Calibration and / or validation tools

Abstract

The present invention relates to calibration and / or verification tools, assemblies, and methods for calibrating and / or verifying a system for measuring the gas concentration of a gas diffused percutaneously. The calibration and / or verification tool (1) is a tool for calibrating and / or verifying a system (100) for measuring gas concentration, the system (100) having a sensor (101) for detecting percutaneous gas, the sensor (101) having a contact surface (102) that can be directed toward a measurement site on the skin of a human subject or animal subject. The calibration and / or verification tool (1) comprises a compartment (2) for surrounding a reference environment (3), an interface (4) for connecting the sensor (101) so that the contact surface (102) is exposed to the reference environment (3) in the compartment, and means for providing a clearly defined gas concentration in the compartment. The calibration and / or verification tool (1) is a standalone mobile device, preferably a single-use device and / or disposable device.

Description

Technical Field

[0001] The present invention is directed to calibration and / or verification tools, assemblies, and methods for calibrating and / or verifying a system for measuring the gas concentration of a gas diffused transdermally.

Background Art

[0002] Current systems for measuring gases utilize various measurement principles. In medical technology, electrochemical sensors are mainly used for measuring gases diffused transdermally, i.e., gases diffused through the skin of a human patient or an animal. Current sensors for measuring transcutaneous CO2 are very sensitive and exhibit excellent response times. Electrochemical sensors for measuring transcutaneous gases are known, for example, from WO2008 / 132205 and EP3024390B21.

[0003] However, those sensors drift over long measurement periods and require frequent calibration. Therefore, at the time of use, the user has to use a rather bulky and expensive calibration instrument, including a calibration gas supply device. The calibration and maintenance of the sensors reduce the ease of use of this technology.

[0004] Known calibration stations are integrated within the measuring device. For example, EP0074498 B1 discloses a measurement system comprising a sensor connected to a measuring device, and a calibration system combining a calibration device and the measuring device.

Summary of the Invention

Problems to be Solved by the Invention

[0005] In currently known calibration systems, the user can insert a test gas canister and place the sensor inside a docking station. Closing the docking station door creates a seal around the PCO2 sensing element by pressing the sensor against an O-ring. A software-controlled mechanical valve then regulates the gas flow from the canister to the sensor. This system has several usability issues, which can lead to gas leaks and calibration failures. Troubleshooting can be time-consuming and frustrating for customers.

[0006] The object of the present invention is to avoid the drawbacks of the prior art, and in particular to provide a simple, inexpensive, robust, and accurate tool and method for calibrating and verifying a system for measuring the gas concentration of gases diffused percutaneously. [Means for solving the problem]

[0007] According to the present invention, this objective is achieved by calibration and / or verification tools, assemblies, and methods as defined in the independent patent claims.

[0008] Calibration and / or validation tools are tools for calibrating and / or validating a system for measuring gas concentrations. The system comprises a sensor for detecting transcutaneous gases and a contact surface that can be directed towards a measurement site on the skin of a human subject or animal subject.

[0009] The calibration and / or verification tool includes a compartment for surrounding a reference environment. The calibration and / or verification tool also includes an interface for connecting sensors so that their contact surfaces are exposed to the reference environment within the compartment. The calibration and / or verification tool further includes means for providing a clearly defined gas concentration within the compartment.

[0010] The compartment may contain a gas having a clearly defined gas concentration, and / or may be adapted to receive a gas having a clearly defined gas concentration.

[0011] Preferably, the calibration and / or verification tool, in particular the compartment, does not contain a liquid medium, especially a liquid medium that releases a reference gas or a liquid medium that is in dynamic equilibrium with the reference gas.

[0012] Generally, when gas concentrations are generated by evaporation from a fluid, it is not possible to provide properly defined gas concentrations, particularly clearly defined CO2 concentrations.

[0013] The compartment may have a volume of 0.05 ml to 15 ml. The interface may include receptacles for corresponding parts of the sensor. The interface may also include fastening elements such as clips, clamping elements, screws, locking rings with castle-type slots, or closure plugs with castle-type lugs for bayonet closures.

[0014] Since the sensors in a system for measuring gas concentration drift over time, it is necessary to verify that the settings are still acceptable and / or to recalibrate the system. In either case, a reference environment may be presented to the system.

[0015] After connecting the sensor to the calibration and / or verification tool, the contact surface is exposed to a volume containing a reference environment. The reference environment can be provided by a reference gas in a static or dynamic manner.

[0016] When a calibration and / or verification tool is connected to a system for measuring gas concentrations, the system should provide gas concentration values ​​corresponding to each gas concentration in its compartments. If not, the system must be calibrated until the respective values ​​are provided. If the values ​​provided by the system do not correspond to the preset gas concentrations in the compartments, the user understands that the system is unsuitable for measurement unless it is recalibrated.

[0017] Preferably, the calibration and / or verification tool comprises detection means that can be recognized and / or read by a system for measuring gas concentration. The detection means may be formed by an RFID tag and / or NFC tag, a magnetic switch, or a Hall sensor. The detection means may include information about the calibration and / or verification tool, such as a serial number or expiration date.

