RU2791101C2 - Method for assessment of lighting condition suitability for analyte determination in sample, using mobile device camera - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: invention relates to a method for assessment of lighting condition suitability for analyte determination in a sample, using a mobile device camera, and to a method for analyte determination in a sample, using a mobile device camera. Method (110) for assessment of lighting condition suitability for analyte determination in a sample, using mobile device (114) camera (112), includes: a) (117) obtainment of at least one first image of at least one test strip (116), while test strip (116) is made with the possibility of analyte determination in a sample, wherein test strip (116) contains at least one test field (118) containing at least one test chemical for a reaction of optical determination in the presence of analyte, while lighting source (120) of mobile device (114) is turned off during obtainment of the first image; b) (122) obtainment of at least one second image of test strip (116), while lighting source (120) of mobile device (114) is turned on during obtainment of the second image; c) (124) comparison of the first and the second images obtained at stages a) (117) and b) (122), thereby determining the difference in lighting conditions between the first image and the second image; and d) (126) obtainment of at least one information about suitability based on comparison at the stage c) (124), while information about suitability contains information about lighting condition suitability for analyte determination.

EFFECT: invention provides reliability and accuracy of measurements.

13 cl, 9 dwg

Description

FIELD OF TECHNOLOGY

The present application relates to a method for evaluating the suitability of lighting conditions for detecting an analyte in a sample using a mobile device camera and a detection method for detecting an analyte in a sample using a mobile device camera. This invention also relates to a computer program with software for performing the methods in accordance with this invention. In addition, this invention relates to a mobile device. Methods, computer programs and mobile devices in accordance with the present invention can be used in medical diagnostics for the qualitative or quantitative determination of one or more analytes in one or more biological fluids. However, other applications of the present invention are possible.

BACKGROUND OF THE INVENTION

In the field of medical diagnostics, in many cases it is necessary to detect one or more analytes in samples of a biological fluid, such as blood, interstitial fluid, urine, saliva, or other types of biological fluids. Examples of analytes to be determined are glucose, triglycerides, lactate, cholesterol, or other types of analytes commonly found in these biological fluids. Depending on the concentration and/or presence of the analyte, an appropriate treatment can be selected if necessary.

Typically, devices and methods known to those skilled in the art use test elements containing one or more test chemicals that, in the presence of an analyte, are capable of performing one or more detectable detection reactions, such as optically detectable detection reactions. For these test chemicals, reference may be made to, for example, J. Hoenes et al.: The Technology Behind Glucose Meters: Test Strips, Diabetes Technology & Therapeutics, Volume 10, Supplement 1, 2008, S-10 to S- 26. Other types of test chemical are possible and may be used to practice the present invention.

In the case of analytical measurements, especially analytical measurements based on color reactions, one of the technical problems is to evaluate the color change that occurs as a result of the detection reaction. In addition to the use of specialized analytical devices such as portable glucometers, the use of publicly available electronic devices such as smartphones and laptop computers has become increasingly popular in recent years. WO 2012/131386 A1 describes a test device for performing an assay, the test device comprising: a container containing a reagent, the reagent reacting with the applied test sample to exhibit a color or pattern change; a portable device, such as a mobile phone or a laptop computer, comprising a processor and an imaging device, wherein the processor is configured to process data received by the imaging device and output a test result for the applied test sample.

WO 2014/025415 A2 describes a method and apparatus for testing biological materials based on a color reaction. The method includes obtaining and interpreting digital images of an unexposed and then exposed instrument in an automatically calibrated environment. This device contains a label with a unique identification (UID; Unique Identification), a reference color bar (RCB; Reference Color Bar), providing standardized color samples for image color calibration, and several test specific sequences of chemical test pads (CTP; Chemical Test Pad). In addition, the method includes locating a tool in an image, extracting a UID, extracting an RCB, and locating a plurality of CTPs in each image. In addition, the method reduces image distortion in the CTP and automatically calibrates the image according to illumination measurements made on the RCB. In addition, the method determines the test results by comparing the color of the CTP image with colors from the manufacturer's interpretation color chart (MICC; Manufacturer Interpretation Color Chart). This method shows these results in a graphical or quantitative manner.

EP 1801568 A1 describes a test strip and a method for measuring the concentration of an analyte in a sample of a biological fluid. This method includes placing a camera near the test strip to graphically determine a color indicator and a reference color area. The measured value is determined for the relative position between the chamber and the strip and compared with the required range. The chamber is moved to reduce the deviation relative to the strip during the deviation between the measured value and the desired value. The area of the image assigned to the indicator is localized in the color image that the camera detects. The concentration of the analyte in the sample is determined using the value for comparison.

EP 1963828 B1 describes a method for measuring the concentration of at least one analyte that is contained in a sample of a biological fluid, a) preparing a test strip that has at least one control point, at least one time indicator and at least one a reference color range that includes white and/or a color scale, b) wherein the liquid sample is brought into contact with the control point and a time indicator, c) wherein the color indicator is located at the control point as a function of analyte concentration; d) while the color of the time indicator changes as a function of the length of time that the liquid was in contact with the test point, and regardless of the concentration of at least one analyte, e) while the chamber is located on the test strip, f) while determining at least one measured value for the relative position between the chamber and the test strip and compared with the nominal value range, g) whereby when there is a discrepancy between the measured value and the nominal value range, the camera is moved relative to the test strip to reduce the discrepancy, and steps f are repeated ) and g), h) while the camera is used to record a color image, which depicts at least a color indicator, a time indicator and a reference color range, j) while areas of the image that are associated with a color indicator, a time indicator and a reference color range, localize in a color image and determine the color values of these areas image, k) wherein the length of time between bringing the liquid sample into contact with the control point and recording the color image is determined based on the color value determined for the time indicator using the given reference values, and 1) wherein the concentration of the analyte in the sample is determined based on the values colors determined for the color indicator, and a reference color range made and based on the length of time using the given values for comparison.

The reliability and accuracy of analytical measurements using mobile computing devices usually depend on a large number of technical factors. In particular, a huge number of mobile devices with cameras are available on the market, all of which have different technical and optical properties that must be taken into account in analytical measurements. WO 2007/079843 A2 describes a method for measuring the concentration of an analyte contained in a biological fluid sample. In said method, a test strip is provided that contains at least one reference dot and at least one reference color area spanning white and/or a color bar. The liquid sample is brought into contact with the control point, and a color indicator is placed on the control point according to the concentration of the analyte. A camera is placed on the test strip. At least one measured value is determined for the relative position between the chamber and the test strip and compared with a predetermined range of values. If the measured value deviates from the specified value range, the camera is moved relative to the test strip to reduce the deviation. A color image, in which at least a color indicator and a reference color area are presented, is determined using a camera. The areas of the image assigned to the color indicator and the area of color matching are found, and the values of the colors of the indicated areas of the image are determined. The concentration of the analyte in the sample is determined based on the color values using the given values for comparison. EP 3108244 A1 and WO 2015/120819 A1 describe a test strip module comprising a sheath, a sheathed test strip, and a positioner extending down past the mating surface to the face of the mobile computing device. The position lock has a shape corresponding to the element on the front surface of the mobile computing device.

US 2015/233898 A1 describes a test strip module that includes a sheath, a sheathed test strip, and a positioner extending down past the mating surface to the face of the mobile computing device. The position lock has a shape corresponding to the element on the front surface of the mobile computing device.

Despite the advantages associated with the use of mobile computing devices for analytical measurements, a number of technical challenges remain. In particular, it is necessary to improve and ensure the reliability and accuracy of measurements. The reliability and accuracy of the analytical measurement can be significantly affected by the lighting conditions at the time of imaging the test strip for the analytical measurement when using a cell phone camera. In particular, ambient lighting can have a significant effect on lighting conditions, for example, due to the presence of different means of illumination in different specific locations and/or depending on where the image is taken and when the image is taken during day or night. In particular, ambient light can interfere with the evaluation of the color formed on the reagent field of the test strip.

Problem to be solved

Therefore, it is desirable to provide methods and devices that solve the above technical problems of analytical measurements using mobile devices, such as mobile consumer electronics devices, in particular, multifunctional mobile devices that are not designed for analytical measurements, such as smartphones or tablet computers. In particular, methods and devices should be proposed to ensure the reliability and accuracy of measurements.

SUMMARY OF THE INVENTION

This problem is solved by a method for evaluating the suitability of lighting conditions for determining an analyte in a sample using a camera of a mobile device, a method for determining for determining an analyte in a sample using a camera according to a method using a mobile device, a computer program and a mobile device with elements according to independent claims . Advantageous embodiments of the invention, which can be implemented separately or in any arbitrary combination, are given in the dependent claims.

As used hereinafter, the terms "have", "comprise" or "include" or any arbitrary grammatical variations thereof are used in a non-exclusive manner. Thus, these terms can refer both to a situation in which, in addition to the feature represented by these terms, other features are absent in the object described in this context, and to a situation in which one or more additional features are present. For example, the expressions "A has B", "A contains B" and "A includes B" can refer to a situation in which, in addition to B, there is no other element in A (i.e., a situation in which A consists only and exclusively from B), and to the situation in which, in addition to B, there are one or more additional elements in object A, such as element C, elements C and D, or even other elements.

In addition, 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, will generally be used only once when presenting the corresponding feature or element. In the following, in most cases, when it comes to the corresponding feature or element, the expressions "at least one" or "one or more" will not be repeated, despite the fact that the corresponding feature or element may be present once or more than once. times.

