Plasma Glucose Measurement via Hematocrit Correction

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Solution Overview

Problem

Existing methods for measuring plasma glucose concentration using whole blood as a specimen face challenges due to individual differences in hematocrit values, leading to measurement errors, and previous technologies have not adequately addressed these issues to achieve high accuracy and speed simultaneously.

Innovation Solution

A method and device that calculate the plasma glucose concentration by using the hemocyte/plasma ratio, liquid content ratio of hemocytes, and liquid content ratio of plasma, allowing for accurate measurement by hemolyzing hemocytes in blood and applying a multiplying factor to the whole blood glucose concentration, while also incorporating steps for measuring hemoglobin concentration and correcting enzymatic reaction rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If whole blood is used as a specimen to avoid centrifugation and improve analysis speed, then productivity is improved, but measurement precision deteriorates due to individual differences in hematocrit values

Engineering Contradiction:
Improveanalysis speedVSAvoidplasma glucose concentration accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The invention changes the measurement parameter from direct whole blood glucose to plasma glucose concentration by introducing correction factors. The correction process transforms the raw measurement into an accurate plasma glucose value by accounting for hematocrit variations, thus resolving the contradiction between using whole blood for speed and needing plasma accuracy.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces the mechanical centrifugation process with a computational correction system. Instead of physically separating plasma from blood cells through centrifugation, the system uses mathematical algorithms to calculate and correct the glucose concentration based on hematocrit values, achieving both speed and accuracy.

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

2Measurement precision

If hemolyzed samples are used to eliminate hemocyte interference, then measurement precision is improved, but the complexity of sample preparation increases

Engineering Contradiction:
Improveglucose concentration accuracyVSAvoidsample preparation process
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention extracts and measures hemoglobin concentration separately from the glucose measurement process. By isolating the hemocyte component measurement (via hemoglobin) and using it as a correction parameter, the system eliminates the interference of hemocytes in the glucose measurement while maintaining a relatively simple overall process.

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If multiple correction factors are applied to achieve accurate plasma glucose concentration, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveplasma glucose concentration accuracyVSAvoidcalculation system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention creates a universal correction algorithm that handles multiple sources of error (hematocrit variations, hemolyzed sample effects, enzymatic reaction rate differences) through a single integrated calculation system. This multi-functional correction approach improves precision without proportionally increasing device complexity, as the same computational framework addresses multiple issues simultaneously.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 significantly reduces measurement errors and achieves accurate plasma glucose concentration measurements, maintaining analysis speed by using a hemolyzed sample and correcting for enzymatic reaction rate influences, resulting in values close to actual plasma glucose concentrations.

Implementation Method 1

detects, with an electrode, an oxidation-reduction current of a product caused by an enzyme reaction of glucose and a glucose oxidoreductase

Methodology Applied
Scientific EffectOxidation-reduction reaction: Redox Reactions

Implementation Method 2

an enzyme reaction of glucose and a glucose oxidoreductase to convert the detected current into a glucose concentration

Methodology Applied
Scientific EffectEnzyme catalysis: Enzyme

Implementation Method 3

reacting hemoglobin flowing out the of red hemocytes and a mediator, and detecting a current caused by this reaction

Methodology Applied
Scientific EffectOxidation-reduction reaction: Redox Reactions

Data Source

PatentEP2400031B1Method for measuring plasma glucose
Publication Date: 2016.08.10 ARKRAY INC
  • EP2400031B1 patent drawingFigure 1
  • EP2400031B1 patent drawingFigure 2
  • EP2400031B1 patent drawingFigure 3

AI summary

A measurement of plasma glucose is carried out through the following steps, a sample preparation step (S101, S102) of preparing a measurement sample by hemolyzing hemocytes in blood, a step of measuring whole blood glucose (S 103 to S 1 05) of measuring a glucose concentration in whole blood with the measurement sample, and a step of calculating a liquid content ratio of whole blood (S109) of calculating a liquid content ratio of whole blood from a hemocyte/plasma ratio in the blood hemocyte and predetermined ratios of liquid components of hemocytes and of liquid components of plasma.