A method for detecting an analyte in a sample

Abstract

The present invention discloses a method, computer program and device for detecting at least one analyte in at least one sample (114). The method comprises: a) providing at least one mobile device (112), the mobile device having at least one camera (118) and at least one illumination source (120); b) providing at least one test strip (116), the test strip having at least one test area (124), the test area containing at least one test chemistry (126), the test chemistry for performing an optical detection reaction in the presence of the analyte; c) applying the at least one sample (114) to the test area (124); d) capturing a plurality of images (142) of at least one area (144) of the test strip (116), the area (144) comprising the sample (114) applied to the test area; at least a portion of the test zone (124) of the sample (114), the capturing comprising: d1) capturing at least one image (142) with the illumination source (120) turned off before the sample (114) is applied to the test zone (124); d2) capturing at least one image (142) with the illumination source (120) turned on before the sample (114) is applied to the test zone (124); and d3) capturing at least one image (142) after the sample (114) is applied to the test zone (124); e) determining the concentration of an analyte in the sample (114) by using the image (142) captured in step d).

Description

Technical Field

[0001] The present application relates to a detection method for detecting an analyte in a sample. The present invention further relates to a computer program having program tools for performing the method according to the present invention. In addition, the present invention relates to a mobile device and a test kit. The method, computer program, mobile device and test kit according to the present invention can be used for medical diagnosis in order to qualitatively and / or quantitatively detect one or more analytes in one or more body fluids. However, other fields of application of the present invention are also possible. Background Art

[0002] In the field of medical diagnostics, in many cases, one or more analytes must be detected in a sample of body fluids, such as blood, tissue fluid, urine, saliva, or other types of body fluids. Examples of analytes to be detected include glucose, triglycerides, lactate, cholesterol, or other types of analytes commonly found in these body fluids. If necessary, an appropriate treatment method can be selected based on the concentration and / or presence of the analyte.

[0003] Typically, devices and methods known to the skilled person utilize test elements comprising one or more test chemicals that, in the presence of an analyte to be detected, can perform one or more detectable detection reactions, such as optically detectable detection reactions. Regarding these test chemicals, reference may be made, for example, to J. Hoenes et al.: The Technology Behind Glucose Meters: Test Strips, Diabetes Technology & Therapeutics, Vol. 10, Supplement 1, 2008, S-10 to S-26. Other types of test chemicals are also possible and can be used to perform the present invention.

[0004] In analytical measurements, especially those based on color forming reactions, a technical challenge is to evaluate the color change caused by the detection reaction. In addition to the use of dedicated analytical equipment such as handheld blood glucose meters, the use of general electronic devices such as smart phones and portable computers has become increasingly common in recent years. WO 2012 / 131386 A1 discloses a test device for performing an assay, the test device comprising: a container containing a reagent, the reagent reacting with an applied test sample to produce a color or pattern change; a portable device, such as a mobile phone or a laptop computer, comprising a processor and an image capture device, wherein the processor is configured to process data captured by the image capture device and output a test result of the applied test sample.

[0005] WO 2015 / 078954 A1 discloses a method, an analysis device and an analysis system for determining the concentration of at least one analyte in a body fluid. The method comprises: a) applying a body fluid sample to a test carrier; b) illuminating the test carrier with at least one light source; c) receiving light transmitted by the test carrier by using at least one detector; d) determining the concentration of the analyte by evaluating at least one detector signal generated by the detector. The at least one light source is modulated by using at least two modulation frequencies. The detector signal is demodulated using the at least two modulation frequencies to generate at least two demodulated detector signals, each demodulated detector signal corresponding to one of the modulation frequencies. The method comprises performing fault detection based on a comparison of the at least two demodulated detector signals.

[0006] US 2017 / 0343480 A1 describes a method for measuring blood sugar level using a portable terminal of a strip module. The strip module includes a dye pad whose color changes in response to a sample applied to the dye pad. The strip module also includes a transparent strip having a first side and a second side. The first side is opposite to the second side. The dye pad is mounted on the first side of the transparent strip, and the transparent strip reflects light provided from a light source of the portable terminal located near the second side and transmits the light to the dye pad.

[0007] US 2015 / 233898 A1 describes a test strip module including a housing, a test strip located in the housing, and a position anchor extending downward through a mating surface to a surface of a mobile computing device. The position anchor has a shape that matches features of the surface of the mobile computing device.

[0008] US 6 267 722 B1 describes systems and methods for medical diagnosis or risk assessment of patients. These systems and methods are designed to be employed at the point of care, such as in emergency rooms and operating rooms, or in any situation where rapid, accurate results are required. These systems and methods process patient data, particularly data from point-of-care diagnostic tests or assays, including immunoassays, electrocardiograms, x-rays, and other such tests, and provide an indication of a medical condition or risk, or an indication of the absence of a medical condition or risk. These systems include instruments for reading or evaluating test data and software for converting the data into diagnostic or risk assessment information.

[0009] The reliability and accuracy of analytical measurements using mobile computing devices generally depends on a number of technical factors. Specifically, there are a large number of mobile devices with cameras on the market, which have different technical and optical characteristics, which must be taken into account in analytical measurements. For example, EP 3 108 244 A1 and WO 2015 / 120819 A1 disclose the measurement of physical and biochemical parameters using mobile devices, wherein a test strip module is described, which includes a housing, a test strip located in the housing, and a position anchor extending downward through a mating surface to a surface of a mobile computing device. The position anchor has a shape that matches the features of the surface of the mobile computing device.

[0010] Furthermore, the reliability and accuracy of analytical measurements made using mobile computing devices often depends heavily on the lighting and illumination conditions during the measurement. For example, in US 6,574,425 B1, a modulated light source emits light to illuminate a target surface having a specific color and hue. The light reflected by the target surface is detected using an optical detector. The output of the optical detector is processed and fed back to the optical detector to compensate for any offset caused by ambient light, temperature or other external factors, and is differentially amplified to generate an output signal indicative of the color and shading of the target surface. The output signal of the differential amplifier is then demodulated using a synchronous detector to produce a substantially stable DC voltage indicative of the color or hue of the target surface. In the case where the color of the target surface indicates a specific measurable quantity or quality (such as analyte concentration), a lookup table or mathematical formula is used to convert the stable DC voltage into a corresponding quantity or quality measurement. In making this conversion, any changes in the intensity of the modulated light source caused by temperature changes are compensated.

[0011] US 4,553,848 A discloses a method and apparatus for detecting and evaluating the optical properties of a sample, the method and apparatus utilizing a light source having alternating bright and dark phases, a detector that picks up light from the light source through the sample being inspected, and a circuit for integrating and digitizing the signal received from the detector, the circuit comprising an integrator and connectable to the detector. During at least a portion of the bright phase and at least a portion of the dark phase, the signal emitted by the detector is integrated. The integral obtained during the dark phase is subtracted from the integral obtained during the bright phase to determine the result. The purpose of the integrator for integrating the signal is similar to that of a dual-integrating analog-to-digital converter for converting the integral into a digital signal. In order to obtain the highest accuracy and simplicity in the integration and digitization stages, each portion of the bright or dark phase is followed by a measurement voltage period during which the signal from the detector is applied to a single integrator in sequence with opposite mathematical signs. Integration is performed over the entire measurement voltage period to obtain a total integral.

[0012] EP 1 912 058 A1 discloses a device and a method for detecting and evaluating optical signals. The arrangement has a mixer unit, which generates an optical control signal from two different control signals (AN1, AN2), and a light source, which is controlled by the optical control signal. The signal source generates one of the control signals with a frequency and an intensity. The measurement signal and the control signal are supplied to a frequency-selective amplifier. The output signal (A1, A2) is supplied to an evaluation unit, which compares the output signals. Based on the comparison result, the external light determines information about the measurement disturbance. An independent claim is also included, which discloses a method for detecting and analyzing optical signals for detecting an analyte in an analysis fluid.

[0013] Although there are many advantages to using mobile computing devices for analytical measurements, there are still many technical challenges. Specifically, the reliability and accuracy of the measurements need to be enhanced and ensured. A major difficulty is the presence and influence of ambient light. When using a mobile phone's camera, the reliability and accuracy of the analytical measurements may depend to a large extent on the lighting conditions during the capture of the test strip image for analytical measurement. Specifically, ambient light may have a significant impact on the lighting conditions, for example, due to the presence of various lighting tools in different specific locations and / or depending on the location of the captured image and the time of day or night when the image is captured. In particular, ambient light may interfere with the evaluation of the color formed on the reagent area of ​​the test strip.