[0018] The detection means may provide information about whether a calibration and / or verification tool is connected to the system for measuring gas concentration. Using such means, the calibration process can be fully automated, minimizing the necessary user interaction.

[0019] In this context, the "clearly defined" gas concentration within the compartment means that the concentration has a precision range that corresponds to the measurement accuracy of the system.

[0020] The calibration and / or verification tool is a standalone mobile device, preferably a single-use device and / or a disposable device.

[0021] In this application, “standalone” means particularly isolated from a system, and the device preferably does not include electronic components, displays, and electronic interfaces, except for passive detection means.

[0022] However, a display may be required during use. This display may be provided by the system during use.

[0023] In the present application, "mobile" means that a calibration and / or verification tool can be moved away from the system, particularly. The calibration and / or verification tool can be used with various systems where the interface is appropriate and / or with any system where the interface is suitable and requires verification and / or calibration.

[0024] The calibration and / or verification tool may be a handheld device. The calibration and / or verification tool can be small and can have a total volume of less than 0.25 L, preferably less than 0.1 L, and most preferably less than 0.025 L.

[0025] The calibration and / or verification tool can be lightweight and can have a weight of less than 250 g, preferably lighter than 100 g, and most preferably less than 25 g.

[0026] In the present application, "disposable" means that the calibration and / or verification tool can be discarded as general household waste because it meets the relevant waste requirements. In particular, "disposable" means that the device does not contain toxic or explosive electronic components (except for possible passive detection means) or any materials.

[0027] The interface may include a sealing element. The sealing element provides a connection between the compartment and the contact surface in a manner that seals sufficiently, preferably in an airtight manner. The sealing element can be an O-ring made of an elastomer such as ethylene propylene diene rubber (EPDR), polyacrylate rubber (ACM), chloroprene rubber (CR), fluorine rubber (FKM), and silicone rubber (VMQ).

[0028] The calibration and / or verification tool may comprise a removable packaging sealing element. Alternatively or additionally, the calibration and / or verification tool may comprise a removable gas-impermeable packaging.

[0029] In the present application, "gas-impermeable" means being sufficiently airtight for the intended purpose. In particular, this means that it should be able to sufficiently expel ambient CO2 over the intended quality retention period (generally 24 months).

[0030] In view of the relatively low partial pressure, the packaging may comprise, for example, a MAP (modified atmosphere packaging) material used in food packaging.

[0031] In calibration and / or verification tools based on the use of a gas having a known CO2 concentration or a CO2 absorption material, the packaging is an important element for their quality retention period. A gas-impermeable packaging material can extend the life of the device. The life of the device can also be extended by filling the package with nitrogen or any other calibration gas at a defined concentration. This is important for the shipment and storage of the calibration and / or verification tool.

[0032] The calibration and / or verification tool may comprise a hygroscopic material for drying the reference environment, especially for drying the reference gas provided in the compartment.

[0033] The calibration and / or verification tool may comprise means for providing a clearly defined gas concentration in the compartment, adapted to provide a carbon dioxide (CO2) concentration in the compartment of less than 300 ppm, preferably less than 100 ppm, most preferably less than 50 ppm.

[0034] In this case, the calibration and / or verification tool is suitable for calibrating and / or verifying a system for measuring transcutaneous carbon dioxide (CO2) concentration.

[0035] When connected to a system for measuring CO2 concentration, the system should provide a value for the lowest CO2 concentration corresponding to the lowest CO2 concentration in the compartment. If it does not, the system must be calibrated.

[0036] This can be an automated process. It is not necessary to display the detected values ​​to the user.

[0037] In this case, the reference environment is essentially free of CO2, or at least has a carbon dioxide concentration lower than the typical measurement accuracy of the system used to measure CO2 concentration.

[0038] Calibration and / or verification tools may include means for providing a clearly defined gas concentration, which is either a carbon dioxide (CO2) absorbent material or formed by a carbon dioxide (CO2) absorbent material.

[0039] The CO2 absorbing material can be any chemical substance that can react with CO2 in a bonding reaction. A commonly used technical term is "CO2 removal device." It is preferable to use soda lime, which is a mixture of sodium hydroxide (NaOH) and calcium oxide (CaO) or calcium hydroxide (Ca(OH)2). Other CO2 removal materials may be, for example, potassium hydroxide (KOH), lithium hydroxide (LiOH), and lithium peroxide (Li2O2).

[0040] The absorbent material can be provided as a powder, granules, or fibers. The granular form may include spherical granules, hemispheres, bullet-shaped particles, broken fragments, or cylinders. The granular particles may have pores and large surface areas.

[0041] Most preferably, the absorbent material is provided as a concave hemisphere because it offers excellent gas diffusion while providing a high surface area. Furthermore, it is easy to handle and generates minimal dust.

[0042] CO2 absorbing materials are essentially provided to remove all CO2 from the compartment.

[0043] Calibration and / or verification tools may include a removable packaging sealing element for sealing the CO2 absorbing material from the environment before use.

[0044] For example, an airtight film, such as aluminum foil, which must be peeled off before the contact surface is connected to the interface, may be attached to the edge of the compartment.

