Flow Cytometer Mask Blocks Diffraction Patterns

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Solution Overview

Problem

Flow cytometer systems face inaccuracies in intermediate angle scatter measurements due to diffraction patterns caused by flat beam profiles and mismatched refractive indices between sheath fluid and liquid samples, leading to contamination of scatter signals.

Innovation Solution

Incorporating a mask positioned across the intermediate angle scatter light detector to block horizontal diffraction patterns, combined with beam shaping optics creating a horizontally flat beam profile and a sheath fluid source for hydrodynamic focusing, allowing accurate measurement of intermediate angle scatter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If beam shaping optics create a horizontally flat beam profile to improve illumination uniformity, then illumination intensity is improved, but diffraction patterns are generated that contaminate scatter signals

Engineering Contradiction:

Improveillumination uniformityVSAvoiddiffraction patterns

Core Design Contradiction:

Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and removes the harmful diffraction pattern from the detection path by positioning a mask to block the horizontal diffraction pattern on the intermediate angle scatter detector, while preserving the useful flat beam profile illumination and scatter signal measurement

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a mask as an intermediary element between the flow cell and the intermediate angle scatter detector to block the harmful diffraction pattern while allowing the useful scatter light to reach the detector

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If a mask is added to block diffraction patterns on the detector, then measurement precision is improved, but device complexity increases

Engineering Contradiction:

Improvescatter signal accuracyVSAvoidoptical component count

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs a simple, inexpensive mask that can be easily manufactured and replaced if needed, rather than implementing a complex optical correction system. The mask is a straightforward component that blocks diffraction without requiring sophisticated design or maintenance

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Ease of operation

If sheath fluid with mismatched refractive index is used for hydrodynamic focusing, then sample stream focusing is improved, but diffraction patterns are created that contaminate measurements

Engineering Contradiction:

Improvehydrodynamic focusingVSAvoiddiffraction patterns

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent accepts the refractive index mismatch between sheath fluid and sample as beneficial for hydrodynamic focusing, while converting the resulting diffraction harm into a blocked signal by strategically positioning the mask to eliminate the diffraction pattern from the detection path

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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

The solution effectively blocks diffraction patterns, ensuring accurate intermediate angle scatter measurements even with mismatched refractive indices, enhancing the reliability of flow cytometer systems.

Implementation Method 1

a mask disposed horizontally across a portion of the IAS light detector, between the flow cell and the IAS light detector, and covering at least a central portion of the IAS light detector so as to block a horizontal diffraction pattern created by the flat beam profile irradiating the liquid sample

Methodology Applied

Scientific EffectDiffraction: Diffraction

Data Source

PatentUS10190962B2Flow cytometry systems and methods for blocking diffraction patterns

Publication Date: 2019.01.29 ABBOTT LAB INC

AI summary

Flow cytometer systems are provided having intermediate angle scatter detection capability. In some aspects, systems are provided that include an intermediate angle scatter (IAS) light detector positioned to measure intermediate angle scatter emitted from a flow cytometer. The system further includes a mask disposed across a portion of the IAS light detector and positioned between the flow cell and the IAS light detector to cover at least a central portion of the IAS light detector so as to block a diffraction pattern observed at the detector. In some instances, the diffraction pattern is created by a flat beam profile irradiating the sample. Methods are also provided for configuring a flow cytometer to block a diffraction pattern created by (1) a flat laser beam profile irradiating a flow cytometer liquid sample, or (2) a mismatched index of refraction between a sheath fluid and a liquid sample in a flow cytometer.