METHOD AND DEVICE FOR QUALITY CONTROL OF A BREATHING DEVICE AND BREATHING DEVICE

Description

State of the art

[0001] The invention relates to a device and a method for quality control of a breathalyzer and a breathalyzer according to the preamble of the independent claims. The present invention also relates to a computer program.

[0002] Laboratory equipment, such as medical devices, must be regularly checked for functionality as part of quality assurance. Quality assurance serves to demonstrate that the entire system under test delivers results within the permissible accuracy range in the specified measurement or analysis area. Currently, substitute samples similar to human samples are frequently used for quality control.

[0003] US Patent 2003 / 21 6660 A1 discloses a breath test procedure. To increase measurement accuracy, the results of the breath tests are used for continuous and automatic self-calibration. Disclosure of the invention

[0004] Against this background, the approach presented here introduces an improved method and an improved device for quality control of a respiratory measuring device, an improved respiratory measuring device, and finally a corresponding computer program according to the main claims. Advantageous further developments and improvements of the device specified in the independent claim are possible through the measures listed in the dependent claims.

[0005] The approach presented here ensures consistently high-quality measurement results from a respiratory monitoring device based on human samples, thereby enabling reliable therapy for patients with conditions such as asthma. In a first embodiment of the approach, human samples can be tested for their suitability as reference values. In a second embodiment, previously tested human samples can be used to verify the respiratory monitoring device.

[0006] A method for quality control of a breathalyzer is presented, comprising a first sub-method for qualifying a test subject and, additionally or alternatively, a second sub-method for quality testing of the breathalyzer itself. The method can thus be understood as a method for operating the breathalyzer, with both sub-methods contributing to the successful execution of the breathalyzer's quality control. Regardless of whether the first or second sub-method is performed, the method includes a comparison step and, when the first sub-method is performed, an additional storage step, and, when the second sub-method is performed, an additional categorization step and preferably also a storage step of measured gas concentrations.

[0007] In the comparison step, a test value is compared to a tolerance band, the width of which is limited by a first threshold and a second threshold. The first and second thresholds represent values ​​calculated using a mean and a variation (e.g., a standard deviation) of reference values, as well as the accuracy of the breathalyzer. The test value and the reference values ​​represent gas concentrations measured using the breathalyzer.

[0008] In the saving step, the reference values ​​for a subsequent execution of the second sub-procedure are saved if the test value is within the tolerance band.

[0009] In the categorization step, the breathalyzer is categorized as functional or defective. If categorized as defective, the user is preferably informed, for example via a display, that the breathalyzer is not functioning and preferably informed that a service partner or the device manufacturer must be contacted.

[0010] The procedure can be performed, for example, in a breathalyzer, such as one intended for individuals with asthma. The test value can, for instance, indicate the amount of nitric oxide taken from a human breath sample after the subject has blown into the breathalyzer. The breath sample can be analyzed using a suitable analytical unit within the breathalyzer. This analytical unit can include sensors already used in breathalyzers. For example, the analytical unit can be configured to detect the amount of nitric oxide in the breath sample and display it as a measured value. The first and second threshold values ​​can define a range of values ​​representing the tolerance band within which the test value is located when the breathalyzer is ready for use.The first embodiment of the method, carried out in the first part of the process, allows for verification that the reference values ​​are breath samples from a healthy person. In this case, the reference values ​​and the test value can originate from the same individual. In the second embodiment of the method, carried out in the second part of the process, the reference values ​​have already been verified and can now be used to verify the breathalyzer. Because the reference values ​​and the test value originate from the same individual, values ​​from the same person can be used and compared. The reference values ​​can be measured values ​​acquired and stored using the breathalyzer. For example, the reference values ​​can be read from a memory device of the breathalyzer. The test value can be a measured value currently acquired using the breathalyzer.The test value can be read, for example, from an analysis unit of the breathing device or, in the case of intermediate storage, from a storage unit of the breathing device.

[0011] Advantageously, the first sub-procedure for qualifying a test subject can be performed first, followed by the second sub-procedure for quality control of the breathalyzer. Both sub-procedures can be performed using the same breathalyzer.

[0012] Furthermore, the procedure includes a step of determining the mean and the variance using the reference values.