[0045] The airtight film may be installed so as to cover the interface as well, protecting the fastening elements before use.

[0046] Alternatively, calibration and / or verification tools may be stored in gas-impermeable packaging before use.

[0047] After removing the packaging seal, the compartment is filled with ambient air. After connecting to the sensor's contact interface, it takes time for all carbon dioxide to be removed from the compartment. Generally, the user will have to wait up to 3 minutes until the desired, clearly defined gas concentration is achieved.

[0048] Preferably, once the packaging sealing element or package is removed, the calibration and / or verification tools must be used within one day, preferably within a few minutes.

[0049] Absorbent material may be placed inside the compartment. A separation element, such as a filter element, mesh element, or sieve element, or a perforated tube, may be placed between the absorbent material and the interface, particularly between the absorbent material and the reference environment.

[0050] Filter elements, mesh elements, or sieve elements can hold the absorbent material in a compartment behind the separating element, especially before and after use, i.e., when the calibration and / or verification tool is not connected to the sensor, and can also prevent contact between the absorbent material and the contact surface during use. In particular, they prevent the freely flowing absorbent material from leaving the compartment. Especially when the absorbent material is supplied as a fine powder, the mesh or filter must prevent it from coming into contact with the sensor's contact surface, because this could affect the measurement performance and / or impair the biocompatibility of the contact surface.

[0051] The compartment may host a desiccant that can absorb humidity and dry the reference gas.

[0052] Water (H2O) is necessary for most CO2 absorbents to absorb carbon dioxide. However, excess water reduces the efficiency of CO2 absorption because it can cause the absorbent material to solidify. In some cases, water is a byproduct of the reaction between CO2 and the CO2 absorbent material, which can increase the humidity inside the compartment. High humidity can affect CO2 measurements and potentially impact the performance of the sensor.

[0053] In that case, a small amount of desiccant may be added to the compartment before calibration / verification begins. The desiccant may be a silicon dioxide-based material such as silica gel.

[0054] The compartment may comprise a housing having two parts, the first part which hosts a moisture-absorbing material and the second part which hosts a CO2-absorbing material.

[0055] Each component may be equipped with an independent sealing gasket, because moisture-absorbing material and CO2-absorbing material should not be stored together to prevent the absorbent material from drying out.

[0056] In addition, neither of these parts should be exposed to the surrounding air, because ambient CO2 or water vapor could saturate the absorbent or desiccant, respectively.

[0057] These parts must be assembled, and each seal must be broken for it to function.

[0058] The compartment may be made of a material and thickness that can prevent aging of the CO2 absorbing material. This material may be a polymer with a low CO2 diffusion coefficient, such as polyethylene terephthalate (PET), polyimide (PI), polyoxymethylene (POM), or polyamide (PA).

[0059] The thickness of the compartment walls may be in the range of 1 mm to 4 mm. Calibration and / or verification tools may include a pressurized unit for moving a gas, particularly air or nitrogen, through an absorbent material.

[0060] The pressurizing unit may be positioned to allow gas to be pumped into and / or through the compartment.

[0061] The compartment can be purged with gas if a pressurized unit is used. The pressurizing unit can be a simple manual pump.

[0062] The pressurizing unit may include a syringe having a plunger. An absorbent material may be placed inside the syringe, between the tip of the syringe and a portion of the cylinder, and the plunger moves to remove CO2. A compartment may be formed between the tip and the absorbent material.

[0063] The syringe cylinder may be pre-filled with air or nitrogen, which is held between the plunger and the absorbent material, before use.

[0064] Preferably, the calibration and / or verification tool comprises an elongated tube and / or a one-way valve for releasing the gas from the compartment into the external environment. A flow limiter may be located in the elongated tube. The elongated tube for guiding the gas outside the compartment may have a one-way valve at its distal end.

[0065] In this application, the “elongated” tube is a tube that is longer than the diameter of the opening of the tube, preferably at least 10 times longer, and more preferably at least 100 times longer.

[0066] The plunger can be pushed so that air or nitrogen is forced to pass through an absorbent material that removes CO2. Essentially, a gas without CO2 can reach the compartment. Due to its flow, the air leaks out of the compartment through a one-way valve, or preferably through an elongated tube with a flow limiter at the end, and as a result, the compartment is eventually filled with a low-CO2 concentration gas.

[0067] The pressurizing unit may preferably be a manual pump for supplying air in a closed loop. The calibration and / or verification tool may comprise a circular tube, where a portion of the tube hosts absorbent material, and another portion forms a compartment and provides an interface. A manual pump may be positioned as part of the circular tube.

[0068] The calibration and / or verification tool comprises, for example, two one-way valves located in a pipe, upstream and downstream of a manual pump.

[0069] CO2 absorbent material may be filled along a tube, and a manual pump moves air through the tube in a closed loop. The air may be forced to pass through the CO2 absorbent material multiple times to eliminate any traces of CO2. A compartment may be part of the tube located between the manual pump and the absorbent material.

