Bioimpedance Imaging Using Multi-Directional AC Current Sensing

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Solution Overview

Problem

MRI requires a significant measurement time due to the need to observe relaxation phenomena until atoms return to a steady state, making it challenging to quickly acquire multiple tomographic images of different body positions for detecting abnormalities.

Innovation Solution

A measurement apparatus that applies AC currents in multiple directions using a pair of electrodes, detects magnetic fields, calculates impedance, and generates internal information based on these measurements, allowing for rapid acquisition of tomographic images without waiting for relaxation to steady state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If MRI observes relaxation phenomenon until atoms return to steady state, then measurement precision is improved, but measurement time increases significantly

Engineering Contradiction:
Improvemeasurement precisionVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts only the essential information needed for measurement by detecting impedance changes during the AC current application, rather than waiting for the complete relaxation phenomenon to occur. This allows obtaining sufficient measurement data without observing the full relaxation process, thereby reducing measurement time while maintaining diagnostic capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs preliminary measurement actions by applying AC currents and detecting impedance changes before the relaxation process completes. By capturing impedance variations during the transient phase, the system obtains useful measurement information in advance, eliminating the need to wait for steady state recovery.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If multiple tomographic images are acquired at different body positions, then diagnostic accuracy is improved, but measurement time increases to tens of minutes or more

Engineering Contradiction:
Improvediagnostic accuracyVSAvoidmeasurement time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent maintains continuous useful action by sequentially applying AC currents at different frequencies and positions without interrupting the measurement flow. The impedance detection continues throughout the process, allowing multiple measurement points to be collected in a continuous manner, thereby acquiring comprehensive diagnostic information more efficiently than traditional MRI.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent changes measurement parameters by varying AC current frequencies and applying currents at different body positions to obtain impedance characteristics from multiple angles. This multi-parameter approach provides comprehensive diagnostic information similar to multiple tomographic images, but with significantly reduced measurement time due to the simplicity of impedance measurement compared to MRI sequence acquisition.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If simple measurement configuration is used, then device complexity is reduced, but measurement capability may be limited

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement capability
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent achieves multi-functionality by using a single impedance measurement system to obtain various types of physiological information. By analyzing impedance changes at different frequencies and positions, the system can detect blood flow, tissue characteristics, and organ function, making a simple device capable of multiple diagnostic functions that would otherwise require complex specialized equipment.

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

Solution Approach 2:

The patent extracts rich measurement capability from a simple configuration by varying AC current frequencies and measurement positions. These parameter changes allow the basic impedance measurement system to capture diverse physiological information, effectively increasing measurement capability without adding device complexity through multiple specialized sensors or systems.

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

Enables rapid acquisition of internal body information with a simple configuration, reducing measurement time and enabling quick detection of abnormalities.

Implementation Method 1

a magnetic field detecting element that detects a magnitude of a magnetic field generated from the portion of the measurement target in response to the plurality of AC currents

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4245214B1Measuring device and measuring method
Publication Date: 2025.12.24 ASAHI INTECC CO LTD
  • EP4245214B1 patent drawingFigure 1
  • EP4245214B1 patent drawingFigure 2
  • EP4245214B1 patent drawingFigure 3

AI summary

The present invention provides a measurement apparatus and a measurement method including: a plurality of current applying parts applying a plurality of AC currents oriented in a plurality of directions toward a portion of a measurement target via an electrode pair; a magnetic field detecting element that detects a magnitude of a magnetic field generated from the portion of the measurement target in response to the plurality of AC currents; a calculating part for calculating impedance of the portion of the measurement target, based on a detection result of the magnetic field detecting element; and an internal information output part for generating information including an internal component of the measurement target, based on the calculated impedance.