Assay Reader Window Shape for Position Tolerance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electronic assay reading devices are sensitive to the position of the detection zone within the window, leading to variable signal intensity due to non-uniform illumination and light detection, causing misinterpretation of assay results, especially in lateral flow assays where the detection zone can be displaced during manufacturing or use.
Innovation Solution
The assay result reading apparatus features a non-rectangular window shape that compensates for minor mis-positioning of the detection zone by up to +/-0.4mm, ensuring that the light detected varies by less than 10% compared to the intended position, achieved through a process of measuring relative signal intensity at different positions and adjusting the window shape to counteract displacement effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a rectangular window is used in the assay reader, then the device structure is simple and easy to manufacture, but the reading apparatus becomes sensitive to minor mis-positioning of the detection zone, causing variable signal intensity
Solution Approach 1:
The patent applies asymmetry by changing the window shape from a conventional rectangular form to an asymmetric shape that is wider at the top than at the bottom. This asymmetric geometry compensates for the typical downward displacement of the detection zone during manufacturing and use, ensuring that the light path remains optimized even when the detection zone is mispositioned by up to +/-0.4mm. The asymmetric window design maintains consistent signal intensity without requiring complex mechanical positioning systems.
2Adaptability or versatility
If the detection zone is allowed to displace by +/-0.4mm, then manufacturing tolerances are accommodated, but the signal intensity varies by more than 10% from the intended position
Solution Approach 1:
The patent applies local quality by creating a non-uniform light distribution across the window area, with the light intensity being highest at the regions where the detection zone is most likely to be positioned (accounting for expected displacements). The window shape and light source positioning are optimized so that even when the detection zone displaces within +/-0.4mm, it remains in a region of the window that provides adequate illumination and maintains signal intensity within acceptable limits.
3Device complexity
If a rectangular window is used, then the assembly process is straightforward, but interpretation of assay results becomes ambiguous due to variable signal strength
Solution Approach 1:
The asymmetric window shape simplifies the assembly process by eliminating the need for precise positioning mechanisms, while simultaneously improving result interpretation clarity. The window geometry is designed to ensure that the detection zone, regardless of minor displacements, receives consistent illumination that produces reliable and unambiguous signal intensities, making it easier for users to interpret assay results accurately.
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 design renders the reading apparatus insensitive to minor mis-positioning of the detection zone, providing consistent and unambiguous assay results by maintaining signal intensity variability within acceptable limits, thus improving user confidence and accuracy in interpreting test results.
Implementation Method 1
a light detector (6) to detect the amount of light reflected and/or transmitted by the detection zone
Implementation Method 2
a light detector (6) to detect the amount of light reflected and/or transmitted by the detection zone
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Disclosed is an assay result reading apparatus for use with an assay in which a detectable substance tends to accumulate within a detection zone of the assay, the reading apparatus comprising: a housing or baffle, having a window therein; a light source which emits light through the window so as to illuminate the detection zone of the assay; and a light detector to detect the amount of light reflected and/or transmitted by the detection zone, which amount is at least partly dependent on the amount of detectable substance accumulated in the detection zone; wherein the shape of the window is adapted to render the reading apparatus less sensitive, preferably insensitive, to minor mis-positioning of the detection zone relative to one or more of the window, the light source and the light detector.