Method for determining a final numerical analyte result value corresponding to the concentration of an analyte in a body fluid using a mobile device

Abstract

A method for determining an analyte concentration in a body fluid using a mobile device equipped with a camera, as well as a corresponding computer program, a non-transitory computer-readable storage medium equipped with corresponding instructions, a corresponding mobile device, and a corresponding kit. The method includes step a: determining a numerical analyte result value from an image of the color development of a reagent test area; and step b: displaying the numerical analyte result value and / or a corresponding analyte value range and / or a corresponding message. In step c), after step a) and before step b), if the numerical analyte result value exceeds an upper threshold, an upper bias is added to the numerical analyte result value, or if it is below a lower threshold, a lower bias is subtracted, or if it does not exceed either threshold, it is maintained without change.

Description

Technical Field

[0001] The present application relates to a method for determining a final numerical analyte result value corresponding to the concentration of an analyte in a body fluid using a mobile device having a camera, a processing device, and a display device. The invention further relates to a computer program comprising computer-executable instructions for performing the method, a non-transitory computer-readable storage medium comprising instructions for causing a mobile device to perform the method when executed by the mobile device, 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] Several different devices and methods for determining one or more analytes in a body fluid, such as blood, urine, interstitial fluid, and saliva, are known from the prior art. Without limiting the scope, the present invention will be specifically described with respect to blood glucose measurement. However, it should be noted that the present invention may be used for other types of analytical measurements using test elements.

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

[0004] In analytical measurements based on a color reaction, one technical problem lies in the evaluation of the color change resulting from the detection reaction. In addition to using dedicated analytical devices such as portable blood glucose meters, the use of generally available electronic devices such as smartphones and portable computers has become increasingly common in recent years. Such methods of detecting analyte concentration using mobile devices are known from European Patent No. 3591385A1.

[0005] International Publication No. 2017 / 272095A2 discloses a method including the steps of obtaining blood glucose reading values over a diurnal period for each of multiple days and determining an estimated variability of blood glucose over the diurnal period or multiple days. A user can adjust a blood glucose target by adjusting a fear of hypoglycemia (FHI). The above adjustment can add or subtract a predefined value from a previously used blood glucose target.

[0006] International Publication No. 2017 / 124006A1 relates to a method for generating an insulin delivery profile, wherein for the profile, a blood glucose target for a particular mid-day period can be set or changed based on a patient's past blood glucose pattern.

[0007] International Publication No. 2020 / 214780A1 discloses an individualized closed-loop system and method for insulin delivery in which one or more operation mode control parameters are automatically adjusted.

[0008] Monitoring analytes related to human health is particularly important to avoid missing a critical state, i.e., a critical analyte concentration, due to measurement methods and / or measurement errors.

[0009] Therefore, particularly when using a consumer electronic mobile device, especially a multi-purpose mobile device such as a smartphone or a tablet computer, which is not dedicated to analytical measurement, it is desirable to provide a method and an apparatus for addressing the above technical problems of analytical measurement. Specifically, a method, a computer program, and an apparatus that are widely applicable to available mobile devices, enable convenient handling for users, and are suitable for improving reliability and safety should be proposed.

Summary of the Invention

[0010] This problem is addressed by a method, a computer program, and an apparatus having the features of the independent claims. Advantageous embodiments that can be implemented alone or in any combination are described in the dependent claims.

[0011] When used hereinafter, the terms "having", "comprising", or "including", or any grammatical variants thereof, are used in a non-exclusive manner. Thus, these terms may refer to both situations where there are no additional features in the entity described in this context in addition to the features introduced by these terms, and situations where one or more additional features are present. As an example, the expressions "A has B", "A comprises B", and "A includes B" all refer to situations where, in addition to B, there are no other elements in A (i.e., the situation where A consists solely and exclusively of B), and situations where, in addition to B, there are one or more additional elements such as element C, elements C and D, and even further elements in entity A.

[0012] Furthermore, it should be noted that terms such as "at least one" or "one or more" or similar expressions indicating that a feature or element may be present one or more times are typically used only once when introducing each respective feature or element. In the following, in most cases, when referring to each respective feature or element, the expressions "at least one" or "one or more" are not repeated, despite the fact that each respective feature or element may be present one or more times.

