Optical System Depth of Field for Blood Sample Analysis

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Solution Overview

Problem

Existing automatic image analysis systems for blood samples are time- and resource-intensive due to the need for multiple image captures at different focal planes and focusing operations, leading to inefficient data acquisition and analysis.

Innovation Solution

An apparatus and method that enable three-dimensional analysis of samples by using a light emitting diode (LED) with near-parallel light, a lens arrangement with a depth of field greater than the sample thickness, and image data processing techniques to exclude overexposed and underexposed regions, generate low pass filtered data, and identify high intensity pixels, allowing for improved detection of objects at different distances from the image sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple images are taken at different focal planes to achieve three-dimensional analysis, then measurement precision is improved, but loss of time and productivity deteriorate

Engineering Contradiction:
Improvethree-dimensional analysis accuracyVSAvoidtime for image acquisition and focusing
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent transitions from two-dimensional image analysis to three-dimensional analysis by increasing the depth of field of the optical system. This allows objects at different distances from the image sensor to be captured in a single image plane, eliminating the need for multiple focal plane captures while maintaining spatial analysis capability.

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

Solution Approach 2:

The optical system is pre-configured with a large depth of field design that anticipates the need to capture objects at various depths simultaneously. This preliminary design choice eliminates the need for subsequent focusing operations between image captures, reducing time loss.

Inventive Principle:
Principle #10Preliminary action

2Illumination intensity

If a large aperture is used to improve light gathering, then illumination intensity is improved, but manufacturing precision deteriorates due to reduced depth of field

Engineering Contradiction:
Improvelight gathering capabilityVSAvoiddepth of field control
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent changes the optical parameters of the system by designing a optical train with specific focal lengths and spacing that produces a large depth of field. This parameter configuration allows the system to maintain adequate illumination while achieving the required depth of field for three-dimensional analysis.

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 allows for more accurate and efficient analysis of objects in blood samples by providing better image data quality and object representation, reducing the need for extensive focusing and image acquisition, while maintaining detectability of objects despite deteriorated detail resolution.

Implementation Method 1

a light emitting diode (LED) with near-parallel light

Methodology Applied
Scientific EffectLight emitting diode: Light Emitting Diode

Implementation Method 2

an optical system and a sample onto an image sensor

Methodology Applied
Scientific EffectOptical transmission and focusing: Lens

Data Source

PatentEP1947441B1Apparatus for determining positions of objects contained in a sample
Publication Date: 2013.07.10 HEMOCUE AB
  • EP1947441B1 patent drawingFigure 1
  • EP1947441B1 patent drawingFigure 2
  • EP1947441B1 patent drawingFigure 3

AI summary

The invention relates to an apparatus for determining positions of objects contained within a sample. The apparatus comprises an image sensor configured to transform incident light to image data, an optical system comprising a lens arrangement and an aperture, a light emitting device configured to generate light towards said image sensor, and an image data processor configured to receive image data from said image sensor and to determine positions for objects in said image data. The optical system is configured such that a depth of field of said optical system is larger than or equal to a thickness of said sample.