Method for evaluating suitability of lighting conditions for detecting an analyte in a sample using a camera of a mobile device

Patent metadata

Field	Value
Publication number	US-12360104-B2
Application number	US-202318490132-A
Country	US
Kind code	B2
Filing date	Oct 19, 2023
Priority date	Jun 11, 2018
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

A method of evaluating suitability of lighting conditions for detecting an analyte in a sample using a mobile device camera. A test strip is provided for detecting the analyte. A first image of the test strip is captured while an illumination source of the mobile device is turned off and a second image of the test strip is captured while the illumination source is turned on. A sample is applied to the test strip and the first and second images are compared to thereby determine the difference in lighting conditions between the first image and the second image. The comparison is used to derive information on suitability of the lighting conditions for analyte detection. The lighting conditions are indicated as suitable when a predetermined threshold amount of light intensity used for illumination of the test strip originates from the illumination source.

First claim

What is claimed is:

1. A method of evaluating suitability of lighting conditions for detecting an analyte in a sample applied to a test strip configured for detecting the analyte in the sample and having at least one test field with a test chemical for an optical detection reaction, using a mobile device having a camera, the method comprising:
providing an app for downloading to the mobile device, wherein installing the app on the mobile device configures the mobile device to evaluate the suitability of lighting conditions by:
i) capturing a first image of the test strip while an illumination source of the mobile device is turned off;
ii) capturing a second image of the test strip with a sample applied to the test strip while the illumination source is turned on, and the illumination source generates illumination having a known or predetermined spectral composition;
iii) comparing the first and second images and thereby determining a difference in lighting conditions between the first image and the second image, wherein the camera captures the images in steps i) and ii) in at least one color channel and the camera and/or a processor of the mobile device determines first and second intensity distributions, respectively, for the at least one color channel associated with the first and second images, wherein the comparing the first and second images comprises comparing the first intensity distribution and the second intensity distribution of the at least one color channel;
iv) determining an intensity of the illumination which originates from the illumination source used for illumination of the test strip when capturing the second image as a function of the known or predetermined spectral composition;
V) deriving suitability information of the lighting conditions for analyte detection from the comparison in step iii) and the determination of step iv); and
vi) determining that the lighting conditions are suitable for subsequent analyte detection using the second image when at least 70% of light intensity used for illumination of the test strip in the second image originates from the illumination source; and

wherein the app is adapted to work with mobile devices having illumination sources which comprise at least one white light LED, wherein the at least one white light LED is controlled using a short current pulse to illuminate the test strip continuously during capture of the second image and wherein illuminance of flashes generated by the at least one white light LED are from 80 to 300 lux at an object distance of 1m.

2. The method according to claim 1 , further comprising:
distributing the app over a data network.

3. The method according to claim 1 , wherein the mobile device includes a display on a first side and the illumination source is on a second side of the mobile device opposite the first side.

4. A method of evaluating suitability of lighting conditions for detecting an analyte in a sample applied to a test strip configured for detecting the analyte in the sample and having at least one test field with a test chemical for an optical detection reaction, using a mobile device having a camera, the method comprising:
providing an app for downloading to the mobile device, wherein installing the app on the mobile device configures the mobile device to evaluate the suitability of lighting conditions by:
i) capturing a first image of the test strip while an illumination source of the mobile device is turned off;
ii) capturing a second image of the test strip with a sample applied to the test strip while the illumination source is turned on and wherein the illumination source generates illumination having a known or predetermined spectral composition;
iii) comparing the first and second images and thereby determining a difference in lighting conditions between the first image and the second image, wherein the camera captures the images in steps i) and ii) in at least one color channel and the camera and/or a processor of the mobile device determines first and second intensity distributions, respectively, for the at least one color channel associated with the first and second images, wherein the comparing the first and second images comprises comparing the first intensity distribution and the second intensity distribution of the at least one color channel;
iv) determining an intensity of the illumination which originates from the illumination source used for illumination of the test strip when capturing the second image as a function of the known or predetermined spectral composition;
v) deriving suitability information of the lighting conditions for analyte detection from the comparison in step iii) and the determination of step iv); and
vi) determining that the lighting conditions are suitable for subsequent analyte detection using the second image when at least 70% of light intensity used for illumination of the test strip in the second image originates from the illumination source; and

providing the app with a lookup table with a known spectral composition of a white light LED.

5. A method of evaluating suitability of lighting conditions for detecting an analyte in a sample applied to a test strip configured for detecting the analyte in the sample and having at least one test field with a test chemical for an optical detection reaction, using a mobile device having a camera, the method comprising:
providing an app for downloading to the mobile device, wherein installing the app on the mobile device configures the mobile device to evaluate the suitability of lighting conditions by:
i) capturing a first image of the test strip while an illumination source of the mobile device is turned off;
ii) capturing a second image of the test strip with a sample applied to the test strip while the illumination source is turned on and wherein the illumination source generates illumination having a known or predetermined spectral composition;
iii) comparing the first and second images and thereby determining a difference in lighting conditions between the first image and the second image, wherein the camera captures the images in steps i) and ii) in at least one color channel and the camera and/or a processor of the mobile device determines first and second intensity distributions, respectively, for the at least one color channel associated with the first and second images, wherein the comparing the first and second images comprises comparing the first intensity distribution and the second intensity distribution of the at least one color channel;
iv) determining an intensity of the illumination which originates from the illumination source used for illumination of the test strip when capturing the second image as a function of the known or predetermined spectral composition;
v) deriving suitability information of the lighting conditions for analyte detection from the comparison in step iii) and the determination of step iv); and
vi) determining that the lighting conditions are suitable for subsequent analyte detection using the second image when at least 70% of light intensity used for illumination of the test strip in the second image originates from the illumination source; and

providing the app with a lookup table with an outline of at least part of the test strip and wherein the app configures the mobile device to superimpose the outline on a display of the mobile device to thereby provide guidance for positioning camera relative to the test strip when capturing the first image and the second image.

6. The method according to claim 1 , further comprising:
providing the app with user instructions.

7. A method of evaluating suitability of lighting conditions for detecting an analyte in a sample using a mobile device having a camera, the method comprising:
a) providi

Assignees

• Roche Diabetes Care Inc

Inventors

• Berg Max
• Hailer Fredrik
• Klein Timo
• Limburg Bernhard
• Melchinger Christian
• Tuerck Volker

Classifications

• G01N2021/7759

  Dipstick; Test strip · CPC title

• G01N21/77

  by observing the effect on a chemical indicator · CPC title

• G01N2021/8887

  based on image processing techniques · CPC title

• G01N21/8806

  Specially adapted optical and illumination features · CPC title

• G01N33/526 Primary

  the element being adapted for a specific analyte · CPC title