[0013] Advantageously, this allows a first value to be compared with at least one other value, or with a plurality of other values.

[0014] According to one embodiment, the method can include a step of establishing the first and second threshold values ​​using the mean, variability, and accuracy of the respiratory measuring device. Advantageously, this allows a range of values ​​to be determined within which the comparative result can advantageously fall, for example, to ensure reliable therapy for asthma patients.

[0015] During the formation step, the width of the tolerance band can be determined using the first and second threshold values. The mean value and the fluctuation in the determined width can be inversely correlated.

[0016] According to one embodiment, in the threshold value calculation step, the fluctuation in the form of the standard deviation of the reference values ​​can be multiplied by a first factor if the standard deviation or the mean is smaller than a predetermined gas concentration value. Furthermore, the threshold values ​​can be multiplied by a second factor if the standard deviation or the mean is larger than the predetermined gas concentration value. Advantageously, the use of the first and second factors allows for the consideration of physiological fluctuations in the test subject during a functional test of the breathing apparatus.

[0017] For example, in the threshold calculation step, the fluctuation in the form of the standard deviation of the reference values ​​can be multiplied by a factor dependent on the mean. Different factors can be specified for different means or different ranges of means.

[0018] Furthermore, the procedure can include a step of recording reference values ​​using the respiratory monitoring device. This allows measured values ​​to be recorded on the device and also stored there in the form of reference values.

[0019] According to the first part of the procedure, the process includes the step of storing the reference values ​​for a subsequent quality check of the breathalyzer. The reference values ​​can therefore be stored if the verification of the reference values ​​shows that they are human samples suitable for testing the breathalyzer. This can be the case if the test value is greater than the first threshold and less than the second threshold. Ideally, the test value is within the range such that the quality check of the test subject is advantageously classified as passed. Storing the values ​​allows for later use of the reference values ​​for repeated verification of the breathalyzer. According to one embodiment, the test value can be stored as a further reference value.

[0020] The procedure may also include a step for reading the test value. This reading step can be repeated after a minimum duration to trigger a repetition of the second sub-procedure, reading another test value representing a further gas concentration measured using the breathalyzer. Re-reading can be performed if the test value is less than the first threshold, or if the test value is greater than the second threshold, indicating that the test value is outside the tolerance range. This means that the procedure can be repeated if the comparison result falls outside the range of values. For example, the first sub-procedure can be repeated with a different test subject as part of a qualification process.In this case, additional reference values ​​from another test subject can be imported and used instead of the original reference values. In the second sub-procedure, the procedure can be repeated with the same test subject during quality control, for example, after a waiting period of approximately 5 minutes.

[0021] In the second sub-process, a display signal can be provided during the initial setup step. This signal represents a question directed at the user if, after the re-reading step, the test value is lower than the first threshold or if it is higher than the second threshold. This means that, for example, after a repeated run of the second sub-process, a user of the breathalyzer will be asked about an illness, such as a cold, if the test value is outside the threshold values. Advantageously, this can rule out a malfunction of the breathalyzer if the user confirms the question.

[0022] According to the second sub-method, a quality signal can be output in one step of the output process, indicating that the breathalyzer has passed the quality test if the test value is greater than the first threshold, and additionally or alternatively if the test value is less than the second threshold. This advantageously allows the breathalyzer to be used, for example, with asthma patients.

[0023] The process of reading another test value can be prevented if the value is outside the tolerance range. This allows the breathing apparatus to be locked as a safety precaution, for example, for a minimum period of time.

[0024] This process can be implemented, for example, in software or hardware, or in a hybrid form of software and hardware, for example in a control unit.

[0025] Furthermore, a respiratory measuring device is presented with a device configured to control the procedure according to one of the previously presented variants. The respiratory measuring device is configured to measure a gas concentration.

[0026] This can be advantageous, for example, for asthma patients who depend on using the breathing monitor.

[0027] The approach presented here further creates a device designed to perform, control, and implement the steps of a variant of the method presented here in appropriate facilities. This embodiment of the invention in the form of a device also allows the problem underlying the invention to be solved quickly and efficiently.