[0014] Problem to be solved

[0015] Therefore, it is desirable to provide methods and devices to address the above technical challenges when performing analytical measurements using mobile devices such as consumer electronic mobile devices (specifically, multi-function mobile devices such as smart phones or tablets that are not specifically used for analytical measurements). Specifically, methods and devices should be proposed to ensure the reliability and accuracy of the measurements. Summary of the invention

[0016] This problem is solved by a detection method, a computer program, a mobile device and a kit for detecting at least one analyte in at least one sample having the features of the independent claims. Advantageous embodiments are listed in the dependent claims which can be realized in isolation or in any combination.

[0017] As used below, the terms "having", "comprising" or "including" or any grammatical variations thereof are used in a non-exclusive manner. Thus, these terms may refer to the absence of other features in the entity described in this context in addition to the features introduced by these terms, or to the presence of one or more other features. As an example, the expressions "A has B", "A comprises B" and "A includes B" may refer to the case where, in addition to B, no other elements are present in A (i.e., A consists only and entirely of B); or to the case where, in addition to B, one or more other elements are present in entity A, such as element C, element C and D or even other elements.

[0018] 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 are usually used only once when introducing the corresponding feature or element. In the following, in most cases, when referring to the corresponding feature or element, despite the fact that the corresponding feature or element may be present once or more than once, the expression "at least one" or "one or more" is not repeated.

[0019] Furthermore, as used below, the terms "preferably", "more preferably", "particularly", "more particularly", "specifically", "more specifically" or similar terms are used in conjunction with optional features without limiting the alternative possibilities. Therefore, the features introduced by these terms are optional features and are not intended to limit the scope of the claims in any way. As the skilled person will recognize, the present invention may be carried out using alternative features. Similarly, the features introduced by "in an embodiment of the present invention" or similar expressions are intended to be optional features without any limitation on alternative embodiments of the present invention, without any limitation on the scope of the present invention, and without any limitation on the possibility of combining the features introduced in this manner with other optional or non-optional features of the present invention.

[0020] In a first aspect, a detection method for detecting at least one analyte in at least one sample is disclosed. The method comprises the following steps, which steps may be performed in a given order as an example. However, it should be noted that different orders are also possible. In addition, one or more of the method steps may be performed once or repeatedly. In addition, two or more method steps may also be performed simultaneously or in a temporally overlapping manner. The method may further comprise unlisted steps.

[0021] The detection method comprises the following steps:

[0022] a) providing at least one mobile device having at least one camera and at least one illumination source;

[0023] b) providing at least one test strip having at least one test zone containing at least one test chemistry for performing an optical detection reaction in the presence of an analyte;

[0024] c) applying the at least one sample to a test area;

[0025] d) capturing a plurality of images of at least one area of ​​the test strip, the area including at least a portion of the test zone to which the sample is applied, the capturing comprising:

[0026] d1) before applying the sample to the test area, capturing at least one image with the illumination source turned off;

[0027] d2) capturing at least one image with the illumination source turned on, prior to applying the sample to the test area; and

[0028] d3) capturing at least one image after applying the sample to the test area;

[0029] e) determining the concentration of the analyte in the sample by using the image captured in step d).

[0030] As used herein, the term "detecting an analyte in a sample" is a broad term and will be given its ordinary and conventional meaning to those of ordinary skill in the art, and is not limited to a special or customized meaning. The term may specifically refer to, but is not limited to, quantitatively and / or qualitatively determining at least one analyte in any sample. For example, a sample may include a body fluid such as blood, tissue fluid, urine, saliva, or other types of body fluids. For example, the result of the analytical measurement 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, and thus the result of the analytical measurement may be, for example, a blood glucose concentration.

[0031] For example, in step a), a mobile device having at least one camera and at least one illumination source may be provided. As used herein, the term "mobile device" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and is not limited to a special or customized meaning. The term may specifically refer to, but is not limited to, a mobile electronic device, and more specifically to a mobile communication device such as a cellular phone, a smart phone. Additionally or alternatively, as further outlined in detail below, a mobile device may also refer to a tablet computer, a laptop computer, or any other type of portable computer having at least one camera and at least one illumination source.

[0032] As used herein, the term "camera" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and is not limited to a special or customized meaning. The term may specifically refer to, but is not limited to, a device having at least one imaging element configured to record or capture spatially resolved one-dimensional, two-dimensional, or even three-dimensional optical information. As an example, a camera may include at least one camera chip, such as at least one CCD chip and / or at least one CMOS chip, configured to record an image. For example, the camera may be a color camera including at least three color pixels. The camera may be a color CMOS camera. For example, the camera may include black and white pixels and color pixels. The color pixels and black and white pixels may 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 black and white CMOS. The camera may include at least one black and white CMOS chip. The camera may generally include an image sensor, such as a one-dimensional or two-dimensional array of pixels. As an example, the camera may include 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 cameras are also feasible. The camera may be a camera of a mobile communication device. The invention is particularly applicable to cameras which are typically used in mobile applications such as notebook computers, tablet computers or in particular mobile phones such as smartphones. Thus, in particular, the camera may be part of a mobile device which, in addition to at least one camera, also comprises one or more data processing devices, such as one or more data processors. However, other cameras are also feasible. In addition to at least one camera chip or imaging chip, the camera may also comprise other elements, such as one or more optical elements, for example one or more lenses. As an example, the camera may be a fixed focus camera with at least one lens which is fixedly adjusted relative to the camera. However, alternatively, the camera may also comprise one or more variable lenses which can be adjusted automatically or manually.

[0033] The camera may specifically be a color camera. Thus, for example, for each pixel, color information may be provided or generated, such as color values ​​of three colors R, G, B. A greater number of color values ​​is also feasible, such as four colors per pixel. Color cameras are well known to the skilled person. Thus, as an example, each pixel of a camera chip may have three or more different color sensors, such as color recording pixels, such as a red (R) pixel, a green (G) pixel and a blue (B) pixel. The value of each pixel, such as R, G, B, may be recorded by the pixel, such as a numerical value between 0 and 255, depending on the intensity of the respective color. As an example, a four-color group, such as C, M, Y, K, etc., may be used instead of a three-color group, such as R, G, B.

[0034] As used herein, the term "illumination source of a mobile device" refers to any light source of the mobile device. The term "illumination source" refers to at least one device suitable for generating light for illuminating an object. As used herein, the term "light" generally refers 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 light used in the present invention is light in the visible spectral range. The illumination source may include at least one light emitting diode integrated in the mobile device. In particular, the illumination source may be a backlight of the mobile device, in particular a mobile phone. The mobile device may include additional illumination devices, such as at least one illumination source for illuminating a display and / or the display may be designed as an additional illumination source itself.

[0035] The illumination source may have two states, an on state and an off state; in the on state, the illumination source generates a light beam for illuminating the test strip; in the off state, the illumination source is off. As used herein, the term "on" means that the illumination source is activated and / or turned on to illuminate the test strip. The term "off" means that the illumination source is in an off state or is actively turned off. As outlined above, in step d1), at least one image is captured in which the illumination source of the mobile device is turned off. This can allow the capture of an image that includes only the light intensity of the ambient light source and is independent of the illumination provided by the illumination source of the mobile device. In step d2), the illumination source is turned on, enabling the capture of a second image that includes both the illumination intensity from the ambient light and the illumination from the illumination source of the mobile device.

[0036] The illumination source may include at least one light emitting diode (LED) integrated into the mobile device. The illumination source may include at least one white light LED. The white light LED may be controlled using short current pulses such that the white light LED may be adapted to produce a bright flash. The illumination source may be adapted to always illuminate the test strip during image capture. Compared to electronic flash, the flash duration of a white light LED may be up to hundreds of milliseconds, which may allow the illumination source to always illuminate the test strip during image capture in the flash mode of the LED. Alternatively, the LED may be adapted to permanently illuminate the test strip in a non-flash mode.