[0013] Furthermore, when used hereinafter, terms such as "preferably", "more preferably", "in particular", "even more particularly", "specifically", "more specifically", or similar terms are used with optional features without limiting the possibility of alternatives. Thus, the features introduced by these terms are optional features and are not intended to limit the technical scope of the claims in any way. The present invention may be practiced, as would be understood by those skilled in the art, by using alternative features. Similarly, features introduced by "in an embodiment of the present invention" or similar expressions are optional features that are not accompanied by any limitations regarding alternative embodiments of the present invention, are not accompanied by any limitations regarding the technical scope of the present invention, and are not accompanied by any limitations regarding the possibility of combining such introduced features with other optional or non-optional features of the present invention.

[0014] In a first aspect, a method is disclosed for determining a final numerical analyte result value corresponding to the concentration of an analyte in a bodily fluid using a mobile device having a processing device and a display device. The method includes determining, by the processing device, an initial numerical analyte result value from a colorimetric image of a reagent test area; and displaying the final numerical analyte result value, and / or an analyte value range from a group of preset analyte value ranges corresponding to the final numerical analyte result value, 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 and at least one lower threshold; adding a preset upper bias to the initial numerical analyte result value to form the final numerical analyte result value if the initial numerical analyte result value exceeds the upper threshold, or subtracting a preset lower bias from the initial numerical analyte result value to form the final numerical analyte result value if the initial numerical analyte result value is below the lower threshold, or using the unchanged initial numerical analyte result value to form the final numerical analyte result value if the initial numerical analyte result value does not exceed the upper threshold and does not fall below the lower threshold.

[0015] "Analyte" refers to a substance or chemical component that is the subject of an analytical procedure, and is also referred to as a component or chemical species. As an example, one or more analytes involved in metabolism, such as blood glucose, may be determined. Additionally or alternatively, other types of analytes or parameters, such as pH value, may be determined. The analyte is contained in at least one sample of bodily fluid and causes a color reaction with a test chemical substance, also called a test reagent. To cause the reaction, the bodily fluid is applied to a reagent test area, which is part of, but not limited to, a test strip and includes the test reagent.

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

[0017] "Color formation" refers to the color of the reagent test area resulting from a color-forming reaction, i.e., a chemical, biological, or physical reaction in which the color of at least one element involved in the reaction, specifically the reflectance, changes according to the concentration of the analyte involved in the reaction. The term "color" as used herein is a broad term and may refer to any form of light reflected from an area having color. In particular, the term "color" may also refer to black, white, or gray, as well as red or green or blue, etc. Thus, the concentration of the analyte in the body fluid can be determined by evaluating the color formation in the reagent test area, i.e., the color change due to the reaction.

[0018] This method is based on the use of a mobile device for at least one measurement of the analyte concentration, and "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 or smartphone. Additionally or alternatively, the mobile device may refer to a tablet computer or another type of portable computing device having 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 for presenting information in a visual or tactile form, including but not limited to an LCD display, an LED display, or a tactile electronic display.

[0020] "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 comprise 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" relates to data recorded using a camera, such as a plurality of electronic readout values from an imaging device such as the pixels of a camera chip. The image may be captured by the camera of a mobile device. Alternatively, the image may be captured by any other camera and transmitted to the processing device of the mobile device by any suitable form of wired or wireless communication.

[0022] The camera and / or cameras of the mobile device into which the image is captured may be color cameras. Thus, for each pixel etc., color information such as color values of the three colors R, G, B may be provided or generated. It is also possible to realize more color values, such as four color values per pixel, for example R, G, G, B, etc. Color cameras are generally known to those skilled in the art. Thus, as an example, a camera chip may be composed of a plurality of three or more different color sensors such as color recording pixels like one pixel for red (R), one pixel for green (G), and one pixel for blue (B). For each pixel such as R, G, B, values corresponding to the intensity of each color, such as digital values in the range of 0 to 255, may be recorded by the pixel. As an example, instead of using three sets of colors such as R, G, B, four sets such as R, G, G, B may be used. The color sensitivity of the pixel can be generated by a color filter or by the appropriate inherent sensitivity of the sensor element used in the camera pixel. These techniques are generally known to those skilled in the art.