[0028] For this purpose, the device may have at least one processing unit for processing signals or data, at least one storage unit for storing signals or data, at least one interface to a sensor or actuator for reading sensor signals from the sensor or for outputting data or control signals to the actuator, and / or at least one communication interface for reading or outputting data embedded in a communication protocol. The processing unit may, for example, be a signal processor, a microcontroller, or the like, and the storage unit may be flash memory, EEPROM, or a magnetic storage device.The communication interface can be configured to read or output data wirelessly and / or via wired connections, whereby a communication interface that can read or output wired data can, for example, read this data electrically or optically from or output it into a corresponding data transmission line.

[0029] In this context, a device can be understood as an electrical device that processes sensor signals and outputs control and / or data signals accordingly. The device may have an interface, which can be implemented in hardware and / or software. In the case of a hardware-based interface, the interfaces can, for example, be part of a so-called system ASIC, which incorporates various functions of the device. However, it is also possible that the interfaces are separate integrated circuits or consist at least partially of discrete components. In the case of a software-based interface, the interfaces can be software modules, which, for example, are present on a microcontroller alongside other software modules.

[0030] Also advantageous is a computer program product or computer program with program code that can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out, implement and / or control the steps of the method according to one of the embodiments described above, in particular if the program product or program is executed on a computer or device.

[0031] Examples of the approach presented here are shown in the drawings and explained in more detail in the following description. It shows: Fig. 1 a schematic representation of a breathing apparatus with a device according to an exemplary embodiment; Fig. 2 a schematic sequence of a procedure for quality control of a breathing measuring device according to an embodiment with two sub-procedures; Fig. 3 a flowchart of a procedure for qualifying a test subject according to an exemplary implementation; and Fig. 4 A flowchart of a procedure for quality control of the breathing apparatus according to an exemplary embodiment.

[0032] In the following description of favorable embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and acting similarly, without repeating these elements.

[0033] Fig. 1 Figure 1 shows a schematic representation of a breath analyzer 100 with a quality control device 102 according to an exemplary embodiment. The breath analyzer 100 is designed for use, for example, in the therapy of asthma patients. For such a breath analyzer 100, it is essential that a quality check be performed. Such a quality check can, for example, be carried out at regular intervals. This allows the functionality of the breath analyzer 100 to be checked. According to this exemplary embodiment, the breath analyzer 100 has a mouthpiece 103, a body 104, an analysis unit 105, and the quality control device 102. The mouthpiece 103 is designed to direct a breath sample 107 from a person into the body 104 to the analysis unit 105.The analysis device 105 is designed to analyze the breath sample 107 and provide a measured value representing an analysis result related to the breath sample 107. Such a measured value can be used as a test value 108 or reference value when quality control is performed using the device 102. According to this embodiment, the body 104 is designed as a housing to protect, for example, the device 102 and the analysis device 105 from external influences.

[0034] The device 102 is configured to execute or control a method for quality control of the breathalyzer 100. A first embodiment of the method is particularly applicable for qualifying a test subject. If the test subject qualifies, then measured values ​​generated from breath samples of the test subject can be used as reference values. A second embodiment of the method is particularly applicable for quality testing of the breathalyzer 100 using such reference values.

[0035] In both embodiments, a current measured value, here the test value 108, which represents a gas concentration measured using the analysis device 105, is read in by a reading unit 110 and compared with a first threshold value and a second threshold value using a reference unit 112 to obtain a comparison result 114. The test value is read in via an internal interface of the breathalyzer 100, for example, by the analysis device 105. According to the invention, the first threshold value and the second threshold value represent values ​​calculated using a mean value and a standard deviation of reference values. The reference values ​​also represent gas concentrations measured using the analysis device 105.According to this embodiment, the comparison result 114 or information determined using the comparison result can be displayed via a display device 116. The display device 116 can, for example, be implemented as a display. Depending on the comparison result, a question or an instruction can also be issued to the test subject using the display device 116.

[0036] According to the first embodiment, the display device 116 indicates, for example, whether a person is suitable as a test subject or not. A person qualifies as a test subject if breath samples 107 provided by that person are suitable for establishing reference values. In this case, the reference values, or the mean and standard deviation calculated therefrom, or the threshold values ​​calculated therefrom, are stored, for example, in a storage device of the breathalyzer 100 or made available via an output interface for use in subsequent quality control of the breathalyzer 100. If the person does not qualify as a test subject, the display device 116 indicates, for example, that the procedure should be repeated with another person to obtain suitable reference values.