[0037] In step b), at least one test strip having at least one test zone may be provided. As used herein, the term "test strip" is a broad term and will be given its common and conventional meaning for a person of ordinary skill in the art, and is not limited to a special or customized meaning. The term may specifically refer to, but is not limited to, any element or device configured for performing a color change detection reaction. The test strip may particularly have a test zone comprising at least one test chemistry for performing an optical detection reaction in the presence of an analyte to detect the at least one analyte. As an example, the test element may include at least one substrate, such as at least one carrier, to which the at least one test zone is applied or integrated. As an example, the at least one carrier may be in the form of a strip, so that the test element becomes a test strip. These test strips are generally widely used and widely available. A test strip may have one or more test zones with the same or different test chemicals contained therein. At least one sample may be applied to the test strip. In particular, the test strip may be a top-fed test strip, such as a test strip configured for applying at least one sample on a second side and further configured for performing a color change detection reaction so that a color change can be identified on a first side of the test strip, specifically, the first side of the test strip is arranged opposite to the second side.

[0038] As used herein, the term "test area" is a broad term and will be given its ordinary and customary meaning to those of ordinary skill in the art and is not limited to a special or customized meaning. The term may specifically refer to, but is not limited to, a coherent amount of a test chemistry, such as an area, such as a circular, polygonal, or rectangular area having one or more layers of material, wherein at least one layer of the test area contains the test chemistry. Other layers may be present that provide specific optical properties such as reflective properties, provide scattering properties for scattering a sample, or provide separation properties such as for separating particulate components (such as cellular components) of a sample.

[0039] As used herein, the term "test chemical" is a broad term, and will be given its common and conventional meaning for those of ordinary skill in the art, and is not limited to a special or customized meaning. The term may specifically refer to, but is not limited to, a compound or a plurality of compounds, such as a mixture of compounds suitable for carrying out a detection reaction in the presence of an analyte, wherein the detection reaction may be detected by a specific method such as optics. The detection reaction may specifically be analyte specific. In this example, the test chemical may specifically be an optical test chemical, such as a color-changing test chemical, which changes color in the presence of an analyte. The color change specifically depends on the content of the analyte present in the sample. As an example, the test chemical may include 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, etc. Test chemicals are well known to technicians, and reference may be made to J. Hoenes et al.: Diabetes Technology and Therapeutics, Vol. 10, Supplement 1, 2008, pp. 10-26. However, other test chemicals are also feasible.

[0040] As used herein, the term "analyte" is a broad term and will be given its ordinary and conventional meaning to those of ordinary skill in the art and is not limited to a special or customized meaning. The term may specifically refer to, but is not limited to, one or more specific compounds and / or other parameters to be detected and / or measured. As an example, the at least one analyte may be a compound involved in metabolism, such as one or more of glucose, cholesterol, or triglycerides. Additionally or alternatively, other types of analytes or parameters such as pH may be determined.

[0041] As used herein, the term "image" may specifically relate to, but is not limited to, data recorded using a camera, such as multiple electronic readings from an imaging device (such as pixels of a camera chip). Thus, the image itself may include pixels, the pixels of which are related to the pixels of a camera chip. Thus, when "pixel" is mentioned, it refers to a unit of image information generated by a single pixel of a camera chip, or directly to a single pixel of a camera chip. An image may include raw pixel data. For example, an image may include data in RGGB space, monochrome data from one of the R, G or B pixels, a Bayer pattern image, etc. An image may include evaluated pixel data, such as a full-color image or an RGB image. The raw pixel data may be evaluated, for example, using a demosaicing algorithm and / or a filtering algorithm. These techniques are well known to the skilled person.

[0042] The term "capturing at least one image" refers to one or more of imaging, image recording, image acquisition, image capture. The term "capturing at least one image" may include capturing a single image and / or multiple images such as a series of images. The capture of the at least one image may be initiated by a user operation or may be automatically initiated, for example, upon automatic detection of the presence of at least one object within the field of view of the camera and / or within a predetermined sector of the field of view. These automatic image acquisition techniques are known, for example, in the field of automatic barcode readers, for example in automatic barcode reading applications.

[0043] For example, in step d), multiple images of at least one area of ​​the test strip may be captured. The at least one area of ​​the test strip may include at least a portion of a test zone to which a sample may be applied. In particular, as outlined above, the images captured in step d) may be used, for example, to determine the concentration of an analyte in the sample in step e).

[0044] In addition, the detection method may further include a step f), which compares the corresponding images captured in step d) with the illumination source turned on and turned off, and determines the light intensity difference. In particular, the term "corresponding image" may refer to but is not limited to at least two images of an object such as a test strip, wherein one of the at least two images is captured with the illumination source turned on, and wherein the other of the at least two images is captured with the illumination source turned off, preferably with other conditions remaining unchanged. As an example, at least one image captured in step d1) may be compared with at least one image captured in step d2). Additionally or alternatively, for example, at least one image captured in step d3) may be compared with one of the images captured in step d1) and / or step d2). In particular, step f) may include determining information about the light intensity difference between the corresponding images captured in step d).

[0045] Furthermore, step e) may, for example, comprise using the result of step f) to determine the concentration of the analyte in the sample. Specifically, the light intensity difference determined in step f) may be used for the concentration of the analyte in the sample. Thus, information such as the light intensity difference may be taken into account when determining the concentration of the analyte in the sample.

[0046] Furthermore, step f) may for example comprise:

[0047] f1) deriving, for each image to be compared, at least one item of color information of the portion of the test area to which the sample is applied;

[0048] f2) converting the color information item into at least one light intensity information item by using at least one camera specific conversion function; and

[0049] f3) determining a light intensity difference by using the light intensity information items of corresponding images captured with the illumination source switched on and switched off.

[0050] As used herein, the term "color information item" is a broad term and will be given its ordinary and conventional meaning for a person skilled in the art and is not limited to a special or customized meaning. The term may specifically refer to, but is not limited to, an indication or information about the color of any object, such as in this case the color of at least a portion of a test area to which a sample may be applied. As an example, the color information item may indicate the color of the portion of the test area by using coordinates for describing colors in an arbitrary color coordinate system. Thus, the at least one color information item may specifically imply at least one photometric information item indicating the light intensity of the illumination and weighted with one or more spectral sensitivity functions, such as one or more spectral sensitivity functions determined by the spectral sensitivity of a camera or its components (e.g. a camera chip and / or one or more filters, such as R, G, B filters). A variety of color coordinate systems are well known to the skilled person and may also be used in the context of the present invention. In particular, the color information item may include information about one, more than one or even all color coordinates of a plurality or even all pixels of at least one image, the image showing at least a portion of the test area to which a sample may be applied. As an example, the color information item may be digital information. In particular, the color information item may be or may include at least one numerical value in the range of 0 to 255, for example for one or more color coordinates (eg for one or more of R, G and B).

[0051] As an example, in particular in the case of evaluating only one color coordinate, the color information item may in particular contain information about the intensity. Thus, as an example, in particular in the case of considering and / or evaluating one color coordinate, the color information may be or may include color channels or color coordinate values, wherein, as an example, high values ​​may also correspond to high intensities and low values ​​may correspond to low intensities. In general, changes in color may also be accompanied by changes in intensity. In particular, in this case, the steps f1) and f2) listed above are not necessarily separate method steps. Therefore, steps f1) and f2) may be at least partially combined.

[0052] In a simple case, as an example, the color information item may be or may include a color coordinate value known to occur most significantly or most profoundly during a color change or color forming reaction of a test chemical. As an example, if a particular test chemical is known to change its hue most profoundly in the blue spectral range during a color change reaction for detecting an analyte, a blue color coordinate may be used, and the color information item may be or may include a blue color coordinate value determined for all pixels or at least a group of pixels of at least a portion of a test area within an image to which a sample may be applied.

[0053] As described above, in sub-step f2), the color information item may be converted into at least one light intensity information item by using at least one camera-specific conversion function. As used herein, the term "light intensity information item" is a broad term and will be given its ordinary and conventional meaning for a person of ordinary skill in the art and is not limited to a special or customized meaning. The term may specifically refer to, but is not limited to, an indication of information about the light intensity of an arbitrary object (e.g., in this case, at least a portion of a test area to which a sample may be applied), specifically an indication of information about the illumination intensity or exposure level. As an example, the light intensity information item may indicate the light intensity of the portion of the test area in terms of an exposure value (EV), such as an exposure level. The at least one light intensity information item may specifically imply at least one information item indicating the radiant power per unit area, such as in terms of W / m 2 In particular, the light intensity information item may be derived by using at least one camera-specific conversion function.

