Method for determining final numerical analyte result value corresponding to concentration of analyte in bodily fluid using mobile device

Abstract

The present invention provides a method of determining an analyte concentration in a bodily fluid using a mobile device with a camera; the invention further relates to a corresponding computer program, to a non-transitory computer readable storage medium having corresponding instructions, to a corresponding mobile device, and to a corresponding kit. The method comprises a step a: determining a numerical analyte result value from an image formed by colors of a reagent test region, a step b: displaying the numerical analyte result value and / or a corresponding analyte value range and / or a corresponding message, in which in step c) after step a) and before step b), if the numerical analyte result value exceeds an upper threshold value, the analyte value is displayed. If both thresholds are exceeded, an upper deviation is added to the numerical analyte result value, or if the numerical analyte result value is below a lower threshold, a lower deviation is subtracted, or if both thresholds are not exceeded, the numerical analyte result value remains unchanged.

Description

Technical Field

[0001] The present application relates to a method for determining a final numerical analyte result value corresponding to a concentration of an analyte in a body fluid using a mobile device having a camera, a processing device, and a display device. The present invention further relates to a computer program comprising computer executable instructions for running the method; a non-transitory computer readable storage medium comprising instructions, which when executed by a mobile device, causes the mobile device to run the method; a mobile device having a camera, the mobile device being configured to determine the concentration of an analyte in a body fluid; and a kit for determining the concentration of an analyte in a body fluid, the kit comprising at least one mobile device and at least one optical test strip having at least one test area. Background Art

[0002] Many different devices and methods for determining one or more analytes in body fluids, such as blood, urine, interstitial fluid and saliva, are known in the prior art. Without narrowing the scope, the present invention will be specifically described with respect to blood glucose measurement. However, it should be noted that the present invention can also be used for other types of analytical measurements using test elements.

[0003] Several test elements are known in the art, which comprise at least one test chemical, also called test reagent, which undergoes a color reaction in the presence of at least one analyte to be detected. Some basic principles regarding test elements and reagents, which can also be used within the scope of the present invention, are described in, for example, J. et al.: Diabetes Technology and Therapeutics, Volume 10, Supplement 1, 2008, Pages 10-26.

[0004] In analytical measurements based on color-forming reactions, one technical challenge is to evaluate the color change caused by the detection reaction. In addition to the use of dedicated analytical devices such as handheld blood glucose meters, the use of general electronic devices such as smartphones and portable computers has become increasingly popular in recent years. Such a method for detecting analyte concentrations using a mobile device is known from EP 3 591 385 A1.

[0005] WO 2017 / 272095 A2 discloses a method comprising the steps of obtaining blood glucose level readings for a diurnal period for each of a plurality of days and determining an estimated variability of blood glucose levels for the diurnal period or the plurality of days. A user can adjust a blood glucose target by adjusting their fear of hypoglycemia index (FHI). The adjustment may add or subtract a predetermined value from a previously used blood glucose target.

[0006] WO 2017 / 124006 A1 relates to a method for generating an insulin delivery profile, wherein a profile blood glucose target for a specific diurnal period can be set or changed based on a patient's historical blood glucose pattern.

[0007] WO 2020 / 214780 A1 discloses a personalized closed-loop system and method for insulin delivery, in which one or more operating mode control parameters are automatically adjusted.

[0008] When monitoring analytes relevant to human health, it is particularly important not to miss critical states (ie, critical analyte concentrations) due to measurement methods and / or measurement errors.

[0009] Therefore, it is desirable to provide methods and apparatus that can solve the above-mentioned technical challenges of analytical measurement, especially when using mobile devices such as consumer electronic mobile devices, in particular multifunctional mobile devices such as smartphones or tablet computers that are not dedicated to analytical measurement. In particular, methods, computer programs and apparatuses that can be widely applicable to available mobile devices and are suitable for improving reliability and safety while being convenient for user operation should be proposed. Summary of the invention

[0010] This problem is solved by a method, a computer program and an apparatus having the features of the independent claims. Advantageous embodiments are listed in the dependent claims, which can be realized individually or in any arbitrary combination.

[0011] As used hereinafter, the terms "having", "comprising" or "including" or any grammatical variations thereof are used in a non-exclusive manner. Thus, these terms may refer both to situations in which, apart from the features introduced by these terms, no further features are present in the entity described herein, and to situations in which one or more further features are present. As an example, the expressions "A has B", "A comprises B" and "A includes B" may all refer to situations in which, apart from B, no other elements are present in A (i.e., situations in which A consists only and exclusively of B) and may also refer to situations in which, apart from B, one or more further elements (e.g., element C, elements C and D or even further elements) are present in entity A.

