CN211069602U - Device for the diagnostic measurement of nitric oxide, NO - Google Patents

Abstract

A device for diagnostic measurement of nitric oxide, NO, is disclosed, the device comprising a valve, a pump, and a sensor capable of detecting NO at a concentration of 5ppm in exhaled breath, at least one NO scrubber containing potassium permanganate for supplying NO-free air to the sensor for performing a baseline measurement, characterized in that the device has a protective cover that is openable such that the scrubber is accessible from outside the device.

Description

Device for the diagnostic measurement of nitric oxide, NO

Technical Field

The present disclosure relates to the field of diagnostic gas analysis, and in particular to an apparatus for determining endogenous Nitric Oxide (NO) in exhaled breath of humans.

Background

The original report of the presence of Nitric Oxide (NO) in exhaled breath of mammals, including humans (Gustafsson L E, L eon AM, Persson MG, Wiklund NP, Moncada S. endogenesis nitrile oxide present in the exhaled air of rabbits, guinea pigs and humans (endogenous nitric oxide is present in exhaled breath of rabbits, guinea pigs and humans), Biochem Biophys Res Commun (biochemical and biophysical research communication), 1991; 181: 852-.

Initially, most measurements were performed using a fixed chemiluminescence-based NO analyzer, which provided new insights in research laboratories, but they were not suitable for primary health care environments. It is quickly realized that portable and even hand-held NO analyzers are of value in both professional and primary health care. NIOX

And NIOX

(Circassia AB, sweden) represents a breakthrough in user-friendliness and has found application in global doctor's offices and healthcare centers.

As a requirement for clinical use, it is recommended that the patient should inhale NO-containing air before exhaling into the device. This is an important feature because ambient air may contain highly variable concentrations of various oxides of nitrogen (commonly referred to as NOx). Major sources of NOx include motor vehicles, power plants, and other fossil fuel combustion industries. Indoor exposure may be primarily due to un-gassed combustion, such as gas burners and space heaters. In densely populated areas, outdoor NOx is also affected by traffic cadence, peaking in the morning and afternoon rush hour periods.

When the diagnostic NO ranges from 5ppb to 50ppb, and the maximum environmental one hour exposure reported by the environmental protection agency is 200ppb, it is clearly necessary to eliminate or at least minimize the effects of environmental NO.

In most NO analyzers, a built-in NO scrubber or NO scavenging filter ensures that the patient inhales NO-free air. Typically, such NO scavengers or NO scrubbers comprise a suitable filter material, preferably potassium permanganate KMnO4 or potassium permanganate in combination with granular carbon. Potassium permanganate has the advantage that it binds NO and forms manganese dioxide. This maintains its filtering capacity in a wet environment, even better than in a dry environment.

The built-in NO scrubber is also used to generate NO-free air for calibrating the sensor and ensuring its correct operation. In NIOX

The zero-age sample is aspirated by an internal, built-in NO scrubber and directed to the NO sensor. This measurement serves two purposes. First, if the result is above 5ppb, a fault is indicated. This may be due to sensors, problems with control electronics, or exhaustion of the internal NO scrubber, and indication that ambient air with a high NO concentration reaches the sensor. If the measurement is in the interval of 0ppm to 5ppm, the result is taken as the baseline measurement. The device uses an algorithm to calculate the difference between the NO measurement and the baseline for the patient sample. The algorithm also takes into account other factors, such as ambient relative humidity, temperature, pressure, etc., to generate a presented FeNO value (exhaled NO fraction).

For devices with another scrubber (i.e. devices that ensure that the patient inhales NO-free air before exhaling into the apparatus for diagnostic measurement of exhaled NO), the internal scrubber is also used to verify the proper functioning of the patient scrubber. The device draws a sample of ambient air through the patient scrubber, analyzes the NO concentration, and then draws a sample of ambient air through the internal scrubber. The requirement is that the two measurements should not differ by more than 10 ppb.

In the widespread use of NIOX

After the apparatus, the present inventors noted that there was a case where the deterioration of the internal scrubber had occurred. The device has displayed an error message indicating that the baseline is too high or that the contrast between the internal and patient scrubbers has shifted. Visual inspection of the scrubber showed that the scrubber material had been completely exhausted in some cases.