[0054] As used herein, the term "camera-specific transfer function" is a broad term and will be given its ordinary and customary meaning to a person of ordinary skill in the art and is not limited to a special or customized meaning. The term may specifically refer to, but is not limited to, a mathematical operation that is used to describe any action or behavior of a camera when converting illumination or light intensity from at least one object (specifically at least a portion of a test area to which a sample may be applied) into color information (such as into at least one color information item). The camera-specific transfer function may specifically depend on the technical features of the camera, such as an imaging chip or one or more sensors, a data processing device (such as a processor), an optical element (such as one or more lenses), or any other technical feature of the camera.

[0055] The camera-specific transfer function may be determined, for example, empirically or semi-empirically, and, as an example, may be predetermined or may be determined by one or more calibration processes, which may also be part of the method. Thus, as an example, the camera-specific transfer function may be determined in whole or in part by using one or more reference areas with known color coordinates or known color characteristics. To determine the camera-specific transfer function, as an example, one or more reference areas may be illuminated under one or more known lighting conditions (e.g., with one or more known intensities), and color information such as at least one color information item may be measured using a camera. Thereby, a relationship between the at least one color information item and the intensity may be determined. For example, the camera-specific transfer function may be determined or stored by using one or more of a curve, a graph, an analytical transfer function, a table, a matrix, or any other way of indicating intensity values ​​for a specific color information item, or vice versa. As an example, the camera-specific transfer function may be stored in a data storage device, such as a volatile or non-volatile data storage device. As an example, the camera-specific transfer function for a specific type of camera may be predetermined. Thus, as an example, a plurality of camera-specific conversion functions, eg for a plurality of specific mobile devices, may be predetermined, and the method may imply selecting an appropriate camera-specific conversion function from the plurality of camera-specific conversion functions depending on the type of mobile device.

[0056] Furthermore, for step e), the light intensity difference can be converted into the difference of the color information items of the corresponding images. In particular, the light intensity difference can be converted into the difference of the color information items of the corresponding images by using the inverse function of the camera-specific conversion function.

[0057] In particular, the camera specific transformation function may be a non-linear function. As an example, the camera specific transformation function may allow a light intensity, for example measured in exposure values ​​(EV), to be converted into color information such as RGB values. Thus, the camera specific transformation function may for example be a non-linear light intensity transfer function. Additionally or alternatively, as an example, the camera specific transformation function may allow a light intensity or exposure level, for example measured in exposure values ​​(EV), to be converted into color information such as JPEG brightness. Thus, the camera specific transformation function may for example be a non-linear exposure level sensitivity function. In particular, the camera specific transformation function may for example be one or more of a non-linear light intensity transfer function and a non-linear exposure level sensitivity function.

[0058] Furthermore, the sub-step or step d3) may comprise at least two further sub-steps. In particular, d3) may comprise:

[0059] d3i) capturing at least one image with the illumination source turned off; and

[0060] d3ii) capturing at least one image with the illumination source turned on.

[0061] In particular, step e) may further comprise using the light intensity difference between the images captured in d31) and d3ii). Thus, step e) of the detection method may further comprise using the light intensity difference between the images captured in d3i) and d3ii) to determine the concentration of the analyte in the sample.

[0062] Furthermore, one or more of steps d1) to d3) may be repeated. In particular, repeating one or more of steps d1), d2) and / or d3) may, for example, allow monitoring of the kinetic measurement curve of the optical detection reaction. Thus, the detection method may further comprise monitoring the kinetic measurement curve of the optical detection reaction.

[0063] In step c) of the detection method, the sample may be applied to the test area from a side opposite to the camera. The test strip, in particular a top-fed test strip, may be positioned relative to the camera such that one side of the test area may face the camera, wherein the other side of the test area may be away from or facing away from the camera. In particular, the sample may be applied to a side of the test area opposite to or away from the camera.

[0064] In particular, the holder may be used to position the test strip relative to the mobile device. In particular, the test strip may be positioned such that the test area is at a distance from a camera, in particular a camera of the mobile device. As an example, the mobile device may be arranged such that the camera may face a first direction, such as an upward direction, in particular facing a first side of the test area, and the sample may be applied to a second side of the test area, the second side being opposite to the first side. Thus, the detection method may include using a holder to position the test strip relative to the mobile device, wherein the test strip is positioned such that the test area is at a distance from the camera, wherein the camera may be on a first side of the test area, and wherein the sample may be applied from a second side opposite to the first side.

[0065] Specifically, the holder may be open toward the second side so that the test area may be exposed on the second side. In particular, the holder may not cover the second side of the test area so that the holder may not interfere or hinder when applying the sample to the second side of the test area. In addition, the holder may include an opening so that the test area may also be exposed on the first side.

[0066] Furthermore, the test area may be, for example, at least partially translucent. In particular, in step e) of the detection method, the contribution of ambient light that passes through the test area and irradiates the camera may be determined. As used herein, the term "translucent" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, the characteristic or property of any object that allows light (particularly incident light) to pass through the object. Wherein a translucent object may generally transmit light, thereby allowing more than 0% of light to pass through, while a translucent object may further not completely transmit the incident light or ambient light, thereby allowing less than 100% of light to pass through. As an example, a translucent test area may allow a limited amount of light to pass through the test area. In particular, the incident light or ambient light, for example, incident light irradiating the test area, may be at least partially transmitted by the test area. In particular, the test area may, for example, transmit up to 60% of the incident light. Preferably, the test area may transmit up to 40% of the incident light. More preferably, the test area may transmit up to 30% of the incident light. Specifically, the test area may, for example, transmit 1% to 60% of the incident light, preferably transmit 1% to 40% of the incident light, more preferably transmit 1% to 30% of the incident light. However, the transmittance may depend on the spectral characteristics of the incident light. In addition, the transmittance may depend specifically on the state or condition of the test area, such as on the dry or wet state of the test area. Therefore, the transmittance may depend in particular on the wetting condition, humidity condition or moisture condition of the test area, in particular on the wetting of the test area by the sample. As an example, in particular, a test area under dry conditions may show a higher transmittance of incident light than the same test area under moist or wet conditions (such as a test area with a sample applied). As an example, the above transmittance values ​​may be given for at least one wavelength in the visible spectrum range.

[0067] The test strip may for example further comprise a reference zone. In particular, at least a portion of the reference zone may for example be constituted by a region of the test strip, in particular by a region of the test strip comprising at least a portion of the test zone. Thus, the reference zone and the test zone may in particular be arranged in close proximity, for example adjacent to each other.

[0068] Furthermore, the reference region may be opaque. Specifically, the term "opaque" may refer to, but is not limited to, a feature or characteristic of any object that does not allow light to pass through the object. In particular, an opaque reference region may be configured such that incident light or ambient light cannot pass through the reference region. As an example, the reference region may allow less than 3%, preferably less than 2%, and more preferably less than 1% of ambient light to pass through the reference region. Specifically, the reference region may be, for example, 100% opaque, so, as an example, the reference region may allow 0% of incident light or ambient light to pass through the reference region.

[0069] Step d) of the detection method may further comprise a sub-step d4) in which at least one image of the reference zone is captured. Furthermore, an image of the reference zone may be taken into account, for example, in step e).

[0070] For example, the reference area may include at least one white area. In particular, the white area, specifically the white area consisting of the reference area, can be used, for example, to calibrate a camera, such as to set the white balance of the camera.

[0071] The detection method may further comprise at least one step of checking camera-specific characteristics. For example, a camera-specific transformation function may be determined in the step of checking camera-specific characteristics. In said step, other camera-specific characteristics, such as color authenticity, may also be checked.

[0072] On the other hand, a computer program is disclosed, which includes program tools for performing the detection method in whole or in part. Therefore, in particular, step d), step e) and optionally step f) of the detection method can be performed by a computer program. In particular, the computer program includes program tools, such as computer executable instructions, which are used to perform the detection method in whole or in part when the computer program is executed on a computer or on a computer network (such as on a processor of a mobile device). In particular, the computer can be fully or partially integrated into the mobile device, and the computer program can be specifically implemented as a software application. In particular, the computer program is stored on a computer-readable data carrier, such as a memory or data storage device of the mobile device. However, alternatively, at least a part of the computer can also be located outside the mobile device.

[0073] The present invention further discloses and proposes a data carrier having a data structure stored thereon, which, after being loaded into a computer or a computer network, such as after being loaded into a working memory or a main memory of the computer or the computer network, can perform the detection method according to one or more embodiments disclosed herein, such as steps d) and e) and optionally f) (including possible sub-steps).