[0023] The initial numerical analyte result value in a sample of body fluid is determined based on an image of the reagent test area. The image may be taken by a camera of a mobile device or by any other camera of the reagent test area after applying the sample of body fluid to the reagent test area. The color development, i.e., the color of the reagent test area in the image, is determined by a processing device, and the initial numerical analyte result value corresponding to the determined color development is identified by the processing device. The "initial numerical analyte result value" refers to a numerical display of the analyte concentration in the body fluid sample corresponding to the color development.

[0024] To communicate the result to the user, the final numerical analyte result value is displayed on a display device of the mobile device. Additionally or alternatively, an analyte value range corresponding to the final numerical analyte result value, and / or a message corresponding to the corresponding analyte value range, are displayed on the display device of the mobile device. The related or corresponding "message" refers to any displayable symbol that can inform the user of the state of the analyte concentration range, i.e., the state of the determined analyte value range. The message may comprise one or more of corresponding values such as a range name, range limit values, corresponding recommendations, alarms, symbols, etc.

[0025] The "analyte value range" refers to a part of the measurement range, i.e., the range of measurable values. The analyte value range extends between a lower range limit and an upper range limit, i.e., it comprises all values of the measurement range between the upper range limit and the lower range limit. Specifically, the measurement range may be divided by a series of analyte value ranges such that all values of the measurement range belong to one of the analyte value ranges. For example, the upper range limit of an analyte value corresponds to the lower range limit of an adjacent analyte value, and the range limit values belong to one of their adjacent analyte value ranges, and the other ranges comprise all values that are smaller or larger than their respective range limit values. The analyte value range corresponding to the final numerical analyte value is the range that comprises each respective final numerical analyte result value. In other words, the final numerical analyte result value is within the corresponding analyte value range.

[0026] Typically, for any analyte in a body fluid, a specific concentration value is "normal", while other concentration values are "out of range", either too high or too low, which may have an adverse effect on health. For example, glucose concentration values in the range of 71 mg / dl to 130 mg / dl are typically classified as within the range, concentration values below 71 mg / dl are typically classified as hypoglycemic conditions, and concentrations exceeding 180 mg / dl are typically classified as hyperglycemic conditions. The analyte value range may represent such pre-set categories or classes of analyte concentrations.

[0027] The final numerical analyte result value is determined based on the initial numerical analyte result value. In particular, the final numerical analyte result value either corresponds to the initial numerical analyte result value or is the result of biasing the initial numerical analyte result value, depending on the result of comparing the initial numerical analyte result value with at least two threshold values.

[0028] It should be understood that the bias, i.e., the upper bias and the lower bias, each includes one or more positive values. As a result, an initial numerical analyte result value exceeding the upper threshold value is increased by adding the upper bias to form the final numerical analyte result value, and an initial numerical analyte result value below the lower threshold value is decreased by subtracting the lower bias to form the final numerical analyte result value.

[0029] Furthermore, in some embodiments, the method steps are repeated periodically, for example, in response to a request by a user, or according to a pre-set schedule, or by a trigger event or message, etc.

[0030] As with any measurement, the numerical analyte result value determined by this 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 may be assumed to be symmetric, for example, Gaussian in shape. Thus, for the actual concentration value of a body fluid sample that is very close to or the same as the range limit between two adjacent analyte value ranges, the actual analyte concentration has exactly a 50% or approximately 50% probability of being associated with either of the two adjacent analyte value ranges.

[0031] For range limits with "extremer" ranges, i.e., analyte value ranges that cover respectively small or very small, or high or very high measurement values, this has the risk of overlooking those "extremer" ranges and wrongly communicating the final numerical analyte result value or the corresponding analyte value range that is not so extreme. In other words, wrongly overlooking to ascribe an extreme final numerical analyte result value or analyte value range may mean that the user overlooks warning the user about a critical condition regarding the analyte concentration in the body fluid, such as an extremely high or low blood glucose concentration, which may have health- or life-threatening consequences.

[0032] By having an artificial bias for all initial numerical analyte result values that are below or above their respective threshold values, higher or lower result values represent an "extremer" state and the likelihood of falling into the "extremer" range increases. Thereby, the likelihood of overlooking extremely high or low analyte concentrations is reduced and the reliability and safety of the measurement method are improved.

