Breath gas analyzer comprising a gas analyzing circuit

Abstract

There is provided a breath gas analyzer (1) comprising a sample container (200) configured to capture and store an exhaled air sample from the flow of exhale air (2) received from a blowtube (100). The breath gas analyzer (1) further comprises a gas analyzing circuit (300) configured to analyze the captured exhaled air sample, the gas analyzing circuit (300) comprises a first pump (301), a gas sensor (302), and a conduit (303), wherein the first pump (301) is arranged to generate a flow (304) of the captured exhaled air sample through the conduit (300), and the gas sensor (302) is arranged to measure a property of the captured exhaled air sample flowing through the conduit (303). There is further provided a method for operating the breath gas analyzer.

Description

[0001] BREATH GAS ANALYZER COMPRISING A GAS ANALYZING CIRCUIT

[0002] THE FIELD OF THE INVENTION

[0003] The present invention relates to the field of pulmonary function testing, particularly pulmonary function testing relating to the field of exhaled gas analysis.

[0004] BACKGROUND

[0005] Exhaled gas analysis is a technique for providing data relating to biomarkers which may be present in the exhaled breath of a patient. The biomarkers may be volatile organic compounds (VOCs) which can be indicative of disease, or a degree of a disease, such as lung cancer, asthma, and chronic obstructive pulmonary disease.

[0006] The data relating to the VOCs in a patients exhaled breath may support a physician in the assessment of an individual's clinical state. Frequent monitoring using exhaled gas analysis provides the patient and / or the physician with data for tracking the progression of a determined disease. For example, the impact of medication and / or changes in lifestyle may be tracked by frequent consecutive exhaled gas analysis. For consecutive exhaled gas measurements to be comparable to one another, for the purpose of tracking the clinical status of a patient, it is of high importance that the measuring of the VOCs in the exhaled breath is accurate, and that the sampling of the exhaled breath is accurate in its repetition.

[0007] Although research on exhaled gas analysis began many years ago, its clinical application for disease assessment remains limited. Furthermore, the various devices existing on the market today for the analysis of the presence of VOC in the exhaled breath of a patient suffer from inconsistencies in the measurements of the VOCs. Some of these inconsistencies may be ascribed to how the sampling of the exhaled breath is performed, or how the exhaled breath is analyzed, or both. Furthermore, current technology is limited in the minimum amounts of VOCs which can be accurately determined in an exhaled breath, thereby limiting the usefulness of current technology. Accordingly, there is a need for new technology which improves the accuracy of exhaled gas analysis, and the minimum amount of VOC that can be determined in an exhale breath analysis.SUMMARY

[0008] The invention is set out in the appended set of claims. This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description.

[0009] In view of the presented background, a general object of the present technology is to provide an improved breath gas analyzer which overcomes at least some of the deficiencies of the current technology.

[0010] According to a first aspect of the invention there is provided a breath gas analyzer comprising: a blowtube comprising an inlet configured to receive a flow of exhaled air, and at least one outlet; a sample container, the sample container defining a chamber, which chamber comprises an inlet which is fluidly connected to one of the at least one outlet of the blowtube, and wherein the chamber is configured to capture and store an exhaled air sample from the flow of exhaled air received from the outlet of the blowtube, and wherein the chamber further comprises an outlet configured to allow an excess of the flow received from the blowtube to exit the chamber via an outlet, and wherein the breath gas analyzer further comprises a gas analyzing circuit configured to analyze the captured exhaled air sample, the gas analyzing circuit comprising: a first pump, a gas sensor, and a conduit, wherein the conduit is arranged to provide a fluid by-pass between a first and a second position of the chamber, and wherein the first pump is arranged to generate a flow of the captured exhaled air sample through the conduit, and wherein the gas sensor is arranged to measure a property of the captured exhaled air sample flowing through the conduit.

[0011] Accordingly, there is provided a breath gas analyzer comprising a gas analyzing circuit, which gas analyzing circuit may recirculate a captured air sample from a first position to a second position of a chamber of a sample container, and past a gas sensor of the gas analyzing circuit. Thus, compared to the art, a larger portion of the VOCs present in a captured air sample may be measured by the gas sensor of the gas analyzing circuit. This allows for improved consistency in the measurement of VOCs in exhaled breath samples compared to gas analyzers known in the art.

[0012] The recirculation of the captured air sample according to the first aspect of the invention further enables the gas analyzing circuit to accurately and consistently, determine an amount of VOCs in a captured air sample even when the concentrations of VOCs in the sample are low. Tests have shown that, for example, carbon monoxide gas (CO) in an exhaled breath having a concentration as low as 0.1 ppm may be detected.

[0013] Accordingly, the gas analyzing circuit of the disclosed breath gas analyzer contributes to an improvement with respect to the minimum amounts of VOCs which can be accurately determined in exhaled air, thereby allowing accurate quantification of low concentrations of VOCs in exhaled air. This improved accuracy enables a more detailed monitoring of pulmonary function compared to the art, thereby improving the monitoring of the progression of pulmonary diseases.

[0014] Further, the device may be designed compact, as a handheld device, thereby allowing a self-assessment by the patients themself to track the progression of their disease. This is advantageous as it allows a more frequent assessment of a disease without increasing the burden on healthcare providers. A further benefit associated with such self-assessment is that the patients themselves may observe impacts of medication and / or changes in lifestyle, which in turn could instill motivation to the patients to maintain positive lifestyle changes.

[0015] Furthermore, the improved accuracy of the gas analyzing circuit renders the breath gas analyzer according to the first aspect capable of monitoring the pulmonary function of healthy subjects. For example, athletes, may have interest in monitoring the development of their pulmonary function. Moreover, the improved accuracy renders the breath gas analyzer capable of monitoring a development of pulmonary function with respect to exposure to hazardous conditions, such as occupational exposure to volatile substances, gases, powders, or the like. For example, the breath gas analyzer may be used to monitor the development of pulmonary function of subjects who are repeatedly exposed to combustion-related gases, i.e., smokers, firefighters, or the like.

[0016] The blowtube comprising the inlet and the at least one outlet of the blowtube may, in the simplest configuration simply be a tube configured to guide a received amount of exhaled air from the inlet to the at least one outlet of the blowtube, wherein said amount of exhaled air is a flow of exhaled air received at the inlet of the blowtube. The inlet of the blowtube may be provided with a filter for dehumidifying the received flow of exhaled air. Dehumidifying the received flow of exhaled air may be of value as some sensors, particularly gas sensors, may be adversely affected by a humidity of the received flow of exhaled air.

[0017] One of the at least one outlet of the blowtube is fluidly connected to the inlet of a sample container. The fluid connection may for example be enabled by a flexible tube.

[0018] Accordingly, the principal function of the blowtube is to act as a receiving unit for the flow of exhaled air, optionally measuring the flow of the received exhaled air, and subsequently to guide an amount of exhaled air received at the inlet, via its fluid connection to the sample container.

[0019] The blowtube may be configured with one outlet, in which case the amount of exhaled air which is guided to the sample container corresponds to the amount of exhaled air received at the inlet of the blowtube. Alternatively, the blowtube may be configured with two or more outlets, in which case the exhaled air received in the inlet of the blowtube will be divided between the two or more outlets of the blowtube. Accordingly, in embodiments comprising two or more outlets wherein only one outlet is fluidly connected to the sample container, the amount of exhaled air which is guided to the sample chamber may be less than the total amount of exhaled air received at the inlet of the blowtube. The amount of exhaled air which is guided to the sample container may be a minor portion of the total amount of the exhaled air received in the blowtube. The remainder portion of the total exhaled air may be guided to the one or more further outlets of the blowtube. The skilled person realizes that the relative amounts of the total of the exhaled air which is guided to each respective two or more outlets of the blowtube may be determined by the relative flow rates allowed though each respective outlet. The flow rate may, for example, be determined by the size of the outlets. For example, a blowtube comprising two outlets configured to allow the same flow rate are expected to receive equal amounts of the total of the exhaled air received in the blowtube. Accordingly, for a blowtube comparing two or more outlets, the relative amount of the exhaled air which is guided to the sample containermay be determined by the flow rate allowed though each respective outlet. The sample container defines a chamber having a volume, which chamber is configured to hold a corresponding volume of air, i.e., an exhaled air sample. The chamber is provided with an outlet configured to allow a flow of exhaled air received from the blowtube to displace a volume of air already held by the sample container. Worded differently, the outlet of the chamber may hinder any build-up of pressure inside the chamber due to the receiving of exhaled air from the blowtube by allowing an excess of air in the chamber to be vented out though the outlet. Preferably, the outlet is configured to only allow fluid displacement in a direction defined as out from the chamber. Accordingly, the outlet may be formed as a valve, for example a one-way valve.

[0020] The chamber may have a volume in the range of 10-150 ml. This volume may be less than or equal to the volume of exhaled air received from the blowtube. Accordingly, the sample container, i.e., the chamber thereof, is configured to capture and store a portion of the total of exhaled air received at the inlet of the chamber. The captured exhaled air in the chamber constitutes a captured exhaled air sample.

[0021] The gas analyzing circuit of the gas analyzer comprises a conduit which is arranged to fluidly connect a first position of the chamber to a second position of the chamber to thereby form a recirculation loop. The gas analyzing circuit further comprises a first pump arranged to generate a flow through the conduit, i.e., a recirculating flow between the first and the second positions of the chamber.

[0022] By the meaning of position in this regard, it is here meant a first and a second point of the chamber, at which respective points the conduit of the gas analyzing circuit is fluidly connected. The first and the second positions of the chamber may be any two positions of the chamber. However, it is preferred that the two positions, i.e., the first and the second position, are positioned at a distance from one another.

[0023] As used herein, the term "distance" is understood as a fluid distance defined by a fluid path between the two positions. The distance may by way of example be in the range of 10-200 mm. Preferably, the respective positions of the first and the second positions are chosen such that the fluid distance between the first and second position is maximized with respect to the extension of the chamber.

[0024] In case the chamber comprises a partitioning wall forming an internal channel, the fluid distance may be maximized with respect to the extension of the internal channel, thereby contributing to a compact design of the breath gas analyzer. The first position may be positioned in a vicinity of the inlet of the chamber, and the second position may be positioned in a vicinity of the outlet of the chamber, i.e., in the vicinity of the one-way valve. The respective positioning of the first and the second positions in the vicinity of the respective inlet and outlet of the chamber is particularly preferred in a chamber comprising an internal channel being formed by a partitioning wall.