[0074] This document further discloses and proposes a computer program product having program code means stored on a machine-readable carrier, so that when the program is executed on a computer or a computer network, the detection method according to one or more embodiments disclosed herein, such as steps d) and e) and optionally f) (including possible sub-steps) is performed. As used herein, a computer program product refers to a program that is a tradable product. The product can generally exist in any format (such as a paper format) or on a computer-readable data carrier. In particular, the computer program product can be distributed on a data network.

[0075] Finally, this document discloses and proposes a modulated data signal comprising instructions readable by a computer system or a computer network, which are used to perform a detection method according to one or more embodiments disclosed herein, specifically for performing one or more steps of the detection method described above or further described below, such as steps d) and e) and optionally f) (including possible sub-steps).

[0076] Specifically, this article further discloses:

[0077] - a computer or a computer network comprising at least one processor, wherein the processor is adapted to carry out the detection method according to one of the embodiments described in this specification, such as steps d) and e) and optionally f) (including possible sub-steps),

[0078] - a computer-loadable data structure, which is suitable for carrying out the detection method according to one of the embodiments described in this specification, such as steps d) and e) and optionally f) (including possible sub-steps), when the data structure is executed on a computer,

[0079] - a computer program, wherein the computer program is suitable for carrying out the detection method according to one of the embodiments described in this description, such as steps d) and e) and optionally f) (including possible sub-steps), when the program is executed on a computer,

[0080] - a computer program comprising program means for carrying out the detection method according to one of the embodiments described in the present description, such as steps d) and e) and optionally f) (including possible sub-steps), when the computer program is executed on a computer program or a computer network,

[0081] - a computer program comprising a program means according to the preceding embodiments, wherein the program means is stored on a computer-readable storage medium, such as steps d) and e) and optionally f), including possible sub-steps,

[0082] - a storage medium, on which a data structure is stored, and wherein the data structure is suitable for carrying out the detection method according to one of the embodiments described in this description, such as steps d) and e) and optionally f) (including possible sub-steps), after loading into a main memory and / or a working memory of a storage device, and

[0083] - A computer program product with program code means, wherein the program code means can be stored or stored on a storage medium for carrying out the detection method according to one of the embodiments described in the present description, for example steps d) and e) and optionally f) (including possible sub-steps), if the program code means are executed on a computer or a computer network.

[0084] In another aspect of the present invention, a mobile device is disclosed. The mobile device comprises:

[0085] I) at least one camera;

[0086] II) at least one illumination source; and

[0087] III) At least one processor.

[0088] The mobile device is configured to perform a detection method according to the present invention (e.g., according to any of the embodiments described above and / or further described below) in combination with a test strip having at least one test zone, wherein the test zone contains at least one test chemical that undergoes an optical detection reaction in the presence of an analyte.

[0089] For most of the terms used herein and possible definitions thereof, reference is made to the description of the detection methods described above or further below.

[0090] As an example, the processor may comprise program means for fully or partially performing the detection method as disclosed above or as further disclosed below. In particular, the program means are configured for performing steps d) and e) and optionally f) of the detection method.

[0091] In another aspect, a kit for detecting at least one analyte in at least one sample is disclosed. The kit comprises a mobile device according to the present invention and at least one test strip having at least one test zone containing at least one test chemistry for performing an optical detection reaction in the presence of the analyte.

[0092] For most of the terms used herein and possible definitions thereof, reference is made to the description of the detection method and / or the description of the mobile device described above or further below.

[0093] In addition, the test kit may include at least one holder for positioning the test strip relative to the mobile device, wherein the test strip can be positioned by the holder so that the test area is a certain distance away from the camera, wherein the camera can be on a first side of the test area, and wherein the sample can be applied from a second side opposite to the first side.

[0094] In addition, the holder may be open toward the second side so that the test area may be exposed at the second side. Specifically, the holder may be configured to leave the second side of the test area uncovered so that the sample may be applied to the second side of the test area without interfering with the holder.

[0095] In particular, the holder, the test strip and the mobile device may form an inner space. The space may be surrounded, for example, by the mobile device, the holder and the test strip. In particular, the holder, the test strip and the mobile device may be arranged so that they may form the inner space. In addition, the camera and the illumination source may face the inner space. In particular, the holder may position the test strip so that the illumination source can illuminate the test area.

[0096] Compared with known methods and devices for analytical measurement, the methods and devices according to the present invention can provide a large number of advantages. Compared with methods known in the art, the present invention can improve the reliability and user-friendliness of methods for detecting analytes in samples. In particular, compared with known applications or computer programs, the present invention can improve the reliability and user-friendliness of applications (e.g., applications including computer executable instructions for detecting analytes in samples). In particular, the present invention can ensure stable detection of analytes under changing or unstable imaging conditions. In particular, since the influence of ambient light is taken into account when determining the results (particularly when detecting analytes in samples), the present invention can use the camera image of the mobile device to improve the reliability and accuracy of the application or computer program.

[0097] As a summary and without excluding other possible embodiments, the following embodiments may be envisaged:

[0098] Embodiment 1. A detection method for detecting at least one analyte in at least one sample, the method comprising:

[0099] a) providing at least one mobile device having at least one camera and at least one illumination source;

[0100] b) providing at least one test strip having at least one test zone containing at least one test chemistry for performing an optical detection reaction in the presence of an analyte;

[0101] c) applying the at least one sample to a test area;

[0102] d) capturing a plurality of images of at least one area of ​​the test strip, the area including at least a portion of the test zone to which the sample is applied, the capturing comprising:

[0103] d1) before applying the sample to the test area, capturing at least one image with the illumination source turned off;

[0104] d2) capturing at least one image with the illumination source turned on, prior to applying the sample to the test area; and

[0105] d3) capturing at least one image after applying the sample to the test area;

[0106] e) determining the concentration of the analyte in the sample by using the image captured in step d).

[0107] Embodiment 2. The method according to the above embodiment further comprises:

[0108] a) Comparing corresponding images captured in step d) with the illumination source on and off, and determining the light intensity difference.

[0109] Embodiment 3. The method according to the preceding embodiment, wherein step e) comprises using the result of step f) to determine the concentration of the analyte in the sample.

[0110] Embodiment 4. The method according to any one of the preceding two embodiments, wherein step f) comprises:

[0111] f1) deriving, for each image to be compared, at least one item of color information of the portion of the test area to which the sample is applied;

[0112] f2) converting the color information item into at least one light intensity information item by using at least one camera specific conversion function;

[0113] f3) determining a light intensity difference by using the light intensity information items of corresponding images captured with the illumination source switched on and switched off.

[0114] Embodiment 5. The method according to the first two embodiments, wherein for step e), the light intensity differences are converted into differences in color information items of the corresponding images by using an inverse function of a camera-specific conversion function.

[0115] Embodiment 6. The method according to any of the two preceding embodiments, wherein the camera-specific conversion function is a non-linear function that converts the color information item into the light intensity information item.

[0116] Embodiment 7. The method according to any of the preceding three embodiments, wherein the camera-specific transfer function is one or more of a non-linear light intensity transmission function and a non-linear exposure level sensitivity function.

[0117] Embodiment 8. The method according to any one of the preceding embodiments, wherein step d3 comprises:

[0118] d3i) capturing at least one image with the illumination source turned off; and

[0119] d3ii) capturing at least one image with the illumination source turned on.

[0120] Embodiment 9. The method according to the preceding embodiment, wherein step e) further comprises using the light intensity difference between the images captured in d3i) and d3ii).

[0121] Embodiment 10. The method according to any one of the preceding embodiments, wherein one or more of steps d1) to d3) are repeated.

[0122] Embodiment 11. The method according to the preceding embodiment, wherein the kinetic measurement curve of the optical detection reaction is monitored.

[0123] Embodiment 12. The method of any one of the preceding embodiments, wherein in step c), the sample is applied to the test area from a side opposite to the camera.

[0124] Embodiment 13. A method according to the above embodiment, wherein a holder is used to position the test strip relative to the mobile device, wherein the test strip is positioned so that the test area is a certain distance away from the camera, wherein the camera is on a first side of the test area, and the sample is applied from a second side opposite to the first side.

[0125] Embodiment 14. The method of the preceding embodiment, wherein the holder is open toward the second side such that the testing area is exposed at the second side.

[0126] Embodiment 15. The method of any of the two preceding embodiments, wherein the holder comprises an opening such that the testing area is exposed at the first side.