[0033] On the other hand, it is less important if the actual in-range concentration is wrongly classified as belonging to a more extreme range and the corresponding "extremer" result value or range is communicated to the user. A preferable communication of a more critical condition may even have a preferable impact on the user's behavior.

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

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

[0036] The term "bias" as used herein is used for, but not limited to, a constant positive value or function. A constant upper offset value increases all initial numerical analyte result values exceeding the upper threshold value by a constant value. Correspondingly, a constant lower offset value decreases all initial numerical analyte result values below the lower threshold value by a constant value.

[0037] Alternatively, the upper or lower bias is an upper or lower transition function, and the specific bias value added to or subtracted from the initial numerical analyte result value to form the final numerical analyte result value depends on the distance to each threshold value of the numerical analyte result value. "Distance" here refers to the absolute value of the difference between the initial numerical analyte result value and each threshold value. The "absolute value" used in this specification is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to a special or customized meaning. The absolute value of a number, also called a coefficient, may specifically refer to the non-negative value of the number regardless of its sign.

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

[0039] Increasing the size of the offset value increases the probability that the final numerical analyte result value falls within the extreme analyte value range. For example, the size of the offset value may be selected considering the size of the expected measurement error, which may encourage selecting different offset values for the upper offset value and the lower offset value respectively. For example, a larger upper bias, i.e., when the upper offset value is larger than the lower offset value, may be added to any initial numerical analyte result value exceeding the upper threshold, taking into account that the relative measurement error is larger for larger values.

[0040] In one embodiment, the upper transition function and / or the lower transition function gradually increase with an increase in the 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] "To gradually increase" or "gradual increase" refers to a continuous or stepwise increase. Thus, here, a gradually increasing function refers to a function having a function value that increases and / or remains constant within an interval as the distance from each respective threshold increases, such as a linear function where the function value is proportional to the distance, or an increasing step function, or a combination thereof. Accordingly, the upper bias and / or the lower bias gradually increase as the distance increases, such 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 falling below the lower threshold gradually increase.

[0042] In one embodiment, the upper transition function and / or the lower transition function includes a first region that gradually increases with an increase in the respective distance and a second region having a constant value. Here, "region" refers to an interval or segment of the transition function and may be defined by specifying a range of initial analyte result values.

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

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

[0045] In one embodiment, the proportional correlation is applied to the upper or lower transition function as a whole. Alternatively, the proportional correlation is applied to a region of the measurement range, i.e., a part or portion of the possible initial numerical analyte result values, such as the first region.

[0046] In one embodiment, the upper threshold and the lower threshold are the same.

[0047] When the upper and lower thresholds are different from each other, the final numerical analyte result value is the same as the initial numerical analyte result value included in the central region between the two thresholds, while in the region above the upper threshold and the region below the lower threshold, the final numerical analyte result value is formed by increasing or decreasing the initial numerical analyte result value respectively.

[0048] When the upper and lower thresholds are the same, all, or all except one initial numerical analyte result value that is the same as the threshold, are formed by biasing the initial numerical analyte result value.

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

[0050] The second lower threshold may be less than the lower threshold and greater than an upper threshold, such that for all initial numerical analyte result values that fall below the lower threshold and exceed the second lower threshold, the final numerical analyte result value is formed by subtracting a lower bias from the initial numerical analyte result value, and for all initial numerical analyte result values that fall below the second lower threshold, the final numerical analyte result value is formed by the initial numerical analyte result value that has not been changed. Correspondingly, the final numerical analyte result value is formed by biasing the initial numerical analyte result value, i.e., by adding an upper bias, only when the initial numerical analyte result value is greater than the upper threshold and less than the second upper threshold. This ensures that it is not necessary to miss important analyte concentrations of final numerical analyte result values that are very likely to be classified as critical, e.g., 70% or 90% or 95% or more, so the bias step may be reduced / omitted for "very extreme" values.

[0051] Concentration values that are classified as being within the range but are closer or very close to the critical value, e.g., close to the category boundary or range limit of a category / range designated as out of range, i.e., it may be sufficient to apply a bias only to the initial numerical analyte result value. Alternatively, it may be sufficient to apply an additional bias only to the initial numerical analyte result value that is slightly classified as out of range.

[0052] In one embodiment, the analyte is blood glucose and the body fluid is either 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 a further 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 that includes computer-executable instructions for performing the above-described method.