[0012] Further, it should be noted that the terms "at least one", "one or more" or similar expressions indicating that a feature or element may be present once or more than once are usually used only once when introducing the corresponding feature or element. In the following, in most cases, when referring to the corresponding feature or element, the expression "at least one" or "one or more" is not repeated even though the corresponding feature or element may be present only once or more than once.

[0013] In addition, as used hereinafter, the terms "preferably", "more preferably", "particularly", "more particularly", "specifically", "more specifically" or similar terms are used in conjunction with optional features without limiting the alternative possibilities. Therefore, the features introduced by these terms are optional features and are not intended to limit the scope of the claims in any way. As the skilled person will recognize, the present invention can be implemented by using alternative features. Similarly, the features introduced by "in one embodiment of the present invention" or similar expressions are intended to be optional features without any limitation on alternative embodiments of the present invention, without any limitation on the scope of the present invention, and without any limitation on the possibility of combining the features introduced in this manner with other optional or non-optional features of the present invention.

[0014] In a first aspect, a method for determining a final numerical analyte result value corresponding to a concentration of an analyte in a body fluid using a mobile device having a processing device and a display device is disclosed. The method comprises the following steps: determining an initial numerical analyte result value by a processing device from an image formed from the color of a reagent test area, and displaying the final numerical analyte result value and / or an analyte value range corresponding to the final numerical analyte result value in a set of preset analyte value ranges and / or a message corresponding to the corresponding analyte value range. The final numerical analyte result value is determined by comparing the initial numerical analyte result value with at least one upper threshold value and with at least one lower threshold value; and if the initial numerical analyte result value exceeds the upper threshold value, adding a preset upper deviation to the initial numerical analyte result value to form the final numerical analyte result value, or if the initial numerical analyte result value is below the lower threshold value, subtracting a preset lower deviation from the initial numerical analyte result value to form the final numerical analyte result value, or if the initial numerical analyte result value is neither above the upper threshold value nor below the lower threshold value, using the initial numerical analyte result value unchanged to form the final numerical analyte result value.

[0015] "Analyte" refers to a substance or chemical of interest in an analytical procedure, and is also referred to as a component or chemical substance. As an example, one or more analytes involved in metabolism, such as blood sugar, may be determined. Additionally or alternatively, other types of analytes or parameters, such as pH values, may be determined. The analyte is contained in at least one body fluid sample and causes a color forming reaction in a test chemical (also referred to as a test reagent). In order to cause the reaction, the body fluid is applied to a reagent test area, which is not limited to a portion of a test strip, etc. and includes the test reagent.

[0016] "Body fluid" refers to any fluid in the body, such as blood, interstitial fluid, urine, saliva, etc.

[0017] "Color formation" refers to the color of the reagent test area produced by the color formation reaction (i.e., chemical, biological or physical reaction), during which the color of at least one element participating in the reaction, specifically the reflectivity, changes depending on the concentration of the analyte participating in the reaction. The term "color" as used herein is a broad term and may refer to any form of light reflected by the area including the color. In particular, the term "color" also refers to black, white or gray, and to red or green or blue, etc. Thus, the concentration of the analyte in the body fluid can be determined by evaluating the color formation (i.e., the color change occurring in the reagent test area due to the reaction).

[0018] The method is based on at least a single measurement of the analyte concentration using a mobile device, wherein "mobile device" refers to a mobile electronic device, i.e. a portable device comprising at least one processing device, at least one display device and optionally a camera. The mobile device may specifically refer to a mobile communication device such as a mobile phone and a smartphone. Additionally or alternatively, the mobile device may also refer to a tablet computer or another type of portable computing device with a display device and optionally a camera.

[0019] "Processing device" refers to any device capable of processing data such as a data processor, and "display device" refers to an output device that presents information in visual or tactile form, such as but not limited to an LCD display, LED display or tactile electronic display.

[0020] A "camera" refers to a device having at least one imaging element configured to record or capture spatially resolved one-dimensional, two-dimensional, or even three-dimensional optical data or information. As an example, a camera may include at least one camera chip such as at least one CCD chip and / or at least one CMOS chip configured to record an image.

[0021] Correspondingly, the term "image" may refer to data recorded using a camera, such as a plurality of electronic readings from an imaging device, such as pixels of a chip of a camera. The image may also be captured by a camera of a mobile device. Alternatively, the image may be captured by any other camera and transmitted to a processing device of the mobile device by any suitable form of wired or wireless communication.

