Electrical Impedance Tomography Voltmeter Gain Adjustment
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Solution Overview
Problem
Conventional electrical impedance tomography (EIT) instruments face challenges in precisely detecting electrical characteristics of the human body due to noise in measured voltages and complex, large-sized configurations with high costs.
Innovation Solution
A system for electrical impedance tomography that includes a plurality of electrodes for current injection and voltage detection, a current source, voltmeters with adjustable gains, and a main controller for imaging, which injects current via selected electrode pairs, measures voltages using unselected electrodes, adjusts voltmeter gains based on maximum voltage values, and amplifies signals to improve imaging precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional EIT measurement is performed, then voltage signals are obtained, but noise contaminates the measured voltage making precise detection difficult
Solution Approach 1:
The patent converts the harmful noise by adjusting the gain of each voltmeter based on the maximum absolute value of detected voltages. This gain adjustment optimizes the signal-to-noise ratio by amplifying useful signals while keeping noise within acceptable ranges, thereby transforming the noise problem into a manageable parameter that can be optimized through computational methods
Solution Approach 2:
The patent performs preliminary gain adjustment on each voltmeter before final imaging processing. By pre-adjusting the gains based on maximum voltage values detected during the measurement phase, the system prepares the voltage signals in advance to minimize noise impact during subsequent imaging operations
2Measurement precision
If conventional EIT instrument is constructed with multiple devices, then voltage detection capability is achieved, but the configuration becomes complicated and size increases
Solution Approach 1:
The patent merges multiple voltmeters into a single integrated measurement system where each voltmeter is controlled by a centralized main controller. This consolidation maintains the multi-channel voltage detection capability while reducing overall system complexity through unified control architecture and shared processing resources
Solution Approach 2:
The main controller performs multiple functions including controlling current source operation, adjusting individual voltmeter gains, collecting voltage data from multiple channels, and executing imaging algorithms. This multi-functional design eliminates the need for separate dedicated devices for each function, thereby simplifying the overall configuration
3Measurement precision
If conventional EIT instrument is constructed with multiple devices, then voltage detection capability is achieved, but product cost increases
Solution Approach 1:
The patent combines multiple voltmeter functions and control logic into a single integrated system with shared hardware resources. This merging reduces the total number of discrete components required, lowering manufacturing costs while maintaining full multi-channel voltage detection capability through software-based gain control and centralized processing
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
The system effectively reduces noise and simplifies configuration, enabling precise detection of electrical characteristics within the measurement target by using multiple electrodes and voltmeters to adjust and amplify voltage signals, resulting in improved imaging accuracy and reduced system size and cost.
Implementation Method 1
injecting a current to a measurement target via at least one electrode pair selected from a plurality of electrodes attached to the measurement target, detecting voltage of a surface of the measurement target using a plurality of voltmeters connected to the electrodes that are not selected
Implementation Method 2
adjusting gains of the voltmeters according to maximum values of the detected voltages, respectively, amplifying the detected voltages using the gain-adjusted voltmeters, respectively
Data Source
AI summary
A system for electrical impedance tomography and method thereof are disclosed, by which electrical characteristics within a measurement target can be precisely detected. The present invention includes the steps of injection a current to a measurement target via at least one electrode pair selected form a plurality of electrodes (250) attached to the measurement target, detecting voltage of a surface of the measurement target using a plurality of voltmeters (260) connected to the electrodes that are not selected, respectively, adjusting gains of the voltmeters according to maximum values of the detected voltages, respectively, amplifying the detected voltages using the gain-adjusted voltmeters, respectively, and imaging an internal part of the measurement target based on the amplified voltages.