In addition, as used hereinafter, the terms "preferably", "more preferably", "especially", "in particular", "more specifically" or similar terms are used together with optional features, without limiting alternative possibilities. Thus, the features represented by these terms are optional features and are in no way intended to limit the scope of the claims. This invention, as will be clear to a person skilled in the art, can be implemented using alternative features. Likewise, features represented by "in an embodiment of the present invention" or similar expressions are intended to be used as optional features, without any limitation as to alternative embodiments of the present invention, without any limitation as to the scope of the present invention, and without no restrictions as to the possibility of combining the features thus presented with other optional or non-optional features of the present invention.

In a first aspect, a method is described for evaluating the suitability of lighting conditions for detecting an analyte in a sample using the camera of a mobile device. The method includes the following steps, which, for example, can be performed in this order. However, it should be noted that another order is also possible. In addition, it is also possible to perform one or more method steps one or more times. It is also possible to perform two or more method steps simultaneously or in an overlapping manner. The method may include additional method steps that are not shown.

The method includes the following steps:

a) obtaining at least one first image of at least one test strip, wherein the test strip is configured to detect an analyte in a sample, wherein the test strip contains at least one test field containing at least one test chemical to perform an optical detection reaction in the presence of an analyte, while during the acquisition of the first image, the light source of the mobile device is turned off;

b) obtaining at least one second image of the test strip, while during the acquisition of the second image, the light source of the mobile device is turned on;

c) comparing the first and second images obtained in steps a) and b), thus determining the difference in lighting conditions between the first image and the second image; And

d) obtaining at least one suitability information based on the comparison in step c), wherein the suitability information includes information about the suitability of the lighting conditions for analyte detection.

As used herein, the term "mobile device" is a broad term and its common and conventional meaning should be left to those skilled in the art and should not be limited to a specific or individual meaning. This term may specifically refer to, without limitation, a mobile electronics device, more specifically a mobile communication device such as a cellular phone or smartphone. Additionally or alternatively, as will be described in more detail below, a mobile device may also refer to a tablet computer or other type of portable computer containing at least one camera.

As used herein, the term "test strip" is a broad term, and its usual and generally accepted meaning should be left to the person skilled in the art and should not be limited to a special or individual meaning. The specified term, in particular, may refer, without limitation, to an arbitrary element or device, made with the possibility of carrying out a reaction to determine the color change. The test strip, in particular, may have a test field containing at least one test chemical for determining at least one analyte. The test strip, for example, may contain at least one substrate, such as at least one carrier, coated on it or integrated into it at least one test field. By way of example, at least one carrier may be in the form of a strip, thereby converting the test element into a test strip. These test strips are commonly used and widely available. One test strip may contain one test field or a combination of test fields containing identical or different test chemicals. At least one sample may be applied to the test strip.

As used herein, the term "test field" is a broad term, and its common and conventional meaning should be left to those skilled in the art and should not be limited to a special or individual meaning. The term particularly may refer to, without limitation, a coherent amount of a test chemical, such as a field, such as a round, polygonal or rectangular field, containing one or more layers of material, with at least one layer of test field containing a test Chemical substance. Other layers may be present to provide certain optical properties, such as reflective properties, to provide distribution properties for spreading the sample, or to provide separation properties, for example to separate particulate components in the sample, such as cellular components.

Diabetes Technology and Therapeutics, Vol. 10, Supplement 1, 2008, pp. 10-26. Однако практически возможны и другие тестовые химические вещества.As used herein, the term "test chemical" is a broad term, and its usual and generally accepted meaning should be left to the person skilled in the art and should not be limited to a special or individual meaning. This term, in particular, may refer, without limitation, to a chemical compound or collection of chemical compounds, for example, a mixture of chemical compounds, suitable for conducting a detection reaction in the presence of an analyte, while the detection reaction can be determined by a specific method, for example optically. The determination reaction, in particular, may be specific to the analyte. The test chemical in this case, in particular, may be an optical test chemical, such as a color change test chemical that changes color in the presence of an analyte. The color change, in particular, may depend on the amount of analyte present in the sample. The test chemical, for example, may contain at least one enzyme, such as glucose oxidase and/or glucose dehydrogenase. In addition, other components may be present, such as one or more dyes, mediators, and the like. Test chemicals are generally known to those skilled in the art and reference may be made to

Diabetes Technology and Therapeutics, Vol. 10, Supplement 1, 2008, pp. 10-26. However, other test chemicals are practical.

As used herein, the term "analyte" is a broad term, and its usual and generally accepted meaning should be left to a person skilled in the art and should not be limited to a special or individual meaning. The term, in particular, may refer, without limitation, to one or more specific chemical compounds and/or other parameters to be detected and/or measured. As an example, at least one analyte may be a chemical compound that takes part in biotransformation, such as one or more of glucose, cholesterol, or triglycerides. Additionally or alternatively, other types of analytes or parameters may be determined, such as pH.

As used herein, the term "determination of an analyte in a sample" is a broad term, and its usual and generally accepted meaning should be left to a person skilled in the art and should not be limited to a special or individual meaning. This term, in particular, may refer, without limitation, to the quantitative and/or qualitative determination of at least one analyte in an arbitrary sample. For example, the sample may contain a body fluid such as blood, interstitial fluid, urine, saliva, or other types of body fluid. The result of an analytical measurement, for example, may be the concentration of the analyte and/or the presence or absence of the analyte to be determined. Specifically, as an example, the analytical measurement may be a blood glucose measurement, thus the result of the analytical measurement may be, for example, a blood glucose concentration.

The term "suitability" may refer, without limitation, to the characteristic of an element or device to perform one or more specified functions and to the suitability of environmental conditions to ensure the reliability and accuracy of the determination of an analyte in a sample. Thus, the term refers to one or both of the device characteristics and environmental conditions. Suitability can be determined and/or quantified by determining whether a given requirement is met. A predetermined requirement, for example at least one threshold value, can be obtained, for example, on the basis of experiments or on the basis of certain boundary conditions, for example in terms of the accuracy achieved. The term "suitability information" may refer, without limitation, to an indication or information regarding suitability, especially in this case, the suitability of lighting conditions for the purpose of performing an analytical measurement. The suitability information element, for example, may be a boolean value or numeric information, such as a "pass" or "fail"/"fail" indication. However, additionally or alternatively, the suitability information may comprise a quantitative result, such as a grade of suitability. For example, the suitability information may include information about the sufficient intensity of illumination from the illumination source of the mobile device to illuminate the test strip. In particular, the suitability information may comprise information about the sufficiency of the intensity of light emitted from the light source of the mobile device to illuminate the test strip in relation to and/or compared to ambient light intensities and/or ambient light conditions.

As used herein, the term "evaluating the suitability of lighting conditions" refers to testing and/or determining and/or evaluating and/or determining lighting conditions. As used herein, the term "lighting conditions" refers to imaging conditions, specifically both ambient lighting conditions and light intensities provided by a mobile device's light source. In addition, the term "illumination conditions" refers to reflective conditions, in particular reflective properties of the test strip, for example due to the material of the test strip. The terms "ambient lighting" or "ambient lighting conditions" refer to the illumination from available natural or artificial light sources illuminating the test strip independently of the illumination provided by the mobile device's illumination source. Ambient lighting can be generated and/or provided by artificial light sources such as indoor light sources such as lamps and/or natural light sources such as the sun, moon, starlight, lightning. Lighting conditions may depend on time, in particular the time of day or night. Lighting conditions may be location dependent, particularly if the image is taken outdoors, indoors, or geographic location. Particularly for outdoor measurements, lighting conditions may be affected by weather conditions. For indoor measurements, lighting conditions may depend on room lighting, which may vary depending on activity, such as in homes, supermarkets, theaters, etc.

As used herein, the term "camera" is a broad term and its common and conventional meaning should be left to those skilled in the art and should not be limited to a specific or individual meaning. This term, in particular, may refer, without limitation, to a device containing at least one imaging element, configured to record or obtain spatially resolved one-dimensional, two-dimensional, or even three-dimensional optical information. By way of example, the camera may comprise at least one camera chip, such as at least one charge-coupled device (CCD) chip and/or at least one complementary metal oxide semiconductor (CMOS) chip configured to image recording. For example, the camera may be a color camera, as will be described in detail below, having at least three color pixels. The camera may be a CMOS color camera. For example, a camera may contain black and white pixels and color pixels. Color pixels and black and white pixels can be combined inside the camera. The camera may include at least one color camera and at least one black and white camera, such as a CMOS black and white camera. The camera may include at least one CMOS chip for black and white photography. A camera typically may comprise a one-dimensional or two-dimensional group of image sensors, such as pixels. For example, a camera may contain at least 10 pixels in at least one dimension, such as at least 10 pixels in each dimension. However, it should be noted that other chambers are practically possible. The camera may be a camera of a mobile communication device. In particular, the invention should be applicable to cameras that are commonly used in mobile communication devices such as laptop computers, tablets or, in particular, cellular phones such as smartphones. Thus, in particular, the camera may be part of a mobile device, which, in addition to at least one camera, contains one or more data processing devices, such as one or more data processors. However, it is practically possible to use other cameras. Said camera, in addition to at least one camera chip or imaging chip, may contain additional elements such as one or more optical elements, such as one or more lenses. As an example, the camera may be a fixed focal length camera including at least one lens that is stably adjusted with respect to the camera. However, in the alternative, the camera may also include one or more adjustable lenses that can be adjusted automatically or manually.

