METHOD OF DETERMINING THE CONCENTRATION OF AT LEAST ONE ANALYTE IN A BODY FLUID

Abstract

A method of determining concentration of an analyte in a body fluid uses a mobile device having a camera and an ambient light detector. The ambient light detector has an ambient light sensor and/or an additional camera. An ambient light check is performed. In the ambient light check, ambient light is used to determine an item of ambient light information. If a validity criterion is determined to be met, the concentration of the analyte is determined by evaluating an image of at least a part of a reagent test region of an optical test strip having a sample of body fluid applied thereto. The image is captured by the camera. A mobile device, a kit, a computer program and a computer-readable storage medium are also disclosed.

Claims

1. A method of determining concentration of an analyte in a body fluid using a mobile device having a camera and an ambient light detector, the ambient light detector having an ambient light sensor and/or an additional camera, the method comprising: i. performing an ambient light check, comprising: i.1 using the ambient light detector for determining an item of ambient light information, and i.2 determining if a validity criterion on the item of ambient light information is fulfilled; and ii. when the validity criterion is fulfilled, determining the concentration of the analyte by evaluating an image of at least a part of a reagent test region of an optical test strip having a sample of the body fluid applied thereto, the image being captured by the camera.

2. The method according to claim 1, wherein step i.2 comprises comparing the item of ambient light information with a threshold value.

3. The method according to claim 2, wherein the validity criterion is fulfilled when the item of ambient light information has a value below the threshold value or not exceeding the threshold value.

4. The method according to claim 1, further comprising: iii. when the validity criterion is not fulfilled, automatically at least partially preventing the determining of the concentration of the analyte in the body fluid.

5. The method according to claim 4, wherein step iii. comprises preventing at least one of: capturing the image of the reagent test region; requesting a user to position the optical test strip within a field of view of the camera; requesting a user to apply the sample of the body fluid to the reagent test region of the optical test strip; pricking of a user's finger to apply the sample of the body fluid to the reagent test region of the optical test strip; and evaluating a color formation reaction of the reagent test region.

6. The method according to claim 1, wherein step ii. comprises: ii.1 capturing the image of the at least one part of the at least one reagent test region having the sample of the body fluid applied thereto; ii.2 determining an item of optical information indicative of a color formation reaction of the reagent test region; and ii.3 deriving the concentration of the analyte using the item of optical information.

7. The method according to claim 6, wherein step ii. further comprises at least one of: ii.4 prompting a user to apply the sample of the body fluid to the reagent test region; ii.5 prompting a user, before performing step ii.1, to position the optical test strip within a field of view of the camera; ii.6 prompting a user, before performing step ii.1, to position at least one color reference card within a field of view of the camera, the color reference card comprising a plurality of color reference fields having known reference color values.

8. The method according to claim 1, wherein the camera and the ambient light detector are located on opposing sides of the mobile device.

9. The method according to claim 1, wherein the mobile device comprises a display having the light sensor.

10. The method according to claim 1, wherein the additional camera comprises at least one front camera located on a front side of the mobile device, the front side of the mobile device comprising at least one operation element.

11. The method according to claim 1, further comprising running a software application on the mobile device, wherein the software application guides a user through a measurement sequence having at least step ii., and wherein step i. is performed fully or partially before and/or during the measurement sequence.

12. A mobile device having a camera and an ambient light detector comprising at least one of an ambient light sensor and an additional camera, wherein the mobile device is configured for performing the method according to claim 1.

13. A kit, comprising the mobile device according to claim 12 and an optical test strip having at least one reagent test region.

14. A non-transitory computer readable medium having stored thereon computer-executable instructions for performing the method according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0132] The above-mentioned aspects of exemplary embodiments will become more apparent and will be better understood by reference to the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0133] FIG. 1 shows an embodiment of a kit and a mobile device configured for performing a method of determining the concentration of at least one analyte in a body fluid in a perspective view;

[0134] FIG. 2 shows a flow chart of an embodiment of a method of determining the concentration of at least one analyte in a body fluid by using a mobile device; and

[0135] FIG. 3 shows a flow chart of an embodiment of an ambient light check.

DESCRIPTION

[0136] The embodiments described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of this disclosure.

[0137] In FIG. 1, an exemplary embodiment of a kit 110 is shown in a perspective view. The kit 110 comprises a mobile device 112 having at least one camera 114. The kit 110 further comprises at least one optical test strip 116 having at least one reagent test region 118. The kit 110 may comprise at least one color reference card 120.