[0025] The arranging of the fluid connections between the chamber and the conduit, i.e., at the first and second positions of the chamber according to the above, enables the first pump of the gas analyzing circuit to generate recirculating flow through the conduit, thereby achieving an efficient circulation of the volume of air held in the chamber, for example a captured exhaled air sample.By the meaning of an efficient circulation, it is here meant that the positions of the first and second positions of in the chamber are selected so as to limit the formation of any volumes in the chamber which experience a limited or no circulation. A complete circulation of the entire volume of air in the chamber, for example a captured exhaled air sample, is preferred as it improves the measurement of the at least one property of the captured air.

[0026] When the first or the second position of the chamber is in a vicinity of the inlet of the chamber, the inlet of the chamber may be provided with a gas guide. The gas guide is configured to direct a flow of exhaled air away from the position of fluid connection to the conduit. The purpose of the gas guide is to hinder the flow of exhaled air received at the inlet of the chamber to flow into the conduit of the gas analyzing circuit. The hindering the flow of exhaled air to flow into the conduit of the gas analyzing circuit improves the displacing of pre-existing volumes of air already held in the chamber.

[0027] The improved lower limit of quantification of VOCs in the captured exhaled air sample of the gas analyzing circuit of the present disclosure is enabled by measuring the at least one property of a captured exhaled air sample whilst recirculating the captured exhaled air sample through the conduit and past the gas sensor of the gas analyzing circuit. The gas sensor may be arranged in such a manner that the sensor is exposed to the flow generated in the conduit by the first pump. Accordingly, the sensor may be arranged either downstream or upstream from the first pump. The gas analyzing circuit may comprise a gas sensor configured to measure a plurality of properties of the captured exhaled air sample. Furthermore, the gas analyzing circuit may comprise a plurality of sensors of different types. Each sensor of the plurality of different sensors may be configured to measure a respective one or more properties of the captured exhaled air. Accordingly, the gas analyzing circuit is capable of concurrently measuring a plurality of properties of a gaseous volume, for example, a captured exhaled air sample. In case of a plurality of gas sensors, the plurality of gas sensors may be arranged one after the other with respect to the flow in the conduit generated by the first pump.

[0028] The breath gas analyzer may further comprise a second pump configured to provide fluid transport from one of the at least one outlet of the blowtube to the inlet of the chamber of the sample container.

[0029] Accordingly, the second pump may form part of the fluid connection between the blowtube and the sample container. The second pump may be configured to only allow fluid communication between the blowtube and the sample container whilst the second pump is set to operate, i.e., when the second pump is set to provide fluid transport. Accordingly, when the second pump is set to not operate, the fluid connection between the blowtube and the sample container may be closed.

[0030] The skilled person realizes that the volume of exhaled air which is fluidly transported from the blow to the sample container by the second pump is dependent on the operational setting of the second pump and the duration of operation. That is, the total volume of exhaled air fluidly transported to the sample container is a function of the rate of fluid transport per unit time as well as the time period, i.e., sampling time, during which the second pump is set to operate. For example, the second pump may be set to fluidly transport 50 ml of exhaled air per second for a time period of 3 seconds, thereby resulting inthe fluid transport of 150 ml of exhaled air from the blowtube to the sample container. Accordingly, the second pump is advantageous in that it allows for a precise volume of exhaled air to be fluidly transported to the sample container. Thus, in embodiments comprising a second pump, the relative amount of the total of the exhaled air received in the sample chamber may be independent with respect to any further outlet provided to the blowtube. This is advantageous as it allows the blowtube to be provided with a further outlet to thereby ensure a flow path though the blowtube for a flow of exhaled air received at the inlet of the blowtube, regardless of the operational status of the second pump.

[0031] Furthermore, the further outlet may be configured to allow large flows without adversely affecting the sampling of exhaled air such that the further outlet does not impose a limitation on the expiration of a user when exhaling into the blowtube. As will be discussed later, configuring the further outlet of the blowtube to allow for large flows is advantageous as it allows the gas analyzing unit to perform further pulmonary function tests which require large flows though the blowtube, for example measurements of spirometry.

[0032] An embodiment comprising a second pump is further advantageous as it allows for the selection of a temporal fraction, i.e., a time-based fraction, of the flow of exhaled air which is to be fluidly transported to the sample container. As used herein, "temporal fraction of the flow of exhaled air" defines a time window during the flow of the exhaled air, i.e., during a receiving of exhaled air at the inlet of the blowtube, during which the exhaled air is sampled, i.e., fluidly transported to the sample container. For example, the second pump may be configured to start operating as soon as a flow of exhaled air is received at the inlet of blowtube to thereby sample a volume of the flow which corresponds to an early temporal fraction. Alternatively, the second pump may be configured to start operating, i.e., to start sampling, with a delay with respect to the onset of a flow of exhaled air through the blowtube to thereby sample a temporal fraction of the flow which corresponds to a middle or tail portion of the flow. Thus, the second pump may not only be configured to fluidly transport an accurate volume of exhaled air, the second pump may further be configured to fluidly transport select temporal fraction of the flow of exhaled air received in the blowtube.

[0033] The gas analyzer may further comprise a first three-way valve. A first port of the first three-way valve fluidly connects to the outlet of the blowtube, a second port of the three-way valve fluidly connects to the inlet of the chamber of the sample container, and a third port fluidly connects the breath gas analyzer to a first exhaust.

[0034] The first three-way valve may be arranged downstream from the blowtube, and upstream from the sample container, as seen relative to a direction of the flow of exhaled air received and the inlet of the blowtube. The first three-way valve may be set between a first and a second valve state, wherein each valve state is associated with a fluid connection between two of the ports of the three-way valve. The first valve state is associated with a fluid connection between the outlet of the blowtube and the first exhaust. The second valve state is associated with a fluid connection between the outlet of the blowtube and the inlet of the chamber of the sample container.

[0035] When the first three-way valve is set to the first valve state, a flow of exhaled air received at the inlet of the blowtube will be directed by the first three-way valve towards the first exhaust of the gas analyzer. When the first three-way valve is set to the secondvalve state, the flow of exhaled air received at the inlet of the blowtube will be directed by the first three-way valve towards the chamber of the sample container. Accordingly, setting the first three-way valve between the first and second valve states allow for selecting of a portion of the flow of exhaled air received at the inlet of the blowtube, which portion is to be captured in the chamber of the sample container. The total volume of exhaled air directed to the sample container is hence a function of the flow of exhaled air through the outlet of the blowtube and the time period, i.e., sampling time, during which the first three-way valve is set to its second valve state. The first three-way valve may be set to the first valve state upon first receiving an exhaled air flow at the inlet of the blowtube. The valve state of the first three-way valve may then be set to the second valve state, thereby enabling a capture of the flow received in the chamber of the sample container. The first three-way valve may remain in the second valve state before being returned to the first valve state. The timing of the setting of the valve states of the first three valve with respect to the flow of exhaled air allows the third three-valve to select a temporal fraction of the flow of exhaled air in a corresponding fashion as embodiments comprising a second pump. In embodiments comprising a first three-way valve, there is always a flow path available for the flow of exhaled air, regardless of the valve state of the first three-way valve, accordingly, there is no need to provide any further outlets to the blowtube. In embodiments comprising a first three-way valve, the blowtube is preferable provided with one outlet. As discussed earlier, this improves the directing of exhaled air which is to be captured and stored the sample container.

[0036] The conduit of the gas analyzer may comprise a second three-way valve, wherein a first port of the second three-way valve fluidly connects to a first branch of the conduit of the gas analyzing circuit, a second port fluidly connects to a second branch of the conduit of the gas analyzing circuit, and a third port fluidly connects to a second exhaust. The second three-way valve may be set between a first and a second valve state, wherein each valve state is associated with a fluid connection between two of the ports of the second three-way valve. The first valve state of the second three-way valve enables a fluid connection between the first and the second branches of the conduit of the gas analyzing circuit, i.e., between the first and second positions of the chamber according to the above. Accordingly, the first valve state of the second three-way valve enables the first pump to circulate the captured exhaled air sample in the chamber, through the conduit, and past the at least one gas sensor.

[0037] The second valve state of the second three-way valve enables a fluid connection between the first branch of the conduit and the second exhaust. Preferably, the first pump of the gas analyzing circuit may be arranged in the first branch of the conduit. Such an arrangement of the first pump allows the first pump to generate a flow from the intake of the blowtube towards the second exhaust via the chamber of the sample container. That is, via the longest fluid path of the gas analyzer.

[0038] The skilled person realizes that in embodiments of the breath gas analyzer which comprise both a second three-way valve and a second pump, the second three-way valve must be set to its second valve state and the second pump must be in operation to enable said flow from the inlet of the blowtube towards the second exhaust provided by the three-way valve. Correspondingly, the skilled person realizes that for breath gas analyzers comprising both a first and a second three-way valve, both the first and the second three-way valves must be set to their respective second valve states to enable said flow from the intake of the blowtube towards the second exhaust via the chamber of the sample container.

[0039] The flow generated by the first pump, from the intake of the blowtube towards the second exhaust via the chamber of the sample container may achieve a cleaning or purging of the gas analyzer before or after use.

[0040] Preferably, the gas sensor is also arranged in the first branch of the conduit.

[0041] Arranging the gas sensor in the first branch of the conduit allows the gas sensor to monitor at least one property of the air flowing from the intake of the blowtube towards the second exhaust via the chamber of the sample container during cleaning or purging. Accordingly, an output signal from the gas sensor may be used to determine whether or not a sufficient cleaning or purging has been achieved, based on the at least one measured property of the air flowing towards the second exhaust.

[0042] In some embodiments the second pump may have a higher capacity for fluid transport per unit time than the first pump. The amount of fluid transport provided by the second pump which exceeds the capacity of the first pump will thus be vented out from the sample container via the outlet of the sample container. Accordingly, the cleaning or purging of the gas analyzer may be performed more quickly in embodiments comprising a second pump. Furthermore, the cleaning and / or purging of the gas analyzer may be performed regardless of whether the gas analyzer comprises a second three-way valve or not.