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

[0056] In another aspect, a mobile device is disclosed that includes a processing device, a display device, a camera, and a memory storing instructions that configure the mobile device to perform the above-described method when executed by the processing device.

[0057] In a further aspect, a kit for determining the concentration of an analyte in a body fluid is disclosed, the kit including at least one of the above-described mobile devices and at least one optical test strip having at least one test zone.

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

[0059] Additional optional features and embodiments are preferably disclosed in further detail in the following description of the embodiments in conjunction with the dependent claims. In that context, each optional feature may, as will be understood by those skilled in the art, be implemented in an independent manner and in any practicable combination. The scope of the present invention is not limited by the preferred embodiments. The embodiments are schematically illustrated in the figures.

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DETAILED DESCRIPTION OF THE INVENTION

[0068] FIG. 1 schematically shows a method for determining a final numerical analyte value corresponding to the concentration of an analyte in a body fluid. This method is executed by a mobile device comprising a processing device, a display device, and optionally a camera. In a first step 102, an initial numerical analyte result value is determined from the color development of a reagent test area. The image is captured by a camera of the mobile device or any other camera, transferred to the mobile device, and the determination process is executed by the processing device. The reagent test area may form part of a test strip, may contain a test reagent, and the color reaction of the test reagent in the reagent test area is caused by applying the body fluid to the reagent test area.

[0069] In the second step 104, the initial numerical analyte result value is compared with the upper threshold value and the lower threshold value, and the final numerical analyte result value is formed by the initial numerical analyte result value that is not changed or by adding or subtracting a bias value to the initial numerical analyte result value according to the result of the comparison.

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

[0071] If the initial numerical analyte result value is below the lower threshold value, that is, is less than the lower threshold value, a preset lower bias is subtracted from the initial numerical analyte result value to form the final numerical analyte result value. Accordingly, the final numerical analyte result value is decreased or made smaller compared to the initial numerical analyte result value. To the same extent as the upper bias, the preset lower bias can be a value constant for all initial numerical analyte result values, or a value depending on another quantity such as the initial numerical analyte result value itself or its distance to the lower threshold value.

[0072] If the initial numerical analyte result value does not exceed the upper threshold value and does not fall below the lower threshold value, that is, is less than the upper threshold value and greater than the lower threshold value, the final numerical analyte result value is formed by the initial numerical analyte result value that is not changed. Accordingly, in this case, the final numerical analyte result value is the same as the initial numerical analyte result value.

[0073] It should be understood that each threshold forms part of one of two ranges separated by the threshold. For example, in the first embodiment, the initial numerical analyte result value that is the same as the upper or lower threshold is maintained without change. Alternatively, the initial numerical analyte result value that is the same as the upper or lower threshold may be biased.

[0074] Step 106 follows step 104, and step 106 proceeds to the final numerical analyte result value resulting from step 104, i.e., 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 resulting from step 104, and / or the analyte value range corresponding to the final numerical analyte result value resulting from step 104, and / or the message associated with the corresponding analyte value range. The associated message, i.e., the corresponding message, may be any message suitable for informing the user of the determined analyte concentration.

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

[0077] In one embodiment, a series of analyte value ranges that divide the measurement range are predefined, i.e., for example, by defining the range limits that divide the measurement range and separating adjacent analyte value ranges, each analyte value range in the series is preset. Here too, it should be understood that each range limit forms part of one of the two analyte value ranges it separates. In the corresponding embodiment, step 106 includes the step of determining the analyte value range of the series of analyte value ranges that cover, i.e., include, the final numerical analyte result value. Step 106 may also include determining the message associated with the corresponding analyte value range, for example, using a look-up table or the like.

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

[0079] FIG. 2 shows a first embodiment of the bias of the initial numerical analyte result value for forming the final numerical analyte result value. The dashed line 202 indicates the identity function or identity relationship, i.e., the final numerical analyte result value that is the same as the initial numerical analyte result value that has not been changed across the measurement range 204. Accordingly, each initial numerical analyte result value in the measurement range 204 along the abscissa 206 is mapped to the same final numerical analyte result value on the ordinate 208.

