Disposable Hemolysis Sensor Using Acoustic Plasma Separation

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Solution Overview

Problem

Current automated blood analyzers cannot effectively measure hemolysis in whole blood samples within disposable test cartridges, as hemolysis testing is typically performed on separated plasma, not directly on whole blood.

Innovation Solution

A disposable hemolysis sensor module is designed for installation in existing blood analysis instruments, using acoustic separation and multicolor LED illumination to measure plasma hemoglobin levels, with a self-contained housing and optical imaging to process images and correct for interferences, allowing for accurate hemolysis measurement in whole blood.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If hemolysis testing is performed on separated plasma using conventional methods, then measurement accuracy is improved, but device complexity and processing time increase due to centrifugation requirements

Engineering Contradiction:
Improvehemolysis measurement accuracyVSAvoidcentrifugation equipment requirement
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the plasma separation function from complex centrifugation equipment and implements it using a simple acoustic field generated by a piezoelectric transducer. The acoustic field causes blood cells to migrate to the periphery of the flow cell while plasma remains in the center, enabling plasma extraction without mechanical centrifugation devices.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical centrifugation system with an acoustic field-based separation method. A piezoelectric transducer generates acoustic waves that create a standing wave pattern in the fluid, causing blood cells to move to high-pressure regions (periphery) and plasma to remain in low-pressure regions (center), eliminating the need for mechanical centrifuges.

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

2Device complexity

If acoustic separation is used to separate plasma from whole blood, then device complexity is reduced, but measurement precision may deteriorate due to potential misalignment and interference

Engineering Contradiction:
Improveseparation mechanism simplicityVSAvoidplasma hemoglobin measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent transitions from one-dimensional linear alignment to three-dimensional spatial positioning by creating a standing acoustic wave field that establishes distinct radial zones within the flow cell. The acoustic field creates a three-dimensional separation pattern where blood cells concentrate at the periphery while plasma occupies the central region, enabling optical sensors to selectively measure plasma properties.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent uses multicolor LED illumination sources that emit at different wavelengths (including 570nm and 610nm) to illuminate the plasma region. By selecting specific wavelengths that correspond to hemoglobin absorption characteristics and using color-based detection, the system can accurately measure plasma hemoglobin concentration while distinguishing it from other components.

Inventive Principle:
Principle #32Color changes

3Ease of operation

If a disposable sensor module is designed for in-line installation, then ease of operation is improved, but manufacturing precision requirements increase to ensure proper alignment

Engineering Contradiction:
Improvein-line installation simplicityVSAvoidoptical component alignment tolerance
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent integrates the flow cell, acoustic transducer, multicolor LED illumination sources, and optical detection sensors into a single pre-assembled disposable sensor module. This modular design combines all critical components with pre-established alignment relationships, allowing the entire module to be installed as one unit in the blood analysis instrument, thereby simplifying operation while maintaining manufacturing precision within the factory-controlled assembly process.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent divides the blood analysis system into separate functional modules: a reusable instrument platform and a disposable sensor module. The disposable module contains all components necessary for plasma separation and hemolysis measurement, which can be easily replaced after each use. This segmentation allows manufacturing precision to be concentrated in the factory assembly of the disposable module while keeping the overall system easy to operate through simple module replacement.

Inventive Principle:
Principle #1Segmentation

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

Enables reliable measurement of hemolysis in whole blood samples within existing automated blood analyzers, providing accurate plasma hemoglobin levels with reduced interference and misalignment issues, enhancing the diagnostic capabilities of these systems.

Implementation Method 1

operation of the disclosed sensor employs acoustic separation of whole blood into blood cells and plasma within a flow cell

Methodology Applied
Scientific EffectAcoustic separation: Acoustic Radiation Pressure

Implementation Method 2

a multicolor light emitting diode LED illumination source

Methodology Applied
Scientific EffectLight emitting diode illumination: Light Emitting Diode

Implementation Method 3

a camera configured to acquire images of the plasma while separated from the blood cells. The images are later processed to obtain a plasma hemoglobin level

Methodology Applied
Scientific EffectOptical imaging: Photography

Data Source

PatentEP4220131A1Disposable hemolysis sensor
Publication Date: 2023.08.02 INSTRUMENTATION LABORATORY COMPANY
  • EP4220131A1 patent drawingFigure 1
  • EP4220131A1 patent drawingFigure 2
  • EP4220131A1 patent drawingFigure 3

AI summary

A disposable hemolysis sensor module (100) is described. The module comprises a flow cell (104) for housing a column of whole blood, an acoustic transducer (106) for generating acoustic forces on said flow cell for temporarily partitioning the whole blood in the flow cell into a first region comprising cell free plasma and a second region comprising blood cells, a light source (108), such as a light source comprising red LED and a yellow LED, for illuminating the cell free plasma in the first region, one or more optical imaging sensors (110), such as a camera, for acquiring one or more digital images of the cell free plasma in the first region while said cell free plasma is illuminated by said light source, and a housing (112) configured for removable installation in an instrument cartridge of a blood analysis instrument, wherein the housing is further configured to locate the flow cell, the light source and the optical imaging sensors in fixed alignment relative to each other.