Test Cartridge Illumination Layout to Avoid Strip Reflection Errors
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Solution Overview
Problem
Existing immunochromatographic test devices face issues with misidentification due to reflection of impurities in the strip affecting image capture and inadequate illumination of the test region, leading to potential misinterpretation of the color development state.
Innovation Solution
A test device with an illumination unit positioned separately from the observation window, using diffuse reflection through a translucent case material to ensure adequate illumination of the test region, and incorporating a suppression portion to minimize leakage light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the emission end portion is disposed at a position corresponding to the test region on the rear surface side of the cartridge case, then the test region can be illuminated from the rear surface side, but impurities in the strip may be reflected in the captured image causing misidentification
Solution Approach 1:
The invention extracts the harmful function (direct rear-illumination causing impurity reflection) and replaces it with a different illumination approach. The emission end portion is moved to the side surface of the cartridge case, separating the illumination path from the observation path, thereby eliminating impurity reflection while maintaining test region illumination.
Solution Approach 2:
The side surface of the cartridge case acts as an intermediary medium. The emission end portion illuminates the test region through the side surface rather than directly from the rear, using the case material as a mediator to achieve uniform illumination without direct line-of-sight reflection paths that cause misidentification.
2Device complexity
If the emission end portion is disposed next to the imaging element to irradiate the test region in an oblique direction, then the structure is simplified, but a sufficient amount of illumination light may not reach the test region due to eclipse at the edge of the observation window
Solution Approach 1:
The invention applies local quality by positioning the emission end portion at a specific location on the side surface of the cartridge case. This localized positioning optimizes the illumination angle and path to ensure sufficient light reaches the test region without causing eclipse at the observation window edge, balancing structural simplicity with illumination effectiveness.
Solution Approach 2:
The invention transitions from two-dimensional positioning (rear surface or next to imaging element) to utilizing the third dimension by placing the emission end portion on the side surface of the cartridge case. This spatial reconfiguration allows illumination light to reach the test region from a different angular dimension, avoiding eclipse while ensuring adequate illumination.
3Measurement precision
If the emission end portion is disposed at a position separated from the observation window on the outer surface of the case, then impurity reflection is reduced, but the illumination light path becomes more complex
Solution Approach 1:
The invention merges the illumination function with the cartridge case structure itself. The side surface of the case serves dual purposes: as the structural housing and as the illumination path medium. This integration simplifies the overall device by eliminating separate illumination path components while achieving the goal of reduced impurity reflection.
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
The solution reduces the risk of misidentification by ensuring uniform and effective illumination of the test region, enhancing the accuracy of color development state analysis.
Implementation Method 1
the illumination light is transmitted from the outer surface of the case to an inside of the case, reaches the test region while being diffuse-reflected by an inner surface of the case
Data Source
AI summary
A cartridge has a strip that is provided with the test region and a case in which the strip is accommodated and in which an observation window for observing the test region from an outside is formed in a surface. A emission end portion, through which illumination light for illuminating a test region, is disposed at a position separated from the observation window on a rear surface of the case. A detection unit, that optically detects the color development state of the test region irradiated with the illumination light, is disposed at a position facing the observation window on a surface side of the case. The illumination light is transmitted from the rear surface of the case to an inside of the case, reaches the test region while being diffuse-reflected by an inner surface of the case, and illuminates the test region from the surface side.