[0037] According to the second embodiment, in which reference values ​​obtained by carrying out the first embodiment are used, the display device 116 indicates, for example, whether the breathing apparatus 100 has passed the quality test or not.

[0038] In normal operation of the breathalyzer 100, i.e., outside of quality control procedures, the display unit 116 shows, for example, the measured value currently recorded by the analysis unit 105 or information derived from the measured value. According to one embodiment, the breathalyzer 100 includes a suitable control unit for controlling the display shown by the display unit 116.

[0039] In other words, the respiratory measuring device 100 is presented for a method of quality assurance of the respiratory measuring device 100 for respiratory gas analysis with a human sample, here the breath sample 107, taking into account interpersonal and intrapersonal physiological variations of the samples. According to this embodiment, a consistently high quality of measurement results can thus be ensured, thereby enabling reliable therapy for, for example, asthma patients. Preferably, the standard deviation is used as a static measure so that the interpersonal and intrapersonal physiological variations are taken into account.

[0040] Compared to asthmatics or individuals with other respiratory diseases, healthy individuals exhibit relatively constant FeNO (fractionated exhaled nitric oxide) values. Studies have shown that individuals with low FeNO values, for example, less than 50 ppb, exhibit very consistent values ​​when healthy. For values ​​below 50 ppb, fluctuations are approximately less than 3 ppb. Therefore, the standard deviation is a suitable parameter for observing this consistency. In otherwise healthy individuals, physiological fluctuations in FeNO values ​​can occur, which are due to various influencing factors such as physical activity, climbing stairs, or an infection. According to this example, the standard deviation should ideally be less than 3 ppb, preferably less than 1 ppb, when, for example, there is no infection or malfunction of the respiratory monitoring device 100.If the standard deviation increases, this embodiment suggests that there is a fault with the respiratory monitoring device 100 or that the test subject is ill. To distinguish physiological fluctuations from a defect or inaccuracy of the respiratory monitoring device 100, they must be excluded from the quality control process.

[0041] Fig. 2 Figure 200 shows a schematic sequence of a method 200 for quality control of a respiratory measuring device according to an embodiment with a selection option 201 between two sub-methods 202 and 204. The method 200 is applicable in a device such as that described in Figure 200. Fig. 1 as described. According to this embodiment, the method 200 for quality control of the respiratory measuring device comprises the first sub-method 202 for qualifying a test subject, as described below with reference to Fig. 3 is described in more detail below, and the second sub-procedure 204 for the quality testing of the breathing apparatus, as described below using the following examples: Fig. 4 This will be described in more detail. This allows for a two-part quality control system to be implemented.

[0042] Sub-procedures 202 and 204 can be executed sequentially. In the first sub-procedure, 202, it can first be verified whether a person qualifies as a test subject. If so, reference values ​​generated from this person's breath samples can be stored or made available for subsequent execution of the second sub-procedure, 204. In the second sub-procedure, 204, these reference values ​​can be used to perform the quality check of the breathalyzer. The second sub-procedure, 204, is executed repeatedly at predetermined intervals, for example, to perform the quality check based on the previously generated reference values. This quality check determines, for instance, whether the breathalyzer is functioning correctly or is defective. Sub-procedures 202 and 204 can also be executed independently of each other, or only one of them can be performed.

[0043] Procedure 200 enables quality control using user-generated measurements and considering a correlation between a level, such as a mean, and the standard deviation of these measurements. To obtain a measurement, the user may be asked to exhale into the breathalyzer so that the user's breath can be analyzed and the result of the analysis provided as the measurement.

[0044] At low levels of NO concentration in exhaled air, or "FeNO levels," the natural fluctuation of the measured values, and thus the standard deviation (SD), is also lower than at high levels. This fact is now being used to define the width of a tolerance band, both for the suitability of the user as a test subject and for the validity of the quality assurance.

