Impedance Angle Analysis for Rapid Bacterial Charge Detection

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Solution Overview

Problem

There is a need for a simple, reliable, and cost-effective method to quickly determine bacterial charge in liquid or semi-liquid food products, particularly in the food sector, where high microbial concentrations can pose health risks and require on-site, rapid detection.

Innovation Solution

An apparatus comprising a container, heating means, electronic measuring unit, and calculator unit that applies a variable electrical voltage signal to measure the impedance angle of the product, allowing for the derivation of bacterial charge concentration based on the time trend of impedance values, using a formula that calculates the angle of impedance and compares derivatives to determine bacterial concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional methods are used to determine bacterial charge, then measurement reliability is maintained, but measurement time is excessive and cost is high

Engineering Contradiction:
Improvemeasurement speedVSAvoidmeasurement time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent replaces traditional mechanical/cultural methods of bacterial detection with an electronic measurement system that uses impedance analysis. The system applies an electrical signal to the sample and measures the resulting current to calculate impedance angle, which correlates with bacterial concentration. This substitution of electronic measurement for traditional methods enables rapid results without lengthy incubation periods.

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

Solution Approach 2:

The patent changes the measurement parameter from direct bacterial counting or cultural methods to electrical impedance angle measurement. By monitoring the impedance angle of the sample at different frequencies and calculating its derivative, the system can determine bacterial concentration rapidly. This parameter change enables fast measurement while maintaining reliability through the specific mathematical relationship between impedance angle derivative and bacterial charge.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If simple and inexpensive methods are used, then cost is reduced, but measurement reliability and accuracy deteriorate

Engineering Contradiction:
Improvedevice costVSAvoidmeasurement reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces complex traditional laboratory equipment with a simplified electronic measurement system consisting of basic electrical components (signal generator, electrodes, current sensor, calculator unit). This substitution dramatically reduces equipment cost while maintaining measurement reliability through the robust impedance-based detection method and mathematical analysis of the impedance angle derivative.

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

Solution Approach 2:

The patent employs simple, inexpensive measuring electrodes and basic electronic components that can be easily manufactured or replaced. The system uses affordable electrical measurement devices rather than expensive specialized microbiological equipment, achieving cost-effective bacterial charge determination without sacrificing measurement accuracy through the intelligent use of impedance angle analysis.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If complex equipment is used to ensure accuracy, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvebacterial charge measurement precisionVSAvoidapparatus complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and isolates the specific parameter of impedance angle and its derivative, focusing measurement on this single key characteristic rather than using complex multi-parameter systems. By taking out only the essential measurement element (impedance angle derivative) and relating it directly to bacterial charge, the system achieves high precision with minimal device complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces complex mechanical or biological measurement systems with a simple electronic circuit that measures electrical impedance. The calculator unit performs mathematical operations (derivative calculation) on the impedance angle to determine bacterial concentration, achieving high measurement precision through intelligent data processing rather than through complex physical measurement apparatus.

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

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

Enables accurate, fast, and reliable detection of bacterial charge in food products, ensuring product safety by providing a precise measurement of microbial content without extensive equipment or expertise.

Implementation Method 1

heating means (6) (or heater, preferably electrical) associated with the supporting frame (2) and, in use, in thermal contact with the removable container (3) to heat the liquid or semi-liquid product to be tested

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

an electronic measuring unit (7) comprising: a signal generator (8) (electronic) adapted to generate an electrical voltage signal Vref which is variable over time; measuring electrodes (9) electrically connected to the signal generator (8) and mounted inside the internal containing space (5) of the removable container (3); a sensor (10) adapted to measure a current (lout) flowing through the measuring electrodes (9) and the liquid or semi-liquid product consequent upon the electrical voltage signal Vref; a calculator unit (11) configured to calculate, based on the current lout measured by the sensor (10) and based on the electrical voltage signal Vref, a value α representing an angle of electrical impedance of the liquid or semi-liquid product

Methodology Applied
Scientific EffectElectrical Impedance: Electrical Resistance

Data Source

PatentEP3396364B1Apparatus and method for determining the bacterial charge in a liquid or semi-liquid product
Publication Date: 2021.01.13 ALI SPA CARPIGIANI GRP
  • EP3396364B1 patent drawingFigure 1~4
  • EP3396364B1 patent drawingFigure 2~3
  • EP3396364B1 patent drawingFigure 5

AI summary

A method for determining the bacterial charge in a liquid or semi-liquid product, comprising: - preparing a quantity of liquid or semi-liquid product to be analysed; - keeping that quantity of liquid or semi-liquid product at a preset measuring temperature (Tm) and deriving values (α) representing an angle of electrical impedance of the liquid or semi-liquid product at predetermined time instants; - deriving an indication of the presence of a bacterial charge in the liquid or semi-liquid product as a function of the time trend of the values (α) representing the angle of the electrical impedance.