In particular, the camera may be a color camera. Thus, for example, for each pixel, color information, such as color values for the three colors of the red, green, blue (R, G, B) palette, can be provided and generated. More color values are also practical, such as four colors for each pixel. Color cameras are generally known to those skilled in the art. Thus, as an example, each pixel of a camera chip can have three or more different color sensors, such as color shooting pixels, such as one pixel for red (R), one pixel for green (G), and one pixel for blue (B). . For each of the pixels, eg R, G, B, the pixels may record values, eg numerical values ranging from 0 to 255, depending on the intensity of the corresponding color. Instead of using three-color variants such as R, G, B, as an example, four-color variants such as C, M, Y, K, or RGGB, BGGR, RGBG, GRGB, RGGB, and the like may be used. The color sensitivity of the pixels may be generated by color filters such as color filter arrays, for example at least one Bayer filter, or by the corresponding intrinsic sensitivity of the sensor elements used in the camera pixels. These methods are generally known to the person skilled in the art.

As used herein, without limitation, the term “image” specifically may refer to data recorded by a camera, such as a collection of electronic readings from an imaging device, such as pixels on a camera chip. Thus, the image itself may contain pixels, the pixels of the image being correlated with the pixels of the camera chip. Therefore, "pixels" refer to either units of image information generated by the individual pixels of the camera chip, or directly to the individual pixels of the camera chip. The image may contain raw pixel data. For example, an image may contain data in the RGGB range, one color data for one of the R, G, or B pixels, a Bayer pattern image, and the like. The image may contain estimated pixel data such as a full color image or an RGB image. The raw pixel data may be evaluated, for example, using demosaicing algorithms and/or filtering algorithms. These methods are generally known to the person skilled in the art.

The term "obtaining at least one image" refers to one or more of the following: image formation, image recording, image acquisition, image acquisition. The term "obtaining at least one image" may include obtaining a single image and/or a collection of images, such as a sequence of images. Acquisition of at least one image may be initiated by a user action or may be initiated automatically, for example, as soon as the presence of at least one object in the field of view and/or within a given sector of the camera's field of view is automatically determined. These automatic imaging techniques are known, for example, in the field of automatic barcode readers, for example from applications for automatic barcode reading.

As used herein, the term "mobile device light source" refers to an arbitrary light source of a mobile device. The term "light source" refers to at least one device configured to generate lighting to illuminate an object. As used herein, the terms "illumination", "light" generally refer to electromagnetic radiation in one or more of the visible spectral range, the ultraviolet spectral range, and the infrared spectral range. The term "visible spectral range" generally refers to the spectral range from 380 nm to 780 nm. Preferably, the illumination used in the present invention is illumination in the visible spectral range. The light source may include at least one light emitting diode embedded in the mobile device. In particular, the light source may be the backlight of a mobile device, in particular a mobile phone. The mobile device may include additional lighting devices, such as at least one light source illuminating the display, and/or the display may be designed as an additional light source.

The light source may have two states: an on state in which it generates a light beam to illuminate the test strip, and an off state in which the light source is turned off. As used herein, the term "on" refers to the fact that the light source is activated and/or turned on to illuminate the test strip. The term "off" refers to the fact that the light source is in the off state or actively turned off. As described above, in step a) a first image is acquired with the mobile device's light source turned off. This may make it possible to obtain an image containing only the illumination intensities of the ambient light sources and independently of the illumination provided by the illumination source of the mobile device. In step b), the light source is turned on so that a second image can be determined containing the light intensities from both the ambient light and the illumination from the mobile device's light source.

The light source may include at least one light emitting diode (LED) built into the mobile device. The light source may comprise at least one white light LED. The white light LED can be driven by a short current pulse such that the white light LED can be configured to generate a bright flash of light. The light source may be configured to continuously illuminate the test strip during image acquisition. Unlike electronic flashes, the flash duration of a white light LED can be several hundred (100) ms. This may allow the light source to continuously illuminate the test strip during the acquisition of the LED flash image. Alternatively, the LED may be configured to continuously illuminate the test strip in a non-flash mode.

The light source may be configured to be brighter than the ambient light. The light source may be essentially the dominant light source in the test strip imaging in step b). The term "substantially dominant" refers to the fact that the illumination from the illumination source exceeds the illumination from the ambient illumination, while possibly weak illumination from the ambient illumination. Illumination from flashes generated by a white light LED used in mobile devices can range from 80 lux to 300 lux at a distance of 1 m from an object. Thus, at a distance from an object of 0.1 m, illumination from flashes generated by LED white light, can range from 8000 lux to 30000 lux. For comparison, full daylight illumination can be 10752 lux, overcast day 1075 lux, very dark day 107 lux, and twilight 10.8 lux, see https://www.noao.edu/education /QLTkit/ACTIVITY_Documents/Safety/LightLevels_outdoor+indoor.pdf. The illumination source may be configured to generate at least one light beam to illuminate the test strip, the light intensities of which are greater than the ambient light intensities. The light intensity of the illumination generated by the light source may exceed the ambient light intensity by two times, preferably 10 times, and more preferably 100 times.

Step c) includes comparing the first and second images obtained in steps a) and b), thereby determining the difference in lighting conditions between the first image and the second image. As mentioned above, each camera chip pixel may have three or more different color sensors, such as color shooting pixels, such as one pixel for red (R), one pixel for green (G), and one pixel for blue (B). Each of the color sensors and/or color image pixels may be configured to generate a single signal or a plurality of sensor signals in response to illumination. The sensor signal may be or may comprise at least one electrical signal, such as at least one analog electrical signal and/or at least one digital electrical signal. In addition, raw sensor signals may be used, or processed or pre-processed sensor signals may be used, such as sensor signals pre-processed by filtering or the like. The camera may be configured to acquire the first and second images in steps a) and b) in at least one color signal channel, in particular in at least one color signal channel selected from the group consisting of an R channel, a G channel, and channel B. The camera may be configured to acquire the first and second images in steps a) and b) in each of the channels of the color signal. As used in this document, the term "color signal channel" refers to color capture pixels of a camera chip for the same color. The camera and/or processor, in particular the mobile device processor, can be configured to determine, based on the first image, at least one first intensity distribution and, based on the second image, at least one second intensity distribution for at least one of the color signal channels. . Preferably, the first intensity distribution and the second intensity distribution may be determined for each of the color signal channels. For at least one color signal channel, the camera and/or the processor, in particular the processor of the mobile device, can be configured to determine based on the corresponding first intensity distribution of the first intensity spectrum of the corresponding color signal channel and based on the corresponding second intensity distribution of the second intensity spectrum of the corresponding color channel. As used herein, the term "intensity spectrum" refers to the distribution of intensity as a function of wavelength. The term "comparison of the first and second images" refers to the comparison of the first intensity distribution and the second intensity distribution of at least one of the channels of the color signal and/or the comparison of the first intensity spectrum and the second intensity spectrum of at least one of the channels of the color signal.

Said comparison may include at least one mathematical operation, such as subtracting the respective sensor signals generated by the color image pixels of one color signal channel and/or subtracting intensity distributions of one color channel channel and/or subtracting intensity spectra of one color signal, and /or division of respective sensor signals of one color signal channel and/or division of intensity distributions of one color signal channel and/or division of intensity spectra of one color signal channel. For example, said comparison may include determining a difference between a first intensity distribution and a second intensity distribution of at least one of the color signal channels. In particular, for channels R, G and B, the difference Δ can be determined by the equation:

представляет собой разницу в соответствующем канале цветового сигнала,

представляет собой распределение интенсивности второго изображения соответствующего канала цветового сигнала и

представляет собой распределение интенсивности первого изображения соответствующего канала цветового сигнала. Дополнительно или альтернативно, сравнение может включать в себя определение частного путем деления первого распределения интенсивности и второго распределения интенсивности и/или путем деления кратных и/или деления линейных комбинаций первого распределения интенсивности и второго распределения интенсивности по меньшей мере одного из каналов цветового сигнала. В частности, для каналов R, G и В частное может быть определено посредством уравнения:and color=R, G, B, where

represents the difference in the corresponding color signal channel,

is the intensity distribution of the second image of the corresponding channel of the color signal and

represents the intensity distribution of the first image of the corresponding channel of the color signal. Additionally or alternatively, the comparison may include determining the quotient by dividing the first intensity distribution and the second intensity distribution and/or by dividing multiples and/or dividing linear combinations of the first intensity distribution and the second intensity distribution of at least one of the color signal channels. In particular, for channels R, G and B, the quotient can be determined by the equation:

представляет собой частное в соответствующем канале цветового сигнала,

представляет собой распределение интенсивности второго изображения соответствующего канала цветового сигнала и