[0070] Alternatively, means for providing a clearly defined gas concentration may include a tank containing a reference gas having a CO2 concentration of less than 300 ppm. The compartment may be equipped with a one-way valve or an elongated tube between the compartment and the external environment. A pressure relief valve may be located between the tank and the compartment. The tank may be connected to, or can be connected to, a pressurizing unit for pushing the reference gas through the pressure relief valve.

[0071] The tank may be equipped with a housing made of a material and thickness capable of maintaining zero or very low CO2 concentrations within the tank. This material may be metal.

[0072] Alternatively, the material for the tank housing may be any material that does not have specific requirements regarding gas permeability, combined with airtight packaging.

[0073] The calibration and / or verification tool may comprise a syringe, and the pressurization unit is formed by the plunger of the syringe. The interface may be located at the tip of the syringe, and a compartment may be formed between the tip and a pressure relief valve.

[0074] The portion of the syringe cylinder below the pressure relief valve and above the plunger may form a tank that can be filled with a reference gas having a CO2 concentration of less than 300 ppm, such as nitrogen.

[0075] After the sensor is attached to the interface, the plunger can be pushed forward in the direction toward the tip. The reference gas is pushed through the pressure relief valve, replacing the air leaking out of the compartment through the one-way valve. The one-way valve also prevents ambient air from entering the interior during calibration.

[0076] Once the plunger is fully pushed in, the compartment is filled with a reference gas with a low or no CO2 concentration.

[0077] As an alternative, the calibration and / or verification tool may include a vacuum device for creating a vacuum within the compartment.

[0078] The vacuum device may be equipped with a plunger that can cause a rapid increase in the volume inside the syringe cylinder, and thus create a vacuum.

[0079] The calibration and / or verification tool may be equipped with a syringe, the tip of which may have an interface. Before use, the plunger may be positioned near the interface.

[0080] The plunger may be made of a deformable material, such as rubber, that allows it to provide a seal, or it may have a contact surface made of a deformable material. When the plunger is moved backward, a low pressure or vacuum is created in the space between the plunger and the tip that forms the compartment.

[0081] The plunger can be tensioned by a spring mechanism, which can be released to allow the plunger to move backward at high speed.

[0082] In this context, "vacuum" means that the compartment has a CO2 concentration below the system's measurement accuracy.

[0083] The plunger may be equipped with a one-way valve that allows gas to leak out of the compartment between the tip and the plunger. The plunger can be moved forward and backward several times to deliver gas to the outside of the compartment.

[0084] A means for providing a clearly defined gas concentration within a compartment may comprise at least two substances that, when reacting with each other, generate a gas having a clearly defined gas concentration.

[0085] The calibration and / or verification tool may be equipped with a one-way valve or elongated tube between the compartment and the external environment, thereby encouraging any gases generated within the compartment to exit through the one-way valve or elongated tube.

[0086] For example, nitrogen can be produced by the reaction of these two substances. Possible reactions are illustrated by the following examples: Sodium nitrite solution (NaNO2) can react with solid sulfamic acid (HSO3NH2) to form solid NaHSO4, liquid water H2O, and gaseous nitrogen (N2).

[0087] At the end of the reaction and after the ambient air has been expelled from the compartment, the contact surface may be exposed to a pure nitrogen atmosphere.

[0088] These materials may be placed in compartments separated by the dividing elements so that they can come into contact with and react with each other when the removable or repositionable dividing elements are removed or replaced.

[0089] The calibration and / or verification tool may include a syringe with an interface at its tip. The substance and dividing element may be placed inside a cylinder, the first substance may be solid and placed on the first side of the dividing element near the tip, and the second substance may be liquid and placed on the other side of the dividing element. Before use, the dividing element may seal the upper part of the compartment inside the cylinder from the lower part.

[0090] The forward movement of the plunger can push the liquid substance located in the lower part of the cylinder toward the dividing element, which can then be repositioned or broken to release the seal. The dividing element may be a movable block that can be pushed toward a region of the cylinder with a larger diameter, for example, so that the liquid substance can enter the upper part of the cylinder and initiate a reaction.

[0091] Alternatively, at least one substance may be placed within the compartment, and the dividing element may be a membrane within the housing of the compartment. A second substance may be placed in a container that can be inserted into the compartment at least partially through this membrane, and this container may be adapted to be opened during or after insertion to release the second substance into the compartment.

[0092] The calibration and / or verification tool may include means for providing a clearly defined gas concentration within the compartment, adapted to provide a clearly defined CO2 concentration of a clearly defined value higher than 300 ppm within the compartment or within a tank sealed and connected to or capable of being sealed and connected to the compartment.

[0093] Preferably, the CO2 concentration is in the range of 3 to 13%, more preferably in the range of 6 to 10%.

[0094] The calibration tool may include a tank containing a reference gas, in this case a gas having a clearly defined CO2 concentration higher than 300 ppm.

[0095] The tank may preferably be equipped with a metal housing, such as a pressurized steel canister, to prevent any diffusion of the pressurized calibration gas.

[0096] The compartment may be equipped with a one-way valve and / or an elongated tube between the compartment and the external environment. Preferably, a flow limiter is located at the distal end of the elongated tube.