[0043] The capacity for fluid transport of the second pump, i.e., the maximum rate of fluid transport of the second pump, may be at least 0.5 l / min, preferably at least 0.75 l / min, most preferably at least 1 l / min. Meanwhile the capacity for fluid transport of the first pump, i.e., the maximum rate of fluid transport of first the pump, may be at least 200 ml / min, preferably at least 250 ml / min, most preferably at least 300 ml / min. The skilled person realizes that the rate at which the first and second pumps operate during use of the gas analyzer may be set. Accordingly, the rate of fluid transport of the first and second pumps may vary during purging, sampling, measuring, and cleaning.

[0044] The gas analyzing circuit may further comprise a gas guide configured to guide the flow generated by the first pump onto the gas sensor.

[0045] The gas guide ensures that a larger portion of the flow generated in the conduit by the first pump comes into contact with the gas sensor. Accordingly, the gas guide may reduce any turbulence in the vicinity of the gas sensor which could adversely affect the measuring of the at least one property of the circulated exhaled air sample.

[0046] The blowtube may comprise a flow sensor which is configured to measure the flow of exhaled air through the blowtube.

[0047] The blowtube and the flow sensor may be configured to be removably attached to one another. For example, the blowtube may comprise a socket for a press fitting of the flow sensor to the blowtube. Alternatively, the flow sensor may be removably attached to the blowtube by screwing the sensor onto the blowtube, or vice versa. The skilled personrealizes that there are a number of plausible alternatives for achieving a removable attachment of the flow sensor to the blowtube.

[0048] The flow sensor may be a pressure sensor configured to measure a differential pressure in the blowtube, which differential pressure corresponds to a flow through the blowtube. It may for example be the flow of exhaled air received at the inlet of the blowtube. The blowtube may comprise an internal flow restricting element. The pressure sensor may be configured to measure a differential pressure, on either side of the restricting element, resulting from the flow of exhaled air passing through the restricting element. Measuring of flows using differential pressure measurements are well known in the art and are hence not described here in detail. The use of a pressure sensor for the measuring of the flow of the received exhaled air is but one example of how said flow may be measured. The skilled person realizes that the flow of exhaled air received at the inlet of the blowtube may be measured using a variety of sensor types, wherein each such sensor type requires various adaptations to the blowtube in order to adequately measure said flow. Other examples of sensor types that may be used include ultrasonic flow sensors, temperature flow sensors, turbine flow sensors or target type flow sensors. While these other types of sensors for the measuring the flow of exhaled air are plausible alternatives, a pressure sensor for the measuring of the flow of exhaled air, i.e., a differential pressure flow sensor, is preferred as it allows measuring a variety of flow rates, for example both high flows and low flows, without requiring any modifications.

[0049] The breath gas analyzer may further comprise a control unit configured to receive an output signal from the flow sensor and / or from the gas sensor respectively, and to control the first and the second pump.

[0050] Accordingly, the control unit may be configured to control the measuring, cleaning, and / or purging of the gas analyzer by controlling the operation of first and the second pump, optionally in combination with the controlling of the second three-way valve. Hence, with reference to the above discussion on embodiments comprising a second pump, the control unit may determine the volume of the flow of exhaled air received at the inlet of the blowtube which is to be captured in the chamber of the sample container by controlling the operation of the first and second pump. The control unit may be configured to control the measuring, cleaning, and / or purging of the gas analyzer by controlling the first and the second pump.

[0051] Correspondingly, for embodiments comprising a first three-way valve, the breath gas analyzer may comprise a control unit configured to receive an output signal from the flow sensor and the gas sensor respectively, and to control the first pump and the setting of the first and the second three-way valves.

[0052] Thus, the control unit may determine the volume of the flow of exhaled air received at the inlet of the blowtube which is to be captured in the chamber of the sample container by controlling the valve state of the first three-way valve. Correspondingly, the control unit may be configured to control the measuring, cleaning, and / or purging of the gas analyzer by controlling the first pump and the first and second three-way valves.The control unit may be configured to control the second pump or the first and the second three-way valves, based on a predetermined timing sequence and / or output signals received from the flow sensor, or the gas sensor.

[0053] For example, the control unit may set the second pump operate, to thereby fluidly transport exhaled air from a flow of exhaled air in the blowtube once a predetermined condition has been fulfilled. The control unit may further be configured to set the second pump to not operate, to thereby break the fluid connection between the blowtube and the sample container, after a predetermined sampling time. Accordingly, the control unit may determine the total amount of exhaled air which is fluidly transported by the second pump by controlling rate at which the second pump operates and the duration of operating the second pump. Meanwhile, the temporal fraction of the flow of exhaled air from which exhaled air is sampled may be controlled by the control unit by timing the setting of the second pump to operate with respect to onset of the flow of exhaled air.

[0054] Correspondingly, the control unit may be configured to set the first three-way valve from the first valve state to the second valve state, thereby enabling a capture of the received flow of exhaled air once a predetermined condition is fulfilled.

[0055] The predetermined condition according to the above may be that the output signal from the flow sensor of the blowtube indicates that a predetermined flow of the received exhaled air has been maintained for a predetermined amount of time. For example, a predetermined flow may be in a range of 45-65 ml / s, and the time for maintaining said flow rate may be, for example, 7 seconds. The control unit may further be configured to stop capturing exhaled air from the flow of exhaled air, i.e., by return the first three-way valve from the second valve state to the first valve state or by setting the second pump to not operate, after a predetermined capture time, for example after 3 seconds. Returning the first three-way valve to its first position or setting the second pump to no operate effectively breaks the fluid connection between the blowtube and the sample container, thereby sealing the captured exhaled air sample in the chamber. For example, upon fulfillment of the predetermined condition, the second pump may be set to fluidly transport 50 ml / s, and the capture time may be 3 s, equating to a total amount of 150 ml of the flow of exhaled air received at the inlet of the blowtube. Correspondingly, the total amount of exhaled air directed to the chamber of the sample container by a first three-way valve is a function of the predetermined flow rate and the predetermined capture time before returning to the first valve state. For example, the predetermined flow rate may be 50 ml / s, and the predetermined capture time may be 3 s, equating to a total amount of 150 ml of the flow of exhaled air received at the inlet of the blowtube being directed to the chamber of the sample container.

[0056] Regardless of whether the capturing of an exhaled air sample involves the control of a second pump or a first three-way valve, and in the case that the chamber of the sample container has a volume which is less than the total volume of exhaled air directed thereto, an excess of said flow will be vented out via the outlet of the chamber of the sample container. After an exhaled air sample has been captured, i.e., sampled, in the chamber of the sample container, the control unit may be configured to operate the first pump and to set any second three-way valve to its first valve state, thereby enabling a recirculation of thecaptured exhaled air sample though the conduit and past the gas sensor of the gas analyzing circuit.

[0057] The control unit may be configured to keep the first pump in operation and any second three-way valve in its first valve state until the captured exhaled air sample has been measured. For example, the control unit may be configured to keep the first pump in operation and the second three-way valve in its first valve state for a predetermined measurement time. Alternatively, the control unit may be configured to keep the first pump in operation and the second three-way valve in its first valve state until a measurement condition is fulfilled. The measurement condition may be based on an output signal received from the gas sensor. For example, the measurement condition may be that an output signal from the gas sensor, representing at least one property of the captured exhaled air samples, has peaked, reached a plateau, and / or begun to decline.

[0058] In addition to the above, for breath gas analyzers comprising both a second pump and a second three-way valve, the control unit may further be configured to not operate the second pump during measuring of the captured exhaled air sample, thereby ensuring a sealing of the sample container during the measuring.

[0059] Correspondingly, for breath gas analyzers comprising both a first and a second three-way valve, the control unit may further be configured to keep the first three-way valve in its first valve state to ensuring a sealing of the sample container.

[0060] The control unit may be configured to set the second three-way valve to its second valve state, and to operate the first pump, thereby allowing a cleaning or purging of the chamber of the sample container and the conduit by generating a flow from the intake of the blowtube towards the second exhaust via the chamber of the sample container.

[0061] Accordingly, the cleaning and purging may be understood as a flushing of the sample container and the conduit with ambient air. The control unit may be configured to keep the second three-way valve in its second valve state, and to keep the first pump in operation, for a predetermined clean / purging time or until an output from the gas sensor indicates that at least one property of the flow through the first branch of the conduit fulfills a predetermined condition.

[0062] Correspondingly, in embodiments of the breath gas analyzer comprising a second pump, the control unit may further be configured to keep the first and second pumps in operation during cleaning / purging of the gas analyzer until an output from the gas sensor indicates that at least one property of the flow through the first branch of the conduit fulfills a predetermined condition.

[0063] Correspondingly, in embodiments of the breath gas analyzer comprising both a second pump and a second three-way valve, the control unit may further be configured to keep the first and second pumps in operation during cleaning / purging of the gas analyzer until an output from the gas sensor indicates that at least one property of the flow through the first branch of the conduit fulfills a predetermined condition.

[0064] Correspondingly, for breath gas analyzers comprising both a first and a second three-way valve, the control unit may further be configured to keep the first three-way valve in its second valve state for the purpose of enabling fluid communication between the blowtube and the chamber of the sample container.Purging may be performed prior to collecting a sample while cleaning may be performed after a measurement of a collected sample. During purging, the control unit may be configured to flush the sample container and the conduit with ambient air according to the above for a predetermined purging time. After the predetermined purging time the control unit may store an output from the one or more gas sensors as a baseline value representative of VOCs levels in the ambient atmosphere.

[0065] During cleaning, the control unit may be configured to flush the sample container and the conduit with ambient air according to the above until the gas sensor indicates that at least one property of the flow through the first branch of the conduit fulfills a predetermined condition. The predetermined condition of the at least one property of the flow though the conduit may be that output from the gas sensor indicates that VOC levels are within a predetermined acceptable range or corresponds to the baseline value representative of VOCs levels in the ambient atmosphere which has been stored by the controller during a previous purging of the device.

[0066] The control unit may be configured to compute at least one parameter representing a health-metric for pulmonary function based on the output signal from the flow sensor. The health metric may be a measurement of spirometry, optionally in combination with fractional exhaled carbon monoxide measurements. The control unit may be configured to calculate the at least one parameter representing a health-metric simultaneous to the capturing and storing of an exhaled air sample form the flow of exhaled air according to the above. Alternatively, the control unit may be configured to calculate the at least one parameter representing a health-metric from a flow of exhaled air whilst no capturing or storing of an exhaled air takes place. That is, the control unit may be configured to calculate the at least one parameter representing a health-metric from a flow of exhaled air whilst the second pump is not being operated, or whilst the first three-way valve is in the first valve state.

