Microfluidic Cartridge with Bubble Removal for Multiplexed Analysis

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Solution Overview

Problem

Existing fluid sample analysis systems face challenges in achieving consistent and repeatable results, particularly in multiplexing tests and handling impurities in sample fluids, with limitations in sample handling and fluid flow control.

Innovation Solution

The system employs a microfluidic cartridge with separate channels, reagent pads, and sensor pads, featuring a distribution chamber and absorbent pads to manage fluid flow, separate bubbles, and impurities, and includes an optical detection reader for simultaneous analysis across multiple channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple tests are multiplexed in one housing, then productivity increases, but device complexity increases and reliability decreases due to sample cross-over risks

Engineering Contradiction:
Improveextent of multiplexingVSAvoidconsistency and repeatability of results
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system divides the sample analysis into multiple separate channels (first channel, second channel, third channel) within a single cartridge. Each channel is physically isolated with its own reagent pad, sensor pad, and fluid pathway, preventing sample cross-over while enabling multiplexed analysis of different analytes simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention extracts and removes bubbles and impurities from the sample fluid through dedicated removal zones positioned upstream of the sensor pads. Bubble removal zones and impurity removal zones are separately integrated into each channel to eliminate interfering substances before they reach the sensing elements, ensuring reliable results.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If separate channels are used for each test, then reliability improves by preventing sample cross-over, but device complexity increases

Engineering Contradiction:
Improveconsistency and repeatability of resultsVSAvoidchannel structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple separate channels are merged into a single integrated cartridge structure with common fluid management components. The distribution chamber serves all channels, and the housing integrates all channels, reagent pads, sensor pads, and removal zones into one compact unit, reducing overall system complexity while maintaining channel separation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The distribution chamber serves multiple functions: it receives sample fluid from the common inlet, distributes fluid to multiple channels, and positions reagent pads for each channel. The housing provides both structural support and fluid management functions, reducing the need for separate components.

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

3Measurement precision

If bubbles and impurities are removed from sample fluid, then measurement precision improves, but device complexity increases due to additional removal mechanisms

Engineering Contradiction:
Improvedetection accuracy of target analytesVSAvoidfluid handling structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Bubble removal zones and impurity removal zones are positioned upstream of the sensor pads in each channel, performing bubble and impurity removal before the sample reaches the sensing elements. This preliminary action ensures that only clean, bubble-free sample fluid contacts the sensor pads, improving measurement precision.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The bubble removal zones and impurity removal zones are nested within the channel structure, with removal zones integrated into the channel walls or as embedded components. The distribution chamber nests multiple channel inlets and reagent pads in a compact arrangement, reducing overall device complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 configuration enables rapid, reliable, and multiplexed analysis of fluid samples with improved sensitivity and reproducibility, effectively handling complex samples and reducing non-specific binding, thus enhancing the detection of target analytes like drugs of abuse.

Implementation Method 1

an absorbent pad spaced apart from the analyzing area by a non-porous portion of the channel, and configured to extract fluid from the fluid analyzing area

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

an interface between the top and the bottom reservoir configured to separate or eliminate a bubble in sample fluid above the interface from sample fluid flowing in the first direction across the interface into the bottom reservoir

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 3

The reagent pad comprises a conjugate of a drug and label, wherein the conjugate is soluble in a fluid

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 4

The sensor pad comprises an antibody, an antigen, or molecular imprinted polymer on a substrate

Methodology Applied
Scientific EffectAntibody-antigen binding: Adsorption

Data Source

PatentEP2200744B1An analysis system
Publication Date: 2020.05.27 BIOSENSIA PATENTS
  • EP2200744B1 patent drawingFigure 1
  • EP2200744B1 patent drawingFigure 2
  • EP2200744B1 patent drawingFigure 3

AI summary

An analysis system comprises a sampling cartridge (11) comprising a housing (21, 22) having an inlet (23) for receiving a fluid sample, a sensor (26, 45), and a guide (40, 42) extending between the inlet and the sensor for guiding sample into contact with the sensor. The system also has an optical detection reader (13) for optically inspecting the sensor. The cartridge housing has an inspection window (34) and the reader (13) comprises a socket to receive the cartridge (11), and an optical system (1183, 1186) for inspecting the sensor through the window. The cartridge comprises parallel microfluidic channel (42) for flow of sample from the inlet into contact with the sensor. The sensor comprises discrete sensor pads (45) in at least one channel, with an antibody, an antigen, or molecular imprinted polymer. The channels are of microfluidic size, having a cross-sectional area in the range of about 0.3 mm2 to about 5 mm2. At least one channel comprises a reagent pad (43) upstream of the sensor (45). The inlet of ihe cartridge comprises an extraction chamber (23) communicating with a draining chamber having a top reservoir (61) and a bottom reservoir (63), in turn communicating with a distribution chamber (40). Together, these chambers and the interfaces between them guide sample flow in a uniform manner between the channels and also remove impurity particles and bubbles.