[0022] The camera of the mobile device and / or the camera with which the image is captured may be a color camera. Thus, for example, for each pixel, color information may be provided or generated, such as color values ​​of three colors R, G, B. A greater number of color values ​​is also feasible, such as four color values ​​per pixel, for example R, G, G, B. Color cameras are generally known to those skilled in the art. Thus, as an example, a camera chip may consist of a plurality of color sensors, each chip containing three or more color sensors, such as color recording pixels, such as one pixel for red (R), one pixel for green (G) and one pixel for blue (B). For each pixel, such as for R, G, B, individual values ​​may be recorded per pixel, such as digital values ​​in the range of 0 to 255, according to the intensity of the corresponding color. As an example, a quaternion, such as R, G, G, B, may be used instead of a color triplet, such as R, G, B. The color sensitivity of a pixel may be generated by a color filter or by the appropriate intrinsic sensitivity of the sensor element used in the camera pixel. These techniques are well known to the skilled person.

[0023] An initial numerical analyte result value within the bodily fluid sample is determined based on the image of the reagent test area. After the bodily fluid sample is applied to the reagent test area, an image of the reagent test area may be captured by a camera of the mobile device or by any other camera. A color formation, i.e., the color of the reagent test area in the image, is determined by the processing device, and an initial numerical analyte result value corresponding to the determined color formation is then identified by the processing device, wherein an "initial numerical analyte result value" refers to a numerical indication of the concentration of an analyte in the bodily fluid sample that corresponds to the color formation.

[0024] In order to convey the result to the user, the final numerical analyte result value is displayed on the display device of the mobile device. Additionally or alternatively, the analyte value range corresponding to the final numerical analyte result value and / or the message corresponding to the corresponding analyte value range is displayed on the display device of the mobile device. An associated or corresponding "message" refers to any displayable sign that can inform the user of the state of the analyte concentration range, i.e., the determined analyte value range. The message may include one or more of the range name, the corresponding value such as the range limit value, the corresponding recommendation, the alarm, the symbol, etc.

[0025] "Analyte value range" refers to a portion of a measurement range, i.e., a range of measurable values, wherein the analyte value range extends between a lower range limit and an upper range limit, i.e., includes all values ​​of the measurement range between the lower range limit and the upper range limit. Specifically, the measurement range can be divided into a series of analyte value ranges in a certain manner so that all values ​​of the measurement range belong to one of the analyte value ranges. For example, the upper range limit of the analyte value range corresponds to the lower range limit of an adjacent analyte value range, wherein the range limit value belongs to one of those adjacent analyte value ranges, and the other range includes all values ​​that are less than or greater than the range limit value, respectively. The analyte value range corresponding to the final numerical analyte value is a range that includes the corresponding final numerical analyte result value, or in other words, the final numerical analyte result value falls within the corresponding analyte value range.

[0026] Typically, for any analyte in a bodily fluid, certain concentration values ​​are "normal" while other concentration values ​​are "out of range," either too high or too low, and both may have a negative impact on health. For example, glucose concentration values ​​between 71 mg / dl and 130 mg / dl are typically classified as being in range, while concentration values ​​below 71 mg / dl are typically classified as a hypoglycemic state, and concentrations above 180 mg / dl are typically classified as a hyperglycemic state. Analyte value ranges may represent such preset classifications or categories of analyte concentrations.

[0027] The final numerical analyte result value is determined based on the initial numerical analyte result value, and in particular, the final numerical analyte result value corresponds to the initial numerical analyte result value or is produced by biasing the initial numerical analyte result value depending on the results of comparing the initial numerical analyte result value to at least two threshold values.

[0028] It should be understood that these deviations, i.e., the upper deviation and the lower deviation, each include one or more positive values, such that initial numerical analyte result values ​​exceeding the upper threshold are increased by adding the upper deviation to form the final numerical analyte result value, and initial numerical analyte result values ​​below the lower threshold are decreased by subtracting the lower deviation to form the final numerical analyte result value.

[0029] Furthermore, in some embodiments, the method steps are repeated periodically, such as upon request of a user, or following a preset schedule, or due to a triggering event or message, etc.

[0030] For any measurement, the numerical analyte result value determined by the method exhibits a measurement error, i.e., the difference between the determined initial numerical analyte result value and the actual analyte concentration value in the body fluid. The error distribution can be assumed to have a symmetric shape, such as a Gaussian shape. Thus, for any actual concentration value of a body fluid sample that is very close to or equal to a range limit between two adjacent analyte value ranges, the probability that the actual analyte concentration is associated with either of the two adjacent analyte value ranges is exactly or approximately 50%.

[0031] With regard to range limits with "extreme" ranges, i.e., analyte value ranges covering small or very small or high or very high measured values, respectively, this carries the risk of missing those "extreme" ranges and erroneously delivering final numerical analyte result values ​​or corresponding analyte value ranges that are less extreme. In other words, erroneously missing the attribution of extreme final numerical analyte result values ​​or analyte value ranges may mean missing a warning to the user about a critical state of the analyte concentration in his body fluid, e.g. a critically high or low blood glucose concentration, which may have health-threatening or even life-threatening consequences.