[0138] The mobile device 112 further comprises at least one ambient light detector 122. The ambient light detector 122 comprises at least one of an ambient light sensor 124 and an additional camera 126. The mobile device 112 is configured for performing a method of determining the concentration of at least one analyte in a body fluid. The method will be described with reference to exemplary embodiments shown in a flowchart illustrated in FIG. 2. Thus, reference may be made to the description of FIG. 2. As can be seen in FIG. 1, the camera 114 and the ambient light detector 122 may be located on opposing sides of the mobile device 112. For example, the camera 114 may be located on a back side 128 of the mobile device 112. The back side may 128 refer to the side of the mobile device 112 facing one or more of the optical test strip 116, the reagent test region 118 and the color reference card 120. The ambient light detector 122 may be located on a front side 130 of the mobile device 112. The front side 130 of the mobile device 112 may face a user of the mobile device 112.

[0139] Further, the mobile device 112 may comprise at least one display 132. The ambient light sensor 124 may be comprised by the display 132 of the mobile device 112. The ambient light sensor 124 may comprise at least one photosensitive element, specifically at least one of a photodiode; a phototransistor; a photoconductor; a semiconductor element. The display 132 and, thus, the ambient light sensor 124, may be located on the front side 130 of the mobile device 112.

[0140] The additional camera 126 may comprise at least one front camera 134. The front camera 134 may be located on the front side 130 of the mobile device 112. The front side 130 of the mobile device 112 may comprise at least one operation element 136 of the mobile device 112. Specifically, the operation element 136 may be at least one touchscreen 138. The operation element 136, specifically the touchscreen 138, may form part of the display 132 of the mobile device 112.

[0141] The mobile device 112 may further comprise at least one processor 140. The processor 140 may be configured, such as by software programming, for performing and/or supporting one or more or even all of the method steps of the method of determining the concentration of at least one analyte in a body fluid. Specifically, the processor 140 may be configured for supporting capturing of at least one image of at least one part of the at least one reagent test region 118 of the optical test 116 strip by using the camera 114. The processor 140 may further be configured for determining at least one analyte concentration value from color formation of the reagent test region 118. The processor 140 may further be configured for performing an ambient light check 178 and for preventing the determining of the concentration of the analyte if a validity criterion may not be fulfilled. The processor 140 may be configured for supporting sample application to the optical test strip 116, such as by providing user guidance, e.g., in a visual format and stuff or in an audible format. For example, the user guidance may be provided via the display 132 of the mobile device 112 in a visual format.

[0142] The color reference card 120 may comprise a plurality of color reference fields 142 having known reference color values. The color reference card 120 may further comprise a plurality of gray reference fields 144 having known gray levels. The plurality of color reference fields 142 and the plurality of gray reference fields 144 may be disposed on a surface of the color reference card 120, specifically such that the plurality of color reference fields 142 and the plurality of gray reference fields 144 may be visible when capturing the image of the optical test strip 116.

[0143] The color reference card 120 may fully or partially be integrated into the optical test strip 116. Alternatively or additionally, the color reference card 120 may comprise at least one window element 146, wherein the window element 146 may be configured for receiving the optical test strip 116. The optical test strip 116 may be visible to the camera 114 of the mobile device 112 when the optical test strip 116 is received by the window element 146 of the color reference card 120.

[0144] The color reference card 120 may further comprise at least one position marker 148. The mobile device 112, specifically the processor 140 of the mobile device 112, may be configured for identifying a position and/or an orientation of the color reference card 120 by recognizing the position marker 148 in the at least one image captured by the camera 114.

[0145] FIG. 2 shows a flow chart of an exemplary embodiment of a method of determining the concentration of at least one analyte in a body fluid by using the mobile device 112, the mobile device 112 having the at least one camera 114 and the at least one ambient light detector 122, the ambient light detector 122 comprising at least one of an ambient light sensor 124 and an additional camera 126.

[0146] The method comprises the following steps, which may specifically be performed in the given order. Still, a different order may also be possible. It may be possible to perform two or more of the method steps fully or partially simultaneously. It may further be possible to perform one, more than one or even all of the method steps once or repeatedly. The method may comprise additional method steps that are not listed.

[0147] The method comprises: [0148] i. (denoted by reference number 150) performing the at least one ambient light check 178, the ambient light check 178 comprising: [0149] i.1 (denoted by reference number 152) using the ambient light detector 122 for determining at least one item of ambient light information; and [0150] i.2 (denoted by reference number 154) determining if at least one validity criterion on the item of ambient light information is fulfilled; [0151] ii. (denoted by reference number 156) if the validity criterion is fulfilled, determining the concentration of the analyte in the body fluid by evaluating at least one image of at least a part of the at least one reagent test region 118 of the optical test strip 116 having a sample of the body fluid applied thereto, the image being captured by the camera 114 of the mobile device 112.

[0152] The item of ambient light information determined in step i.2 may specifically comprise one or more of: an irradiance measurement value; a relative irradiance measurement value; a brightness measurement value; a relative brightness measurement value; an exposure measurement value; a relative exposure measurement value.