[0097] The tank may be installed in the compartment such that, after installation, a flow limiter is placed between the tank and the compartment, and a reference gas can enter the compartment through the flow limiter to establish a reference environment within the compartment.

[0098] Preferably, the reference gas is under pressure. As soon as the flow limiter is opened, for example by attaching a tank to the compartment, the reference gas enters the compartment, replaces the air, and leaks into the environment through a one-way valve, or preferably through an elongated tube having a flow limiter at its end. The compartment can be purged by the reference gas.

[0099] The compartment will eventually be filled with standard gas. Alternatively, the calibration tool may include a tank containing a reference gas with a CO2 concentration higher than 300 ppm. The compartment includes a one-way valve or elongated tube positioned between the compartment and the external environment. A pressure relief valve, such as a one-way valve, is positioned between the tank and the compartment.

[0100] The tank may be connected to a pressurizing unit to push a reference gas through a pressure relief valve.

[0101] An assembly for the calibration and / or verification of a system for measuring gas concentration comprises a system for measuring gas concentration and the calibration and / or verification tool described above.

[0102] In particular, the above system is a system for measuring gases diffused through the skin, especially CO2.

[0103] The system described above has one or more sensors for detecting transcutaneous gases, particularly CO2. The sensors have contact surfaces that can be directed toward a measurement site on the skin of a human subject or animal subject. The system also has a monitor.

[0104] In this application, the monitor is not merely a screen or display, but a medical device for monitoring a patient's vital signs.

[0105] A monitor may have a display, or may be able to connect to a display. The monitor does not necessarily need to have a calibration function.

[0106] However, systems with monitors that have calibration capabilities can still be used with calibration and / or verification tools. Therefore, the calibration capabilities of the monitor do not necessarily need to be maintained.

[0107] The calibration and / or verification tool has a compartment and an interface for connecting sensors such that the contact surface is exposed to a reference environment within the compartment.

[0108] The monitor or sensor may include a reader for reading the detection means, mounted on a calibration and / or verification tool. The monitor or sensor may include a control unit adapted to receive data from the detection means and initiate and / or execute a calibration and / or verification process. This may be a largely automated process controlled by software.

[0109] The control unit may be adapted to compare the measured concentration detected by the monitor with the gas concentration provided by the calibration and / or verification tool, and to initiate sensor recalibration if the difference between the measured concentration and the gas concentration is greater than a predetermined threshold.

[0110] A method for calibrating and / or verifying an assembly for measuring gas concentration, which has a sensor having a contact surface that can be directed toward the measurement point, and a monitor, includes the step of using the calibration and / or verification tool described above.

[0111] The calibration and / or verification tool has a compartment and an interface for connecting sensors such that the contact surface is exposed to a reference environment within the compartment.

[0112] The above method further includes the step of connecting the contact surface to the interface of the calibration tool.

[0113] Subsequently, it is verified whether the measured concentration detected by the monitor corresponds to the gas concentration provided by the reference environment in the compartment of the calibration and / or validation tool.

[0114] In particular, if necessary, the sensor is calibrated by adjusting the measured concentration detected by the monitor based on the gas concentration provided by the verification and / or calibration tool.

[0115] If the concentration detected by the monitor differs from the gas concentration provided by the calibration and / or verification tool by more than a predetermined concentration range, recalibration may be necessary. This range may depend on the gas concentration provided by the verification and / or calibration tool.

[0116] The final results of the calibration and / or verification process, and / or the status along the process, may be displayed by a system for measuring CO2 concentration, so that the user can see whether the process has started, is in progress, or has finished.

[0117] The present invention will be further described with reference to preferred embodiments and the following drawings. [Brief explanation of the drawing]

[0118] [Figure 1] This is a cross-sectional view of the first example of a calibration and / or validation tool. [Figure 2] A perspective view of the first example of a calibration and / or verification tool, shown without the sealing element (6). [Figure 3] This figure shows a second example of a calibration and / or verification tool. [Figure 4] This figure shows a third example of a calibration and / or verification tool. [Figure 5] This figure shows a fourth example of a calibration and / or verification tool. [Figure 6a]This figure shows a fifth example embodiment of a calibration and / or verification tool. [Figure 6b] This figure shows a fifth example embodiment of a calibration and / or verification tool. [Figure 7] This figure shows a sixth example of a calibration and / or verification tool. [Figure 8] This figure shows the seventh example of a calibration and / or verification tool. [Figure 9] This figure shows an assembly equipped with calibration and / or verification tools and systems. [Modes for carrying out the invention]

[0119] Figure 1 is a cross-sectional view of a first example of the calibration and / or validation tool 1. The calibration and / or validation tool 1 is a tool for calibrating and / or validating a system 100 (see Figure 9) for measuring gas concentrations, the system 100 having a sensor 101 (see Figure 9) for detecting transcutaneous gas, the sensor 101 having a contact surface 102 (see Figure 9) that can be directed toward a measurement site on the skin of a human subject or animal subject.

[0120] The calibration and / or verification tool 1 is a standalone mobile device and includes a compartment 2 for surrounding a reference environment 3.