[0032] With all initial numerical analyte result values ​​artificially biased below or above the corresponding threshold, the probability of higher or lower result values ​​representing "extreme" conditions and falling within the "extreme" range increases. Therefore, the probability of missing critical high or low analyte concentrations decreases, which increases the reliability and safety of the measurement method.

[0033] On the other hand, it is less critical if the actual in-range concentration is misclassified as belonging to a more extreme range and a corresponding "extreme" result value or range is communicated to the user. Preferred communication of more critical states may even have a favorable influence on user behavior.

[0034] In one embodiment, the upper deviation is a constant upper offset value or an upper transfer function having a function value that depends on the initial numerical analyte result value and / or on the absolute value of the difference between the initial numerical analyte result value and an upper threshold value.

[0035] In one embodiment, the lower deviation is a constant lower offset value or a lower transfer function having a function value that depends on the initial numerical analyte result value and / or on the absolute value of the difference between the initial numerical analyte result value and a lower threshold value.

[0036] Here, the term "bias" is used without limitation to a constant positive value or function. A constant upper offset value causes all initial numerical analyte result values ​​exceeding the upper threshold to be increased by a constant value. Correspondingly, a constant lower offset value causes all initial numerical analyte result values ​​below the lower threshold to be decreased by a constant value.

[0037] Alternatively, the upper deviation or lower deviation is an upper transfer function or a lower transfer function such that the specific deviation value added or subtracted from the initial numerical analyte result value to form the final numerical analyte result value depends on the distance of the numerical analyte result value from the corresponding threshold value. Here, "distance" refers to the absolute value of the difference between the initial numerical analyte result value and the corresponding threshold value. The term "absolute value" as used herein is a broad term and is given a common and customary meaning to a person of ordinary skill in the art, and is not limited to a special or customized meaning. The absolute value of a number, also known as the modulus, may specifically refer to the non-negative value of the number without regard to its sign.

[0038] In one embodiment, the lower offset value is the same as the upper offset value or different from each other.

[0039] As the magnitude of the offset value increases, the probability that the final numerical analyte result value falls within the extreme analyte value range increases. For example, the magnitude of the offset value can be selected by considering the magnitude of the measurement error to be expected, and this can prompt the selection of different offset values ​​for the upper offset value and the lower offset value, respectively. For example, as a larger upper deviation (i.e., the upper offset value is greater than the lower offset value) is added to any initial numerical analyte result value that exceeds the upper threshold, an explanation can be given for the greater relative measurement error of the larger value.

[0040] In one embodiment, the upper transfer function and / or the lower transfer function gradually increases with increasing distance given by the absolute value of the difference between the numerical analyte result value and the upper threshold or the lower threshold, respectively.

[0041] "Gradually increase" or "gradual increase" refers to a continuous increase or a stepwise increase. Therefore, here, a gradually increasing function refers to a function having a function value that increases as the distance from the corresponding threshold increases and / or remains constant in the intercept, such as a linear function or an increasing step function or a combination thereof with a function value proportional to the distance. Therefore, as the distance increases, the upper deviation and / or the lower deviation gradually increases, so that the increase in the initial numerical analyte result value exceeding the upper threshold and / or the decrease in the initial numerical analyte result value below the lower threshold gradually increases.

[0042] In one embodiment, the upper transfer function and / or the lower transfer function comprises a first region that gradually increases with increasing corresponding distance and a second region having a constant value.Here, "region" refers to a segment or fragment of a transfer function and can be defined by specifying a range of initial analyte result values.

[0043] In an embodiment, the first zone extends between an upper threshold and a second, larger upper threshold or between a lower threshold and a second, smaller lower threshold, respectively, and the second zone is adjacent to the first zone, covering all values ​​greater than the second upper threshold or less than the second lower threshold, respectively. It should be understood that each threshold belongs to one of the two adjacent zones.

[0044] In one embodiment, the incremental increase of the upper transfer function and / or the lower transfer function is proportional to the absolute value of the difference between the numerical analyte result value and the upper threshold value or the lower threshold value, respectively.

[0045] In one embodiment, the proportional dependence is applied to the upper transfer function or the lower transfer function as a whole.Alternatively, the proportional dependence is applied to a region of the measurement range, ie to a portion or part of the possible initial numerical analyte result values, for example to a first region.

[0046] In one embodiment, the upper threshold is the same as the lower threshold.