[0153] Specifically, step i.2 may comprise comparing the at least one item of ambient light information with at least one threshold value. Based on the comparison of the item of ambient light information with the at least one threshold value, the at least one validity criterion may be determined. The validity criterion may be fulfilled if one of the following conditions is fulfilled: the at least one item of ambient light information has a value below the threshold value; at least one item of ambient light information has a value not exceeding the threshold value.

[0154] As illustrated in FIG. 2, step i.2 (denoted by reference number 154) may be a branching point of the method. The branching point may indicate a condition query, such as deciding between a first branch 158 and a second branch 160. The condition query in step i.2 may use the validity criterion. The validity criterion may comprise a numerical value indicating the validity of the item of ambient light information. For example, the validity criterion may comprise a Boolean value such as “fulfilled” (“y”) and “not fulfilled” (“n”) or the like. As an example, in case the item of ambient light information may be below and/or may not exceed the threshold value, the validity criterion may be set to “fulfilled” and the first branch 158 may lead to step ii. of the method. The second branch 160 may indicate a non-valid item of ambient light information, such as an item of ambient light information being above the threshold value, and the validity criterion may be set to “not fulfilled.” Thus, the second branch 160 may lead to optional step iii. of the method.

[0155] The method may further comprise: [0156] iii. (denoted by reference number 162) if the validity criterion is not fulfilled, automatically at least partially preventing the determining of the concentration of the analyte in the body fluid.

[0157] Specifically, step iii. may comprise preventing at least one of: capturing the image of the reagent test region 118; requesting the user to position the optical test strip 116 within a field of view of the camera 114; requesting the user to apply the sample of the body fluid to the reagent test region 118 of the optical test strip 116; pricking of a user's finger to apply the sample of the body fluid to the reagent test region 118 of the optical test strip 116; evaluating a color formation reaction of the reagent test region 118. 101311 The method step ii. may further comprise: [0158] ii.1 (denoted by reference number 164) capturing the at least one image of the at least one part of the at least one reagent test region 118 having the sample of the body fluid applied thereto; [0159] ii.2 (denoted by reference number 166) determining at least one item of optical information indicative of a color formation reaction of the reagent test region 118; and [0160] ii.3 (denoted by reference number 168) deriving the concentration of the analyte by using the item of optical information.

[0161] Step ii.3 may specifically be performed by using at least one measured reference color value derived from the image. For example, by using at least one measured reference color value of one or more color reference fields 142, a color correction may be derived. The color correction may transform measured reference color values into known reference color values. Thus, the color correction may be configured for correcting measured color values in the image. The color correction may also be applied to the color value of the reagent test region 118, specifically to the item of optical information of the color formation reaction of the reagent test region 118.

[0162] Step ii. may further comprise one or more of the following steps: [0163] ii.1 (denoted by reference number 170) prompting the user to apply the sample of the body fluid to the reagent test region 118. [0164] ii.2 (denoted by reference number 172) prompting the user, before performing step ii.1, to position the optical test strip 116 within the field of view of the camera 114. [0165] ii.3 (denoted by reference number 174) prompting the user, before performing step ii.1, to position the at least one color reference card 120 within the field of view of the camera 114, the color reference card 120 comprising the plurality of color reference fields 142 having known reference color values.

[0166] The prompting may specifically comprise providing instructions by the mobile device 112, such as via the display 132 of the mobile device 112, via a loudspeaker of the mobile device 112, via a haptic feedback of the mobile device 112 or the like. For example, verbal instructions and/or pictographic instructions may be prompted to the user on the display 132 of the mobile device 112. Additionally or alternatively, the prompting may comprise playing a sound and/or playing spoken instructions via the loudspeakers of the mobile device 112.

[0167] Further, the method may be computer-implemented. The computer-implementation may comprise a software application running on the mobile device 112. The software application may comprise, after starting the software application, guiding the user through a measurement sequence 176, wherein the measurement sequence 176 may comprise at least step ii. The measurement sequence 176 may further comprise one or more of steps ii.1, ii.2, ii.3, ii.4, ii.5 and/or ii.6. Step i. may be performed fully and/or partially before and/or during the measurement sequence 176.

[0168] In FIG. 3, a flowchart of an exemplary embodiment of the ambient light check 178 is shown. The ambient light check 178 may be started by a user request 180, such as a user request 180 for the measurement sequence 176, for example, a measurement sequence 176 comprising determining the concentration of the analyte in the body fluid. The ambient light check 178 may specifically be performed before the measurement sequence 176 starts. Additionally and/or alternatively, the ambient light 178 check may also be performed during the measurement sequence 176.

