Mobile Device Camera Tone Mapping Compensation for Analyte Concentration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods using consumer-electronics devices like smartphones for determining analyte concentrations in bodily fluids face challenges due to image data processing steps that can affect accuracy.
Innovation Solution
A method involving a mobile device with a camera that takes a series of calibration images to derive key calibration figures, determining a probable tone mapping function, and using this function to analyze images of optical test strips with bodily fluids applied, thereby improving the accuracy of analyte concentration determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If image data processing functions are used to improve image quality, then image quality is improved, but measurement precision deteriorates
Solution Approach 1:
The patent applies preliminary action by capturing multiple raw images at different exposure times before any processing occurs, and by manually capturing reference images of color charts under the same lighting conditions. These preliminary captures allow the system to later compensate for processing effects and lighting variations, resolving the contradiction between image quality improvement and measurement precision.
Solution Approach 2:
The system implements feedback by using the captured reference images and raw image data to calculate correction factors and tone mapping functions. These corrections are then applied to the analysis images to compensate for the distorting effects of automatic image processing and lighting conditions, thereby maintaining measurement precision while using standard mobile device cameras.
2Shape
If tone mapping function is applied to enhance image brightness and contrast, then image quality is improved, but measurement precision deteriorates
Solution Approach 1:
The patent captures multiple raw images at different exposure times before tone mapping is applied, preserving the original linear response data. It also captures reference images of color charts under the same lighting conditions. These preliminary captures enable the system to later reverse the tone mapping effects and recover accurate colorimetric measurements, resolving the contradiction between enhanced image appearance and measurement accuracy.
Solution Approach 2:
The system applies the inverse of the tone mapping function to the processed images to recover the original linear response. By inverting the tone mapping operation and using the reference images to calculate correction factors, the system restores the accurate colorimetric data needed for precise analyte concentration determination while still benefiting from the visual quality improvements of tone mapping for display purposes.
3Measurement precision
If multiple raw images at different exposure times are captured, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent makes the mobile device camera multi-functional by using it both for capturing the test strip images and for capturing reference images of color charts under controlled lighting conditions. The same camera and processing infrastructure are used for both purposes, eliminating the need for separate calibration devices and reducing overall system complexity while maintaining high measurement precision.
Solution Approach 2:
The system performs self-calibration by having the user capture reference images of color charts using the mobile device camera under the same lighting conditions as the test strip measurement. The device automatically processes these reference images to determine correction factors and tone mapping functions, eliminating the need for external calibration equipment and reducing device complexity while improving measurement precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the accuracy of determining analyte concentrations by accounting for the tone mapping function used by the mobile device, thereby mitigating the impact of image data processing on measurement accuracy.
Implementation Method 1
a) taking a series of calibration images of at least one region of interest of an object by using the camera
Implementation Method 2
test strips comprising one or more test chemistries, which, in the presence of the analyte to be detected, are capable of performing one or more detectable detection reactions, such as optically detectable detection reactions
Data Source
AI summary
A method of determining concentration of an analyte in a body fluid using a mobile device having a camera is disclosed. In the inventive method, the camera is used to take a series of calibration images of a region of interest of an object. The calibration images differ in their brightness. A key calibration figure is derived from each calibration image, the key calibration images being characteristic for a tone mapping function of the mobile device. A probable tone mapping function of the mobile device is determined by taking into account the key calibration figures. An analysis image is taken of at least part of a test field of an optical test strip, the test field having a body fluid applied thereto. Analyte concentration is determined from the analysis image of the test field by taking into account the probable tone mapping function of the mobile device.