[0047] If the upper threshold value and the lower threshold value are different from each other, the final numerical analyte result value is the same as the initial numerical analyte result value, consisting of the central area between the two threshold values, and in the area above the upper threshold value and the area below the lower threshold value, the final numerical analyte result value is formed by adding or subtracting the initial numerical analyte result value, respectively.

[0048] If the upper threshold value is the same as the lower threshold value, then all or all but one of the initial numerical analyte result values ​​that are the same as the threshold value are formed by biasing the initial numerical analyte result values.

[0049] In one embodiment, determining the final numerical analyte result value includes comparing the initial numerical analyte result value to a second upper threshold value and a second lower threshold value, and, if the initial numerical analyte result value exceeds the second upper threshold value or is below the second lower threshold value, using the initial numerical analyte result value unchanged to form the final numerical analyte result value.

[0050] The second lower threshold value may be less than the lower threshold value and the second upper threshold value may be greater than the upper threshold value, such that for all initial numerical analyte result values ​​below the lower threshold value and above the second lower threshold value, the final numerical analyte result value is formed by subtracting the lower deviation from the initial numerical analyte result value, and for all initial numerical analyte result values ​​below the second lower threshold value, the final numerical analyte result value is formed by the initial numerical analyte result value without modification. Correspondingly, the final numerical analyte result value is formed by biasing the initial numerical analyte result value, i.e., by adding the upper deviation, only if the initial numerical analyte result value is greater than the upper threshold value and less than the second upper threshold value. Thus, the biasing step may be saved / omitted for "very extreme" values, since it is not necessary to ensure that the critical analyte concentration of such final numerical analyte result value is not missed, for which the probability of being classified as critical is very high, e.g., 70% or 90% or 95% or even higher.

[0051] It may be sufficient to bias only those concentration values, i.e., initial numerical analyte result values, that are classified as being within range but close to or very close to a more critical value (e.g., close to a category boundary or a range limit of a category / range designated as out of range). Alternatively, it may be sufficient to additionally bias those initial numerical analyte result values ​​that are classified as being slightly out of range.

[0052] In one embodiment, the analyte is blood glucose and the body fluid is blood or interstitial fluid.

[0053] In another embodiment, the upper threshold is between 160 mg / dl and 180 mg / dl, or between 165 mg / dl and 175 mg / dl, or between 168 mg / dl and 172 mg / dl, or between 169 mg / dl and 171 mg / dl. In yet another embodiment, the lower threshold is between 60 mg / dl and 90 mg / dl, or between 75 mg / dl and 85 mg / dl, or between 78 mg / dl and 82 mg / dl, or between 79 mg / dl and 81 mg / dl.

[0054] In another aspect, a computer program is disclosed, comprising computer executable instructions for executing the above method.

[0055] In yet another aspect, a non-transitory computer-readable storage medium is disclosed, the computer-readable storage medium comprising instructions that, when executed by a mobile device, cause the mobile device to execute the method described above.

[0056] In another aspect, a mobile device is disclosed, comprising a processing device, a display device, a camera, and a memory storing instructions which, when executed by the processing device, configure the mobile device to execute the method as described above.

[0057] In yet another aspect, a kit for determining the concentration of an analyte in a body fluid comprises at least one mobile device as described above and at least one optical test strip having at least one test area.

[0058] Other technical features of different aspects of the present invention will be apparent to those skilled in the art from the following drawings, descriptions and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Other optional features and embodiments will be disclosed in more detail in the subsequent description of the embodiments, preferably in conjunction with the dependent claims. Wherein, as will be appreciated by those skilled in the art, each optional feature can be implemented in a separate manner and in any arbitrarily feasible combination. The scope of the present invention is not limited by the preferred embodiments. Embodiments are schematically depicted in the accompanying drawings.

[0060] Figure 1 A flow chart illustrating an embodiment of a method of using a mobile device to determine a final numerical analyte result value corresponding to a concentration of a bodily fluid.

[0061] Figure 2 Artificial bias of the measurement results according to the first embodiment is illustrated.

[0062] Figure 3 Artificial bias of the measurement results according to the second embodiment is illustrated.

[0063] Figure 4 Artificial bias of the measurement results according to the third embodiment is illustrated.

[0064] Figure 5 Artificial bias of measurement results according to the fourth embodiment is illustrated.

[0065] Figure 6 Artificial bias of measurement results according to the fifth embodiment is illustrated.

[0066] Figure 7 The impact of measurement error on missing a critical low analyte concentration state is illustrated.

