Urine Analysis Focusing via Phase Difference Detection

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Solution Overview

Problem

Existing methods for imaging tangible components in urine specimens, such as blood cells and crystals, face challenges with low contrast and small object sizes, leading to reduced focusing accuracy when using autofocus methods like contrast-based focusing.

Innovation Solution

An analysis apparatus and method that utilize a focal point adjusting mechanism, including a camera, light source, and flow cell unit, where a test specimen is used to adjust the focus, allowing the sheath liquid and specimen to flow through a flow cell, and the image pickup position is optimized by detecting focusing points in both the Y and Z axes to ensure high accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the contrast method is used for autofocus control, then the focusing method is simple to implement, but the focusing accuracy is lowered when the object has low contrast and small size

Engineering Contradiction:
Improveease of implementationVSAvoidfocusing accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent introduces a phase difference detection mechanism as an intermediary method between simple contrast detection and complex multi-point focusing. By detecting phase differences in light reflected from the object, the system achieves high focusing accuracy for low-contrast, small objects without requiring complex mechanical adjustments or multiple image sensors.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Difficulty of detecting and measuring

If the image pickup position is adjusted to capture small sediment components, then the detection capability is improved, but the focusing accuracy deteriorates due to low object contrast

Engineering Contradiction:
Improvedetection capabilityVSAvoidfocusing accuracy
Core Design Contradiction:
Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent changes the detection parameter from intensity-based contrast (which fails for low-contrast objects) to phase-based detection. By measuring the phase difference of light waves reflected from the object, the system can accurately detect and focus on small sediment components with low contrast against the urine background.

Inventive Principle:
Principle #35Parameter changes

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 approach enables high-focusing accuracy for imaging small, low-contrast objects in urine specimens, overcoming the limitations of traditional autofocus methods by precisely adjusting the focus based on the distribution and flow of the specimen within the flow cell.

Implementation Method 1

a light source 12 for image pickup

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

a phase difference detection unit (14) for detecting phase differences in light

Methodology Applied
Scientific EffectPhase difference detection:

Data Source

PatentEP3428616B1Analysis apparatus and focusing method
Publication Date: 2020.12.09 ARKRAY INC
  • EP3428616B1 patent drawingFigure 1
  • EP3428616B1 patent drawingFigure 2
  • EP3428616B1 patent drawingFigure 3

AI summary

An analysis apparatus comprises a flow cell which has a flow passage for a liquid containing a tangible component; an image pickup unit which picks up images of the liquid flowing through the flow passage; an adjusting unit which adjusts a relative position of the flow cell with respect to the image pickup unit in relation to an optical axis direction of the image pickup unit and a direction in which the liquid flows through the flow passage; and a control unit which determines an image pickup position of the flow cell in at least one of the optical axis direction and the direction in which the liquid flows, on the basis of a number of pieces of the tangible component in focusing states existing in the images of the liquid picked up by the image pickup unit at a plurality of positions at which the relative position differs.