представляет собой распределение интенсивности первого изображения соответствующего канала цветового сигнала. Камера и/или процессор, в частности процессор мобильного устройства, могут быть выполнены с возможностью выполнения указанных операций, предпочтительно с помощью по меньшей мере одного устройства обработки данных и, более предпочтительно, с помощью по меньшей мере одного процессора и/или по меньшей мере одной специализированной интегральной схемы Таким образом, в качестве примера мобильное устройство может содержать по меньшей мере одно устройство обработки данных, на котором хранится программный код, содержащий ряд компьютерных команд. Мобильное устройство может обеспечивать один или более аппаратных элементов для выполнения одной или более из указанных операций и/или может обеспечивать один или более процессоров с выполняемым на них программным обеспечением для выполнения одной или более из указанных операций. Термин «разница» может относиться к отклонениям, в частности в спектре интенсивности, первого и второго изображений. В частности, термин «разница» относится к отклонениям, превышающим статистические колебания. Источник освещения мобильного устройства может иметь известный или заданный спектральный состав. Термин «спектральный состав» относится к спектру интенсивности освещения, генерируемого источником освещения. В частности, по меньшей мере одно распределение интенсивностей освещения как функция длины волны для каждого из каналов R, G, В может быть известно или задано. В частности, спектр излучения светодиода белого света может быть известен или может быть определен эмпирически. Спектральный состав может храниться в таблице или справочной таблице и может быть определен, например, эмпирически и может, например, сохраняться по меньшей мере в одном устройстве хранения данных мобильного устройства, например посредством программного обеспечения, в частности приложения, скачанного из магазина приложений, и т.п. Как правило, освещенная тест-полоска может поглощать свет в определенном диапазоне длин волн, а непоглощенный свет отражается и улавливается камерой. Таким образом, спектральная характеристика или состав света, освещающего тест-полоску, может оказывать прямое влияние на получаемые значения RGB полученного изображения. Поскольку спектральный состав источника освещения является известным или заданным, возможно определить величину интенсивности освещения, используемой для освещения тест-полоски, которое исходит от источника освещения. Мобильное устройство может содержать по меньшей мере один процессор, который может быть выполнен с возможностью сравнения первого изображения и второго изображения.and color=R, G, B, where

represents the quotient in the corresponding channel of the color signal,

is the intensity distribution of the second image of the corresponding channel of the color signal and

represents the intensity distribution of the first image of the corresponding channel of the color signal. The camera and/or processor, in particular the mobile device processor, may be configured to perform these operations, preferably with at least one data processing device and more preferably with at least one processor and/or at least one ASIC Thus, by way of example, a mobile device may include at least one data processing device that stores program code containing a number of computer instructions. The mobile device may provide one or more hardware elements to perform one or more of these operations and/or may provide one or more processors with software running on them to perform one or more of these operations. The term "difference" may refer to deviations, in particular in the intensity spectrum, of the first and second images. In particular, the term "difference" refers to deviations that exceed statistical fluctuations. The mobile device's illumination source may have a known or predetermined spectral composition. The term "spectral composition" refers to the intensity spectrum of illumination generated by an illumination source. In particular, at least one illumination intensity distribution as a function of wavelength for each of the R, G, B channels may be known or given. In particular, the emission spectrum of a white light LED may be known or empirically determined. The spectral composition may be stored in a table or lookup table and may be determined, for example, empirically, and may, for example, be stored in at least one storage device of the mobile device, for example, by means of software, in particular an application downloaded from an application store, etc. .P. Typically, the illuminated test strip can absorb light in a certain wavelength range, and the unabsorbed light is reflected and captured by the camera. Thus, the spectral characteristic or composition of the light illuminating the test strip can have a direct effect on the resulting RGB values of the resulting image. Since the spectral composition of the light source is known or predetermined, it is possible to determine the amount of light intensity used to illuminate the test strip that comes from the light source. The mobile device may include at least one processor that may be configured to compare the first image and the second image.

The first image and the second image can be obtained before applying the sample. Additionally or alternatively, the method may include at least one step of applying a sample, wherein in the step of applying the sample, the sample can be applied to the test strip. In particular, the sample can be applied to the test strip before steps a) and/or b).

Step d) includes obtaining at least one suitability information based on the comparison in step c). Obtaining fitness information in step d) may include comparing the difference in lighting conditions determined in step c) with at least one threshold value. Only if the difference in lighting conditions between the second image and the first image is at least equal to a threshold value, the suitability information can be set to indicate the suitability of the lighting conditions for analyte detection. The threshold value may depend on the ambient light conditions. For example, the user and/or processor may be configured to adjust and/or select a threshold value depending on ambient lighting conditions. The threshold value may be stored in a table or lookup table and may be determined, for example, empirically and may, for example, be stored in at least one storage device of the mobile device, for example, through software, in particular an application downloaded from an application store, etc. .P. For example, suitability information can be set to indicate the suitability of lighting conditions for subsequent analyte determination only if at least 70% of the light intensity used to illuminate the test strip comes from the light source. For example, suitability information can be set to indicate the suitability of lighting conditions for subsequent analyte determination only if at least 80% of the light intensity used to illuminate the test strip comes from the light source. Other threshold values are also possible. For example, suitability information can be set to indicate the suitability of lighting conditions for subsequent analyte determination only if 90% of the light intensity used to illuminate the test strip comes from the light source.

Lighting conditions may be indicated in the display as suitable, even in the case of a bright ambient light source, if the composition of the ambient light essentially matches the expected composition of the illumination generated by the light source. The term "composition" refers to the color composition of the illumination, in particular to the composition of the intensity distributions of the respective channels of the color signal. The term "expected composition" is a given spectral composition.

при этом

представляют собой распределения интенсивности соответствующих каналов цветового сигнала для освещения окружающим освещением,

представляют собой распределения интенсивности соответствующих каналов цветового сигнала для освещения, генерируемого источником освещения, и ε≤0,3, предпочтительно ε≤0,2, наиболее предпочтительно ε≤0,1.The term "substantially compliant" refers to conditions in which the composition of the ambient light matches the expected composition of the illumination produced by the light source within a tolerance of ±30% or less, preferably a tolerance of ±20% or less, most preferably a tolerance of ±10% or less . Lighting conditions can be presented as suitable in the display if

wherein

are the intensity distributions of the respective color signal channels for ambient illumination,

are the intensity distributions of the respective color signal channels for the illumination generated by the illumination source, and ε≤0.3, preferably ε≤0.2, most preferably ε≤0.1.

The method may further include checking and/or evaluating whether the light source provides sufficient light intensity. When checking and/or evaluating whether the light source is configured to provide sufficient illumination, at least one method for determining threshold values may be used. The sufficiency of illumination intensity may depend on the surface properties of the test strip and/or ambient light conditions. In particular, in the event that a test strip having intense reflective properties, a lower illumination intensity compared to dark or weakly reflective properties may be sufficient. In addition, in the case of bright ambient light conditions, such as due to sunlight, a higher intensity may be required compared to shielded ambient light conditions.

In a further aspect of the present invention, a detection method for detecting an analyte in a sample using the camera of a mobile device is described. The method includes the following steps, which, for example, can be performed in this order. However, it should be noted that another order is also possible. In addition, it is also possible to perform one or more method steps one or more times. It is also possible to perform two or more method steps simultaneously or in an overlapping manner. The method may include additional method steps that are not shown. The method includes the following steps:

i) evaluating lighting conditions using a method for evaluating the suitability of lighting conditions in accordance with one of the previous embodiments of the invention;

ii) performing the following steps if the lighting conditions suitability information indicates that the lighting conditions are suitable for analyte detection:

A) providing at least one test strip for detecting an analyte in a sample, the test strip containing at least one test field containing at least one test chemical for performing an optical detection reaction in the presence of the analyte;

B) applying at least one sample to the test area of the test strip;

C) obtaining at least one image of the test field using a camera, while during said acquisition, the illumination source of the mobile device is turned on; And

D) determining, based on the image obtained in step C), the concentration of the analyte in the sample.

With respect to embodiments of the invention and determination of the determination method, reference is made to the above description of the method for evaluating the suitability of lighting conditions and according to the following more detailed description. In particular, with respect to step i) of the method, reference may be made to the above description of the method for evaluating the suitability of lighting conditions.

The determination of the analyte concentration may include an optical determination. As used herein, the term "optical determination" refers to the determination of a reaction using an optical test chemical, such as a color change test chemical that changes color in the presence of an analyte. The color change, in particular, may depend on the amount of analyte present in the sample. Step D) may include analyzing the color of the spot on the test area of the test strip, said spot at least partially containing a sample. Methods for determining the analyte by optical detection and, in particular, the analysis of the color of the spot on the test field, as a rule, are known to the person skilled in the art. To evaluate at least one image and obtain at least one analytic information about it, you can use several algorithms that are generally known to specialists in the field of analytics, for example, in the field of blood glucose monitoring. Thus, by way of example, the color of a test element can be evaluated, such as the color of at least one test field containing at least one test chemical. As an example, when evaluating an image in a test element image, an area of interest, such as an area of interest in a test field of the test element, may be determined, and color analysis such as statistical analysis may be performed. As an example, a rectangular, square, polygonal, oval, or circular area of interest may be defined within that part of the image that is recognized as the test field image. Subsequently, a statistical analysis of the color of the pixels within the region of interest can be performed. By way of example, one or more color coordinates can be obtained for pixels, and a statistical analysis of the color coordinates can be performed on the region of interest. As an example, a distribution center of at least one color coordinate can be determined. Used in this document, the term "color coordinate" is a broad term, and its usual and generally accepted meaning should be left to a person skilled in the art and should not be limited to a special or individual meaning. This term, in particular, may refer, without limitation, to the coordinate of an arbitrary color coordinate system used to describe color using coordinates. A person skilled in the art is generally aware of several color coordinate systems that can also be used in the context of the present invention. Thus, a colorimetric coordinate system or a coordinate system based on human perception, such as the CIE 1964 color space, the Munsell color system, or other coordinate systems such as R, G, B, L, a, b, can be used as an example.