[0067] Accordingly, the breath gas analyzer may be configured to perform fractional exhaled gas analysis in combination with pulmonary function tests such as spirometry. This is advantageous as it allows fractional exhaled gas measurements to be correlated with respect to said at least one parameter representing a health-metric for pulmonary function.

[0068] The least one parameter representing a health-metric for pulmonary function may represent at least one of FEV1, FVC, FEVl / FVC-ratio, PEFR and FEF25, FEF50, FEF75, FEF25-75, BEV, FET, TPEF, FEV6.

[0069] As some of these parameters require large flows though the blowtube it is preferred that embodiments comprising a control unit configured to compute at least one parameter representing a health-metric further comprises a blowtube configured with two or more outlets. Most preferably, embodiments comprising a control unit configured to compute at least one parameter representing a health-metric according to the above further comprises both a blowtube configured with two or more outlets and a second pump. The embodiments just described thus enable two different pulmonary function tests, i.e., both exhaled gas level measurements and measurements of spirometry, in the same device. Accordingly, as an example, fractional exhaled gas measurements of FeCo in the exhaled air may be correlated with a parameter representing the lung volume according to FEV1.In a preferred configuration, the device comprises a control unit configured to prompt and / or enable a user to perform an exhaled carbon monoxide (FeCO) measurement as a first step for baseline determination, and a spirometry measurement as a subsequent step. This sequential approach ensures that a reliable baseline of the exhaled gas composition is established before the user performs the forced expiratory maneuvers required for spirometry.

[0070] The sample chamber may comprise a partitioning wall forming an internal channel. The internal channel of the chamber may act as a guide for guiding the flow of exhaled air received at the inlet of the chamber towards the outlet of the chamber provided with said one-way valve. Accordingly, any mixing between the received exhaled air and a volume of air already held by the sample container is reduced, thereby providing a more efficient displacing of a volume of air already held in the container with the exhaled air received at the inlet of the sample container. An efficient displacing of the volume of air already held in the chamber, which volume may be free of VOCs, is beneficial as it reduces any undesired diluting of the exhaled air received in the chamber.

[0071] In some embodiments, the partitioning wall may be helically shaped.

[0072] This results in a helically shaped internal channel. However, the partitioning wall may have other continuous or intermittent shapes. The internal channel may for example have a meander shape, zig-zag shape, spiral shape, or a pattern of concentric circles.

[0073] Nevertheless, a helically shaped partitioning wall is preferred since a helically shaped internal channel is associated with the least amount of obstruction to the flow through the chamber, and hence the least amount of turbulence.

[0074] The gas sensor or sensors may be a CO-sensor, H2-sensor, NO-sensor, CHa-sensor, Ch-sensor, Isoprene sensor, NHa-sensor, Acetone-sensor, C -sensor, H2S-sensor, C2H4O-sensor, SO2-sensor, or a NO2-sensor.

[0075] The gas analyzing circuit of the present disclosure may be designed compact.

[0076] Accordingly, the gas analyzer may be provided as a handheld device, such as a handheld device for self-assessment. The fact that the breath gas analyzer may be provided as a handheld device enables the patient to carry the breath gas analyzer with them wherever they go, thereby improving the availability of the system to the user, and hence the frequency of self-assessment.

[0077] In some embodiments, the gas analyzer may further comprise a transmitting unit communicationally connected to the control unit and configured to transmit output data to an external mobile device and / or a cloud infrastructure. The transmitted output data may represent at least one of: the measured flow of exhaled air through the inlet of the blowtube, an exhaled gas level measurement, or a measurement of spirometry. The transmitting unit may be a wireless transmitter configured to wirelessly transmit the output data to a wireless receiver. The wireless receiver may for example be a wireless receiver of a mobile device. The outputted data may be saved in the mobile device and / or in the could infrastructure. Furthermore, the outputted data may be relayed to a healthcare provider for a professional assessment of the data.

[0078] According to a second aspect of the invention, there is provided a method of operating a breath gas analyzer.According to the second aspect there is provided a method of operating a breath gas analyzer, the method comprises: receiving a flow of exhaled air in a flow receiving inlet of a blowtube of the breath gas analyzer; capturing a portion of the flow of exhaled air in a chamber of a sample container, said captured portion forming an exhaled air sample; and measuring, using a gas sensor in a gas analyzing circuit, at least one property of the exhaled air sample while circulating said exhaled air sample, through the gas analyzing circuit, from a first position of the chamber to a second position of the chamber via a fluid by-pass provided by a conduit of said gas analyzing circuit, by operating a first pump. The breath gas analyzer may be of the same type as defined by claims 1-15.

[0079] The features and functionality of the gas analyzer have been thoroughly described above and are equally applicable to the method of using such a breath gas analyzer.

[0080] Reference is made to the section above to avoid undue repetition.

[0081] The step of capturing a portion of the flow of exhaled air may further comprise setting a second pump to operate, and a step of setting the second pump to not operate, wherein the operating of the second pump is associated with a fluid transport of exhaled air from the blowtube to the sample chamber.

[0082] The step of capturing a portion of the flow of exhaled air may comprise setting a valve state of a first three-way valve from a first valve state to a second valve state and then returning to the first valve state, wherein said first valve state is associated with the flow of exhaled air being directed towards a first exhaust, and wherein said second valve state is associated with the flow of exhaled air being directed towards the chamber of the sample container.

[0083] The method may further comprise a step of cleaning the breath gas analyzer by circulating ambient air through the breath gas analyzer, from the flow receiving inlet of the blowtube of the breath gas analyzer to a second exhaust provided in the gas analyzing circuit by operating the first pump.

[0084] The step of cleaning the breath gas analyzer may comprise setting a valve state of a second three-way valve from a first valve state to a second valve state, wherein said first valve state enables a fluid flow between a first and a second branch of the conduit of the gas analyzing circuit, and wherein said second valve state enables a fluid flow between the first branch of the conduit and the second exhaust.

[0085] The step of cleaning the breath gas analyzer may comprise setting the first three-way valve to its second valve state or setting the second pump to operate.

[0086] The step of cleaning the breath gas analyzer may include the step of circulating ambient air through the breath gas analyzer, from the flow receiving inlet of the blowtube to an outlet in the sample chamber by setting the second pump to operate.

[0087] The setting of the operation of the second pump may be controlled by a control unit, and wherein said controlling is based on a timing sequence, and / or receiving an output signal from a flow sensor measuring the flow of exhaled air received in the flow receiving inlet of the blowtube, and / or receiving an output signal from the gas sensor being representative of at least one property measured by the gas sensor.

[0088] The setting of valve states may be controlled by a control unit, wherein said controlling is based on a timing sequence and / or receiving of an output signal from a flowsensor measuring a flow of exhaled air received in the flow receiving inlet of the blowtube, and / or receiving an output signal from the gas sensor being representative of at least one property measured by the gas sensor.

[0089] The features and functionality of the gas analyzer have been thoroughly described above. Further objects and advantages of the present invention will be obvious to a person skilled in the art reading the detailed description given below describing different embodiments of the breath gas analyzer.

[0090] BRIEF DESCRIPTION OF THE DRAWINGS

[0091] The invention will be described in detail with reference to the schematic drawings. Fig. 1 shows, highly schematically, an embodiment of the breath gas analyzer. Fig. 2 shows, highly schematically, a sample container comprising a partitioning wall and an internal channel.

[0092] Fig. 3a shows highly schematically, an embodiment of the breath gas analyzer further comprising a second pump.

[0093] Fig. 3b shows, highly schematically, a flow through the breath gas analyzer when the second pump is set not operate.

[0094] Fig. 3c shows, highly schematically, a flow through the breath gas analyzer when the second pump is set operate.

[0095] Fig. 4a shows, highly schematically, an embodiment of the breath gas analyzer further comprising a first three-way valve.

[0096] Fig. 4b shows, highly schematically, a flow through the breath gas analyzer when the first three-way valve is set to a first valve state.

[0097] Fig. 4c shows, highly schematically, a flow through the breath gas analyzer when the first three-way valve is set to a second valve state.

[0098] Fig. 5a shows, highly schematically, an embodiment of the breath gas analyzer further comprising a second three-way valve.

[0099] Fig. 5b shows, highly schematically, a flow through the breath gas analyzer when the second three-way valve is set to a first valve state.

[0100] Fig. 5c shows, highly schematically, a flow through the breath gas analyzer when the second three-way valve is set to a second valve state.

[0101] Fig. 6 shows, highly schematically, an embodiment of the breath gas analyzer comprising a transmitting unit.

[0102] Fig. 7 shows a flow diagram of a series of steps of a method of operating a breath gas analyzer.DETAILED DESCRIPTION

[0103] For an improved understanding of the technology, the main elements of the breath gas analyzer will be discussed below with reference to the figures, beginning with Fig. 1.

[0104] Fig. 1 shows a breath gas analyzer 1 comprising: a blowtube 100 having an inlet 101 configured to receive a flow of exhaled air 2, and an outlet 102; a sample container 200, the sample container defining a chamber 203, which chamber 203 comprises an inlet 201 which is fluidly connected to the outlet 102 of the blowtube 100. The chamber 203 is configured to capture and store an exhaled air sample from the flow of exhaled air 2 received from the outlet 102 of the blowtube 100. The chamber 203 further comprises an outlet 202 configured to allow an excess of the flow 3 received from the blowtube 100 to exit the chamber 203 via a one-way valve 204. The breath gas analyzer 1 further comprises a gas analyzing circuit 300 configured to analyze the captured exhaled air sample. The gas analyzing circuit 300 comprises: a first pump 301, a gas sensor 302, and a conduit 303. The conduit 303 is arranged to provide a fluid by-pass between a first position A and a second position B of the chamber 203. The first pump 301 is arranged to generate a flow 304 of the captured exhaled air sample through the conduit 303. The gas sensor 302 is arranged to measure a property of the captured exhaled air sample flowing through the conduit 303.

[0105] The gas analyzing circuit 300 may circulate a captured air sample from a first position A to a second position B of the chamber, past the gas sensor 302 of the gas analyzing circuit 300.

