Grounding Electrode Current Monitoring in Electric Impedance Tomography

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Electric impedance tomography systems face distortions and errors in image reconstruction due to the disconnection of the grounding electrode, unbalanced current drainage, and interference from external electrically conducting objects or equipment.

Innovation Solution

An equipment that detects the current drained through the grounding electrode, processes this signal through amplification, demodulation, filtering, and analog-digital conversion, and compares it against patterns to detect anomalies, including disconnection and unbalanced conditions, with features like surge protection and low-value resistor measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a floating ground electrode is connected to drain currents, then signal stability is improved, but the risk of electrode disconnection and current imbalance increases

Engineering Contradiction:

Improvesignal stabilityVSAvoidelectrode disconnection and current imbalance

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a monitoring system that continuously measures the current drained by the grounding electrode and compares it against expected values. When disconnection or imbalance is detected, the system generates alerts and can adjust measurements to compensate for the anomaly, creating a closed-loop feedback system that maintains reliability despite potential electrode issues

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent introduces an intermediary monitoring circuit between the grounding electrode and the measurement system. This intermediary component measures the grounding current without disrupting the electrode's primary function, allowing detection of anomalies while maintaining signal stability

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If grounding electrode monitoring is implemented, then detection precision is improved, but device complexity increases

Engineering Contradiction:

Improvegrounding current detection precisionVSAvoidmonitoring equipment complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the grounding current monitoring function with the existing EIT measurement system. The monitoring circuit shares components with the measurement system, and the control unit integrates both EIT data acquisition and grounding current monitoring functions, reducing overall system complexity while maintaining detection precision

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The control unit is designed to perform multiple functions: acquiring EIT measurements, monitoring grounding current, detecting anomalies, and adjusting measurements accordingly. This multi-functional approach eliminates the need for separate dedicated monitoring equipment, reducing device complexity while maintaining measurement precision

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

Effectively prevents image distortions by accurately monitoring and correcting for grounding electrode disconnection and current imbalances, ensuring reliable tomography images and reducing noise levels.

Implementation Method 1

the signal is detected in the form of a voltage measured by means of a low value resistor connected in series with the said grounding electrode

Methodology Applied

Scientific EffectOhm's Law: Ohm's Law

Implementation Method 2

means for signal amplification

Methodology Applied

Scientific EffectSignal amplification:

Implementation Method 3

means for demodulation

Methodology Applied

Scientific EffectDemodulation:

Implementation Method 4

the demodulation is carried out together with filtering that eliminates the high-frequency component of the detected signal, such component being in the range of 30 kHz to 300 kHz, as well as low-frequency oscillations above 0.5 Hz, producing as a result an almost continuous voltage

Methodology Applied

Scientific EffectFiltering: Filter (electronic)

Implementation Method 5

means for analog-digital conversion of the amplified signal

Methodology Applied

Scientific EffectAnalog-digital conversion:

Data Source

PatentUS8749252B2Method and equipment for monitoring the current drained by the grounding electrode in electric impedance tomography

Publication Date: 2014.06.10 TIMPEL MEDICAL BV

AI summary

There are disclosed a method and an equipment for monitoring current drained by a grounding electrode in an electric impedance tomography system. The grounding electrode and a set of electrodes may be simultaneously applied to a patient in an electric impedance tomography apparatus. The equipment may be configured to convert current into a voltage signal and amplify, demodulate, and filter the voltage signal in order to recover its almost continuous component. The equipment may further be configured to compare the value of the continuous component with limit/threshold values proportional to an intensity of an excitation current applied to the set of electrodes. In addition to detecting the disconnection of the grounding electrode, the comparison may also detect the disconnection of one or more tomography electrodes, as well as unbalance in the currents injected through the electrodes and the contact of the patient with voltage sources or conductive bodies.