[0045] The quality control test is considered successful if a test measurement falls within the tolerance band. The width of the tolerance band is determined by considering the device accuracy G (e.g., + / - 5 ppb), the FeNO level of the test subject, and the variability of previously recorded measurements from the test subject, preferably as a weighting of the standard deviation (SD). If the first sub-procedure 202 is performed, a positive quality control result means that the person is qualified as a test subject and the measurements are stored as reference values. If the second sub-procedure 204 is performed, a positive quality control result means that the breathalyzer is categorized as functional. According to one embodiment, the results of both sub-procedures 202 and 204—that is, the result of qualifying the test subject and the result of the quality control of the breathalyzer—are stored in the breathalyzer's internal memory.

[0046] According to one embodiment, the FeNO level and the fluctuation (especially in the form of the standard deviation) are anticorrelated in determining the width of the tolerance band.

[0047] In one embodiment, a threshold value (e.g., 25 ppb) is specified for an FeNO value, below which the fluctuation is factored into the width of the tolerance band by a first weighting value. This weighting value, also referred to as a factor, is, for example, "3". Above the specified FeNO threshold, the fluctuation is factored in by a second weighting value, for example, "2". This means, for example: Bandwidth: (MW - G - 3*SD) ≤ x4 ≤ (MW + G + 3*SD) for FeNO < 25 ppb and (MW - G - 2*SD) ≤ x4 ≤ (MW + G + 2*SD) for FeNO >= 25 ppb, where x4 is the currently measured (and to be verified) FeNO value of the test subject and G denotes the device accuracy. "FeNO" refers in particular to a previously measured FeNO value of the test subject or an average of several previously measured FeNO values ​​of the test subject, for example an average of three previously measured FeNO values ​​of the test subject.

[0048] According to one embodiment, several such FeNO values ​​are specified, each with different weight values ​​for the fluctuation.

[0049] Instead of the specified FeNO value, a specified standard deviation can be used to determine the weight value, as is the case, for example, with the Figuren 3 and 4 is described.

[0050] According to one embodiment, the user is requested to repeat the quality control, in particular the second sub-procedure 204, after a minimum period of time if the quality control is negative, i.e., if the test measurement is outside the tolerance band.

[0051] In one embodiment, the breathing apparatus is locked out, at least for a minimum period of time, if the quality control fails. Fig. 3 The diagram shows a flowchart of procedure 202 for qualifying a test subject according to an exemplary embodiment. Procedure 202 corresponds to the one in Fig. 2 The aforementioned first sub-procedure for qualifying a test subject can be carried out, for example, in a respiratory measuring device, as is the case in Fig. 1 as described. According to this embodiment, in method 202, after a start 300 of method 202, a first reference value 302, a second reference value 304, and a third reference value 306 are acquired in a step 301 of the acquisition process, from which, for example, a mean value is determined in a step 307 and a standard deviation is determined in a step 309. The reference values ​​302, 304, and 306 are, for example, values ​​obtained from the Fig. 1 The analysis device shown provides measurement values ​​that are assigned to a person. Procedure 202 is performed to verify that this person is qualified as a test subject and that the reference values ​​302, 304, and 306 are suitable for quality control of the respiratory measuring device.

[0052] According to this embodiment, the mean value (MW) in step 307 is determined according to the following formula: MW = ∑ i = 1 n x i n

[0053] The standard deviation (SD) is determined accordingly in step 309 according to the following formula: SD = 1 n − 1 ∑ i = 1 n x i − x ¯ 2

[0054] According to this embodiment, method 202 further comprises a reading step 312. In reading step 312, a test value 308, representing a gas concentration measured using the breathing apparatus, is read in via an internal interface. The test value 308 is, for example, one of the values ​​determined by the device in Fig. 1 The measured value provided by the analysis device shown is assigned to the same person as the reference values ​​302, 304, 306. In step 314 of the formation process, a first threshold and a second threshold are formed according to the invention, representing values ​​formed using the mean and standard deviation of the reference values ​​302, 304, 306. According to this embodiment, the standard deviation for forming the thresholds is multiplied by a first factor if the standard deviation is smaller than a predetermined gas concentration value, and by a second factor if the standard deviation is larger than the predetermined gas concentration value.

[0055] In step 316 of the comparison, the test value 308 is then compared with the first threshold and the second threshold according to this embodiment in order to obtain the comparison result 114.