[0127] Embodiment 16. The method according to any one of the preceding embodiments, wherein the test area is at least partially translucent, wherein in step e), the contribution of ambient light that passes through the test area and impinges on the camera is determined.

[0128] Embodiment 17. The method of any preceding embodiment, wherein the test strip further comprises a reference zone, wherein the region of the test strip further comprises at least a portion of the reference zone.

[0129] Embodiment 18. The method according to the preceding embodiment, wherein the reference area is opaque.

[0130] Embodiment 19. The method according to any one of the preceding two embodiments, wherein method step d) further comprises:

[0131] d4) Capturing at least one image of the reference area.

[0132] Embodiment 20. The method according to the preceding embodiment, wherein for step e) an image of a reference area is taken into account.

[0133] Embodiment 21. The method according to any of the three preceding embodiments, wherein the reference zone comprises at least one white zone.

[0134] Embodiment 22. A method according to any of the preceding embodiments, wherein the method further comprises at least one step of checking camera-specific characteristics.

[0135] Embodiment 23. A computer program comprising program tools for fully or partially performing the method according to any of the preceding embodiments, in particular for performing steps d), e) and optionally f) of the method, when the computer program is executed on a computer or a computer network (in particular, on a processor of a mobile device).

[0136] Embodiment 24. A mobile device, comprising:

[0137] I) at least one camera;

[0138] II) at least one illumination source; and

[0139] III) at least one processor,

[0140] The mobile device is configured to be used in combination with a test strip to perform a detection method for detecting at least one analyte in at least one sample according to any of the aforementioned embodiments, the test strip having at least one test area containing at least one test chemical that undergoes an optical detection reaction in the presence of the analyte.

[0141] Embodiment 25. A mobile device according to the preceding embodiments, wherein the processor comprises program means for fully or partially performing the method according to any of the preceding embodiments of the mentioned method, in particular for performing steps d), e) and optionally f) of the method.

[0142] Embodiment 26. A kit for detecting at least one analyte in at least one sample, the kit comprising a mobile device according to any of the preceding embodiments referring to a mobile device, the kit further comprising at least one test strip having at least one test area containing at least one test chemical for performing an optical detection reaction in the presence of the analyte.

[0143] Embodiment 27. According to the test kit described in the above embodiment, the test kit further includes at least one holder for positioning the test strip relative to the mobile device, wherein the test strip is positioned by the holder so that the test area is a certain distance away from the camera, wherein the camera is on a first side of the test area, and the sample is applied from a second side opposite to the first side.

[0144] Embodiment 28. The kit of the preceding embodiment, wherein the holder is open toward the second side such that the testing area is exposed at the second side.

[0145] Embodiment 29. The kit according to any one of the two preceding embodiments, wherein the holder, the test strip and the mobile device form an inner space surrounded by the mobile device, the holder and the test strip.

[0146] Embodiment 30. The kit of any preceding embodiment, wherein the camera and the illumination source face the interior space.

[0147] The kit according to any of the preceding embodiments referring to a kit, wherein the holder positions the test strip such that the illumination source can illuminate the test area. BRIEF DESCRIPTION OF THE DRAWINGS

[0148] Preferably in conjunction with the subordinate embodiments, other optional features and embodiments will be disclosed in more detail in the subsequent description of the embodiments. Wherein, as will be appreciated by those skilled in the art, each optional feature can be implemented in an isolated manner and in any arbitrarily feasible combination. The scope of the present invention is not limited by the preferred embodiments. The embodiments are schematically depicted in the drawings. Wherein, the same reference numerals in these figures refer to the same or functionally comparable elements.

[0149] In the figure:

[0150] FIG1 shows a side view of an embodiment of a kit for performing the detection method according to the present invention, the kit comprising a mobile device;

[0151] FIG2 shows an enlarged cross-sectional view of an embodiment of the kit shown in FIG1 ;

[0152] FIG3 illustrates one embodiment of an image captured by a camera of a mobile device;

[0153] 4A and 4B illustrate embodiments of graphs of the effect of ambient light on the color of a test zone and a reference zone;

[0154] 5A and 5B illustrate embodiments of graphs of camera-specific transfer functions; and

[0155] 6 and 7 show a flow chart embodiment of an embodiment of a detection method. DETAILED DESCRIPTION

[0156] FIG. 1 shows a side view of one embodiment of a kit 110 for detecting at least one analyte in at least one sample 114, the kit comprising a mobile device 112 and a test strip 116. The mobile device 112 as shown in FIG. 1 comprises at least one camera 118, at least one illumination source 120, and at least one processor 122. The test strip 116 comprises at least one test zone 124, the test zone comprising at least one test chemistry 126, the test chemistry being used to perform an optical detection reaction in the presence of the analyte. In addition, three examples of light can be shown in FIG. 1 by three dashed arrows. The first dashed arrow can indicate ambient light or incident light from any ambient light source 128, such as the sun, a lamp, or any other light source, shining onto the test zone 124. The second dashed arrow can indicate light emitted by the illumination source 120 when the illumination source 120 is turned on. Thus, the second dashed arrow can indicate light that is present only when the illumination source 120 is turned on. If the illumination source 120 is turned off, there is no light emitted by the illumination source 120 of the mobile device 112. The third dashed arrow may indicate light irradiated onto the camera 118. Specifically, if the illumination source 120 is off, the light irradiated onto the camera 118, such as the light indicated by the third dashed arrow, may include ambient light or incident light transmitted through the test strip 116 (e.g., through the test area 124) onto the camera 118. Alternatively, if the illumination source 120 is on, the light irradiated onto the camera 118, such as the light indicated by the third dashed arrow, may include light transmitted through the test strip 116 and light emitted by the illumination source 120. In particular, if the illumination source 120 is on, the light irradiated onto the camera 118 may be, for example, reflected by the test strip 116, such as reflected by the test area 124 and / or the holder 130, wherein the holder 130 may be included in the reagent cartridge 110.

[0157] FIG. 2 shows an enlarged cross-sectional view of an embodiment of the test kit 110 as shown in FIG. 1 . In particular, a test strip 116 having a test zone 124 is shown, the test zone 124 comprising at least one test chemical 126. As an example, the test strip 116 may include a substrate or carrier 132, wherein as an example, the test zone 124 may be applied to the carrier 132. As shown in FIG. 2 , the test zone 124 may, for example, include multiple layers, such as a wetting layer 134 for evenly spreading the sample 114, a filter layer 136 for filtering or separating the sample 114 components for subsequent color change detection reaction, which may be performed by the test chemical 126. Other structures or layer stackings may also be feasible. As an example, the test chemical 126 may be arranged so that a color change can be identified at a first side 138 of the test zone 124. In particular, the first side 138 can be arranged opposite the second side 140 of the test area 124, wherein the sample 114 can be applied to the second side 140 of the test area 124. Specifically, the camera 118 can be arranged so that it faces the first side 138 of the test area 124.

[0158] 3 shows one embodiment of an image 142 captured by a camera 118 of a mobile device 112. As an example, the image 142 may be at least one region 144 of the test strip 116, the region including at least a portion of the test zone 124, wherein the test zone 124 may be, for example, semi-transparent. As an example, the region 144 may further include, in whole or in part, a reference zone 146, wherein the reference zone 146 may, as an example, be opaque and may include at least one white region.

[0159] 4A and 4B illustrate embodiments of graphs of the effect of ambient light on the color of the test area 124 and the reference area 146. In the graphs, the x-axis may indicate time t, for example in seconds, and the y-axis may indicate color or reflectance R. The graph in FIG4A illustrates the effect of ambient light on the determined color or reflectance of the test area 124 and the determined color of the reference area 146. In particular, the determined color or reflectance R of the test area 124 is shown in solid lines, and the determined color or reflectance R of the reference area 146 is shown in dashed lines for three different lighting conditions over time. As an example, in a first lighting condition, the ambient light source 128 may be turned off, and the illumination source 120 of the mobile device 112 may be turned on. Specifically, in the figure, the first lighting condition can be used in the time range t1, t3, t5 and t7, where t1 = 0 ≤ t <2 s, t3 = 11 ≤ t < 18 s, t5 = 32 ≤ t < 34 and t7 = 39 ≤ t < 41 s. In the second and third lighting conditions, the lighting source 120 and the ambient light source 128 of the mobile device 112 can both be turned on. However, in the third lighting condition, the ambient light can have a higher brightness than in the second lighting condition. Specifically, in the figure, the second lighting condition can be used in the time range t2, where t2 = 2 ≤ t < 11 s, and the third lighting condition can be used in the time range t4 and t6, where t4 = 18 ≤ t < 32 and t6 = 34 ≤ t < 39 s. In the figure, as shown in FIG4A , the test area 124 exhibits different colors (e.g., different color coordinate values), different color specific intensities, or different intensities or reflectances within a specific spectral color range under each of the three lighting conditions. In particular, the brightness of the first color 148 of the test area 124 determined under the first lighting condition may be lower than the second color 150 of the test area 124 determined under the second lighting condition and the third color 152 of the test area 124 determined under the third lighting condition. In addition, the third color 152 of the determined test area 124 may be brighter than the determined second color 150. Therefore, the lighting conditions may directly affect the determined color of the test area 124. However, as can be seen from the graph shown in FIG4A , the determined color 154 of the reference area 126 may be independent of the lighting conditions.