Thus, in order to obtain analytical information based on an image, it is possible, for example, to track a given or determinable relationship of at least one color coordinate of a test element, such as a test field. As stated above, statistical analysis can be performed on a test element or a portion thereof, for example, in a test field containing at least one test chemical and/or in a region of interest within the test field containing at least one test chemical. substance. Thus, by way of example, at least one test field in a test element image can be recognized, preferably automatically, such as through pattern recognition and/or other algorithms, as described in the examples below. Again, one or more regions of interest may be defined within the partial image of the test field. In the area of interest, color coordinates can be determined, eg again blue color coordinates and/or other color coordinates, eg again using one or more histograms. Statistical analysis may include fitting one or more curve fittings, as described above, to at least one histogram, thus determining, for example, the center of a peak. Thus, the staining reaction can be monitored using one or more images, and for one or more images, the center of the peak can be determined by statistical analysis, thus determining the color change within at least one coordinate. Once the staining reaction is complete or has reached a predetermined or definable endpoint, which is generally known to one skilled in the art, for example, a change in at least one color coordinate or endpoint color coordinates can be determined based on blood glucose monitoring, and it can be converted, for example, to the concentration of the analyte in the sample using a given or determinable correlation between the color coordinate and the concentration. Said correlation, such as a conversion function, a conversion table, or a lookup table, may be determined, for example, empirically, and may, for example, be stored in at least one storage device of the mobile device, for example, by means of software, in particular an application downloaded from an application store. , and so on.

In the event that the lighting condition score in step i) is not set to indicate that the lighting conditions are suitable, the mobile device may be configured to interrupt and/or prevent the determination of the analyte in the sample. Additionally or alternatively, if the lighting condition score in step i) is not set to indicate that the lighting conditions are suitable, the mobile device may be configured to generate at least one alert. Additionally or alternatively, in the event that the lighting conditions score in step i) is not set to indicate that the lighting conditions are suitable, the mobile device may be configured to re-execute step i). Additionally or alternatively, if the evaluation of the lighting conditions in step i) is not determined to indicate that the lighting conditions are suitable, the mobile device may be configured to generate at least one prompt for the user to change the ambient lighting conditions, such as move to another location and/or turn off interfering lights.

After step D), the lighting conditions can be evaluated using the method for evaluating the suitability of lighting conditions according to the present invention. A determined concentration of an analyte may be rejected if the suitability information regarding the suitability of the lighting conditions indicates that the lighting conditions are not suitable for the determination of the analyte. The mobile device may be configured to generate an alert to the user, such as a visual alert message on the display of the mobile device and/or at least one audible alert.

Step C) may include providing a visual indication to the user for positioning the test strip relative to the chamber such that the test field is at least partially within the target area. As used herein, the term "target area" refers to a predetermined or predetermined area in which the test field of a test strip can be expected to be located at the time of image acquisition. A visual indication, such as a visual indication, may be provided to the user prior to receiving the image. The visual indication may comprise at least one instruction, such as a text message and/or a graphical instruction. For example, the visual indication may include visualization of the test strip or portions of the test strip, such as the outline and/or outline of the test strip. The visual indication may comprise a test strip outline or a control area on the test strip, such as a frame that conforms to the shape of the test strip, aligned with the display of the mobile device, providing a visual indication for placement of the camera relative to the test strip. Acquisition of at least one image may be initiated automatically if it is determined that the clarity and/or spatial criteria can be met, in particular if it is determined that the outline of the visual indication test strip is aligned with the test strip. The visual indication may vary depending on the test strip used. For example, a visual indication, such as the contour and/or outline of a test strip, may be empirically determined and/or stored in at least one lookup table and/or at least one mobile device data store, such as software, in particular, at least one application downloaded from the application store, and the like. Additionally or alternatively, audio guidance or other types of guidance may be provided.

As will be described in more detail below, the lighting conditions suitability evaluation method and the determination method may be wholly or partially implemented on a computer, in particular, on a mobile device computer such as a mobile device processor. Thus, in particular, these methods may include using at least one processor and software instructions to perform at least steps c) and d) of a method for evaluating the suitability of lighting conditions and/or step D) of a method according to a method of determining. In particular, the methods can be fully or partially implemented as so-called applications, for example for Android or iOS, and can be downloaded from an application store, for example. The software instructions, in particular the application, may also contain instructions to the user, eg via one or more displays, audio instructions, or other instructions, to support the steps of the method in relation to evaluating the suitability of the lighting conditions and/or the determination method. In this case, as mentioned above, steps a) and b) of the method can also be completely or partially implemented on a computer, for example, by automatically obtaining the first and second images of at least one test strip using a camera when the test strip is in the field view of the camera and/or within a certain range within the field of view. The processor for implementing the method for evaluating the suitability of lighting conditions and/or the method for determining, in particular, may be part of a mobile device.

As indicated above, the mobile device may in particular be a laptop computer and/or a mobile communication device. Thus, in particular, the mobile device may be selected from the group consisting of:

mobile communication devices, in particular a smartphone; portable computer, in particular a laptop; tablet computer.

As indicated above, the additional steps of the method may be implemented on a computer or by means of a computer, in particular by means of a processor of a mobile device.

In a further aspect of the present invention, a computer program is described comprising computer executable instructions for implementing a method for evaluating the suitability of lighting conditions according to any of the embodiments of the invention as described herein. In particular, computer-executable instructions may be suitable for performing one or more of steps a), b), c) and d) of the method. In particular, the program is executed on a computer or on a computer network, in particular on the processor of a mobile device containing at least one camera.

Thus, in general, this document describes and proposes a computer program containing computer-executable instructions for carrying out the method for evaluating the suitability of lighting conditions according to the present invention in one or more of the embodiments of the invention included herein, when the program is executed on a computer or in a computer networks. In particular, the computer program may be stored on a computer-readable storage medium. Thus, in particular, one, more than one or even all of the steps of the method as mentioned above can be carried out using a computer or computer network, preferably using a computer program. In particular, the computer may be wholly or partly integrated into the mobile device, and the computer programs may in particular be implemented as a software application. However, in the alternative, at least a portion of the computer may be located outside the mobile device.

Further, this document describes and proposes a storage medium containing a data structure stored thereon, which, after being loaded into a computer or computer network, for example, into a random access memory or main storage device of a computer or computer network, can perform a method for evaluating the suitability of lighting conditions according to one or more embodiments of the invention described in this document, in particular, according to one or more of the steps of the method mentioned above.

Further, this document describes and proposes a computer program product with program code means stored on a computer-readable medium for implementing a method for evaluating the suitability of lighting conditions according to one or more embodiments of the invention described herein, when executing a program on a computer or in a computer network. As used herein, the term "computer program product" refers to the program as a marketable product. This product, as a rule, can exist in an arbitrary format, for example, in paper format or on a computer-readable data carrier. In particular, the computer program product may be distributed over a data network.

Finally, this document describes and proposes a modulated data signal that contains instructions readable by a computer system or computer network for implementing a method for evaluating the suitability of lighting conditions according to one or more embodiments of the invention described herein, in particular, according to one or more of the steps of the method for evaluating the suitability of lighting conditions, as mentioned above.

In particular, this document further describes:

- a computer or computer network comprising at least one processor, wherein the processor is configured to implement a method for evaluating the suitability of lighting conditions according to one of the embodiments of the invention set forth in this description,

- a data structure that is downloadable to a computer, which is configured to implement a method for evaluating the suitability of lighting conditions according to one of the embodiments of the invention set forth in this description, when executing the data structure on a computer,

- a computer program, and the computer program is configured to implement a method for assessing the suitability of lighting conditions according to one of the embodiments of the invention set forth in this description, when executing the program on a computer, a computer program containing software tools for implementing a method for assessing the suitability of lighting conditions according to one of embodiments of the invention set forth in this description, when executing a computer program on a computer or on a computer network,

- a computer program containing software according to the previous embodiment of the invention, the software being stored on a computer-readable storage medium,

- a storage medium, wherein the data structure is stored on the storage medium, and wherein the data structure is configured to carry out a method for evaluating the suitability of lighting conditions according to one of the embodiments of the invention set forth in this description, after being loaded into the main storage device and / or random access memory of a computer, or computer network, and a computer program product containing program code means, wherein the program code means may be stored or stored on a storage medium, for implementing a method for evaluating the suitability of lighting conditions according to one of the embodiments of the invention set forth in this description, if the program code means are executed on computer or computer network.

In a further aspect of the present invention, a computer program is described that contains computer-executable instructions for performing a determination method according to any of the embodiments of the invention as described herein. In particular, computer-executable instructions may be suitable for performing one or more steps i) and ii) of the method. In particular, the program is executed on a computer or on a computer network, in particular on the processor of a mobile device containing at least one camera.

Thus, in general, this document describes and proposes a computer program containing computer-executable instructions for carrying out the determination method according to the present invention in one or more embodiments of the invention included in this document, when the program is executed on a computer or on a computer network. In particular, the computer program may be stored on a computer-readable storage medium. Thus, in particular, one, more than one, or even all of the steps of the method as mentioned above can be carried out using a computer or computer network, preferably using a computer program. In particular, the computer may be wholly or partly integrated into the mobile device, and the computer programs may in particular be implemented as a software application. However, in the alternative, at least a portion of the computer may be located outside the mobile device.

Further, this document describes and proposes a data carrier containing a data structure stored thereon, which, after being loaded into a computer or computer network, for example, into a random access memory or main storage device of a computer or computer network, can perform a determination method according to one or more options. implementation of the invention described in this document, in particular, according to one or more of the steps of the method mentioned above.

