Dissolvable Sample Carrier for Dried Blood Spot Extraction

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Solution Overview

Problem

Conventional methods for analyzing dried biological fluids, such as dried blood spots, face challenges in detection sensitivity and ease of use due to variations in analyte concentration and the tedious process of punching dried spots, which can lead to carryover and reduced repeatability.

Innovation Solution

A sample carrier with dissolvable collection regions that can be easily extracted using solvents, eliminating the need for punching, where the collection regions are made of materials like cellulose acetate or polysulfone that dissolve in solvents like acetonitrile, allowing for efficient extraction and separation of analytes from unwanted constituents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If punching is used to extract dried spots from sample cards, then sample extraction is achieved, but the process is tedious and leads to carryover reducing repeatability

Engineering Contradiction:
Improveease of useVSAvoidrepeatability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces the mechanical punching system with a chemical dissolution system. Instead of using a sharp punch tool to mechanically extract dried spots, the invention uses solvents to chemically dissolve the collection membrane material, thereby releasing the dried spots into collection wells. This substitution eliminates the mechanical contact that causes carryover and improves repeatability while maintaining ease of operation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical-chemical parameters of the collection membrane by selecting materials with specific solubility characteristics. The collection membrane is made from materials like cellulose acetate or polysulfone that dissolve in specific solvents (e.g., acetonitrile, dichloromethane) at controlled temperatures, allowing selective dissolution and release of dried spots without mechanical intervention.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If conventional punching tools are used repeatedly, then sample extraction is efficient, but carryover occurs reducing detection sensitivity

Engineering Contradiction:
Improveextraction efficiencyVSAvoiddetection sensitivity
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical punching tool with a chemical dissolution process. Solvents are applied to the sample card, dissolving the collection membrane material and releasing dried spots into collection wells. This eliminates repeated mechanical contact that causes carryover, thereby maintaining detection sensitivity while preserving extraction efficiency through automated solvent application.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs disposable collection membranes made from dissolvable materials. Each membrane is designed to be used once and then completely dissolved in the extraction process, eliminating the need for cleaning or sterilization between uses. This disposable approach prevents carryover between samples while maintaining high extraction efficiency.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If entire dried spots are sampled to improve repeatability, then analyte concentration variations are reduced, but sample handling complexity increases

Engineering Contradiction:
ImproverepeatabilityVSAvoidhandling complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the sample card into distinct functional regions: dissolvable collection membranes that hold dried spots, indissolvable separator regions, and collection wells. This segmentation allows the entire dried spot to be automatically released into the collection well through selective dissolution of the membrane, improving repeatability by ensuring complete sample transfer while reducing handling complexity through automated processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The dissolvable collection membrane acts as an intermediary between the dried spot and the collection well. It holds the dried spot during storage and transport, then completely dissolves during extraction to release the entire sample contents into the collection well. This intermediary mechanism ensures complete and consistent sample transfer, improving repeatability while simplifying handling through automated solvent application.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 method enhances repeatability and ease of use by avoiding the limitations of punching, providing efficient extraction and analysis of dried biological samples with improved detection sensitivity and reduced handling complexity.

Implementation Method 1

the collection regions comprise a material that dissolves in one or more solvents

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 2

another solution, for example, water, is added to the vessel so that unwanted sample constituents (e.g., blood proteins) and collection material precipitate out of the solution

Methodology Applied
Scientific EffectPrecipitation: Precipitation

Data Source

PatentEP2815223B1Dried sample carrier having dissolvable sample collection regions
Publication Date: 2019.04.24 WATERS TECHNOLOGY CORP
  • EP2815223B1 patent drawingFigure 1~2
  • EP2815223B1 patent drawingFigure 3A~5D
  • EP2815223B1 patent drawingFigure 4

AI summary

Described are sample carriers and methods of extracting a fluid sample from a dried sample on a sample carrier. The sample carrier has a first carrier portion that receives a fluid sample, and includes a material that adsorbs the fluid sample and dissolves upon application of a solvent. A second carrier portion is attached to the first carrier portion and includes a material that is indissolvable in the solvent. The first carrier portion having a dried sample is dissolved into a solution upon application of the solvent. The solution can be analyzed to determine constituents in the extracted sample. The sample carrier can conveniently be in the form of a card or a dipstick. In alternative embodiments, a carrier portion that includes the dried sample is indissolvable in the solvent but is released from another carrier portion through application of a solvent to an intervening dissolvable carrier portion.