[0121] The calibration and / or verification tool 1 includes an interface 4 for connecting a sensor 101 (see Figure 9) so that its contact surface 102 is exposed to a reference environment 3 within the compartment 2. In this example, the interface 4 includes a clamping element 23 for securing the sensor 101.

[0122] The calibration and / or verification tool 1 comprises means for providing a clearly defined gas concentration within a compartment, in this case a carbon dioxide absorbing material 5 located within the compartment 2.

[0123] The carbon dioxide absorbing material 5 provides a carbon dioxide concentration of less than 300 ppm within compartment 2.

[0124] A filter 7 is placed between the absorbent material 5 and the interface 4 to prevent the absorbent material, generally particulate matter, from leaving the compartment or contaminating the interface 4 and sensor 101.

[0125] The calibration and / or verification tool 1 is attached to the edge 24 of the compartment and includes a packaging sealing element 6 that protects the compartment 2, including the filter 7 and interface 4, before use.

[0126] Interface 4 can support sealing elements such as O-rings (not shown), but is unnecessary when an increase in the amount of CO2 absorbing material can compensate for potential leakage. The same applies to the second, third, and fourth examples shown below.

[0127] Figure 2 is a perspective view of a first example of the calibration and / or verification tool 1 without the sealing element 6 (see Figure 1), filter 7 (see Figure 1), and absorbent material 5 (see Figure 1).

[0128] An adhesive ring 32, equipped with an antenna and / or a tip, may be positioned between the interface 4 and the edge 24 as a detection means. Alternatively, the antenna and / or tip may be positioned at the bottom 33 of the calibration and / or verification tool 1 (see Figure 1).

[0129] Figure 3 shows a second example of the calibration and / or verification tool 1. The second example is similar to the first example, and the means for providing a clearly defined gas concentration in the compartment 2 of the calibration and / or verification tool 1 comprises a carbon dioxide absorbing material 5 placed in the compartment 2.

[0130] Compartment 2 comprises a housing 46 having two parts 47, 48. The first part 47 of the housing 46 has an interface 4 for mounting the sensor 101 and houses a moisture-absorbing material 49. The filter 50 can hold the moisture-absorbing material 49 in place.

[0131] The second portion 48 of the housing 46 is filled with absorbent material 5, which is held in place by the filter 51.

[0132] Before use, each part 47, 48 of the housing is closed separately by an airtight film or foil 52, such as aluminum foil.

[0133] Before attaching the sensor 101 to the interface 4, the sealing element 6 and the wheel 52 are removed from parts 47 and 48 of the housing 46. The second part 48 is attachable to the first part 47 and secured by a connecting clip 53.

[0134] Figure 4 shows a third example of calibration and / or validation tool 1, which is similar to the second example shown in Figure 3.

[0135] Compartment 2 comprises a housing 46 having two parts 47 and 48, the first part 47 being filled with a moisture-absorbing material 49 and the second part 48 being filled with a CO2-absorbing material 5.

[0136] A perforated plate 54 is attached to the first portion 47 of the housing, and the perforated plate 54 is positioned between the first portion 47 and the second portion 48 of the housing 46 after the second portion 48 has been attached to the first portion 47. The perforated plate 54 is provided with puncture elements 55 on both sides.

[0137] Before use, when the user pushes the second part 48 toward the first part 47, the puncture element 55 breaks through both airtight foils or films 52, such as aluminum foil, which do not need to be peeled off before use. After removing the sealing element 6, the sensor 101 can then be attached to the interface 4.

[0138] Figure 5 shows a fourth example of calibration and / or validation tool 1. The calibration and / or verification tool 1 comprises a pressurizing unit 9 for moving a gas, particularly air or nitrogen, through the absorbent material 5. The pressurizing unit 9 comprises a syringe 25 having a plunger 30.

[0139] The absorbent material 5 is placed inside the syringe 25 and separated and held in place by the filter 7. An interface 4 for connecting the sensor 101 is formed at the tip of the syringe 25.

[0140] Compartment 2 is formed between interface 4 and absorbent material 5. When the plunger 30 of the syringe 25 is pushed inward, a gas, such as air or nitrogen, is forced into compartment 2 through the absorbent material 5, and CO2 is removed from the gas.

[0141] In this case, a one-way valve formed by an elongated tube 10 having an optional flow limiter 42 at its end, positioned within the compartment, allows the gas to leak out of compartment 2, resulting in a state where only gas without CO2 remains in compartment 2.

[0142] Figures 6a and 6b show two embodiments of a fifth example of the calibration and / or verification tool 1.

[0143] The calibration and / or verification tool 1 includes a pressurizing unit 9, which is formed as a manual pump 26 for guiding air in a closed loop to pass through the absorbent material 5.

[0144] To allow gas to be supplied in only one direction, a first one-way valve 27 is positioned upstream of the manual pump 26, and a second one-way valve 28 is positioned downstream of the manual pump 26.

[0145] Compartment 2 is located upstream of the one-way valve 27 and between the absorbent material and the manual pump 26.

[0146] According to the first embodiment shown in Figure 6a, the manual pump 26 is integrated into a circular tube 29 that hosts the absorbent material 5. The absorbent material 5 is located inside the circular tube 29 and separated by a filter 7.