In addition, this document describes and proposes a computer program product with program code means stored on a computer-readable medium for implementing the determination method according to one or more embodiments of the invention described herein, when the program is executed on a computer or in a computer network. As used herein, the term "computer program product" refers to the program as a marketable product. This product, as a rule, can exist in an arbitrary format, for example, in paper format or on a computer-readable data carrier. In particular, the computer program product may be transmitted over a data network.

Finally, this document describes and proposes a modulated data signal that contains instructions readable by a computer system or computer network for implementing a determination method according to one or more embodiments of the invention described herein, in particular according to one or more of the steps determination method as mentioned above.

In particular, this document further describes:

- a computer or computer network containing at least one processor, and the processor is configured to implement the method of determining according to one of the embodiments of the invention set forth in this description,

- a data structure loaded on a computer, which is configured to carry out the determination method according to one of the embodiments of the invention set forth in this description, when the data structure is executed on a computer,

- a computer program, wherein the computer program is configured to carry out the determination method according to one of the embodiments of the invention set forth in this description, when the program is executed on the computer,

- a computer program containing software for implementing a method for determining according to one of the embodiments of the invention set forth in this description, when executing a computer program on a computer or in a computer network, a computer program containing software according to the previous embodiment of the invention, and the software is stored on a computer-readable data carrier,

- a data carrier, wherein the data structure is stored on the data carrier, and wherein the data structure is configured to carry out the determination method according to one of the embodiments of the invention described in this description, after being loaded into the main storage device and / or random access memory of a computer or computer network, And

- a computer program product containing a program code means, and the program code means can be stored or stored on a storage medium, for implementing the determination method according to one of the embodiments of the invention set forth in this description, if the program code means are executed on a computer or in a computer network.

In a further aspect of the present invention, a mobile device for performing an analytical measurement is described. The mobile device contains:

- at least one camera;

- at least one light source; And

- at least one processor containing software for implementing a method for evaluating the suitability of lighting conditions according to one of the previous embodiments of the invention.

For most of the terms used in this document and possible definitions, reference to the above description of the methods can be provided.

The processor may further comprise software for implementing the determination method according to any of the preceding embodiments of the invention. The mobile device may be a mobile communication device.

Methods and devices according to the present invention can provide many advantages over known methods and devices for analytical measurements. The present invention can improve the reliability and accuracy of a method for performing an analytical measurement compared to methods known in the art. In particular, the present invention can improve the reliability and accuracy of an application, such as an application containing computer-executable instructions for performing an analytical measurement, compared to known applications or computer programs. In particular, the present invention can make it possible to provide reliable imaging conditions regardless of ambient lighting conditions and for various mobile devices. In particular, this can be achieved by avoiding and/or significantly reducing the influence of ambient lighting.

Summarizing and not excluding additional possible embodiments of the invention, the following embodiments of the invention can be envisaged:

Embodiment 1 of the invention: A method for assessing the suitability of lighting conditions for determining an analyte in a sample using a camera of a mobile device, including the following steps:

a) obtaining at least one first image of at least one test strip, wherein the test strip is configured to detect an analyte in a sample, the test strip having at least one test field containing at least one test chemical to perform an optical detection reaction in the presence of an analyte, while during the acquisition of the first image, the light source of the mobile device is turned off;

b) obtaining at least one second image of the test strip, while during the acquisition of the second image, the light source of the mobile device is turned on;

c) comparing the first and second images obtained in steps a) and b), thus determining the difference in lighting conditions between the first image and the second image; And

d) obtaining at least one suitability information based on the comparison in step c), wherein the suitability information includes information about the suitability of the lighting conditions for analyte detection.

Embodiment 2 of the invention: The method according to the previous embodiment of the invention, characterized in that the light source has a known or predetermined spectral content.

Embodiment 3: A method according to any of the preceding embodiments of the invention, characterized in that the light source is capable of brighter illumination compared to ambient illumination.

Embodiment 4 of the invention: A method according to any of the preceding embodiments of the invention, characterized in that the first image and the second image are obtained before the application of the sample.

Embodiment 5 of the invention: A method according to any of the preceding embodiments of the invention, characterized in that the method includes at least one step of applying a sample, wherein in the step of applying the sample, the sample is applied to the test strip, wherein the sample is applied to the test strip. strip before steps a) and/or b).

Embodiment 6: A method according to any of the preceding embodiments, wherein obtaining the suitability information in step d) comprises comparing the difference in lighting conditions determined in step c) with at least one threshold value.

Embodiment 7: The method according to the foregoing embodiment, characterized in that only if the difference in lighting conditions between the second image and the first image is at least equal to a threshold value, the suitability information is set to indicate the suitability of the lighting conditions for determining analyte.

Embodiment 8: A method according to any of the preceding embodiments, wherein the suitability information is set to indicate suitability of the lighting conditions for the subsequent determination of the analyte only if at least 80% of the light intensity used to illuminate the test is stripes coming from a light source.

Embodiment 9: A method according to any of the preceding embodiments, wherein the method further comprises checking and/or evaluating whether the light source provides sufficient light intensity.

Embodiment 10: A method according to any of the preceding embodiments, wherein the camera is a camera of a mobile communication device.

Embodiment 11: A method according to any of the preceding embodiments, characterized in that the illumination source of the mobile device comprises at least one light emitting diode integrated in the mobile device.

Embodiment 12 of the invention: A determination method for determining an analyte in a sample using a camera of a mobile device, comprising:

i) evaluating lighting conditions using a method for evaluating the suitability of lighting conditions according to any of the preceding embodiments of the invention;

ii) performing the following steps if the lighting conditions suitability information indicates that the lighting conditions are suitable for analyte detection:

A) providing at least one test strip for detecting an analyte in a sample, the test strip containing at least one test field containing at least one test chemical for performing an optical detection reaction in the presence of the analyte;

B) applying at least one sample to the test area of the test strip;

C) obtaining at least one image of the test field using a camera, while during said acquisition, the illumination source of the mobile device is turned on; And

D) determining, based on the image obtained in step C), the concentration of the analyte in the sample.

Embodiment 13: The determination method according to the previous embodiment, characterized in that step D) comprises analyzing the color of a spot on a test field of a test strip, said spot at least partially containing a sample.

Embodiment 14: A detection method according to either of the two preceding embodiments of the invention, wherein step C) includes a visual indication for the user to position the test strip relative to the chamber such that the test field is at least partially located in the target areas.

Embodiment 15: A determination method according to either of the two preceding embodiments, characterized in that after step D), the lighting conditions are evaluated by the lighting conditions suitability evaluation method according to any of the preceding embodiments, wherein the determined analyte concentration is rejected if suitability information regarding the suitability of the lighting conditions indicates that the lighting conditions are not suitable for the determination of the analyte.

Embodiment 16 of the invention: A computer program comprising software for implementing a method for evaluating the suitability of lighting conditions according to one of the previous embodiments of the invention relating to a method for evaluating the suitability of lighting conditions, when executing a computer program on a computer or in a computer network, in particular on a processor mobile device.

Embodiment 17 of the invention: A computer program containing software tools for implementing the determination method according to one of the previous embodiments of the invention relating to the determination method when the computer program is executed on a computer or in a computer network, in particular, on the processor of a mobile device.

Option 18 implementation of the invention: Mobile device containing:

- at least one camera;

- at least one light source; And

- at least one processor containing software for implementing a method for evaluating the suitability of lighting conditions according to one of the previous embodiments of the invention related to a method for evaluating the suitability of lighting conditions.

Embodiment 19: The mobile device according to the previous embodiment, characterized in that the processor further comprises software for implementing the determination method according to any of the preceding embodiments of the invention relating to the determination method.

Embodiment 20: A mobile device according to either of the two preceding embodiments, characterized in that the mobile device is a mobile communication device.

BRIEF DESCRIPTION OF GRAPHICS

Additional optional features and embodiments of the invention will be set forth in more detail in the following description of embodiments of the invention, preferably in conjunction with dependent claims. In this case, the corresponding optional features can be implemented separately, as well as in any arbitrary possible combination, which will be clear to a person skilled in the art. The scope of this invention is not limited to the preferred embodiments of the invention. Embodiments of the invention are schematically depicted in the figures. In this document, identical reference numbers in these figures refer to identical or functionally comparable elements.

Figures include the following:

in fig. 1 shows a flow diagram of a method for evaluating the suitability of lighting conditions and a method for determining an analyte;

in fig. 2 is a perspective view of an embodiment of a mobile device for implementing a method for evaluating the suitability of lighting conditions; And

in fig. 3A-3G show the relative spectral intensity distributions of a standard light source and the experimental results of the effects of ambient light on a camera image.

DETAILED DESCRIPTION OF EMBODIMENTS

In FIG. 1 shows a flow chart of a method 110 for evaluating the suitability of lighting conditions for determining an analyte in a sample using the camera 112 of mobile device 114 and a method for determining analyte 115. The method 110 for evaluating suitability includes the following steps:

a) (denoted by reference numeral 117) obtaining at least one first image of at least one test strip 116, wherein the test strip 116 is configured to detect an analyte in a sample, wherein the test strip 116 contains at least one test field 118 containing at least one test chemical for performing an optical detection reaction in the presence of an analyte, wherein the illumination source 120 of the mobile device 114 is turned off during the first image acquisition;

b) (denoted by reference numeral 122) obtaining at least one second image of the test strip 116, while during the acquisition of the second image, the illumination source 120 of the mobile device 114 is turned on;

c) (labeled 124) comparing the first and second images obtained in steps a) 117 and b) 122, thereby determining the difference in lighting conditions between the first image and the second image; And

d) (denoted by reference numeral 126) obtaining at least one suitability information based on the comparison in step c) 124, wherein the suitability information includes information about the suitability of lighting conditions for analyte detection.