[0106] The blowtube 100 shown in Fig. 1 comprises a tube 103 configured to guide a received amount of exhaled air 2 from the inlet 101 to the outlet 102 of the blowtube 100. Said amount of exhaled air 2 is a flow of exhaled air 2 received at the inlet 101 of the blowtube 100. In the present example, the inlet 101 of the blowtube 100 is provided with a filter 104 for dehumidifying the received flow of exhaled air 2.

[0107] The outlet 102 of the blowtube 100 is fluidly connected to the inlet 201 of a sample container 200. In the example of Fig.l, the fluid connection is achieved by a flexible tube 105. The principal function of the blowtube 100 is to act as a receiving unit for the flow of exhaled air 2, and to direct the flow of exhaled air 2 to the sample container 200 via its fluid connection thereto.

[0108] The sample container 200 defines a chamber 203 having a volume. The chamber 203 is configured to hold a corresponding volume of air, particularly an exhaled air sample. The chamber 203 is provided with an outlet 202 comprising a one-way valve 204 allowing a flow of exhaled air 2 received from the blowtube 100 to displace a volume of air already held by the sample container 200. Worded differently, the one-way valve 204 of the chamber 203 hinders any build up of pressure inside the chamber 203 due to the receiving of a flow of exhaled air 2 from the blowtube 100 via said fluid connection to the blowtube 100, by allowing an excess volume of air 3 to escape via the one-way valve 204. Typically, the volume of the chamber 203 is in the range of 10-150 ml. This volume may be less than or equal to the amount of exhaled air 2 received from the blowtube 100. Accordingly, the sample container 200, i.e., the chamber 203, is configured to capture at least a portion of the flow of exhaled air 2 received at the inlet 201 of the chamber 203.In the embodiments shown in Fig. 2, the chamber 203 of the sample container 200 comprises a partitioning wall 206 forming a highly schematically illustrated internal channel 207. The internal channel 207 of the chamber 203 may function as a guide, guiding the flow of exhaled air 2 received at the inlet 201 of the chamber 203 towards the outlet 202 of the chamber 203 provided with said one-way valve 204. The internal chamber 207 limits any mixing between the received exhaled air 2 and a volume of air already held by the sample container 203, thereby providing a more efficient displacing of a volume of air already held in the container 203 with the exhaled air 2 received at the inlet 201 of the sample container 200. As shown in Fig. 2, the partitioning wall 206 may be helically shaped, thereby resulting in a helically shaped internal channel 207. However, the partitioning wall 206 may have other continuous or intermittent shapes enabling for example a meander shape of the internal channel 206.

[0109] Now returning to Fig. 1, the gas analyzing circuit 300 of the gas analyzer 1 comprises a conduit 303 which is arranged to provide a fluid by-pass between a first position A and a second position B of the chamber 203. The gas analyzing circuit 300 further comprises a first pump 301 arranged to generate a flow 304 through the conduit 303, i.e., a flow between the first position A and the second position B of the chamber 203. The first and the second positions A, B of the chamber 203 may be any two positions of the chamber 203. However, it is preferred that the two positions, i.e., the first and the second position A, B are positioned at a distance from one another, wherein said distance is in the range of 10 - 200 mm. In a preferred embodiment, the respective positions of the first and the second position A, B are chosen such that a fluid distance between the first and second positions A, B is maximized with respect to the extension of the chamber 203. In the example shown in Fig. 1 the first position B is positioned in a vicinity of the inlet 201 of the chamber 203, and the second position A is positioned in a vicinity of the outlet 202 of the chamber 203, i.e., in the vicinity of the one-way valve 204.

[0110] The arranging of the fluid connections between the chamber 203 and the conduit 303, i.e., at the first and second positions A, B of the chamber 203 according to the above, enables the first pump 301 of the gas analyzing circuit 300 to generate a flow 304 through the conduit 303, thereby achieving an efficient circulation of the volume of air held in the chamber 203, i.e., a captured exhaled air sample. By the meaning of an efficient circulation, it is here meant that the positioning of the first and section positions A, B of the chamber 203 limits the formation of any volumes in the chamber 203 which experience a limited or no circulation. A complete circulation of the entire volume of air in the chamber 203, i.e., a captured exhaled air sample, is preferred as it improves a measuring of the at least one property of the captured air sample.

[0111] In the example shown in Fig. 1, the inlet 201 of the chamber 203 is provided with an optional gas guide 205. The gas guide 205 is directed away from the position B of fluid connection to the conduit 303. The purpose of the gas guide 205 at the inlet 201 of the chamber 203 is to limit any flow of exhaled air 2 received at said inlet 201 of the chamber 203 to flow into the conduit 303 of the gas analyzing circuit 300 via the conduit opening adjacent position B.The gas analyzing circuit further comprises a gas sensor 302. In the present example, the gas sensor 302 is arranged such that the sensor 302 is exposed to the flow 304 generated in the conduit 303 by the first pump 301. The gas sensor 302 enables a measuring of at least one property of a captured exhaled air sample, which measuring is enabled by a circulation of said captured exhaled air sample through conduit 303 and past the gas sensor 302 of the gas analyzing circuit 300. While the example of Fig. 1 only shows one gas sensor 302, it is within the scope of the present invention that the gas analyzing circuit 300 may comprise a plurality of sensors 302 of different sensor types, enabling the measuring of a plurality of properties of a gaseous volume, i.e., a captured exhaled air sample. The gas sensor 302 or sensors 302 may be a CO-sensor, H2-sensor, NO sensor, CH3-sensor, Cl2-sensor, Isoprene sensor, NHa-sensor, Acetone-sensor, O2-sensor, H2S-sensor, C2H4O-sensor, SO2-sensor, or a NO2-sensor.

[0112] In the example embodiment shown in Fig.l, the gas analyzing circuit 300 includes an optional gas guide 305 configured to guide the flow 304 generated by the first pump 301 onto the gas sensor 302. The gas guide 305 ensures that a larger portion of the flow 304 generated in the conduit 303 by the first pump 301 comes into contact with the gas sensor 302. The gas guide 305 may reduce any turbulence in the vicinity of the gas sensor 302 which could adversely affect the measuring of the at least one property of the circulated exhaled air sample.

[0113] Fig. 3a shows an example embodiment of the gas analyzer 1, wherein the blowtube 100 further comprises a flow sensor 106 configured to measure the flow of exhaled air 2 through the blowtube 100. In the present example, the blowtube comprises a socket 107 for fastening the flow sensor 106 to the blowtube 100. The flow sensor 106 may be removably attached to the socket 107. The flow sensor 106 may for example be a pressure sensor configured to measure a differential pressure in the blowtube 100, which differential pressure corresponds to a flow through the blowtube 100. In the example shown in Fig. 4a, the blowtube 100 further comprises an internal restricting element 108, and the pressure sensor is configured to measure a differential pressure on either side of the restricting element 108 via channels 108a, 108b on opposite sides of the restricting element 108.

[0114] In the present embodiment, the flow sensor 106 has a position in the blowtube 100 which is downstream from the outlet 102 of the blowtube 100 with respect to the flow of exhaled air 2 received at the inlet 101. However, in alternative embodiments, in may be contemplated that the flow sensor 106 may have a position with respect to the blowtube 100 which is upstream from the outlet 102 of the blowtube 100.

[0115] The embodiment shown in Fig. 3a further comprises a second pump 700. The second pump 700 can be seen to form part of the fluid connection between the outlet 102 of blowtube 100 and the inlet 201 of the sample container 200 otherwise solely provided by the flexible hose 105. The second pump 700 is configured to provide fluid transport from the outlet 102 of the blowtube 100 to the inlet 201 of the sample container 200. The second pump 700 may be configured to only allow fluid communication between the outlet 102 of the blowtube 100 and the inlet 201 of the sample container 200 whilst the second pump 700 is in operation. Accordingly, when the second pump 700 not operating, the fluid connection between the blowtube 100 and the sample container 200 is closed. To ensure aflow path though the blowtube 100 for a flow of exhaled air 2 received at the inlet 101 of the blowtube 100 at all times, i.e., regardless of the operational status of the second pump 700, the blowtube in the present embodiment is provided with a further outlet 102a.

[0116] Figs. 3b and 3c show how a received flow of exhaled air 2 through the gas analyzer 1 is affected by the operating of the second pump 700. When in second pump 700 is not operating, as shown in Fig. 3b, the fluid connection between the blowtube 100 and the sample container 200 is closed as the second pump 700 does not provide any fluid transport. Accordingly, when the second pump 700 is not operating, all flow of exhaled air 2 received at the inlet 101 of the blowtube 100 will be directed towards the further outlet 102a of the blowtube 100.

[0117] When in second pump 700 is operating, as shown in Fig. 3c, the fluid connection between the blowtube 100 and the sample container 200 is open as the second pump 700 provides fluid transport therebetween. Accordingly, when the second pump 700 is operating, a portion of the exhaled air 2 received at the inlet 101 of the blowtube 100 will be fluidly transported by the second pump 700 towards the sample container 200, while the remainder of the flow of exhaled air 2 received at the inlet 101 of the blowtube 100 is directed towards the further outlet 102a of the blowtube 100.

[0118] Accordingly, setting the operational state of the second pump 700 allows for a selecting of a portion of the flow of exhaled air 2 received at the inlet 101 of the blowtube 100, which is to be fluidly transported to the sample container 200, i.e., captured in the chamber 203 of the sample container 200.

[0119] For example, upon first receiving a flow of exhaled air 2 at the inlet 101 of the blowtube 100 the second pump 700 may be set to not operate, thereby letting all of the exhaled air 2 received at the inlet 101 of the blowtube 100 to be guided towards the further outlet 102a of the blowtube 100. At any moment during the receiving of the flow of exhaled air 2, the second pump 700 may be set to operate, thereby enabling a capture of an exhaled air sample by providing fluid transport of a portion of the flow of exhaled air 2 to the chamber 203 of the sample container 200. The second pump 700 may remain in operation for a desired amount of time before being set to not operate and thereby closing the fluid connection between the outlet 102 of the blowtube 100 and the inlet 201 of the sample container 200. The total volume of exhaled air which is fluidly transported to the sample container 200 in the above example is a function of the rate of fluid transport per unit time and the time period during which the second pump 700 is set to operate. The time period during which the second pump 700 is set to the operate may be understood as an amount of time during which sampling of the received flow of exhaled air 2 takes place, i.e., a sampling time.