[0147] According to the second embodiment shown in Figure 6b, the manual pump 26, compartment 2, and absorbent material 5 are integrated into a box 43. The absorbent material 5 is separated by an inner wall 44 and a filter 7, which allow the gas to be pumped in a circular pattern.

[0148] Figure 7 shows a sixth example of a calibration and / or validation tool. In this example, the calibration tool 1 comprises a tank 17 containing a pressurized reference gas 18 having a clearly defined CO2 concentration, for example, 8% or near zero, which can be achieved by, for example, nitrogen filling.

[0149] The tank 17 can be provided as a metal cartridge having a compressed, calibrated reference gas 18.

[0150] Compartment 2 comprises a flow limiter 19, an adapter 41, and a puncture pin 40 that punctures the top surface of the metal cartridge 17 when the tank 17 is installed in compartment 2. After installation, the flow limiter 19 is positioned within the gas path of the tank 17. The reference gas 18 can enter compartment 2 through the flow limiter 19.

[0151] Compartment 2 is provided with an elongated tube 10 between it and the external environment to prevent outside air from entering it while allowing gas to leak out of it. In addition, a flow limiter 42 may be placed at the end of the elongated tube 10.

[0152] After a while, compartment 2 will be completely filled with the standard gas. Interface 4 may include any sealing element (not shown) because any leak will have a direction toward the environment as the pressure in compartment 22 becomes higher than the ambient pressure.

[0153] Figure 8 shows the seventh example of pre-use calibration and / or verification tool 1. The calibration and / or verification tool 1 comprises a tank 17 containing a reference gas 18, for example, a gas with a CO2 concentration less than 300 ppm, preferably close to zero. In this example, the compartment 2 and the tank 17 are located within a syringe.

[0154] A pressure relief valve 21 is located between the tank 17 and the compartment 2. The tank 17 is connected to a pressurizing unit 22, in this case a plunger 30 of a syringe 25, for pushing the reference gas 18 into the compartment 2 through the pressure relief valve 21.

[0155] Compartment 2 includes a one-way valve, in this case an elongated tube 10 having an optional flow limiter 42 at its end, which prevents ambient air from entering compartment 2 and allows gas to leak out of compartment 2. After the sensor 101 is connected to compartment 2, the plunger 30 is pushed inward, allowing the reference gas 18 to be forced into compartment 2, so that compartment 2 is completely filled with the reference gas 18 and can be used for verification and / or calibration of the calibration and / or verification tool 1.

[0156] Interface 4 preferably includes a sealing element (not shown in the figure). A sealing element such as an O-ring is necessary because the CO2-free gas in tank 17 is not pressurized, and the pressurized flow in compartment 2 is maintained for only a few seconds. The sealing element can ensure a low CO2 concentration in compartment 2 after the flow has ended throughout the entire calibration process.

[0157] Figure 9 shows an assembly 200 comprising a calibration and / or verification tool 1 and a system 100.

[0158] System 100 is suitable for measuring gas concentrations, particularly gases diffused through the skin, especially CO2.

[0159] The system 100 includes a sensor 101 for detecting transcutaneous gases, particularly CO2, and the sensor 101 has a contact surface 102 that can be directed toward a measurement site on the skin of a human subject or animal subject.

[0160] The system 100 includes a monitor 110 having a display 111. The sensor 101 can be mounted on a calibration and / or verification tool 1 which has an interface 4 for connecting the sensor 101 so that the contact surface 102 is exposed to a reference environment 3 within a compartment 2 of the calibration and / or verification tool 1.

[0161] After the contact surface 102 is coupled to the interface 4 of the calibration tool 1, it can be automatically verified whether the measured concentration displayed on the display 111 of the monitor 110 corresponds to the gas concentration provided by the reference environment 3 in the compartment 2.

[0162] If necessary, the sensor 101 can be recalibrated by adjusting the measured concentration displayed on the display 111 based on the gas concentration provided by the verification and / or calibration tool 1.

Claims

1. A calibration and / or verification tool (1) for calibrating and / or verifying a system (100) for measuring gas concentration, wherein the system (100) has a sensor (101) for detecting transcutaneous gas, and the sensor (101) has a contact surface (102) that can be directed toward a measurement site on the skin of a human subject or animal subject. The calibration and / or verification tool (1) is A compartment (2) to surround the base environment (3), An interface (4) for connecting the sensor (101) such that the contact surface (102) is exposed to the reference environment (3) within the compartment, The system comprises means (5; 18) for providing a clearly defined gas concentration within the compartment, The calibration and / or verification tool (1) is a standalone mobile device, preferably a single-use device and / or a disposable device.

2. The calibration and / or verification tool according to claim 1, comprising detection means adapted to be recognized and / or read by the system (100) for measuring gas concentration.

3. The calibration and / or verification tool (1) comprises a removable packaging sealing element (6), and / or the calibration and / or verification tool (1) comprises a removable gas-impermeable packaging, according to claim 1 or 2.

4. The calibration and / or verification tool according to any one of claims 1 to 3, further comprising a hygroscopic material (49) for drying the gas in the reference environment (3).