Evidence can be used to suggest that the cause is a chemical reaction between scrubber material, potassium permanganate, and alcohols used in cleaning and disinfecting the equipment itself and/or other objects and surfaces in a clinic or doctor's office.

Disclosure of Invention

The present disclosure addresses this problem and according to a first aspect, there is provided an apparatus for diagnostic measurement of Nitric Oxide (NO), the apparatus comprising a valve, a pump and a sensor capable of detecting NO at a concentration of 5ppb in exhaled breath, at least one NO scrubber containing potassium permanganate for supplying NO-free air to the sensor to perform a baseline measurement, wherein the apparatus has a protective cover that is openable such that the scrubber is accessible from outside the apparatus.

According to a preferred embodiment of said first aspect, said scrubber is connected to the environment via a channel or pipe having a length and a diameter, wherein the length is at least 10 times the diameter, preferably at least 20 times the diameter.

According to a preferred embodiment, the channel or duct is about 100mm to 200mm long.

According to another embodiment, the opening of the channel or duct is located inside the device.

According to a further embodiment, the openable protective cover is closed with a tamper-evident seal and provides instructions to: the washer can only be inspected and replaced by authorized personnel.

According to a preferred embodiment, the scrubber contains 1g to 10g of potassium percarbonate, preferably 1.5g to 5.5g of potassium percarbonate, and most preferably 2g to 3g of potassium permanganate.

All aspects and embodiments can be freely combined with one or more of the listed embodiments, unless clearly indicated otherwise.

Drawings

The invention will be described in more detail in the following description, non-limiting examples and claims with reference to the accompanying drawings, in which:

fig. 1 shows a front view of one example of a device or apparatus 1 for diagnostic measurement of NO, the device or apparatus 1 having an integrated handle 2, a display or touch screen 3, a holder 4 for a handle 5, said handle being connected to the apparatus via a tube 6.

Fig. 2 shows the opposite side of the device of fig. 1, again exposing the openable closure 7 for access and replacement of the NO sensor (not shown), and a second closure 8 according to the invention, the second closure 8 being used for access, inspection and replacement, if necessary, of a scrubber (not shown).

FIG. 3 is a degraded scrubber material

Shows unique peaks compared to the absence of such peaks in the results (lower curve) for the unused scrubber material. This peak corresponds to the various solvents (left to right): ethanol, 2-propanol, acetone, 1-propanol and 1-butanol.

Fig. 4 schematically shows an arrangement according to the invention, wherein a NO scavenging filter or scrubber 9 is seated within the housing 1 of the device for diagnostic measurements of NO and is connected to the environment by a tortuous passage or flow path 10, which tortuous passage or flow path 10 leads to the environment through an orifice 11 in the housing 1. Another channel or flow path (here indicated by a dot-dash line) leads from the scrubber 9 to the sensor via a pump, a suitable valve or the like (not shown). An openable lid 8 is arranged in the housing 1 so that the state of the washer can be checked and the washer can be replaced if necessary.

Fig. 5 schematically shows an arrangement according to the invention, wherein a NO-scavenging filter or scrubber 9 is seated in a housing 1 of the device for diagnostic measurement of NO and is connected to the environment by a channel or flow path 12, the channel or flow path 12 having an opening 13 in the housing 1. Another channel or flow path, indicated with a dash-dot line, leads from the scrubber 9 to the sensor via a pump, a suitable valve or the like (not shown). An openable lid 8 is arranged in the housing 1 so that the state of the washer can be checked and the washer can be replaced if necessary.

Detailed Description

Before the present invention is described, it is to be understood that the terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims and equivalents thereof.

It must be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

The term "scrubber" as in "NO scrubber" refers to a filter comprising a chemically adsorbent material capable of adsorbing, absorbing and/or oxidizing an undesired gaseous component (here NO). One suitable chemical adsorbent is formed from activated alumina and other binder impregnated with potassium permanganate

A series of particles or beads to provide optimal adsorption, absorption and oxidation of a wide variety of gaseous pollutants.