In FIG. 2 shows a perspective view of a mobile device 114 for implementing a method 110 for evaluating the suitability of lighting conditions. Mobile device 114 may be a mobile electronic device, more specifically a mobile communication device such as a cellular phone or smartphone. Additionally or alternatively, mobile device 114 may also refer to a tablet computer or other type of portable computer containing at least one camera. In addition, at least one test strip 116 is shown. The test strip 118 includes a test field 118 containing at least one test chemical for determining at least one analyte. The test strip 116, for example, may comprise at least one substrate, such as at least one carrier, with at least one test field 118 applied to or integrated therein.

Mobile device 114 includes at least one camera 112. Camera 112 may include at least one camera chip not shown here, such as at least one CCD chip and/or at least one CMOS chip configured to image recording. Camera 112 typically may include a one-dimensional or two-dimensional array of image sensors, such as pixels. Camera 112 may be a camera of a mobile communication device. The camera 112 may in particular be a color camera. Camera 112 may be configured to generate color values for at least three colors, such as red (R), green (G), blue (B). For example, each camera chip pixel may have three or more different color sensors, such as color shooting pixels, such as one pixel for R, one pixel for G, one pixel for B.

The method 110 for evaluating the suitability of the lighting conditions may include determining the effect of ambient lighting on image acquisition by the camera 112 of the mobile device 114. For example, the suitability information may comprise information about the sufficient intensity of the light emitted from the illumination source 120 of the mobile device 114 to illuminate the test. -strips 116. In particular, the suitability information may include information about the sufficiency of the intensity of illumination emanating from the illumination source 120 of the mobile device 114 to illuminate the test strip 116 in relation to and/or in comparison with ambient light intensities and/or ambient light conditions. . Ambient lighting can be created and/or provided by artificial light sources such as indoor light sources such as lamps and/or natural light sources such as the sun, moon, starlight, lightning. Lighting conditions may depend on time, in particular the time of day or night. Lighting conditions may be location dependent, particularly if the image is taken outdoors, indoors, or geographic location. Particularly for outdoor measurements, lighting conditions may be affected by weather conditions. For indoor measurements, lighting conditions may depend on room lighting, which may vary depending on activity, such as in homes, supermarkets, theaters, etc.

The light source 120 may include at least one light emitting diode embedded in the mobile device 114. In particular, the light source 120 may be the backlight of the mobile device 114, in particular a mobile phone. Mobile device 114 may include additional lighting devices, such as at least one light source illuminating at least one display 128, and/or display 128 may be designed as an additional light source.

The illumination source 120 may have two states: an on state in which it generates a light beam to illuminate the test strip 116, and an off state in which the illumination source 120 is turned off. As described above, in step a) 117 a first image is obtained with the illumination source 120 of the mobile device 114 turned off. This may make it possible to obtain an image containing only the illumination intensities of the ambient light sources and independently of the illumination provided by the illumination source 120 of the mobile device 114. In step b) 122, the illumination source 120 is turned on so that a second image containing the illumination intensities can be determined as both from ambient lighting and from lighting from the illumination source 120 of the mobile device 114.

The light emitting diode built into the mobile device 114 may include at least one white light LED. The white light LED can be driven by a short current pulse such that the white light LED can be configured to generate a bright flash of light. Light source 120 may be configured to continuously illuminate test strip 116 during image acquisition. Unlike electronic flashes, the flash duration of a white light LED can be several hundred (100) ms. This may allow the illumination source 120 to continuously illuminate the test strip 116 during an LED flash image acquisition. Alternatively, the LED may be configured to continuously illuminate the test strip in a non-flash mode, wherein the LED is configured to continuously generate at least one light beam to illuminate the test strip 116.

Light source 120 may be configured to be brighter than ambient light. Light source 120 may be the substantially dominant light source in image acquisition in step b) 122 test strips 116. Illumination from flashes generated by a white light LED used in mobile devices may range from 80 lux to 300 lux at object distance , which is 1 m. Thus, at a distance of 0.1 m from the object, the illumination from the flashes generated by the white light LED can be from 8000 lux to 30000 lux. For comparison, full daylight illumination can be 10752 lux, overcast day 1075 lux, very dark day 107 lux, and twilight 10.8 lux, see https://www.noao.edu/education /QLTkit/ACTIVITY_Documents/Safety/LightLevels_outdoor+indoor.pdf. The illumination source 120 may be configured to generate at least one light beam 130 to illuminate the test strip 116 whose light intensities are greater than the ambient light intensities. The light intensities of the light beam 130 generated by the illumination source 120 may be twice the ambient light intensities, preferably 10 times, and more preferably 100 times.

Step c) 124 includes comparing the first and second images obtained in steps a) 117 and b) 122, thereby determining the difference in lighting conditions between the first image and the second image. As mentioned above, each camera chip pixel may have three or more different color sensors, such as color shooting pixels, such as one pixel for red (R), one pixel for green (G), and one pixel for blue (B). For example, camera 112 may include at least one Bayer sensor. The camera chip may be configured to generate at least one sensor signal for each of the R, G, B channels. The camera chip may be configured to determine the intensity spectrum of the corresponding R, G, B channel. Camera 112 may be configured to obtain the first and second images in steps a) 117 and b) 122 in at least one color channel, in particular at least one color signal channel selected from the group consisting of an R channel, a G channel, and a B channel. The camera 112 may be configured to acquire the first and second images in steps a) 117 and b) 122 in each of the color signal channels. Mobile device 114 includes at least one processor 132. Camera 112 and/or processor 132 may be configured to determine, based on the first image, at least one first intensity distribution and, based on the second image, at least one second intensity distribution of at least for one of the color signal channels. Preferably, the first intensity distribution and the second intensity distribution may be determined for each of the color signal channels. For at least one color channel, camera 112 and/or processor 132 may be configured to determine based on a respective first intensity distribution of a first intensity spectrum of a respective color channel and based on a respective second intensity distribution of a second intensity spectrum of the respective color channel. For example, said comparison may include determining a difference between a first intensity distribution and a second intensity distribution of at least one of the color signal channels. In particular, for channels R, G and B, the difference A can be determined by the equation:

представляет собой распределение интенсивности второго изображения соответствующего канала цветового сигнала и

представляет собой распределение интенсивности первого изображения соответствующего канала цветового сигнала. Дополнительно или альтернативно, сравнение может включать в себя определение частного путем деления первого распределения интенсивности и второго распределения интенсивности и/или путем деления кратных и/или деления линейных комбинаций первого распределения интенсивности и второго распределения интенсивности по меньшей мере одного из каналов цветового сигнала. В частности, для каналов R, G и В частное может быть определено посредством уравнения:moreover, color=R, G, B, where Δ _color is the difference in the corresponding channel of the color signal,

is the intensity distribution of the second image of the corresponding channel of the color signal and

represents the intensity distribution of the first image of the corresponding channel of the color signal. Additionally or alternatively, the comparison may include determining the quotient by dividing the first intensity distribution and the second intensity distribution and/or by dividing multiples and/or dividing linear combinations of the first intensity distribution and the second intensity distribution of at least one of the color signal channels. In particular, for channels R, G and B, the quotient can be determined by the equation:

представляет собой распределение интенсивности второго изображения соответствующего канала цветового сигнала и

представляет собой распределение интенсивности первого изображения соответствующего канала цветового сигнала. Процессор 132 может содержать вычислительные средства, выполненные с возможностью сравнения первого и второго изображений.where color=R, G, B, where Q _color is a quotient in the corresponding channel of the color signal,

is the intensity distribution of the second image of the corresponding channel of the color signal and

represents the intensity distribution of the first image of the corresponding channel of the color signal. The processor 132 may include computing means configured to compare the first and second images.

Light source 120 of mobile device 114 may have a known or predetermined spectral composition. In particular, at least one illumination intensity distribution as a function of wavelength for each of the R, G, B channels may be known or given. In particular, the emission spectrum of a white light LED may be known or empirically determined. The spectral composition may be stored in a table or lookup table and may be determined, for example, empirically, and may, for example, be stored in at least one storage device of the mobile device, for example, by means of software, in particular an application downloaded from an application store, etc. .P. Because the spectral composition of the light source 120 is known or predetermined, it is possible to determine the amount of light intensity used to illuminate the test strip 116 that comes from the light source 120.

The first image and the second image can be obtained before applying the sample. Additionally or alternatively, the method may include at least one step of applying the sample, wherein in the step of applying the sample, the sample can be applied to the test strip 116. In particular, the sample can be applied to the test strip 116 before steps a) 117 and /or b) 122.

Step d) 126 includes obtaining at least one suitability information based on the comparison in step c) 124. Obtaining the suitability information in step d) 126 may include comparing the difference in lighting conditions determined in step c) 124 to with at least one threshold value. Only if the difference in lighting conditions between the second image and the first image is at least equal to a threshold value, the suitability information can be set to indicate the suitability of the lighting conditions for analyte detection. The threshold value may depend on the ambient light conditions. For example, the user and/or processor 132 may be configured to adjust and/or select a threshold value depending on ambient lighting conditions. The threshold value may be stored in a table or lookup table and may be determined, for example, empirically and may, for example, be stored in at least one storage device of the mobile device, for example, through software, in particular an application downloaded from an application store, etc. .P. For example, suitability information can be set to indicate the suitability of lighting conditions for subsequent analyte determination only if at least 80% of the light intensity used to illuminate the test strip 116 comes from the light source 120. For example, suitability information can be set to indicate suitability of lighting conditions for subsequent analyte determination only if 90% of the light intensity used to illuminate the test strip 116 comes from the light source 120.