[0067] Figure 8 The effect of measurement error on missing a critical high analyte concentration state is illustrated. DETAILED DESCRIPTION

[0068] exist Figure 1 Schematically illustrate the method for determining the final numerical analyte value corresponding to the concentration of analyte in body fluid. The method is performed by a mobile device comprising a processing device, a display device and an optional camera. In a first step 102, the initial numerical analyte result value is determined from the color formation of the reagent test area. The image is taken by the camera of the mobile device or by any other camera and is transferred to the mobile device, and the determination process is performed by the processing device. The reagent test area can form a part for test strips and can include a test reagent, wherein the color formation reaction of the test reagent in the reagent test area is caused by applying the body fluid to the reagent test area.

[0069] In a second step 104, the initial numerical analyte result value is compared to an upper threshold and to a lower threshold, and a final numerical analyte result value is formed from the initial numerical analyte result value unchanged or by adding or subtracting a bias value from the initial numerical analyte result value depending on the comparison results.

[0070] If the initial numerical analyte result value exceeds the upper threshold, i.e., is greater than the upper threshold, then a preset upper deviation is added to the initial numerical analyte result value to form a final numerical analyte result value. Thus, the final numerical analyte result value is increased or enlarged compared to the initial numerical analyte result value. The preset upper deviation may be a value that is constant for all initial numerical analyte result values, or it may be a value that depends on the initial numerical analyte result value itself and / or the distance of the initial numerical analyte result value from the upper threshold, etc. Exemplary embodiments of the upper deviation are described in more detail below.

[0071] If the initial numerical analyte result value is below the threshold, i.e., less than the lower threshold, the preset lower deviation is subtracted from the initial numerical analyte result value to form the final numerical analyte result value. Thus, the final numerical analyte result value is reduced or smaller than the initial numerical analyte result value. As with the upper deviation, the preset lower deviation may be a value that is constant for all initial numerical analyte result values, or a value that depends on another quantity, such as, for example, the initial numerical analyte result value itself or its distance from the lower threshold, etc.

[0072] If the initial numerical analyte result value is neither above the upper threshold nor below the lower threshold, i.e., is less than the upper threshold and greater than the lower threshold, then the final numerical analyte result value is formed from the initial numerical analyte result value without change. Thus, in this case, the final numerical analyte result value is the same as the initial numerical analyte result value.

[0073] It will be appreciated that each threshold value forms part of one of the two ranges separated by the threshold value. For example, in a first embodiment, an initial numerical analyte result value that is the same as an upper threshold value or a lower threshold value remains unchanged. Alternatively, an initial numerical analyte result value that is the same as an upper threshold value or a lower threshold value may be offset.

[0074] Method step 104 is followed by step 106 , wherein step 106 proceeds using the final numerical analyte result value produced by step 104 , ie, the value corresponding to the unchanged initial numerical analyte result value or the biased initial numerical analyte result value.

[0075] In step 106, the measurement result is communicated to the user by displaying the final numerical analyte result value generated by step 104 and / or an analyte value range corresponding to the final numerical analyte result value generated by step 104 and / or a message associated with the corresponding analyte value range. The associated message or, in other words, the corresponding message, may be any message suitable for informing the user of the determined analyte concentration.

[0076] Assigning or determining an analyte value range corresponding to a final numerical analyte result value means determining an analyte value range that includes the final numerical analyte result value.

[0077] In an embodiment, a series of analyte value ranges dividing the measurement range is predefined, i.e., each analyte value range of the series is preset, for example, by defining range limits dividing the measurement range and separating adjacent analyte value ranges. Likewise, it will be appreciated that each range limit forms part of one of the two analyte value ranges it separates. In a corresponding embodiment, step 106 comprises determining an analyte value range in the series of analyte value ranges that covers, i.e., includes, the final numerical analyte result value. Step 106 may also comprise determining a message associated with the corresponding analyte value range, e.g., using a lookup table or the like.

[0078] After step 106, the method may repeat as indicated by arrow 108 to determine a new initial numerical analyte result value and a new final numerical analyte result value based on the new initial numerical analyte result value.

[0079] exist Figure 2 , a first embodiment of biasing initial numerical analyte result values ​​to form final numerical analyte result values ​​is illustrated. Dashed line 202 depicts an identity function or identity relationship, i.e., the final numerical analyte result value is the same as the unchanged initial numerical analyte result value over the entire measurement range 204. Thus, each initial numerical analyte result value of the measurement range 204 along the abscissa 206 is mapped to the same final numerical analyte result value on the ordinate 208.

[0080] Solid line 210 depicts a final numerical analyte result value achieved by biasing initial numerical analyte result values ​​that are less than lower threshold 212 or greater than upper threshold 214 by a constant value. Correspondingly, for values ​​greater than lower threshold 212 and less than upper threshold 214, solid line 210 coincides with dashed line 202. To form the final numerical analyte result value, constant upper bias 216 is added to all initial numerical analyte result values ​​greater than upper threshold 214, such that solid line 210 is correspondingly shifted parallel to and above dashed line 202. Additionally, to form the final numerical analyte result value, constant lower bias 218 is subtracted from all initial numerical analyte result values ​​less than lower threshold 212, such that solid line 210 is correspondingly shifted parallel to and below dashed line 202. In the depicted embodiment, upper bias 216 is the same as lower bias 218.