[0056] If the test value 308 is greater than the first threshold and less than the second threshold, then, optionally, in a saving step 318, the reference values ​​302, 204, 306 are saved for a subsequent quality check, and in an optional output step 320, a quality signal 322 is output, indicating that the test subject has passed the qualification. This can then be further analyzed using... Fig. 4 The described procedure is carried out, in which the reference values ​​302, 204, 306 are used for quality control of the breathing device.

[0057] If, on the other hand, the test value 308 is less than the first threshold or greater than the second threshold, then, according to one embodiment, a selection of another test subject is displayed in step 324. In this case, procedure 202 is executed again, starting with step 300. Steps 301 and 312 are thus executed again to read in further reference values ​​and another test value assigned to a different person. The additional reference values ​​and the additional test value are used accordingly by re-executing steps 307, 309, 314, and 316 to verify whether the additional person qualifies as a test subject. If so, the additional reference values ​​can be used for a subsequent quality check of the breathalyzer.

[0058] Procedure 202 can be repeated until a person has qualified as a test subject.

[0059] In other words, Method 200 enables improved quality assurance with human samples by recognizing physiological variations and preventing them from being classified as errors in the breathalyzer. Furthermore, differences between test subjects are better accounted for, thus allowing for a more reliable sample for quality assurance.

[0060] According to this embodiment, it is advantageous for method 202 if measurements are carried out within one week to obtain the reference values ​​302, 304, 306, with only one measurement being performed per day. According to this embodiment, the three reference values ​​302, 304, 306 are FeNO values, also referred to as FeNO values ​​[x1 ... x3], and are determined by three FeNO measurements. Instead of the three reference values ​​302, 304, 306, a different number of reference values ​​can be used accordingly.

[0061] After carrying out the three measurements to determine the reference values ​​302, 304, 306, the mean and standard deviation are calculated from the three example reference values ​​302, 304, 306, for example as described in steps 307, 309.

[0062] The test value 308 is obtained from carrying out a further, here a fourth, measurement. According to this embodiment, the test value 308 is a further FeNO value, which is also referred to as FeNO value x 4 and is determined by a further FeNO measurement.

[0063] The person whose breath samples were used to determine reference values ​​302, 304, 306 and test value 308 is preferably considered suitable as a test subject if the following conditions are met: Preferably FeNO values ​​[x 1 ... x 4 ] < 50 ppb, and MW − G − 3 * SD ≤ x 4 ≤ MW + G + 3 * SD für SD < 2 , 5 ppb or MW − G − 2 * SD ≤ x 4 ≤ MW + G + 2 * SD für SD > 2 , 5 ppb .

[0064] Here, G represents the accuracy of the breathalyzer, where the accuracy of the breathalyzer in the FeNO measuring range is assumed to be less than 50 ppb and, for example, 5 ppb. As explained, the first factor is, for example, 3 if the standard deviation is less than the predetermined gas concentration value of, for example, 2.5 ppb. And the second factor is, for example, 2 if the standard deviation is greater than the predetermined gas concentration value. As shown by Fig. 2 Alternatively, a predetermined gas concentration value can be used for the FeNO value instead of the standard deviation to define the respective factor, preferably if the following conditions are met: MW − G − 3 * SD ≤ x 4 ≤ MW + G + 3 * SD für FeNO < 25 ppb or MW − G − 2 * SD ≤ x 4 ≤ MW + G + 2 * SD für FeNO > = 25 ppb .

[0065] It is also possible to predefine multiple gas concentration values ​​or gas concentration ranges to specify multiple factors. According to one embodiment, the accuracy of the breathalyzer is incorporated into the determination of the threshold values ​​by simple addition and / or subtraction. For example, the accuracy is subtracted from the mean value to determine the first threshold value and added to the mean value to determine the second threshold value.

[0066] Fig. 4 Figure 1 shows a flowchart of a procedure 204 for quality control of a breathalyzer according to an exemplary embodiment. According to this exemplary embodiment, the procedure 204 is carried out in a breathalyzer as described in Figure 204. Fig. 1 Procedure 204 can also be carried out as a sub-procedure, as described in Fig. 2 was described.