[0169] Followed by the user request 180, the ambient light check 178 may comprise checking if information from the ambient light sensor 124 (denoted by reference number 182) and from the additional camera 126 (denoted by reference number 184) is available. If at least one of these information is available, the ambient light check 178 may comprise reading the information from the ambient light sensor 124 (denoted by reference number 186) and from the additional camera 126 (denoted by reference number 188). As an example, the information may comprise sensor information for the ambient light sensor 124 and pixel information for the additional camera 126, respectively.

[0170] In further steps, the ambient light check 178 may comprise determining the item of ambient light information by using the ambient light sensor 124 (denoted by reference number 190) and by using the additional camera 126 (denoted by reference number 192). As for the additional camera 126, the item of ambient light information may take into account meta information from the image capturing (denoted by reference number 194), such as an ISO-value, an aperture of the additional camera 126 and/or a exposure time. For example, the pixel information from the additional camera 126 may comprise an exposure value, wherein the exposure value may be used for deriving a relative luminance using the meta information from the additional camera 126.

[0171] The ambient light 176 may further comprise comparing the item of ambient light information with the at least one threshold value for each of the item of ambient light information determined by using ambient light sensor 124 (denoted by reference number 196) and the additional camera 126 (denoted by reference number 198). The threshold value may be a predetermined threshold value, such as a threshold value being predetermined by laboratory measurements. Based on the comparison of the item of ambient light information with the threshold value, the at least one validity criterion may be determined.

[0172] In case the validity criterion may indicate an invalid item of ambient light information (“N”), such as an item of ambient light information exceeding the threshold value, the ambient light check 178 may prevent the measurement sequence 176 and may prompt the user to change the ambient light situation (denoted by reference number 200).

[0173] Additionally and/or alternatively, the ambient light check 178 may further comprise combining the independent ambient light assessments from the ambient light sensor 124 and the additional camera 126 for determining the at least one validity criterion (denoted by reference number 202). For example, if both assessments of the validity criterion on the item of ambient light information match (“Y”), the ambient light check 178 may allow performing the measurement sequence 176. If the assessments of the validity criterion on the item of ambient light information do not match (“N”), the ambient light check 178 may prevent performing the measurement sequence 176 and may prompt the user to change the ambient light situation (denoted by reference number 200). The combination of ambient light assessments may be possible if both, the ambient light sensor 124 and the additional camera 126 may be able to determine the item of ambient light situation.

[0174] The ambient light check 178 may use only one of the validity criteria determined by using one of the ambient light sensor 124 and the additional camera 126 if only one of the ambient light sensor 124 and the additional camera 126 is available. In case the validity criterion may indicate a valid item of ambient light information (“Y”), such as an item of ambient light information being below or not exceeding the threshold value, the ambient light check 178 may allow the measurement sequence 176.

[0175] While exemplary embodiments have been disclosed hereinabove, the present invention is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of this disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

LIST OF REFERENCE NUMBERS

[0176] 110 Kit

[0177] 112 mobile device

[0178] 114 Camera

[0179] 116 optical test strip

[0180] 118 reagent test region

[0181] 120 color reference card

[0182] 122 ambient light detector

[0183] 124 ambient light sensor

[0184] 126 additional camera

[0185] 128 back side

[0186] 130 front side

[0187] 132 Display

[0188] 134 front camera

[0189] 136 operation element

[0190] 138 Touchscreen

[0191] 140 Processor

[0192] 142 color reference field

[0193] 144 gray reference field

[0194] 146 window element

[0195] 148 position marker

[0196] 150 performing at least one ambient light check

[0197] 152 using the ambient light detector for determining at least one item of ambient light information

[0198] 154 determining if at least one validity criterion on the item of ambient light information is fulfilled

[0199] 156 determining the concentration of the analyte in the body fluid

[0200] 158 first branch

[0201] 160 second branch

[0202] 162 preventing the determining of the concentration of the analyte in the body fluid

[0203] 164 capturing the at least one image

[0204] 166 determining at least one item of optical information

[0205] 168 deriving the concentration of the analyte

[0206] 170 prompting a user to apply the sample of the body fluid

[0207] 172 prompting a user to position the optical test strip

[0208] 174 prompting a user to position the at least one color reference card

[0209] 176 measurement sequence

[0210] 178 ambient light check

[0211] 180 user request

[0212] 182 checking if information from the ambient light sensor is available

[0213] 184 checking if information from the additional camera is available

[0214] 186 reading the information from the ambient light sensor

[0215] 188 reading the information from the additional camera

[0216] 190 determining the item of ambient light information by using the ambient light sensor

[0217] 192 determining the item of ambient light information by using the additional camera

[0218] 194 taking into account meta information from the image capturing

[0219] 196 comparing the item of ambient light information determined by using the ambient light sensor with the threshold value

[0220] 198 comparing the item of ambient light information determined by using the additional camera with the threshold value

[0221] 200 prompt the user to change ambient light situation

[0222] 202 combining independent ambient light assessments