[0080] The solid line 210 indicates the final numerical analyte result value achieved by the bias of the initial numerical analyte result value of a certain value that is smaller than the lower threshold 212 or larger than the upper threshold 214. Correspondingly, the solid line 210 coincides with the dashed line 202 for values that are larger than the lower threshold 212 and smaller than the upper threshold 214. To form the final numerical analyte result value, a certain upper bias 216 is added to all initial numerical analyte result values that are larger than the upper threshold 214 such that the solid line 210 is shifted correspondingly and parallel above the dashed line 202. Further, to form the final numerical analyte result value, a certain lower bias 218 is subtracted from all initial numerical analyte result values that are smaller than the lower threshold 212 such that the solid line 210 is shifted correspondingly and parallel below the dashed line 202. In the illustrated embodiment, the upper bias 2016 and the lower bias 218 are the same.

[0081] In FIG. 3, a second embodiment of the bias of the initial numerical analyte result value to form the final numerical analyte result value is shown by showing the mapping of the initial numerical analyte result value along the abscissa 302 to the final numerical analyte result value along the ordinate 304. The dashed line 306 again shows the identity function or identity relationship as a reference. The solid line 308 shows the bias of the initial numerical analyte result value, and the size of the bias depends on the initial numerical analyte result value, particularly the distance of the initial numerical analyte result value from each threshold value.

[0082] As shown in FIG. 3, the upper bias is an upper transition function having a function value proportional to the absolute value of the difference between the initial numerical analyte result value and the upper threshold 310. Correspondingly, the lower bias is a lower transition function having a function value proportional to the absolute value of the difference between the initial numerical analyte result value and the lower threshold 312.

[0083] FIG. 4 shows a third embodiment of the bias of the initial numerical analyte result value to form the final numerical analyte result value. As shown by the solid line 210, the upper bias is an upper transition function and the lower bias is a lower transition function.

[0084] The upper transition function and the lower transition function each comprise a first region that gradually increases in proportion to the increase in the respective distance from the upper threshold 408 or the lower threshold 404 of the initial numerical analyte result value, and a second region having a constant value.

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

[0086] FIG. 5 shows a fourth embodiment of a bias of an initial numerical analyte result value for forming a final numerical analyte result value, and a dashed line 502 indicating an identity function is provided as a reference.

[0087] In the illustrated embodiment, the lower threshold and the upper threshold are the same and thus coincide with the mutual threshold 504. The upper bias and the lower bias are an upper transition function and a lower transition function, respectively. Each transition function includes a first region extending between the mutual threshold 504 and a second upper threshold 506 or a second lower threshold 508, and a second region covering all initial numerical analyte result values that are greater than the second upper threshold 506 or less than the second lower threshold 508.

[0088] In the first region, the upper and lower transition functions have function values proportional to the distance to the mutual threshold 504 of the initial numerical analyte result value. In the second region, the function values of the upper and lower transition functions have constant values.

[0089] Correspondingly, a solid line 510 showing the mapping of the initial numerical analyte result value to the final numerical analyte result value has a linear transition between a second lower threshold 508 and a second upper threshold 506 that intersects the dashed line 502 at the mutual threshold 504. In the region above the second upper threshold 506 and the region below the second lower threshold 508, the solid line 510 is shifted parallel to the upper and lower sides of the dashed line 502, respectively.

[0090] FIG. 6 shows a fifth embodiment of a bias of an initial numerical analyte result value for forming a final numerical analyte result value, and a dashed line 612 indicating an identity function is provided as a reference.

[0091] In the illustrated embodiment, as shown by the solid line 602, an initial numerical analyte result value smaller than the lower threshold 604 is decreased by a constant lower bias 608 to form a final numerical analyte result value. An initial numerical analyte result value greater than the upper threshold 606 is increased by a constant upper bias 610 to form a final numerical analyte result value, and the upper bias 610 is greater than the lower bias 608.

[0092] In the graph shown in FIG. 7, using an example of glucose measurement, the influence of measurement error regarding overlooking an extremely low analyte concentration state is shown.

[0093] Blood glucose levels below 70 mg / dl can be critical to human health, and thus it is particularly important to reduce the risk of erroneously determining that it is not critical at the range concentration value when the analyte concentration of the actually applied body fluid sample is out of range, for example, too low.

[0094] In the graph, the horizontal axis 702 indicates the true analyte concentration value of the sample starting from 70 mg / dl and decreasing to 30 mg / dl. The vertical axis 704 indicates the probability of determining a concentration value of at least 70 mg / dl or more, that is, the final numerical analyte result value, and thus the probability of overlooking an extremely low analyte concentration state.