[0081] exist Figure 3, a second embodiment of biasing the initial numerical analyte result value to form the final numerical analyte result value is illustrated by depicting a mapping of the initial numerical analyte result value along abscissa 302 to the final numerical analyte result value along ordinate 304. Dashed line 306 again depicts the identity function or identity relationship as a reference. Solid line 308 depicts biasing the initial numerical analyte result value, wherein the magnitude of the bias depends on the initial numerical analyte result value, and in particular, on the distance of the initial numerical analyte result value from the corresponding threshold value.

[0082] like Figure 3 , the upper deviation is an upper transfer function having a function value proportional to the absolute value of the difference between the initial numerical analyte result value and the upper threshold value 310. Correspondingly, the lower deviation is a lower transfer function having a function value proportional to the absolute value of the difference between the initial numerical analyte result value and the lower threshold value 312.

[0083] exist Figure 4 , a third embodiment of biasing an initial numerical analyte result value to form a final numerical analyte result value is illustrated. As depicted by solid line 210, the upper deviation is an upper transfer function and the lower deviation is a lower transfer function.

[0084] The upper and lower transfer functions include a first region having a gradual increase proportional to an increase in the respective distance of the initial numerical analyte result value from the upper threshold 408 or the lower threshold 404, respectively, and a second region having a constant value.

[0085] In the described embodiment, the first zone extends between the upper threshold 408 and a second, larger upper threshold 410 or between the lower threshold 404 and a second, smaller lower threshold 406, respectively, while the second zone is adjacent to the first zone, covering all values ​​that are respectively greater than the second upper threshold 410 or less than the second lower threshold 406. It should be understood that each threshold belongs to one of the two adjacent zones.

[0086] exist Figure 5 A fourth embodiment of biasing an initial numerical analyte result value to form a final numerical analyte result value is illustrated in , where a dashed line 502 depicting the identity function is given as a reference.

[0087] In the depicted embodiment, the lower threshold is the same as the upper threshold and therefore coincides with the mutual threshold 504. The upper deviation and the lower deviation are the upper transfer function and the lower transfer function, respectively. Each transfer function includes a first region spanning between the mutual threshold 504 and the second upper threshold 506 or the second lower threshold 508, respectively, and a second region covering all initial numerical analyte result values ​​that exceed the second upper threshold 506 or are below the second lower threshold 508, respectively.

[0088] In a first region, the upper transfer function and the lower transfer function include function values ​​that are proportional to the distance of the initial numerical analyte result value from the mutual threshold 504. In a second region, the function values ​​of the upper transfer function and the lower transfer function have constant values.

[0089] Correspondingly, solid line 510 depicting the mapping of initial numerical analyte result values ​​to final numerical analyte result values ​​includes a linear progression between second lower threshold 508 and second upper threshold 506, intersecting dashed line 502 at mutual threshold 504. In the region above second upper threshold 506 and below second lower threshold 508, solid line 510 moves parallel to above and below dashed line 502, respectively.

[0090] exist Figure 6 A fifth embodiment of biasing an initial numerical analyte result value to form a final numerical analyte result value is illustrated in , where a dashed line 612 depicting the identity function is given as a reference.

[0091] In the depicted embodiment, initial numerical analyte result values ​​less than lower threshold 604 are reduced by constant lower deviation 608 to form a final numerical analyte result value, as shown by solid line 602. Initial numerical analyte result values ​​greater than upper threshold 606 are increased by constant upper deviation 610 to form a final numerical analyte result value, wherein upper deviation 610 is greater than lower deviation 608.

[0092] exist Figure 7 In the graph shown, the example of glucose measurement is used to illustrate the effect of measurement error on missing a critical low analyte concentration state.

[0093] Blood glucose levels below 70 mg / dl may be critical to human health, so it is particularly important to reduce the risk of erroneously determining non-critical, in-range concentration values ​​when the analyte concentration of the actual applied body fluid sample is out of range, e.g. too low.

[0094] In this graph, the abscissa 702 depicts the actual analyte concentration values ​​of the samples, starting at 70 mg / dl and decreasing to 30 mg / dl. The ordinate 704 depicts the probability of determining a concentration value, i.e., a final numerical analyte result value of at least 70 mg / dl or greater, and therefore the probability of missing a critical low analyte concentration state.