[0067] According to this embodiment, after a start 400 of the method 204, the process 204 comprises a step 401 of reading in reference values ​​302, 304, 306. The reference values ​​302, 304, 306 are those determined based on Fig. 3 The described reference values, as well as optionally the reference values ​​based on Fig. 3 The described test value and, if procedure 204 has already been performed, also stored measured values ​​from a previously carried out quality test of the breathing apparatus. The reference values ​​302, 304, 306 are read, for example, via an internal interface to a storage device in which the reference values ​​302, 304, 306 are stored. Based on the reference values ​​302, 304, 306, the mean is calculated in step 307 and the standard deviation is calculated in step 309, as already described above. Fig. 3 was described.

[0068] In step 312, a test value 408 is read in, which represents a gas concentration measured using the breathing device.

[0069] The test value is read in, for example, via an internal interface to an analysis unit, which generated test value 408. Test value 408 is therefore, for example, one of the values ​​generated by the [device / system - context needed]. Fig. 1 The measured value provided by the analysis device shown.

[0070] According to this embodiment, in step 316 of the comparison process, the test value 408 read in step 312 of the input process is compared with a first threshold and a second threshold to obtain a comparison result 114. The first and second thresholds represent values ​​calculated using the mean and standard deviation. The thresholds are calculated and the comparison is performed in step 312 as already described above. Fig. 3 described.

[0071] If the comparison result 114 from step 316 indicates that the test value 408 is lower than the first threshold or higher than the second threshold, this may be because the test value 408 was unsuitable or the breathalyzer is defective. If procedure 204 regarding the current quality check of the breathalyzer has only been performed once, meaning the test value 408 originates from a first measurement, the measurement is repeated after a waiting period, for example, five minutes. This is indicated by branch 420. In this case, steps 312 and 316 are executed again to read in another test value and compare it with the thresholds.If procedure 204 regarding the current quality check of the breathalyzer has already been executed twice, meaning the next test value is derived from a second measurement, the breathalyzer is declared defective in step 424 if the test subject is healthy. This is indicated by branch 422. In this case, procedure 204 is terminated.

[0072] To verify the test subject's health, procedure 204 optionally includes a step of providing a display signal to a display unit on the breathalyzer. This display signal is suitable for asking the test subject a question regarding their health status. The question can be displayed, for example, on a screen. If the user answers the question negatively, for example, by entering a response into the breathalyzer, the breathalyzer is categorized as defective in step 424.

[0073] If, on the other hand, the comparison result 114 from step 316 indicates that the test value 408 is greater than the first threshold and less than the second threshold, then the breathalyzer is categorized as functional in step 426. In other words, the breathalyzer has passed the quality test in such a case.

[0074] In other words, according to this embodiment, the reference values ​​302, 304, 306 are stored in the breathalyzer so that the mean and standard deviation can be calculated from them. In addition to the reference values ​​302, 304, 306, and optionally the test value from the data obtained using… Fig. 3 In addition to the qualification of the test subject described above, measurement values ​​obtained from previously carried out measurements within the framework of quality control are also used as reference values.

[0075] The mean and standard deviation can be determined using the following formulas, as already described: MW = ∑ i = 1 n x i n SD = 1 n − 1 ∑ i = 1 n x i − x ¯ 2

[0076] To check the device quality, the user performs a measurement x n+1, whereby the resulting test value 408 is compared with the quality measurements carried out so far, for example with the reference values ​​302, 304, 306.

[0077] The measurement, and therefore the quality assurance, is valid if MW − G − 3 * SD ≤ x n + 1 ≤ MW + G + 3 * SD für SD < 2 , 5 ppb or MW − G − 2 * SD ≤ x n + 1 ≤ MW + G + 2 * SD für SD > 2 , 5 ppb . is given. The following also apply in connection with the Fig. 3 The explanations given, in particular the above-mentioned alternative conditions for a valid measurement and thus quality assurance: MW − G − 3 * SD ≤ x n + 1 ≤ MW + G + 3 * SD für FeNO < 25 ppb or MW − G − 2 * SD ≤ x n + 1 ≤ MW + G + 2 * SD für FeNO > = 25 ppb .

[0078] If the test value 408 is outside this threshold range, the user is prompted to perform another measurement, for example, to repeat the measurement from which the test value 408 resulted after 5 minutes. If the test value 408 is then within the threshold range, the quality test is considered passed. The previous measurement is considered an outlier and discarded.