Potassium permanganate is known to react with alcohols to produce manganese dioxide, potassium carbonate and water. Potassium permanganate has an intense purple color while manganese dioxide is brown, so that the reaction can be visually observed. The color change is also an indicator that the washer has become depleted/degraded.

As shown by way of example, the use of alcohol-containing solutions for cleaning and disinfection in the health care industry results in premature deterioration/exhaustion of scrubber material, potassium permanganate. While this problem can be addressed by instructing the user to avoid alcohol-containing disinfectants, cleaning solutions, and wet wipes, this is by no means a completely satisfactory solution. The use of alcohols in the health care industry for cleaning and disinfecting is well established.

The present disclosure therefore addresses this problem and provides according to a first aspect an apparatus for diagnostic measurement of Nitric Oxide (NO), the apparatus comprising a valve, a pump and a sensor capable of detecting NO at a concentration of 5ppb in exhaled breath, at least one NO scrubber comprising potassium permanganate for supplying NO-free air to the sensor to perform a baseline measurement, wherein the apparatus has a protective cover that is openable such that the scrubber is accessible from outside the apparatus. This has the following advantages: the scrubber can be inspected and-if necessary-replaced without interfering with any other parts of the apparatus. This is particularly important because the device in question provides a diagnostic measure of exhaled nitric oxide which forms the basis for decisions regarding medication and treatment of diseases such as asthma. It is important that the integrity and accuracy of the device is not compromised.

According to a preferred embodiment of said first aspect, said scrubber is connected to the environment via a channel or pipe having a length and a diameter, wherein the length is at least 10 times the diameter, preferably at least 20 times the diameter. As shown in example 3, adding an extra length of tubing can extend the life of the internal scrubber 4-fold to 5-fold.

According to a preferred embodiment, the channel or duct is about 100mm to 200mm long. The length of the tubing creates a barrier to passive inflow of alcohol vapor, but still allows for the intake of an ambient air sample for performing a baseline measurement. But still allow the intake of a sample of ambient air for baseline measurements

According to another embodiment, the opening of the channel or duct is located inside the device. In this embodiment, the outer casing of the device acts as a protective housing, forming a protected air gap inside the device.

According to a further embodiment, the openable protective cover is closed with a tamper-evident seal and provides instructions that the washer can only be inspected and replaced by authorized personnel. This is an important aspect because the device in question is a diagnostic tool and the integrity and accuracy of the device cannot be affected.

According to a preferred embodiment, the scrubber contains 1g to 10g of potassium percarbonate, preferably 1.5g to 5.5g of potassium percarbonate and most preferably 2g to 3g of potassium permanganate. The amount of scrubber material in the internal scrubber should be kept as small as possible so that the apparatus can be kept compact and light.

All aspects and embodiments can be freely combined with one or more of the listed embodiments, unless clearly indicated otherwise. A preferred embodiment may for example be an apparatus for diagnostic measurements of Nitric Oxide (NO), the apparatus comprising a valve, a pump, and a sensor capable of detecting NO at a concentration of 5ppb in exhaled breath, at least one NO scrubber comprising potassium permanganate for supplying NO-free air to the sensor to perform a baseline measurement, wherein:

-the apparatus has an openable protective cover so that the scrubber is accessible from the outside of the apparatus;

-the scrubber comprises from 2g to 5g potassium permanganate;

-the scrubber is connected to the environment via a narrow pipe having a length in the interval 100nm to 200 nm; and

the openable cover for inspection and possibly replacement of the washer is closed with a tamper-evident seal and indicates that only authorized personnel can open the cover.

Examples of the invention

Example 1.Analysis of degraded NO scrubber

The scrubber containing 2g of potassium permanganate (from pilafill corporation, doravial, georgia, usa) was removed from the diagnostic device which had displayed an error message indicating that the scrubber had been exhausted

Chemisorption medium (A)

Chemisorbant Media, Purafil inc. doraville, GA, USA)). Visual inspection showed that the pellets had gone from the original purpleThe color changed to brown-orange, indicating the formation of manganese oxide. Samples were removed and analyzed using gas chromatography-mass spectrometry (GC-MS). This is an established analytical method that combines the features of gas chromatography and mass spectrometry to identify different substances within a test sample. The results are shown in fig. 4, which clearly shows that there are traces of solvent in the deteriorated scrubber and that such solvent is not present at all in the unused scrubber material.

