Short-Time Impedance Spectroscopy Using a Mode-Switching Nonsinusoidal Oscillator: Applicability to Biological Tissues and Continuous Measurement
| Autor: | Akinori Ueno, Emiyu Ogawa, Tomiharu Yamaguchi |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Swine Capacitive sensing Acoustics continuous impedance measurement TP1-1185 DFT Biochemistry Article Analytical Chemistry symbols.namesake Electric Impedance Animals Waveform Electrical and Electronic Engineering frequency switching Instrumentation Electrical impedance Capacitive coupling impedance spectroscopy Fourier Analysis Oscillation Chemical technology Atomic and Molecular Physics and Optics Dielectric spectroscopy Fourier transform Dielectric Spectroscopy capacitive coupling symbols Harmonic biological application nonsinusoidal oscillator |
| Zdroj: | Sensors Volume 21 Issue 21 Sensors, Vol 21, Iss 6951, p 6951 (2021) Sensors (Basel, Switzerland) |
| ISSN: | 1424-8220 |
| DOI: | 10.3390/s21216951 |
| Popis: | Herein, we propose an impedance spectroscopy method using a mode-switching nonsinusoidal oscillator and apply this method for measuring the impedance of biological tissues and continuous impedance measurement. To obtain impedance spectra over a wide frequency range, we fabricated a novel nonsinusoidal oscillator incorporating binary counters and analog switches. This oscillator could periodically switch oscillation frequency through the mode switching of the feedback resistor. From the oscillation waveform at each oscillation frequency of this circuit (oscillator), we determined the impedance spectrum of a measured object using the discrete-time Fourier transform. Subsequently, we obtained the broad impedance spectrum of the measured object by merging odd-order harmonic spectral components up to the 19th order for each oscillation frequency. From the measured spectrum, the resistive and capacitive components of the circuit simulating bioimpedance were estimated with high accuracy. Moreover, the proposed method was used to measure the impedance of porcine myocardium changes in the impedance spectrum of the myocardial tissue due to coagulation could be measured. Furthermore, rapid variations in the resistance value of a CdS photocell could be continuously measured using the proposed method. |
| Databáze: | OpenAIRE |
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