Capillary Blood Sensor Electrode Segmentation

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Solution Overview

Problem

Conventional biological sample measuring devices inaccurately detect the presence of biological samples due to pass-around and seepage effects, leading to incorrect determination of sample sufficiency and potential misinterpretation of measurement results.

Innovation Solution

The system employs a controller that differentiates between normal filling, pass-around, and seepage by analyzing the output results from multiple electrodes along the capillary, using specific voltage applications and slope analysis to accurately determine the degree of biological sample introduction, preventing mistaken auto-starts and ensuring accurate measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the deposition observation time is extended to allow additional deposition when blood is insufficient, then the sensor can accommodate users with insufficient blood volume, but pass-around and seepage effects cause false positive detection of sufficient sample

Engineering Contradiction:
Improveability to handle insufficient blood volumeVSAvoidaccuracy of sample sufficiency detection
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The capillary is divided into multiple segments with electrodes positioned at different locations (first electrode at the end, second electrode in the middle, third electrode near the inlet). This segmentation allows the system to detect sample distribution patterns at different positions, distinguishing between genuine sample filling and false positive effects like pass-around and seepage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple electrodes serve as intermediaries to detect the electrical properties of the biological sample at different positions within the capillary. By measuring conductivity or impedance changes at multiple points, the system can infer sample distribution and identify false positive conditions without directly observing the sample itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If a single threshold value is used to determine sufficient current flow, then the detection method is simple, but it cannot distinguish between normal filling and pass-around/seepage effects

Engineering Contradiction:
Improvesimplicity of detection methodVSAvoidaccuracy of sample introduction detection
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

Instead of using a single threshold for the entire capillary, the system segments the detection into multiple zones corresponding to different electrode positions. Each electrode comparison provides localized information about sample presence, enabling precise detection of abnormal patterns like pass-around (where sample reaches the end but not the middle) and seepage (where plasma reaches the electrode without proper sample filling).

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from one-dimensional detection (single current threshold) to multi-dimensional detection by adding spatial dimension through multiple electrodes at different positions. This allows the system to analyze not just whether current exceeds a threshold, but where in the capillary the sample is present, enabling distinction between normal and abnormal filling patterns.

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

3Measurement precision

If the current threshold is set low to detect insufficient samples, then sensitivity increases, but false positives occur due to pass-around and seepage effects

Engineering Contradiction:
Improvesensitivity of sample detectionVSAvoidfalse positive rate
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The detection is segmented into multiple electrode comparisons, each with its own threshold evaluation. The system requires consistent detection across multiple segments to confirm sufficient sampling, rather than relying on a single low-threshold detection point. This maintains sensitivity while reducing false positives from localized phenomena like pass-around and seepage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system uses feedback from multiple electrode comparisons to validate detection results. When one electrode detects current exceeding the threshold, the system checks other electrodes to confirm the pattern is consistent with normal filling rather than abnormal effects. This feedback mechanism maintains high sensitivity while filtering out false positives through cross-validation.

Inventive Principle:
Principle #23Feedback

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 precise detection of biological sample introduction, preventing misinterpretation and ensuring accurate measurements by distinguishing between normal filling and pass-around or seepage effects, thus enhancing the reliability of biological sample measurements.

Implementation Method 1

a biological sample measuring sensor that uses capillary action to introduce a biological sample deposited at the tip suction opening into a capillary

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP2679992B1Biological sample measuring system
Publication Date: 2019.10.23 PHC HLDG CORP
  • EP2679992B1 patent drawingFigure 1
  • EP2679992B1 patent drawingFigure 2(a)~2(c)
  • EP2679992B1 patent drawingFigure 3

AI summary

This biological sample measuring device in which a deposited biological sample is introduced into a capillary by capillary action, a biological sample measuring sensor in which a reagent and the biological sample provided inside the capillary are reacted is mounted, and the biological sample is measured. The biological sample measuring device comprises a mounting portion, a voltage application section, and a detection component. The biological sample measuring sensor is mounted to the mounting portion. The voltage application section applies a measurement voltage to a plurality of electrodes disposed along the capillary in the biological sample measuring sensor. The detection component eliminates the effect of seepage of the biological sample by pass-around at the end of the capillary, or the effect whereby the plasma component seeps into the reagent, and detects the degree to which the biological sample is introduced into the capillary, on the basis of the output result for the voltage applied by the voltage application section to the electrodes.