[0079] If the test value of 108 is again outside the threshold range, the device will ask the user whether they have, for example, a cold or other illness. If so, the quality test must be repeated with a different user. However, if an infection or similar condition can be ruled out, the test value of 408 or the next test value from the repeat measurement will be included in the evaluation, and the quality test will be considered failed. In this case, a device malfunction is assumed, and appropriate measures can be initiated with the manufacturer's technical service.

[0080] If an embodiment includes an "and / or" connection between a first feature and a second feature, this is to be read as meaning that the embodiment according to one embodiment has both the first feature and the second feature, and according to another embodiment either only the first feature or only the second feature.

Claims

1. Method (200) for quality control of a breath measuring device (100), wherein the method (200) comprises a first sub-method (202) for qualifying a test subject and / or a second sub-method (204) for testing the quality of the breath measuring device (100), comprising the following steps: determining an average value and a fluctuation using reference values (302, 304, 306) representing gas concentrations measured with the breath measuring device (100); comparing (316) a test value (108; 308; 408) with a tolerance band, wherein a width of the tolerance band is limited by a first threshold value and a second threshold value, wherein the first threshold value and the second threshold value represent values formed using the average value and the fluctuation of reference values (302, 304, 306) as well as an accuracy of the breath measuring device (100), wherein the test value (108; 308; 408) represents gas concentrations measured with the breath measuring device (100); and characterized by the following steps: storing (318) the reference values (302, 304, 306) for subsequently performing the second sub-method (204) if the test value (108; 308) lies within the tolerance band and the first sub-method (202) for qualifying a test subject is performed, or categorizing (426) the breath measuring device (100) as functional if the test value (108; 308) lies within the tolerance band and the second sub-method (204) for testing the quality of the breath measuring device (100) is performed.

2. Method (200, 202, 204) according to Claim 1, comprising a step (314) of forming the first threshold value and the second threshold value using the average value and the fluctuation and the accuracy of the breath measuring device (100).

3. Method according to Claim 2, in which the width of the tolerance band is determined in the forming step (314) by means of the first threshold value and the second threshold value, wherein the average value and the fluctuation anti-correlate in the determination of the width.

4. Method (200, 202, 204) according to Claim 2 or 3, wherein, in the forming step (314), the fluctuation in the form of the standard deviation of the reference values (302, 304, 306) for forming the threshold values is multiplied by a first factor if the standard deviation or the average value is less than a predetermined gas concentration value, and is multiplied by a second factor if the standard deviation or the average value is greater than the predetermined gas concentration value.

5. Method (200, 202, 204) according to one of Claims 2 to 4, wherein, in the forming step (314), the fluctuation in the form of the standard deviation of the reference values (302, 304, 306) for forming the threshold values is multiplied by a factor dependent on the average value.

6. Method (200, 202) according to one of the preceding claims, comprising a step (301) of capturing the reference values (302, 304, 306) using the breath measuring device (100).

7. Method (200, 204) according to one of the preceding claims, comprising a step (312) of reading in the test value, wherein the step (312) is carried out again after a minimum period in order, for the purpose of prompting repetition of the second sub-method (204), to read in a further test value representing a further gas concentration measured using the breath measuring device (100) if the test value (108; 308; 408) lies outside the tolerance band.

8. Method (200, 204) according to Claim 7, comprising a step of providing a display signal representing a question directed to a user if, after the step (312) has been carried out again, the further test value (108; 408) is less than the first threshold value or greater than the second threshold value.

9. Method (204) according to one of the preceding claims, in which a step (312) of reading in a further test value is prevented if the test value (408) lies outside the tolerance band.

10. Method (204) according to one of the preceding claims, in which first the first sub-method (202) for qualifying a test subject and then the second sub-method (204) for testing the quality of the breath measuring device (100) are carried out.

11. Apparatus (102) configured to carry out and / or control the steps of the method (200, 202, 204) according to one of the preceding claims in a computing unit and a storage unit, in particular a read-in unit (110) and a comparison unit (112).

12. Breath measuring device (100) having an apparatus (102) according to Claim 11, wherein the breath measuring device (100) is designed to measure a gas concentration.

13. Computer program, comprising instructions that cause the apparatus in Claim 11 to 12 to carry out the method steps according to Claims 1 to 10.

14. Machine-readable storage medium on which the computer program according to Claim 13 is stored.