[0160] It should be noted that given time specifications, such as specific times of time ranges described in the figure descriptions, are given for exemplary purposes and, thus, serve to illustrate possible embodiments and should not be construed as limiting the scope of the present invention.

[0161] The graph in FIG4B shows the effect of the combination of ambient light and illumination source 120 being on or off and sample 114 being applied or not applied to test zone 124 on the determined color of test zone 124 and the determined color of reference zone 146. In particular, the determined color or reflectance R of test zone 124 is shown in solid lines, and the determined color or reflectance R of reference zone 146 is shown in dashed lines for different illumination conditions and sample 114 being applied or not applied to test zone 124. Specifically, in the figure, during time 0 ≤ t < 32 s, sample 114 is not applied to test zone 124. Subsequently, during time 32 ≤ t < 38 s, sample 114 is applied to test zone 124, and a color change detection reaction may be performed by test chemistry 126. During a subsequent time 38 ≤ t < 86 s, a sample is applied to test zone 124, and the color change detection reaction may have terminated. As an example, the example application may be completed within a time frame of one second or less. The sample may penetrate into the test chemical 126, and a color change detection reaction with its characteristic reaction kinetics may occur. In FIG. 4B, three different lighting conditions may also be used, wherein the lighting conditions used in FIG. 4B are different from the lighting conditions used in FIG. 4A.

[0162] In particular, in the first lighting condition used in FIG. 4B , the lighting source 120 of the mobile device 112 is turned on and the ambient light source 128 is also turned on, wherein in this figure, the ambient light source 128 may only be able to adapt to the two stages of "on" and "off". The first lighting condition used in FIG. 4B can be used in the time range t1', t4' and t7', wherein t1' = 0 ≤ t < 5 s, t4' = 16 ≤ t < 58 s and t7' = 75 ≤ t < 82 s. In the second lighting condition, the lighting source 120 is turned off and the ambient light source 128 is turned on. The second lighting condition can be specifically used in the time range t2', t5' and t8', wherein t2' = 5 ≤ t < 13 s, t5' = 58 ≤ t < 68 s and t7' = 75 ≤ t < 82 s. In the third lighting condition, the lighting source 120 is turned on and the ambient light source 128 is turned off. The third lighting condition may specifically be used in the time range t3' and t6', where t3'=13 ≤ t < 16 s and t6'=68 ≤ t < 75 s.

[0163] As can be seen from FIG. 4B , the first color 156 (e.g., first color coordinate value), the intensity of the first color specific, or the intensity within the first specific spectral color range of the determined reference area 146 may be substantially the same under the first lighting condition and the third lighting condition. Thus, for example, only the illumination source 120 (e.g., turned on or off) may affect the determined color of the reference area 146. Specifically, as shown in FIG. 4B , for example, the second color 158 of the reference area 146 determined within the time range during which the illumination source 120 is turned off may, for example, show a color or reflectance of R=0. However, as shown in the figure, the determined color of the test area 124 may show a significant dependence on the lighting conditions and the application of the sample 114. Specifically, the determined colors of the test area 124 under each lighting condition may be different from each other. In addition, even under the same lighting conditions, the determined color of the test area 124 may be different depending on whether the sample 114 is applied to the test area 124. In particular, before the sample 114 is applied to the test area 124, the first color 160 of the test area 124 determined under the first lighting condition may be brighter than the result after the sample 114 is applied. As an example, since the application of the sample 114 to the test area 124 may reduce the translucency of the test area 124, a smaller amount of light may be transmitted through the test area 124 to the camera 118, which may cause the color transition 159. Specifically, after the sample 114 is applied to the test area 124, under the same first lighting condition, the color transition 159 may cause the brightness of the first color 160 of the test area 124 to be lower than before the sample is applied. In addition, as shown in FIG. 4B, the second color 162 of the test area 124 determined and the third color 164 determined are different from each other and different from the first color 160; in addition, the second color 162 and the third color 164 also change in brightness due to the application of the sample 114 to the test area 124.

[0164] 5A and 5B illustrate embodiments of graphs of camera-specific conversion functions 165. Specifically, in the graphs, the exposure level or light intensity I, specifically the intensity of the incident light, may be shown on the x-axis, and the corresponding color or reflectance R, specifically the value of a color channel that determines the color (e.g., one or more of R, G, and B), may be shown on the y-axis. As an example, FIG. 5A and FIG. 5B may illustrate the same camera-specific conversion function 165. However, in FIG. Figure 5A5B , the x-axis may show the light intensity I in arbitrary units on a linear scale of light intensity values, wherein in FIG. 5B , the light intensity I may be shown using a logarithmic scale. In particular, as an example, the camera-specific conversion function 165 shown in the figure may be mathematically described as

[0165] .

[0166] As an example, the inverse function of the nonlinear function (2) can be mathematically described as

[0167] .

[0168] 6 and 7 show a flow chart of a detection method for detecting at least one analyte in at least one sample 114. The detection method comprises step a) (indicated by reference number 166): providing at least one mobile device 112 having at least one camera 118 and at least one illumination source 120. As an example, a mobile device 112 as shown in FIG. 1 may be provided. In addition, the detection method comprises step b) (indicated by reference number 168): providing at least one test strip 116 having at least one test zone 124, the test zone 124 containing at least one test chemistry 126 for performing an optical detection reaction in the presence of an analyte. In particular, as an example, a test strip 116 as shown in FIG. 1 may be provided. In addition, the detection method comprises step c) (indicated by reference number 170): applying at least one sample 114 to the test zone 124. As an example, step c) may be performed by dropping the sample 114 onto the test zone 124, as shown in FIGS. 1 and 2 .

[0169] Furthermore, the detection method comprises a step d) (indicated by reference numeral 172): capturing a plurality of images 142 of at least one region 144 of the test strip 116, the region 144 comprising at least a portion of the test zone 124 to which the sample 114 is applied. The method step d) further comprises the following sub-steps:

[0170] d1) (indicated by reference numeral 174): before applying the sample 114 to the test area 124, capturing at least one image 142 with the illumination source 120 turned off;

[0171] d2) (indicated by reference numeral 176): before applying the sample 114 to the test area 124, capturing at least one image 142 with the illumination source 120 turned on; and

[0172] d3) (denoted by reference numeral 178 ): capturing at least one image 142 after applying the sample 114 to the test area 124 .

[0173] In particular, sub-step d1) may be performed, for example, in the time range t2' in the graph shown in FIG. 4B . In addition, as an example, sub-step d2) may be performed in one or both of the time ranges t1' and t3'. It is also possible to perform sub-step d2) at the beginning of the time range t4' (for example, during 16 ≤ t < 32 s), for example, before performing step e) of applying the sample 114 to the test area 124 (for example, during 32 ≤ t < 38 s). In addition, sub-step d3) may be performed specifically after applying the sample 114 to the test area 124, for example, at the end of the time range t4' (for example, during 38 ≤ t < 58 s) and / or in the time ranges t5', t6', t7' and t8'.

[0174] The detection method further includes step e) (indicated by reference number 180): determining the concentration of the analyte in the sample 114 by using the image 142 captured in step d). As shown in FIG7 , the detection method may further include step f) (indicated by reference number 182): comparing the corresponding images captured in step d) with the illumination source 120 turned on and off, and determining the difference in light intensity. The result of step f) may be used, for example, to determine the concentration of the analyte in the sample 114, so as an example, step e) may include step f), as shown in FIG7 .