[0120] As shown in Fig. 4a, the second pump 700 may be controlled by a control unit 600. Accordingly, the control unit 600 may set operational status of the second pump 700. As such the control unit 600 may control the time period during which the second pump 700 is set to operate and thereby provide fluid transportation according to the above. The control unit 600 may further control the rate of fluid transport per unit time provided by the second pump 700. As such, the control unit 600 may control the volume of exhaled air 2 which is fluidly transported to the sample container 200. The control unit 600 may be configured tocontrol the operational status of the second pump 700 based on a predetermined timing sequence. Alternatively, the control unit 600 may be configured to receive an output signal from the flow sensor 106, and to control the operational status of the second pump 700 based on said output signals received from the flow sensor 106. The control unit 600 may further be configured to set the second pump 700 to operate once a predetermined condition is fulfilled. The predetermined condition may be that the output signal from the flow sensor 106 of the blowtube 100 indicates that a predetermined flow rate has been maintained for a predetermined amount time. For example, a predetermined flow rate may be in a range of 45-65 ml / s, and the time for maintaining said flow rate may be, for example, 7 seconds. Once the second pump 700 is set to operate, shown in Fig. 3c, a portion of the flow of exhaled air 2 received at the inlet 101 of the blowtube 100 will be fluidly transported by the second pump 700 to the sample container 200, thereby enabling a sampling of the received flow of exhaled air 2. The control unit 600 may be configured to set the second pump 700 to not operate after a predetermined capture time, i.e., sampling time, for example after 3 seconds. Again, setting the second pump 700 to not operate effectively breaks the fluid connection between the chamber 203 of the sample container 200 and the blowtube 100, thereby sealing the captured exhaled air sample in the chamber 203.

[0121] Accordingly, the total amount of exhaled air 2 fluidly transported to the chamber 203 of the sample container 200 may be determined by the control unit 600 by a timing of the setting the operational status of the second pump 700, i.e., the sampling time. The total amount of exhaled air 2 fluidly transported to the chamber 203 of the sample container 200 may further be determined by the control unit 600 by controlling the rate of fluid transport per unit time provided by the second pump 700 during said sampling time. For example, the predetermined flow rate and the predetermined capture time. For example, rate of fluid transport per unit time provided by the second pump 700may be 50 ml / s and the sampling time may be 3 s, equating to a total amount of 150 ml of exhaled air 2 being fluidly transported to the chamber 203 of the sample container 200. In the case that the chamber 203 of the sample container 200 has a volume that is less than the volume of exhaled air fluidly transported thereto, an excess 3 of said flow will be vented out via the one-way valve 204 provided at the outlet 202 of the chamber 203 of the sample container 200.

[0122] Alternative to the second pump 700, the gas analyzer 1 may instead be provided with a first three-way valve 400 as shown in the embodiment shown in Fig. 4a. The first three-way valve 400 is arranged downstream from blowtube 100, and upstream from the sample container 200, as seen relative to the direction of the flow of exhaled air 2 received and the inlet 101 of the blowtube 100. A first port 401 of the first three-way valve 400 fluidly connects to the outlet 102 of the blowtube 100, a second port 402 of the three-way valve 400 fluidly connects to the inlet 201 of the chamber 203 of the sample container 200, and a third port 403 fluidly connects the breath gas analyzer 1 to a first exhaust 4. The first three-way valve 400 may be set between a first and a second valve state, wherein each valve state is associated with a fluid connection between two of the ports 401, 402, 403 of the first three-way valve 400.

[0123] Figs. 4b and 4c show how the received flow of exhaled air 2 through the gas analyzer 1 is affected by the setting of the valve states of the first three-way valve 400. When in thefirst valve state, shown in Fig. 4b, the first three-way valve 400 enables a fluid connection between the outlet 102 of the blowtube 100 and the first exhaust 4. Accordingly, when the first three-way valve 400 is set to the first valve state, a flow of exhaled air 2 received at the inlet 101 of the blowtube 100 will be directed by the first three-way valve 400 towards the first exhaust 4 of the gas analyzer 1.

[0124] Setting the first three-way valve 400 to its second valve state, shown in Fig. 4c, enables a fluid connection between the outlet 102 of the blowtube 100 and the inlet 201 of the chamber 203 of the sample container 200. Accordingly, when the first three-way valve 400 is set to the second valve state, the flow of exhaled air 2 received at the inlet 101 of the blowtube 100 will be directed by the first three-way valve 400 towards the chamber 203 of the sample container 200. Accordingly, setting the first three-way valve 400 in between the first and the second valve states allow for a selecting of a portion of the flow of exhaled air 2 received at the inlet 101 of the blowtube 100, which selected portion is to be captured in the chamber 203 of the sample container 200. For example, the first three-way valve 400 may be set to the first valve state upon first receiving a flow of exhaled air 2 at the inlet 101 of the blowtube 100. The valve state of the first three-way valve 400 may then be set to the second valve state, thereby enabling a capture of the flow received in the chamber 203 of the sample container 200. The first three-way valve 400 may remain in the second valve state for a desired amount of time before returning to the first valve state.

[0125] With reference to Fig. 4a, the valve states of the first three-way valve 400 may be controlled by a control unit 600. Accordingly, the control unit 600 may determine the portion of the flow of exhaled air 2 received at the inlet 101 of the blowtube 100 which is to be directed, i.e., captured, in the chamber 203 of the sample container 200 by controlling the valve state of the first three-way valve 400. The control unit 600 may be configured to control the valve state of the first three-way valve 400 based on a predetermined timing sequence. Alternatively, the control unit 600 may be configured to receive an output signal from the flow sensor 106, and to control the valve state of the first three-way valve 400 based on the output signals received from the flow sensor 106. The control unit 600 may be configured to set the first three-way valve 400 from the first valve state to the second valve state once a predetermined condition is fulfilled. The predetermined condition may be that the output signal from the flow sensor 106 of the blowtube 100 indicates that a predetermined flow rate has been maintained for a predetermined amount time. For example, a predetermined flow rate may be in a range of 45-65 ml / s, and the time for maintaining said flow rate may be, for example, 7 seconds. Once the first three-way valve 400 is set to the second valve state, shown in Fig. 4c, a flow of exhaled air 2 received at the inlet 101 of the blowtube 100 will be directed to the sample container 200, thereby enabling a capture of the received flow of exhaled air 2. The control unit 600 may be configured to return the first three-way valve 400 from the second valve state to the first valve state after a predetermined capture time, for example after 3 seconds. Returning the first three-way valve 400 to its first valve state effectively breaks the fluid connection between the chamber 203 of the sample container 200 and the blowtube 100, thereby sealing the captured exhaled air sample in the chamber 203. Accordingly, the total amount of exhaled air 2 directed to the chamber 203 of the sample container 200 may be determined by the controlunit 600 based on the predetermined flow rate and the predetermined capture time. For example, the flow rate may be 50 ml / s, and the predetermined capture time may be 3 s, equating to a total amount of 150 ml of exhaled air 2 being directed to the chamber 203 of the sample container 200. In the case that the chamber 203 of the sample container 200 has a volume that is less than the total amount of flow being directed thereto, an excess 3 of said flow will be vented out via the one-way valve 204 provided at the outlet 202 of the chamber 203 of the sample container 200.

[0126] Fig. 5a shows an embodiment wherein the conduit 303 of the gas analyzer 1 further comprises a second three-way valve 500, wherein a first port 501 of the second three-way valve 500 fluidly connects to a first branch 303a of the conduit 300 of the gas analyzing circuit 300, a second port 502 fluidly connects to a second branch 303b of the conduit 303 of the gas analyzing circuit 300, and a third port 503 fluidly connects to a second exhaust 5.

[0127] The second three-way valve 500 may be set between a first and a second valve state, wherein each valve state is associated with a fluid connection between two of the ports 501, 502, 503 of the second three-way valve 500. While the present embodiment exemplifies the second three-way 500 valve in combination with a first three-way valve 400 governing the fluid connection between the blowtube 100 and the sample container 200, it is equally possible to combine the second three-way 500 valve in combination with a second pump 700.

[0128] Figs. 5b and 5c show how the flow 304 in the gas analyzing circuit 300 is affected by the setting of the valve states of the second three-way valve 500. When in the first valve state, shown in Fig. 5b, the second three-way valve 500 enables a fluid connection between the first and the second ports 501, 502 of the second three-way valve 500, i.e., a fluid connection between the first and the second branches 303a, 303b of the conduit 303 of the gas analyzing circuit 300, thereby enabling a fluid-bypass between positions A and B of the chamber 203 of the sample container 200. Accordingly, the first valve state of the second three-way valve 500 enables the first pump 301 to circulate a captured exhaled air sample in the chamber 203, through the conduit 303, 303a, 303b, and past the at least one sensor 302.

[0129] The second valve state of the second three-way valve 500 is shown in Fig. 5c, which second valve state enables a fluid connection between the first branch of the conduit 303a and the second exhaust 5. In the present example, the first pump 301 of the gas analyzing circuit 300 is arranged in the first branch 303a of the conduit 303. Such an arrangement of the first pump 301 allows the first pump 301 to generate a flow from the intake 101 of the blowtube 100 towards the second exhaust 5 via the chamber 203 of the sample container 200, provided that any first three-way valve 400 is set to its second valve state, or that any second pump 700 is set to operate, according to the previous discussions with respect to the first three-way valve and the second pump. The flow 304 generated by the first pump 301, i.e., from the intake 101 of the blowtube 100 towards the second exhaust 5 via the chamber 203 of the sample container 200, may achieve a cleaning or purging of the gas analyzer 1 before or after use, i.e., before and after receiving a flow of exhaled air 2. In the present example, the gas sensor 302 is arranged in the first branch 303a of the conduit 303, thereby allowing the gas sensor 302 to monitor at least one property of the air flowing from theintake 101 of the blowtube 100 towards the second exhaust 5 via the chamber 203 of the sample container 200. Accordingly, the gas sensor 302 may determine whether or not a sufficient cleaning or purging has been achieved, based on the at least one measured property of the air flowing towards the second exhaust 5.

