VW Engineering International, Volume: 1, Issue: 1, 04-11 (2019)
Received: March 30, 2019
Accepted: Sept. 28, 2019
Published online: Oct. 04, 2019
Muhammad Waqas1
Syed Wahajul Haq2
Shahzad Ahmed3
1Department of Computer, Technische Universitat, Chemnitz, Germany
2Department of Electrical Engineering, Air University, Islamabad, Pakistan
3Department of Electronics and Computer Engineering, Hanyang University, Seoul, South Korea
*Corresponding author: mwaqaschaudery@gmail.com
Abstract: In embedded systems, Impedance spectroscopy is used to measure the impedance of the system as a function of frequency. The standard U-1 method for designing impedance analyzer includes use of Gain-Phase Detector (GPO), Peak Detector, Discrete Fourier T ransform (OFT). T his project aims at designing of a microcontroller based impedance measurement system using OFT and Under Sampling to enhance the frequency range in portable bio-impedance measmement systems. The impedance analyzer implements a digital concept with appropriate signal conditioning for voltage and current measurement, early signal digitization and subsequent digital signal processing in order to calculate the components of impedance. The designed impedance analyzer measures the impedance magnitude and phase at frequencies up to l O MHz at low frequencies, the module utilizes the conventional direct conversion method, whereas at high frequendes the under sampling technique is used. The results from the impedance analyzer for commonly used tissue model (Device Under Test) are validated by comparing it with the theoretical results from matlab. The results show a good performance to frequencies up to 3 MHz Above 3 MHz systematic deviations are becoming visible. The system was observed for impedance magnitude and phase out of 10 measurements and shows standard deviation of 0.2 rr (0.2%) for impedance magnitude and a standard deviation of 0.5° for impedance phase.