[0095] In the absence of inventive biasing, whereby the initial numerical analyte result value is taken as the final numerical analyte result value, when the applied sample does have an analyte concentration of 70 dl / mg, the probability of actually accurately determining that 70 mg / dl is 50%, and for lower actual analyte concentrations, the probability decreases progressively, as shown by dashed line 706. Thus, for actual concentrations below but close to the critical value of 70 mg / dl, the probability of missing the identification and transmission of the critical concentration is close to 50%.

[0096] The method of the present invention helps reduce the probability of missing critical conditions by reducing smaller initial numerical analyte result values ​​to form final numerical analyte result values, such as Figure 7 As shown by the solid line 708 in the graph.

[0097] correspond Figure 7 The curve graph in Figure 8 The graph in illustrates the effect of measurement error on missing the critical high analyte concentration state.

[0098] In this graph, abscissa 802 depicts the actual analyte concentration values ​​of the samples, starting at 180 mg / dl and increasing to 220 mg / dl. Ordinal 804 depicts the final numerical analyte result value of the determined concentration value, i.e., 180 mg / dl or less, and thus the probability of missing a critical low analyte concentration state.

[0099] While dashed line 806 depicts the probability when the final numerical analyte result value is determined without biasing any initial numerical analyte result values, solid line 808 illustrates the probability of missing a critical high state by artificially biasing, i.e., adding higher initial numerical analyte result values ​​to form the final numerical analyte result value.

Claims

1. A method of determining a final numerical analyte result value corresponding to a concentration of an analyte in a body fluid using a mobile device having a processing device and a display device, the method comprising the steps of: - determining, by the processing device, an initial numerical analyte result value (102) from the image formed from the color of the reagent test area; - displaying a final numerical analyte result value and / or an analyte value range from a set of preset analyte value ranges corresponding to the final numerical analyte result value and / or a message corresponding to the corresponding analyte value range (106); - wherein the final numerical analyte result value (104) is determined by - comparing the initial numerical analyte result value to at least one upper threshold value and to at least one lower threshold value, and - if the initial numerical analyte result value exceeds an upper threshold, adding a preset upper deviation to the initial numerical analyte result value to form the final numerical analyte result value, or - if the initial numerical analyte result value is below a lower threshold, subtracting a preset lower deviation from the initial numerical analyte result value to form the final numerical analyte result value, or - If the initial numerical analyte result value is neither above the upper threshold value nor below the lower threshold value, using the initial numerical analyte result value unchanged to form the final numerical analyte result value.

2. The method of claim 1 , wherein the upper deviation is a constant upper offset value or an upper conversion function having a function value that depends on the initial numerical analyte result value and / or on the absolute value of the difference between the initial numerical analyte result value and the upper threshold value.

3. The method according to claim 1 or 2, wherein the lower deviation is a constant lower offset value or a lower conversion function having a function value that depends on the initial numerical analyte result value and / or on the absolute value of the difference between the initial numerical analyte result value and the lower threshold value. The method according to claim 2 or 3, wherein the lower offset value is the same as the upper offset value or different from each other.

5. The method of claim 2 or 3, wherein the up-conversion function and / or the down-conversion function gradually increases with increasing distance given by the absolute value of the difference between the numerical analyte result value and the upper threshold or lower threshold, respectively. 6 . The method according to claim 2 , wherein the up-conversion function and / or the down-conversion function comprises a first region that gradually increases with an increase in a corresponding distance and a second region that has a constant value.

7. The method of claim 5 or 6, wherein the gradual increase of the up-conversion function and / or the down-conversion function is proportional to the absolute value of the difference between the numerical analyte result value and the upper threshold value or the lower threshold value, respectively.

8. The method according to any one of claims 1 to 7, wherein the upper threshold is the same as the lower threshold.

9. The method of any one of claims 1 to 8, wherein determining the final numerical analyte result value comprises - comparing the initial numerical analyte result value to a second upper threshold value and a second lower threshold value, and - If the initial numerical analyte result value exceeds the second upper threshold or is below the second lower threshold, using the initial numerical analyte result value unchanged to form the final numerical analyte result value.

10. The method according to any one of claims 1 to 9, wherein the analyte is blood glucose and wherein the body fluid is blood or interstitial fluid.

11. A computer program comprising computer executable instructions for executing the method according to any one of claims 1 to 10. 12 . A non-transitory computer-readable storage medium comprising instructions which, when executed by a mobile device, cause the mobile device to execute the method according to claim 1 .

13. A mobile device, comprising: Processing device; Display device; camera; and A memory storing instructions which, when executed by the processing device, configure the mobile device to execute the method according to any one of claims 1 to 10.

14. A kit for determining the concentration of an analyte in a body fluid, the kit comprising at least one mobile device according to claim 13 and at least one optical test strip having at least one test area.

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