[0095] Without the bias of the present invention, and thus when adopting the initial numerical analyte result value as the final numerical analyte result value, the probability of actually determining exactly 70 mg / dl when the applied sample has an analyte concentration of 70 dl / mg is 50%, and it gradually decreases as the actual analyte concentration is lower as shown by the broken line 706. Therefore, at an actual concentration close to the critical value below the critical value of 70 mg / dl, the probability of overlooking the recognition and transmission of the critical concentration is close to 50%.

[0096] The method of the present invention helps to reduce this probability of overlooking a critical state, as shown by the solid line 708 in the graph of FIG. 7, by reducing the smaller initial numerical analyte result value to form the final numerical analyte result value.

[0097] Corresponding to the graph of FIG. 7, the graph of FIG. 8 shows the influence of measurement error regarding overlooking an extremely high analyte concentration state.

[0098] In the graph, the horizontal axis 802 indicates the true analyte concentration value of the sample starting from 180 mg / dl and increasing up to 220 mg / dl. The vertical axis 804 indicates the probability of determining a concentration value of 180 mg / dl or less, that is, the final numerical analyte result value, and thus the probability of overlooking a very high analyte concentration state.

[0099] The dashed line 806 indicates the probability when determining the final numerical analyte result value without biasing the initial numerical analyte result value, while the solid line 808 indicates that by artificially biasing, that is, increasing a higher initial numerical analyte result value, to form the final numerical analyte result value, the probability of overlooking a very high state is reduced.

Claims

1. A method for determining a final numerical analyte result value corresponding to the concentration of an analyte in a body fluid using a mobile device having an processing device and a display device, - The process involves determining the initial numerical analyte result value from the color image of the reagent testing area using the processing apparatus (102), - The process includes the step (106) of displaying the 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, - The final numerical analysis result value is, - A step of comparing the initial numerical analysis result value with at least one upper threshold and at least one lower threshold, - If the initial numerical analyte result value exceeds the upper threshold, the step of adding a preset upper bias to the initial numerical analyte result value in order to form the final numerical analyte result value, or - If the initial numerical analysis result value falls below the lower threshold, the step of subtracting a preset lower bias from the initial numerical analysis result value in order to form the final numerical analysis result value, or - If the initial numerical analyte result value does not exceed the upper threshold and does not fall below the lower threshold, the step of using the unchanged initial numerical analyte result value to form the final numerical analyte result value, The method is determined by (104).

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

3. The method according to claim 1 or 2, wherein the lower bias is a lower transition function having a function value that depends on a constant lower offset value, or the initial numerical analyte result value and / or the absolute value of the difference between the initial numerical analyte result value and the lower threshold.

4. The method according to claim 2, wherein the lower offset value and the upper offset value are the same or different from each other.

5. The method according to claim 2, wherein the upper transition function and / or the lower transition function gradually increase with increasing distance, which is given by the absolute value of the difference between the numerical analyte result and the upper threshold or lower threshold, respectively.

6. The method according to claim 2, wherein the upper transition function and / or the lower transition function comprises a first region in which they gradually increase with increasing distances and a second region in which they have a constant value.

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

8. The method according to claim 1, wherein the upper threshold and the lower threshold are the same.

9. Determining the final numerical analysis result value is - The initial numerical analysis result value is compared with a second upper threshold and a second lower threshold, - If the initial numerical analyte result value exceeds the second upper threshold or falls below the second lower threshold, the unaltered initial numerical analyte result value is used to form the final numerical analyte result value. The method according to claim 1, including the method described in claim 1.

10. The method according to claim 1, wherein the analyte is blood glucose and the body fluid is either blood or interstitial fluid.

11. A computer program comprising computer executable instructions for performing the method according to claim 1.

12. A non-temporary computer-readable storage medium, wherein, when the computer-readable storage medium is executed by a mobile device, the computer-readable storage medium includes an instruction causing the mobile device to perform the method according to claim 1.

13. A mobile device, Processing device and Display device and Camera and, A memory that stores instructions for configuring the mobile device to perform the method according to claim 1 when executed by the processing device, A mobile device equipped with the following features.

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

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