Example 2.Comparative test

Cleaning of equipment for diagnostic measurement of NO with alcohol-containing disposable wet wipes (of Sweden CIRCASSIA AB

). The device was placed in a hard box and no time was required for the alcohol to dry. The device was then stored in a closed rigid box for 2 days. The test conditions corresponded to friday cleaning equipment and stored for the weekend.

Another device was cleaned using an alcohol-free wet wipe containing benzalkonium chloride and similarly stored. The internal scrubber in the device that had been cleaned with alcohol-containing wet wipes showed a visible color change after two days of storage. In an apparatus that has been cleaned with wet wipes that do not contain alcohol but otherwise treated the same, no color change is seen.

The test was repeated with a new device, with the change being a vent sealed on the side of the device. The purpose of the test was to confirm that the vent was the path for the alcohol to enter the device and reach the scrubber. Despite sealing the vent, after two days of storage, the scrubber still discolored, indicating that alcohol entered the device through another pathway.

Example 3.Long term stability of improved scrubber configuration

The plant was modified by adding a pipe to the inlet side of the internal NO scrubber. In this test, the tubing was 193 mm long. The end of the pipe opens into the environment inside the device. The scrubber with the additional piping and the scrubber in its original design with only a short inlet are stored in a small vessel filled with a high concentration of alcohol vapor. Both scrubbers were tested daily using bottled NO gas to verify their performance. The concentration of NO is measured before and after it passes through the scrubber and the effectiveness of the scrubber is evaluated.

The scrubber with the additional piping was destroyed in 8-10 days, while the scrubber in its original design only lasted 2 days. In summary, it appears that adding additional length of tubing can extend the life of the internal scrubber by a factor of 4 to 5. However, this design change only protects the scrubber when the alcohol is passively entering (i.e., during storage and the equipment is not being used). If there are alcohols in the ambient air where the equipment is being used, actively pumping air through the scrubber as part of establishing the baseline and as part of quality control will result in the same degradation of the scrubber.

Without further elaboration, it is believed that one skilled in the art can, using the present description (including the examples), utilize the present invention to its fullest extent. Moreover, while the invention has been described herein with respect to the preferred embodiments, which constitute the best modes presently known to the inventors, it should be understood that various changes and modifications as would be obvious to one having the ordinary skill in this art may be made without departing from the scope of the invention which is set forth in the claims appended hereto.

Thus, while various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and not limitation, with the true scope and spirit being indicated by the following claims.

Claims (9)

1. A device for diagnostic measurement of nitric oxide, NO, the device comprising a valve, a pump, and a sensor capable of detecting NO at a concentration of 5ppm in exhaled breath, at least one NO scrubber containing potassium permanganate for supplying NO-free air to the sensor for performing a baseline measurement, characterized in that the device has a protective cover that is openable such that the scrubber is accessible from outside the device.

2. The apparatus of claim 1, wherein the scrubber is connected to the environment via a channel or pipe having a length and a diameter, wherein the length is at least 10 times the diameter.

3. The apparatus of claim 1, wherein the scrubber is connected to the environment via a channel or conduit having a length and a diameter, wherein the length is at least 20 times the diameter.

4. The apparatus of claim 2, wherein the channel or conduit is 100mm to 200mm long.

5. The device of any of claims 2-3, wherein the opening of the channel or conduit is located inside the device.

6. The apparatus of claim 1, wherein the openable cover is closed with a tamper evident seal and the openable cover is accompanied by an indication that the washer can only be inspected and replaced by authorized personnel.

7. The apparatus of claim 1, wherein the scrubber comprises 1g to 10g potassium percarbonate.

8. The apparatus of claim 1, wherein the scrubber comprises 1.5g to 5.5g potassium percarbonate.

9. The apparatus of claim 1, wherein the scrubber comprises 2g to 3g potassium permanganate.

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