Multi-Electrode Suspension Impedance Sensing Across Wide Frequencies
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Solution Overview
Problem
Current impedance spectroscopy methods for suspensions, particularly cell suspensions, suffer from inaccuracies and variability in measurement results over a wide frequency range, necessitating improved methods and sensors for reliable and accurate impedance determination.
Innovation Solution
A method and sensor using multiple measuring electrodes and correction functions to calculate impedance values, accounting for geometric and interference factors, combined with sampling and Fourier transforms to enhance measurement accuracy and minimize noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current impedance spectroscopy methods are used, then measurement can be performed, but measurement accuracy is insufficient and results vary considerably over frequency range
Solution Approach 1:
The patent divides the measurement process into multiple independent impedance measurements taken at different time points. By segmenting the measurement into discrete samples and applying statistical evaluation (mean, standard deviation) to multiple measurements, the system achieves higher accuracy and consistency. This is evident in the method where impedance is measured repeatedly and evaluated statistically to obtain reliable results.
Solution Approach 2:
The patent performs preliminary calibration measurements to determine geometric factors before actual impedance measurements. The system pre-determines cell constants and geometric factors through calibration with standard solutions, then uses these pre-established parameters in subsequent measurements to ensure accuracy across the frequency range.
2Measurement precision
If single impedance measurement is taken, then measurement process is simple, but measurement accuracy is insufficient
Solution Approach 1:
The measurement process is segmented into multiple independent impedance measurements that are statistically evaluated. The system performs multiple measurements at different time points and uses statistical methods (calculating mean and standard deviation) to derive the final impedance value, thereby improving accuracy without requiring complex hardware modifications.
Solution Approach 2:
The system implements feedback through iterative measurement and statistical evaluation. Multiple impedance measurements are taken and continuously evaluated using statistical parameters, with the process allowing for refinement of results through repeated measurement and calculation of mean values and standard deviations to achieve target accuracy.
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 method and sensor provide high-accuracy impedance measurements across a wide frequency range, enabling precise determination of cell population properties such as cell number, size, and homogeneity.
Implementation Method 1
a) an oscillating voltage at an oscillation frequency can be generated
Implementation Method 2
determining a first impedance measurement value on the basis of the oscillating voltage and a first current; determining a second impedance measurement value on the basis of the oscillating voltage and a second current
Implementation Method 3
combined with sampling and Fourier transforms to enhance measurement accuracy and minimize noise
Data Source
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AI summary
The invention relates to a method for determining a value indicating the impedance of a suspension, as part of impedance spectroscopy, comprising the following steps: generating an excitation current oscillating at an excitation frequency through the suspension; determining a first impedance measurement value on the basis of the excitation current and a first voltage on a first pair of measurement electrodes; determining a second impedance measurement value on the basis of the excitation current and a second voltage on a second pair of measurement electrodes; determining the value indicating the impedance of the suspension by correlating the first impedance measurement value and the second impedance measurement value.