different kinds. Examples
of plastics that can be used are polyethylene, polystyrene
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or PVC. It is appropriate that the device can be sterilized
by radiation or heat. The absorbent material will vary in
dependence on the component to be indicated. Examples of
carbon dioxide absorbent materials are sodium hydroxide and
soda lime. The colour reaction on the plate that signal~ when
the plate is saturated can be achieved with the use of
commercially available soda lime as a colour indicator. Part
of the device beneath or above the absorbent material will
preferably be transparent, so that the colour reaction can
be observed. Cor.,~ol~ents that are to be detected may, for
instance, be labelled or marked by means of isotopes. The
measuring instrument used to detect labelled components will
vary in accordance with labelling. For instance,
radioactively labelled components can be indicated with a
Geiger Muller tube. From the aspect of mechanical strength,
the device will preferably be packed in an airtight bag in
a durable environment, for instance in a nitrogen gas
environment when a carbon dioxide absorbent material is used.
The device may conveniently be adapted for one-time use only,
for hygienic reasons.