[0130] Now returning to Fig. 5a, the control unit 600 may be further configured to control the valve state of the second three-way valve 500, and the first pump 301 of the gas analyzing circuit. Accordingly, the control unit 600 may be configured to operate the first pump 301 and to set the second three-way valve 500 to its first valve state, thereby allowing a circulation of a captured exhaled air sample though the conduit 303 and past the gas sensor 302 of the gas analyzing circuit 300. The control unit 600 may be configured to keep the first pump 301 in operation and the second three-way valve 500 in the first valve state until the captured exhaled air sample has been measured. For example, the control unit 600 may be configured to keep the first pump 301 in operation, and the first three-way valve 500 in the first valve state, for a predetermined measurement time. Alternatively, the control unit 600 may be configured to keep the first pump 301 in operation, and the second three-way valve 500 in its first valve state until a measurement condition is fulfilled. The measurement condition may be based on an output signal received from the gas sensor 302. For example, the measurement condition may be that an output signal from the gas sensor 302, which output signal being representative of at least one property of the captured exhaled air sample, has peaked, reached a plateau, and / or begun to decline.

[0131] The control unit 600 may further be configured to set the second three-way valve 500 and the first thee-way valve 400 to their respective second valve states, and to operate the first pump 301, thereby allowing a cleaning / purging of the chamber 203 of the sample container 200 by generating a flow from the inlet 101 of the blowtube 100 towards the second exhaust 5 via the chamber 203 of the sample container 200. The control unit 600 may be configured to keep the first and the second three-way valves 400, 500 in their respective second valve states, and to keep the first pump 301 in operation, for a predetermined cleaning time or until an output from the gas sensor 302 indicates that at least one property of the flow though the first branch 303a of the conduit 303 fulfills a predetermined cleaning / purging condition. The predetermined cleaning / purging condition may be that the output signal from the gas sensor 302 indicates that a concentration of VOCs in the flow is below a predetermined level.

[0132] Correspondingly, in embodiments comprising a second pump 700, the control unit 600 may further be configured to set the second three-way valve 500 to its second valve state, and to operate the both the first and the second pump 301, 700, to thereby allow a cleaning / purging of the chamber 203 of the sample container 200. The control unit 600 may be configured to keep the second three-way valve 400 in its second valve state, and to keep the first and second pump 301, 700 in operation, for a predetermined cleaning time or until an output from the gas sensor 302 indicates that at least one property of the flow though the first branch 303a of the conduit 303 fulfills the predetermined cleaning / purging condition.

[0133] Fig. 6 shows an embodiment of the gas analyzer 1 further comprising a transmitting unit 800 communicationally connected to the control unit 600. The transmitting unit 800may be configured to transmit output data to an external device. The transmitting unit 800 may be a wireless transmitter configured to wirelessly transmit the output data to a wireless receiver of the external device. The external device may be a mobile phone 900 and / or a cloud infrastructure 910. In some embodiments the output data is transmitted to the cloud infrastructure by relaying via a mobile phone 900. The transmitted output data may represent at least one of: the measured flow of exhaled air through the inlet of the blowtube 100, one or more parameters representative of an exhaled gas level measurement, or one or more parameters representative of a measurement of spirometry. The output data may be saved in the mobile device and / or in the could infrastructure. Furthermore, the output data may be relayed to a healthcare provider for a professional assessment of the data.

[0134] Now moving on to Fig. 7 which shows a flow diagram of steps according to a method of operating a breath gas analyzer. The method comprises: receiving SI a flow of exhaled air in a flow receiving inlet of a blowtube of the breath gas analyzer; capturing S2 a portion of the flow of exhaled air in a chamber of a sample container, said captured portion forming an exhaled air sample; and measuring S3, by using a gas sensor in a gas analyzing circuit, at least one property of the exhaled air sample while circulating S3a said exhaled air sample through the gas analyzing circuit, from a first position of the chamber to a second position of the chamber via a fluid by-pass provided by a conduit of said gas analyzing circuit.

[0135] Fig. 7 further discloses some optional steps which may be included in some embodiments of the method.

[0136] In some embodiments of the method the step of capturing S2 a portion of the flow of exhaled air comprises setting a valve state S21a of a first three-way valve from a first valve state to a second valve state and then returning S21b the first three-way valve to its first valve state, wherein said first valve state is associated with the flow of exhaled air being directed towards a first exhaust, and wherein said second valve state is associated with the flow of exhaled air being directed towards the chamber of the sample container.

[0137] In some embodiments of the method the step of capturing S2 a portion of the flow of exhaled air comprises setting the second pump to operate S22a and then setting the second pump to not operate S22b, wherein the operating of the second pump is associated with fluid transport of exhaled air from the blowtube to the chamber of the sample container.

[0138] Some embodiments of the method further comprise a step of cleaning S4 the breath gas analyzer by operating the first pump to circulate S4a ambient air through the breath gas analyzer, from the flow receiving inlet of the blowtube of the breath gas analyzer to a second exhaust provided in the gas analyzing circuit.

[0139] In some embodiments of the method, the step of cleaning S4 the breath gas analyzer comprises setting S41 a valve state of a second three-way valve from a first valve state to a second valve state, wherein said first valve state enables a fluid flow between a first and a second branch of the conduit of the gas analyzing circuit, and wherein said second valve state enables a fluid flow between the first branch of the conduit and the second exhaust.In some embodiments of the method, the step of cleaning S4 the breath gas analyzer comprises setting S41a the first three-way valve to its second valve state.

[0140] In some embodiments of the method, said setting / returning S21a, S21b, S41, S41a, S41b of valve states is controlled by a control unit, and wherein said controlling S5 is based on a timing sequence, and / or receiving S51 of an output signal from a flow sensor measuring Sil a flow of exhaled air received in the flow receiving inlet of the blowtube, and / or receiving S52 an output signal from the gas sensor being representative of at least one property measured S4a by the gas sensor.

[0141] In some embodiments of the method, the method of operating the gas analyzer may comprise a step of purging SO the gas analyzer. The step of purging the gas analyzer is identical to the steps of cleaning S4 the gas analyzer, only differing in that the step of purging is performed prior to receiving SI a flow of exhaled air at the flow receiving inlet of the blowtube.

[0142] It is realized by the skilled person that the elements discussed herein may be combined with one another to provide further alternative embodiments.

[0143] ITEMIZED LIST OF EMBODIMENTS

[0144] The invention may be summarized as follows:

[0145] Item 1. A breath gas analyzer (1) comprising: a blowtube (100) comprising an inlet (101) configured to receive a flow of exhaled air (2), and an outlet (102);

[0146] - a sample container (200), the sample container (200) defining a chamber (203), which chamber (203) comprises an inlet (201) which is fluidly connected to the outlet (102) of the blowtube (100), and wherein the chamber (203) is configured to capture and store an exhaled air sample from the flow of exhaled air (2) received from the outlet (102) of the blowtube (100), and wherein the chamber (203) further comprises an outlet (202) configured to allow an excess (3) of the flow (2) received from the blowtube (100) to exit the chamber (203) via a one-way valve (104); and

[0147] wherein the breath gas analyzer (1) further comprises a gas analyzing circuit (300) configured to analyze the captured exhaled air sample, the gas analyzing circuit (300) comprising: a pump (301); a gas sensor (302); and a conduit (303);

[0148] wherein the conduit (303) is arranged to provide a fluid by-pass between a first and a second position (A, B) of the chamber (203); and wherein the pump (301) is arranged to generate a flow (304) of the captured exhaled air sample through the conduit (300), and wherein the gas sensor (302) is arranged to measure a property of the captured exhaled air sample flowing through the conduit (303).

[0149] Item 2. The breath gas analyzer (1) according to item 1, further comprising a first three-way valve (400), wherein a first port (401) of the first three-way valve (400) fluidly connects to the outlet (102) of the blowtube (100), a second port (402) fluidly connects to the inlet (201) of the chamber (203) of the sample container (200), and a third port (403) fluidly connects the breath gas analyzer (1) to a first exhaust (4).

[0150] Item 3. The breath gas analyzer (1) according to item 1 or 2, wherein the conduit (300) comprises a second three-way valve (500), wherein a first port (501) of the second three-way valve (500) fluidly connects to a first branch (303a) of the conduit (303) of the gas analyzing circuit (300), a second port (502) fluidly connects to a second branch (303b) of the conduit (303) of gas analyzing circuit (300), and a third port (503) fluidly connects to a second exhaust (5).

[0151] Item 4. The breath gas analyzer (1) according to any one of the preceding items, wherein the gas analyzing circuit (300) further comprises a gas guide (305) configured to guide the flow (304) generated by the pump (301) onto the gas sensor (302).

[0152] Item 5 The breath gas analyzer (1) according to any one of the preceding items, wherein the blowtube (100) further comprises a flow sensor (106) configured to measure the flow of exhaled air (2) through the blowtube (100).

[0153] Item 6 The breath gas analyzer (1) according to any one of the preceding items, further comprising a control unit (600) configured to receive an output signal from the flow sensor (106) and / or from the gas sensor (302) respectively, and to control the pump (301) and the setting of the first and the second three-way valves (400, 500).

[0154] Item 7 The breath gas analyzer (1) according to item 5, wherein the control unit (600) is configured to control the first and the second valves (400, 500) based on a predetermined timing sequence and / or the output signal received from the flow sensor (106) and / or the gas sensor (302).

[0155] Item 8 The breath gas analyzer (1) according to any one of the preceding items, wherein the chamber (203) comprises a partitioning wall (206) forming a channel (207).

[0156] Item 9 The breath gas analyzer (1) according to any one of the preceding items, wherein the partitioning wall (206) is helically shaped.

[0157] Item 10. The breath gas analyzer (1) according to any one of the preceding items, wherein the gas sensor (302) is a CO-sensor, H2-sensor, NO-sensor, CHa-sensor, Cl2-sensor, Isoprene sensor, NH3-sensor, acetone-sensor, O2-sensor, H2S sensor, C2H4O-sensor, SO2-sensor, or a NO2-sensor.

[0158] Item 11 A method of operating a breath gas analyzer, the method comprising:

[0159] - receiving (SI) a flow of exhaled air in a flow receiving inlet of a blowtube of the breath gas analyzer; capturing (S2) a portion of the flow of exhaled air in a chamber of a sample container, said captured portion forming an exhaled air sample; measuring (S3), using a gas sensor in a gas analyzing circuit, at least one property of the exhaled air sample while circulating said exhaled air sample through the gas analyzing circuit, from a first position of the chamber to a second position of the chamber via a fluid by-pass provided by a conduit of said gas analyzing circuit.