[0175] As further shown in FIG. 7 , step f) may, for example, include the following sub-steps:

[0176] f1) (denoted by reference numeral 184) deriving, for each image to be compared, at least one item of color information of the portion of the test area to which the sample is applied;

[0177] f2) (denoted by reference numeral 186) converting the color information item into at least one light intensity information item by using at least one camera specific conversion function 165;

[0178] f3) (denoted by reference numeral 188) determining a light intensity difference by using light intensity information items of corresponding images captured with the illumination source turned on and turned off.

[0179] As an example, a camera-specific conversion function 165 that can be used in sub-step f2) can be shown, for example, in FIG. 5A and FIG. 5B . Therefore, exemplary calculations that can be performed in the detection method are shown below. The image 142 captured in step d1) can, for example, show R d1 = 230 color or reflectivity, and the image 142 captured in step d2) may, for example, show R d2 = 80 for color or reflectance. As an example, R d1 and R d2 may be included in the color information item derived in step f1). As an example, in step f2), the inverse function of the camera-specific transformation function (2) may be used to transform R d1 and R d2 Converted to light intensity I d1 = 80 and I d2 = 15. Subsequently, the light intensity difference can be determined in step f3), such as I d12 = 80 – 15 = 65. In particular, for step e), as an example, the light intensity differences can be converted into differences in color information items of the corresponding images by using the inverse function (2) of the camera-specific conversion function (1). Therefore, as an example, R can be calculated d12 (I d12 = 65) = 211. In particular, the difference in color information items (e.g., R d12 ) may, for example, contain information about the true color of the test zone, such as the color of the reference zone in the absence of external or ambient light interference before the sample 114 may be applied to the test zone 124.

[0180] After applying the sample 114 to the test area, for example after performing step c), step d3) may be performed. In particular, step d3) may include, for example, sub-step d3i) (denoted by reference numeral 190): capturing at least one image 142 when the illumination source 120 is turned off; sub-step d3ii) (denoted by reference numeral 192): capturing at least one image 142 when the illumination source 120 is turned on. As an example, the image 142 captured in step d3) may show R d3i = 190 and R d3ii = 15 for color or reflectance. As an example, R d3i and R d3iimay be included in the color information item derived in step f1). Likewise, as an example, using the inverse function (2) of the camera-specific conversion function (1), the corresponding light intensity I may be determined, for example, in step f2). d3i = 51 and I d3ii = 7 resulting in a light intensity difference of I d3 = 44. Then, as an example, R d3 (I d3 = 44) = 176. After the color change detection reaction by the test chemical 126, R d3 For example, it may contain information about the true color of the test area 124. Thus, for example, it may be possible to d12 and R d3 The color change is determined by the difference between the incident light and the ambient light, specifically the color difference caused by the concentration of the analyte in the sample 114 and is independent of the incident light or the ambient light.

[0181] Reference Number List

[0182] 110 Kits

[0183] 112 samples

[0184] 114 Mobile devices

[0185] 116 Test Strips

[0186] 118 Camera

[0187] 120 Lighting Source

[0188] 122 processors

[0189] 124 Test Area

[0190] 126 Test Chemicals

[0191] 128 Ambient Light Source

[0192] 130 Holder

[0193] 132 Carrier

[0194] 134 Wetting layer

[0195] 136 filter layer

[0196] 138 First side

[0197] 140 Second side

[0198] 142 images

[0199] 144 Area

[0200] 146 Reference Area

[0201] 148 First color of the test area

[0202] 150 Second color of the test area

[0203] 152 The third color of the test area

[0204] 154 Reference area color

[0205] 156 First color of reference area

[0206] 158 Second color of reference area

[0207] 159 Color Transition

[0208] 160 The first color of the test area

[0209] 162 Second color of the test area

[0210] 164 The third color of the test area

[0211] 165 Camera-specific conversion functions

[0212] 166 Step a)

[0213] 168 Step b)

[0214] 170 Step c)

[0215] 172 Step d)

[0216] 174 Step d1)

[0217] 176 Step d2)

[0218] 178 Step d3)

[0219] 180 Step e)

[0220] 182 Step f)

[0221] 184 Step f1)

[0222] 186 Step f2)

[0223] 188 Step f3)

[0224] 190 Step d3i)

[0225] 192 Step d3ii).

Claims

1. A method for detecting at least one analyte in at least one sample (114), the method comprising: a) providing at least one mobile device (112) having at least one camera (118) and at least one illumination source (120); b) providing at least one test strip (116) having at least one test zone (124), the test zone comprising at least one test chemistry (126) for performing an optical detection reaction in the presence of the analyte; c) applying the at least one sample (114) to the test area (124); d) capturing a plurality of images (142) of at least one region (144) of the test strip (116), the region (144) comprising at least a portion of the test zone (124) to which the sample (114) is applied, the capturing comprising d1) before applying the sample (114) to the test area (124), capturing at least one image (142) with the illumination source (120) turned off; d2) capturing at least one image (142) with the illumination source (120) turned on, before applying the sample (114) to the test area (124); and d3) capturing at least one image (142) after applying the sample (114) to the test area (124); in Step d3) comprises d3i) capturing at least one image (142) with the illumination source (120) turned off; and d3ii) capturing at least one image (142) with the illumination source (120) turned on, e) determining the concentration of an analyte in said sample (114) by using said image (142) captured in step d); Characterized in that the method further comprises: f) comparing the corresponding images captured in step d) with the illumination source (120) turned on and turned off and determining a difference in light intensity, wherein step f) comprises f1) for each image (142) to be compared, deriving at least one item of color information of the portion of the test zone (124) to which the sample (114) is applied; f2) converting the color information item into at least one light intensity information item by using at least one camera specific conversion function (165); f3) determining said light intensity difference by using said light intensity information items of corresponding images with said illumination source (120) turned on and turned off; Wherein step e) comprises using the result of step f) to determine said concentration of analyte in said sample (114).

2. The method according to claim 1, wherein for step e), the light intensity differences are converted into differences in color information items of the corresponding images by using an inverse function of the camera-specific conversion function (165), wherein the camera-specific conversion function (165) is a nonlinear function that converts the color information items into the light intensity information items.

3. The method according to claim 1 or 2, wherein step e) further comprises using the light intensity difference between the images (142) captured in d3i) and d3ii).

4. The method according to claim 1 or 2, wherein in step c), the sample (114) is applied to the test area (124) from a side opposite to the camera (118).

5. The method of claim 4, wherein the test strip (116) is positioned relative to the mobile device (112) using a holder (130), wherein the test strip (116) is positioned so that the test area (124) is a certain distance from the camera (118), wherein the camera (118) is on a first side (138) of the test area (124), and wherein the sample (114) is applied from a second side (140) opposite the first side (138).

6. The method of claim 5, wherein the holder (130) is open toward the second side (140) such that the test area (124) is exposed on the second side (140), wherein the holder (130) includes an opening such that the test area (124) is exposed on the first side (138).

7. The method according to claim 1 or 2, wherein the test area (124) is at least partially translucent, wherein: In step e), the contribution of ambient light that passes through the test area (124) and impinges on the camera (118) is determined.

8. The method of claim 1 or 2, wherein the test strip (116) further comprises a reference zone (146), wherein the region (144) of the test strip (116) further comprises at least a portion of the reference zone (146), wherein the reference zone (146) is opaque, wherein method step d) further comprises: Step d4) captures at least one image (142) of the reference zone (146), and wherein the image (142) of the reference zone (146) is taken into account in step e).

9. A computer program product comprising a computer program for performing at least step d), step e) and step f) of the method according to any one of claims 1 to 8 when the computer program is executed on a computer or a computer network.

10. A mobile device (112), comprising: I) at least one camera (118); II) at least one illumination source (120); and III) at least one processor (122), The mobile device (112) is configured to perform at least step d), step e) and step f) of the method according to any one of claims 1 to 8, wherein the test strip (116) has at least one test area (124), and the test area (124) includes at least one test chemical (126) that undergoes an optical detection reaction in the presence of the analyte.

11. A kit (110) for detecting at least one analyte in at least one sample (114), the kit (110) comprising a mobile device (112) according to claim 10, the kit (110) further comprising at least one test strip (116), the test strip having at least one test area (124), the test area (124) comprising at least one test chemical (126) for performing an optical detection reaction in the presence of the analyte.

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