5. The means (5) for providing a clearly defined gas concentration within the compartment (2) is adapted to provide a carbon dioxide concentration of less than 300 ppm, preferably less than 100 ppm, and most preferably less than 50 ppm, within the compartment (2), as described in any one of the preceding claims.

6. The calibration and / or verification tool according to claim 5, wherein the means (5) for providing a clearly defined gas concentration comprises a carbon dioxide absorbing material (5), particularly soda lime, or is formed from a carbon dioxide absorbing material (5), particularly soda lime.

7. The absorbent material (5) is placed inside the compartment (2), Preferably, a separation element (7), particularly a filter element (7), a mesh element or a sieve element, is disposed between the absorbing material (5) and the interface (4), and in particular between the absorbing material (5) and the reference environment (3), the calibration and / or verification tool according to claim 6.

8. The calibration and / or verification tool according to claim 6 or 7, further comprising a pressurizing unit (9; 26) for moving a gas, particularly air or nitrogen, through the absorbent material (5).

9. The pressurizing unit (9) includes a syringe (25) having a plunger (30), The calibration and / or verification tool according to claim 8, preferably comprising an elongated tube (10) and / or a one-way valve for releasing gas to the external environment from the compartment (2) formed by a portion of the syringe (25).

10. The pressurizing unit is a manual pump (26), The calibration and / or verification tool according to claim 8, preferably comprising two one-way valves (27, 28) positioned upstream and downstream of the manual pump (26).

11. The calibration and / or verification tool comprises a tank (17) containing a reference gas (18) having a CO2 concentration less than 300 ppm, The compartment (2) is provided with an elongated tube (10) preferably having a flow limiter (42) and / or a one-way valve between the compartment (2) and the external environment. A pressure relief valve (21) is positioned between the tank (17) and the compartment (2). The calibration and / or verification tool according to claim 5, wherein the tank is connected to a pressurizing unit (22) for pushing the reference gas (18) through the pressure relief valve (21).

12. The means (18) for providing a clearly defined gas concentration within the compartment is adapted to provide a clearly defined CO2 concentration higher than 300 ppm, particularly in the range of 3 to 13%, more preferably in the range of 6 to 10%, within the compartment or in a tank sealed to or capable of being sealed to the compartment, according to any one of claims 1 to 4.

13. The calibration tool (1) includes a tank (17) that contains a pressurized reference gas (18) having a CO2 concentration higher than 300 ppm. The compartment is provided with an elongated tube (10) preferably having a flow limiter (42) and / or a one-way valve between the compartment and the external environment. Calibration and / or verification tool according to claim 12, wherein the tank (17) comprises a flow limiter (19), and the tank (17) is mounted or can be mounted on the compartment (2) such that the flow limiter (19) is positioned between the tank (17) and the compartment (2), and the reference gas can enter the compartment (2) through the flow limiter (19) to establish a reference environment (3) within the compartment (2).

14. The calibration tool (1) includes a tank (17) that contains a reference gas (18) having a CO2 concentration lower than 300 ppm. The compartment is provided with an elongated tube (10) preferably having a flow limiter (42) and / or a one-way valve between the compartment and the external environment. A pressure relief valve (21) is positioned between the tank (17) and the compartment (2). The calibration and / or verification tool according to claim 12, wherein the tank (17) is connected to a pressurizing unit (22) for pushing the reference gas (18) through the pressure relief valve (21).

15. An assembly (200) for calibration and / or verification of a system (100) for measuring gas concentration, A system (100) for measuring gas concentration, in particular for measuring transcutaneously diffused gas, in particular CO2, wherein the system (100) has a sensor (101) for detecting transcutaneous gas, in particular CO2, the sensor (101) has a contact surface (102) that can be directed toward a measurement site on the skin of a human subject or animal subject, and the system (100) has a monitor (110), The assembly (200) for calibration further comprises a calibration and / or verification tool (1) according to any one of claims 1 to 14, wherein the calibration and / or verification tool (1) has a compartment (2) and an interface (4) for connecting the sensor (101) such that the contact surface (102) is exposed to a reference environment (3) within the compartment, and the calibration and / or verification tool (1) preferably comprises detection means that can be recognized and / or read by the system (100) for measuring gas concentration.

16. A method for calibrating and / or verifying an assembly (200) for measuring gas concentration, having a sensor (101) having a contact surface (102) that can be directed toward a measurement point and a monitor (110), wherein the calibration and / or verification tool (1) comprises a compartment (2) and an interface (4) for connecting the sensor (101) such that the contact surface (102) is exposed to a reference environment (3) within the compartment, and the method is as follows: The steps include connecting the contact surface (102) to the interface (4) of the calibration tool (1), Optionally, the steps include recognizing and / or reading the detection means of the calibration and / or verification tool (1), The steps include: confirming whether the measured concentration detected by the monitor (110) corresponds to the gas concentration provided by the reference environment in the compartment (2) of the calibration and / or verification tool (1); Preferably, the method includes the step of recalibrating the sensor by adjusting the measured concentration detected by the monitor (110) based on the gas concentration provided by the verification and / or calibration tool, if necessary.

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