[0160] Item 12 The method of operating a breath gas analyzer according to item 11, wherein the step of capturing (S2) a portion of the flow of exhaled air comprises setting (S21a) a valve state of a first three-way valve from a first valve state to a second valve state and then returning (S21b) back to the first valve state, wherein

[0161] said first valve state is associated with the flow of exhaled air being directed towards the first exhaust, and wherein said second valve state is associated with the flow of exhaled air being directed towards the chamber of the sample container.

[0162] Item 13 The method of operating a breath gas analyzer according to item 11 or 12, further comprising a step of cleaning (S4) the breath gas analyzer by circulating ambient air throughthe breath gas analyzer, from the flow receiving inlet of the blowtube of the breath gas analyzer to a second exhaust provided in the gas analyzing circuit.

[0163] Item 14. The method of operating a breath gas analyzer according to item 13, wherein the step of cleaning the breath gas analyzer comprises setting (S41) a valve state of a second three-way valve from a first valve state to a second valve state, wherein said first valve state enables a fluid flow between a first and a second branch of the conduit of the gas analyzing circuit, and wherein said second valve state enables a fluid flow between the first branch of the conduit and the second exhaust.

[0164] Item 15. The method of operating a breath gas analyzer according to item 13 and 14, wherein the step of cleaning (S4) the breath gas analyzer comprises setting the first three-way valve to its second valve state and then returning the second three-way valve to its second valve state.

[0165] Item 16. The method of operating a breath gas analyzer according to any one of item 12, 14 or 15 wherein said setting of valve states (S21a, S21b, S41) is controlled by a control unit, and wherein said controlling (S5) is based on a timing sequence, and / or receiving an output signal from a flow sensor measuring a flow (Sil) of exhaled air received in the flow receiving inlet of the blowtube, and / or an output signal from the gas sensor being representative of at least one property measured by the gas sensor.

Claims

28CLAIMS1. A breath gas analyzer (1) comprising:- a blowtube (100) comprising an inlet (101) configured to receive a flow of exhaled air (2), and at least one outlet (102);- a sample container (200), the sample container (200) defining a chamber (203), which chamber (203) comprises an inlet (201) which is fluidly connected to one of the at least one outlet (102) of the blowtube (100), and wherein the chamber (203) is configured to capture and store an exhaled air sample from the flow of exhaled air (2) received from the outlet (102) of the blowtube (100), and wherein the chamber (203) further comprises an outlet (202) configured to allow an excess (3) of the flow (2) received from the blowtube (100) to exit the chamber (203) via an outlet (104); andwhereinthe breath gas analyzer (1) further comprises a gas analyzing circuit (300) configured to analyze the captured exhaled air sample, the gas analyzing circuit (300) comprising:- a first pump (301);- a gas sensor (302); and- a conduit (303); whereinthe conduit (303) is arranged to provide a fluid by-pass between a first and a second position (A, B) of the chamber (203); and whereinthe first pump (301) is arranged to generate a flow (304) of the captured exhaled air sample through the conduit (300), and whereinthe gas sensor (302) is arranged to measure a property of the captured exhaled air sample flowing through the conduit (303).

2. The breath gas analyzer (1) according to claim 1, further comprising a second pump (700) configured to provide fluid transport from one of the at least one outlet (102) of the blowtube (100) to the inlet (201) of the chamber (203) of the sample container (200).

3. The breath gas analyzer (1) according to claim 1, further comprising a first three-way valve (400), wherein a first port (401) of the first three-way valve (400) fluidly connects to the outlet (102) of the blowtube (100), a second port (402) fluidly connects to the inlet (201) of the chamber (203) of the sample container (200), and a third port (403) fluidly connects the breath gas analyzer (1) to a first exhaust (4).

4. The breath gas analyzer according to any one of the preceding claims, wherein the conduit (300) comprises a second three-way valve (500), wherein a first port (501) of the second three-way valve (500) fluidly connects to a first branch (303a) of the conduit (303) of the gas analyzing circuit (300), a second port (502) fluidly connects to a second branch (303b) of the conduit (303) of gas analyzing circuit (300), and a third port (503) fluidly connects to a second exhaust (5).

5. The breath gas analyzer (1) according to any one of the preceding claims, wherein the gas analyzing circuit (300) further comprises a gas guide (305) configured to guide the flow (304) generated by the first pump (301) onto the gas sensor (302).

6. The breath gas analyzer (1) according to any one of the preceding claims, wherein the blowtube (100) further comprises a flow sensor (106) configured to measure the flow of exhaled air (2) through the blowtube (100).

7. The breath gas analyzer (1) according to any one of claim 6, further comprise a control unit (600) configured to receive an output signal from the flow sensor (106) and the gas sensor (302) respectively, and to control the first and the second pumps (301, 700).

8. The breath gas analyzer (1) according to claim 6, further comprising a control unit (600) configured to receive an output signal from the flow sensor (106) and the gas sensor (302) respectively, and to control the first pump (301) and the setting of the first and the second three-way valves (400, 500).

9. The breath gas analyzer (1) according to claim 7 or 8, wherein the control unit (600) is configured to control the second pump (700) or the first and the second valves (400, 500), based on a predetermined timing sequence and / or the output signal received from the flow sensor (106) and / or the gas sensor (302).

10. The breath gas analyzer (1) according to any one of claims 7-9, wherein the control unit (600) is configured to compute at least one parameter representing a health-metric for pulmonary function based on the output signal from the flow sensor (106), and wherein the control unit (600) is configured to prompt and / or enable a user to perform an exhaled carbon monoxide (FeCO) measurement as a first step for baseline determination, and a spirometry measurement as a subsequent step.

11. The breath gas analyzer (1) according to claim 10, wherein the least one parameter representing a health-metric for pulmonary function represents at least one of FEV1, FVC, FEVl / FVC-ratio, PEFR and FEF25, FEF50, FEF75, FEF25-75, BEV, FET, TPEF and FEV6.

12. The breath gas analyzer (1) according to any one of the preceding claims, wherein the chamber (203) comprises a partitioning wall (206) forming a channel (207).

13. The breath gas analyzer (1) according to any one of the preceding claims, wherein the partitioning wall (206) is helically shaped.

14. The breath gas analyzer (1) according to any one of the preceding claims, wherein the gas sensor (302) is a CO-sensor, H2-sensor, NO-sensor, CHa-sensor, Cl2-sensor, Isoprene sensor, NH3-sensor, acetone-sensor, O2-sensor, H2S sensor, C2H4O-sensor, SO2-sensor, or a NO2-sensor.

15. The breath gas analyzer (1) according to any one of the preceding claims, wherein the breath gas analyzer (1) is provided as a handheld device for self-assessment.

16. The breath gas analyzer (1) according to any one of claims 6 to 14, wherein the breath gas analyzer (1) further comprises a transmitting unit (800) communicationally connected to the control unit (600), wherein the transmitting unit (800) is configured to transmit output data to an external mobile device (900) and / or a could infrastructure (910).

17. A method of operating a breath gas analyzer, the method comprising:- receiving (SI) a flow of exhaled air in a flow receiving inlet of a blowtube of the breath gas analyzer;- capturing (S2) a portion of the flow of exhaled air in a chamber of a sample container, said captured portion forming an exhaled air sample;- measuring (S3), using a gas sensor in a gas analyzing circuit, at least one property of the exhaled air sample while circulating (S3a) said exhaled air sample through the gas analyzing circuit, from a first position of the chamber to a second position of the chamber via a fluid by-pass provided by a conduit of said gas analyzing circuit, by operating a first pump.

18. The method of operating a breath gas analyzer according to claim 17, wherein the step of capturing (S2) a portion of the flow of exhaled air further comprises a step of setting (S22a) a second pump to operate, and a step of setting (22b) the second pump to not operate, wherein the operating of the second pump is associated with a fluid transport of exhaled air from the blowtube to the sample chamber.

19. The method of operating a breath gas analyzer according to claim 17, wherein the step of capturing (S2) a portion of the flow of exhaled air comprises setting (S21a) a valve state of a first three-way valve from a first valve state to a second valve state and then returning (S21b) back to the first valve state, whereinsaid first valve state is associated with the flow of exhaled air being directed towards the first exhaust, and wherein said second valve state is associated with the flow of exhaled air being directed towards the chamber of the sample container.

20. The method of operating a breath gas analyzer according to any one of claims 17 to 19, further comprising a step of cleaning (S4) the breath gas analyzer by circulating (S4a) ambient air through the breath gas analyzer, from the flow receiving inlet of the blowtube of the breath gas analyzer to a second exhaust provided in the gas analyzing circuit by operating the first pump.

21. The method of operating a breath gas analyzer according to claim 20, wherein the step of cleaning (S4) the breath gas analyzer comprises setting (S41) a valve state of a second three-way valve from a first valve state to a second valve state, whereinsaid first valve state enables a fluid flow between a first and a second branch of the conduit of the gas analyzing circuit, and wherein said second valve state enables a fluid flow between the first branch of the conduit and the second exhaust.

22. The method of operating a breath gas analyzer according to claim 19 or 20, wherein the step of cleaning (S4) the breath gas analyzer comprises setting (S41a) the first three-way valve to its second valve state, or setting (S42a) the second pump to operate.

23. The method of operating a breath gas analyzer according to claim 17 or 18, further comprising a step of cleaning (S4) the breath gas analyzer by circulating (S4a) ambient air through the breath gas analyzer, from the flow receiving inlet of the blowtube to an outlet in the sample chamber by setting (S42a) the second pump to operate.

24. The method of operating a breath gas analyzer according to any one of claims 18, or 22-23, wherein said setting of the operation of the second pump (S22a, S22b, S42a, S42b is controlled by a control unit, and wherein said controlling (S5) is based on a timing sequence, and / or receiving (S51) an output signal from a flow sensor measuring (Sil) the flow of exhaled air received in the flow receiving inlet of the blowtube, and / or receiving (S52, S53) an output signal from the gas sensor being representative of at least one property measured (S3a, S4b) by the gas sensor.

25. The method of operating a breath gas analyzer according to any one of claims 19-22, wherein said setting of valve states (S21a, S21b, S41a, S41b) is controlled by a control unit, and wherein said controlling (S5) is based on a timing sequence, and / or receiving (S51) an output signal from a flow sensor measuring (Sil) the flow of exhaled air received in the flow receiving inlet of the blowtube, and / or receiving (S52, S53) an output signal from the gas sensor being representative of at least one property measured (S3, S4b) by the gas sensor.

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