In FIG. 3A shows the relative power distribution of standard CIE illuminants A, B, C from 380 nm to 780 nm, see https://en.wikipedia.org/wiki/Standard_illuminant. In FIG. 3B shows the intensity I of the determined RGB signals as a function of wavelength 1 in nm for a 100 mg/dl blood sample illuminated with a standard light source A. FIG. 3C shows the intensity I of the determined RGB signals as a function of wavelength % in nm for a 100 mg/dl blood sample illuminated with standard light source B. FIG. 3D shows the intensity I of certain RGB signals as a function of wavelength λ in nm for a 100 mg/dL blood sample illuminated with standard light source C. The intensity of certain RGB signals was observed as a function of wavelength change as a function of illumination with respective light source A, B. or C. FIG. 3E shows the intensity I of certain RGB signals as a function of wavelength λ in nm for a 100 mg/dL blood sample, the sample being illuminated with a standard light source A at 10% light intensity and an illumination source 120 at 90% light intensity, in this case, the light emitting diode of a Samsung Galaxy® J7 smartphone. It has been observed that the intensity of certain RGB signals as a function of wavelength is independent of illumination by the corresponding light source. Lighting from the light source 120 dominates the lighting conditions.

In accordance with FIG. 1, the determination method 115 includes step i) 134 in which the lighting conditions are evaluated by the lighting conditions suitability evaluation method. The determination method 115 includes step ii) 136 where, if the suitability information regarding the suitability of lighting conditions indicates that the lighting conditions are suitable for analyte determination, the following steps are performed:

A) (denoted by reference numeral 138) providing at least one test strip for detecting an analyte in a sample, wherein the test strip contains at least one test field containing at least one test chemical for performing an optical detection reaction in the presence of the analyte ;

B) (denoted by the reference position 140) applying at least one sample to the test field 118 of the test strip 116;

C) (denoted by reference numeral 142) acquisition of at least one image of the test field 118 using the camera 112, while during said acquisition, the illumination source 120 of the mobile device is turned on; And

D) (denoted by reference position 144) determination based on the image obtained in step C), the concentration of the analyte in the sample.

Step C) 142 may include providing a visual indication to the user to position the test strip 116 relative to the chamber 112 such that the test field 118 is at least partially within the target area. A visual indication, such as a visual indication, may be provided to the user prior to receiving the image. The visual indication may comprise at least one instruction, such as a text message and/or a graphical instruction. For example, the visual indication may include visualization of the test strip 116 or parts of the test strip 116, such as the outline and/or outline of the test strip 116. The visual indication may include the outline of the test strip 116 or a control area on the test strip 116, such as a frame. , which conforms to the shape of the test strip 116 aligned with the display 128 of the mobile device 114, providing a visual indication for placement of the camera 112 in relation to the test strip 116.

In the event that the lighting condition score in step i) 134 is not set to indicate that the lighting conditions are appropriate, the mobile device 114 may be configured to abort and/or prevent the determination of the analyte in the sample. Additionally or alternatively, in the event that the lighting condition score in step i) 134 is not set to indicate that the lighting conditions are suitable, the mobile device 114 may be configured to generate at least one alert. Additionally or alternatively, in the event that the lighting conditions estimate in step i) 134 is not set to indicate that the lighting conditions are suitable, the mobile device 114 may be configured to re-execute step i) 134. Additionally or alternatively, including If the lighting condition score in step i) is not set to indicate that the lighting conditions are suitable, the mobile device 114 may be configured to generate at least one prompt for the user to change the ambient lighting conditions, such as move to another location and/or turn off interfering light sources.

After step D) 144, the lighting conditions can be evaluated using the method 110 for evaluating the suitability of the lighting conditions, as described above. A determined concentration of an analyte may be rejected if the suitability information regarding the suitability of the lighting conditions indicates that the lighting conditions are not suitable for the determination of the analyte. The mobile device 114 may be configured to generate at least one error message if the light conditions suitability information indicates that the lighting conditions were not suitable at the time of analyte determination. The mobile device 114 may be configured to generate an alert to the user, such as a visual alert message on the display 128 of the mobile device 114 and/or at least one audible alert.

List of reference positions

110 way to assess the suitability of lighting conditions

112 camera

114 mobile device

115 method for determining the analyte

116 test strip

117 step a)

118 test field

120 light source

122 step b)

124 stage c)

126 step d)

128 display

130 beam of light

132 processor

134 step i)

136 stage ii)

138 stage A)

140 stage B)

142 stage C)

144 step D).

Claims (31)

1. A method (110) for assessing the suitability of lighting conditions for determining an analyte in a sample using a camera (112) of a mobile device (114), including the following steps: a) (117) obtaining at least one first image of at least one test strip (116), while the test strip (116) is configured to determine the analyte in the sample, and the test strip (116) contains at least one test field (118) containing at least one test chemical for carrying out an optical detection reaction in the presence of an analyte, while during the acquisition of the first image, the illumination source (120) of the mobile device (114) is turned off; b) (122) obtaining at least one second image of the test strip (116), while during the acquisition of the second image, the illumination source (120) of the mobile device (114) is turned on, wherein the light source (120) has a known or predetermined spectral composition, wherein the spectral composition is the intensity spectrum of the light generated by the light source (120); wherein the method includes at least one step of applying the sample, at the same time, at the step of applying the sample, the sample is applied to the test strip (116), wherein the sample is applied to the test strip (116) before steps a) (117) and/or b) (122); c) (124) comparing the first and second images obtained in steps a) (117) and b) (122), thus determining the difference in lighting conditions between the first image and the second image, while the camera (112) is configured to receive of the first and second images in steps a) and b) in at least one color signal channel, wherein the camera (112) and/or the processor (132) of the mobile device (114) are configured to determine, based on the first image, at least one of the first intensity distribution and based on the second image of at least one second intensity distribution for at least one of the color signal channels, and wherein the comparison of the first and second images is a comparison of the first intensity distribution and the second intensity distribution of at least one of the color signal channels signal, since the spectral composition of the light source (120) is known or given, it is possible to determine l the amount of light intensity used to illuminate the test strip (116), which comes from the light source (120); And d) (126) obtaining at least one suitability information based on the comparison in step c) (124), wherein the suitability information contains information about the suitability of the lighting conditions for determining the analyte; wherein the suitability information is set to indicate the suitability of the lighting conditions for subsequent analyte determination only if at least 70% of the light intensity used to illuminate the test strip (116) comes from the light source (120). 2. The method (110) of the preceding claim, wherein the light source (120) is configured to provide brighter illumination compared to ambient illumination. 3. Method (110) according to any one of the preceding claims, wherein the first image and the second image are taken prior to applying the sample. 4. The method (110) according to any one of the preceding claims, wherein obtaining the suitability information in step d) (126) comprises comparing the difference in lighting conditions determined in step c) (124) to at least one threshold value. 5. The method (110) according to any one of the preceding claims, wherein the suitability information is set to indicate the suitability of the lighting conditions for the subsequent determination of the analyte only if at least 80% of the light intensity used to illuminate the test strip (116) comes from the light source (120). 6. The method (110) according to any one of the preceding claims, wherein the method (110) further comprises checking and/or evaluating whether the light source (120) is providing sufficient light intensity. 7. Method (110) according to any one of the preceding claims, wherein the illumination source (120) of the mobile device (114) comprises at least one light emitting diode embedded in the mobile device (114). 8. A detection method for determining an analyte in a sample using a camera (112) of a mobile device (114), including: i) evaluating lighting conditions using the lighting condition suitability assessment method of any one of the preceding claims; ii) performing the following steps if the lighting conditions suitability information indicates that the lighting conditions are suitable for analyte detection: A) providing at least one test strip (116) for detecting an analyte in a sample, wherein the test strip (116) contains at least one test field (118) containing at least one test chemical for performing an optical detection reaction in the presence of the analyte; B) applying at least one sample to the test field (118) of the test strip (116); C) obtaining at least one image of the test field (118) using the camera (112), while during the said acquisition, the illumination source (120) of the mobile device (114) is turned on; And D) determination based on the image obtained in step C), the concentration of the analyte in the sample. 9. A computer-readable storage medium that stores a computer program containing software for implementing the method (110) according to one of paragraphs. 1-7 when executing a computer program on a computer or on a computer network, in particular on the processor of a mobile device. 10. A computer-readable storage medium that stores a computer program containing software for implementing the method (115) according to claim 8 when the computer program is executed on a computer or on a computer network, in particular, on the processor of a mobile device. 11. Mobile device (114), containing: - at least one chamber (112); - at least one source (120) of illumination; And - at least one processor (132) containing software for implementing the method (110) for assessing the suitability of lighting conditions according to one of the preceding paragraphs related to the method for assessing the suitability of lighting conditions. 12. The mobile device (114) according to the preceding claim, wherein the processor (132) further comprises software for implementing the determination method (115) according to any one of the preceding determination method claims. 13. A mobile device (114) according to any one of the preceding two claims, wherein the mobile device (114) is a mobile communication device.

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