Lateral Flow Assay Strip Subpad for Reproducible Sample Loading

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Solution Overview

Problem

Conventional lateral flow assays are prone to inaccuracies and variability in results due to differences in sample amount applied, requiring precise measurement and frequent changes in strip and cartridge structures, which is inconvenient and error-prone.

Innovation Solution

A strip and cartridge design featuring a subpad with a dipping portion and slant, integrated or detachable from the sample pad, allowing capillary flow and enabling accurate and reproducible results without precise sample measurement, with the sample applied to a well rather than directly on the strip, and guides within the cartridge to manage sample flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If exact amount of sample is loaded directly onto sample pad to obtain reproducible result, then measurement precision is improved, but ease of operation deteriorates and device complexity increases

Engineering Contradiction:
Improvereproducibility of detection resultVSAvoidconvenience of sample loading
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The sample pad is segmented into a subpad (first sample pad) and a main sample pad (second sample pad). The subpad receives the sample first and transfers a controlled amount to the main sample pad, separating the sample reception function from the detection function. This allows users to load sample conveniently without precise measurement while maintaining reproducible results through the subpad's flow control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The subpad acts as an intermediary between the sample source and the main sample pad. It receives the sample load and mediates the transfer to the main sample pad, controlling the sample amount through capillary flow. This intermediary structure eliminates the need for precise sample measurement by users while ensuring consistent sample delivery to the detection zone.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If exact amount of sample is loaded directly onto sample pad to obtain reproducible result, then measurement precision is improved, but device complexity increases due to frequent structural changes

Engineering Contradiction:
Improvereproducibility of detection resultVSAvoidfrequency of structural modifications
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The subpad is pre-configured with specific flow characteristics and dimensions to automatically control sample transfer. This preliminary design of flow control properties allows the device to maintain reproducible results across different sample loads without requiring structural modifications, eliminating the need for frequent device redesigns.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The subpad's physical parameters (dimensions, porosity, material properties) are optimized to provide consistent capillary flow control across a range of sample volumes. By designing the subpad with specific parameter ranges, the device maintains measurement precision without requiring structural changes when sample volumes vary within the designed range.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If subpad with dipping portion and slant is introduced to enable accurate results without precise measurement, then ease of operation is improved, but device complexity increases

Engineering Contradiction:
Improveconvenience of sample loadingVSAvoidstructural complexity of sample pad
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The subpad integrates multiple functions into a single component: sample reception, flow control, and transfer to main sample pad. The dipping portion receives sample, the slant directs flow, and the body transfers to the main pad, all in one integrated structure. This merging reduces operational complexity despite the enhanced structural features.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The subpad serves multiple purposes: it acts as a sample receiver, a flow regulator, a transfer medium, and a structural guide (with slant). This multi-functionality consolidates several potential components into one, improving ease of operation while managing device complexity through functional integration rather than proliferation of separate parts.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 ensures accurate and reproducible results regardless of sample amount variations, simplifies the loading process, reduces user error, and allows for convenient changes in sample volume without altering the cartridge or strip, leading to cost savings and improved user convenience.

Implementation Method 1

the sample moves through the chromatographic medium to the absorption pad by capillary action

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP2910946B1Strip for lateral flow assay, comprising subpad, and cartridge for lateral flow assay used therewith
Publication Date: 2019.11.27 BODITECHMED INC
  • EP2910946B1 patent drawingFigure 1a~1b
  • EP2910946B1 patent drawingFigure 2a~2b
  • EP2910946B1 patent drawingFigure 3

AI summary

The present application relates to: a strip for lateral flow assay, comprising a support, a medium for development, a sample pad comprising a subpad, and an absorption pad; and a cartridge for lateral flow assay, comprising the same. According to the present application, the strip adopts a novel sample loading method, thereby obtaining reproducible results irrespective of the volume of an injected sample, and it is possible to readily change the amount of a sample, as necessary, thereby improving the reproducibility of measured results and convenience.