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Slavica Gajić, Platon Sovilj
Design, metrological analysis and optimization of solenoid for homogenization of electromagnetic fields in biomedical experiments

In recent years, usage of electromagnetic field of static magnets in biomedical experiments is increased. It has been shown that extremely lowfrequency (ELF) magnetic fields improve the impact of oncological therapy on cancer cells. Therefore, there is a huge need for ELF magnetic fields usage in biomedical experiments. In this paper, different designs and optimizations of solenoid for electromagnetic field homogenization along its axis, as well as in experimental volume, is compared. Using metrological analysis, the best design based on achieved homogenization of electromagnetic field and design complexity is selected. Also, a number of series expansions in 1st and 2nd kind of Elliptical integrals calculations is analysed in order to emphasize computer resources necessary for numerical modelling process.

Erika Pittella, Alice Bologni, Roberta Cervoni, Vincenzo Fortunato, Emanuele Piuzzi
Comparison between a PPG Wearable Device and an AFE4403-Based Pulse Oximeter

The paper shows a comparison between a photoplethysmography wearable device and a bare pulse-oximeter based on an analog front-end for optical bio-sensing applications. In particular, a specific experimental set-up was implemented, simulating an artery, which allows to compare and acquire signals from both proposed devices on a repeatable system. Results both on the artery model and on a healthy volunteer are shown.

Jozef Kromka, Jan Saliga, Ondrej Kovac, Luca De Vito, Francesco Picariello, Ioan Tudosa
A novel CS-based measurement method for radial artery pulse wave estimation

This paper presents a compressive sampling (CS) based measurement method for estimation of radial artery pulse wave from bio-impedance (Bio-Z) variation. The mathematical steps of the method, the 3D electrical model of the wrist used for simulations as well as the preliminary simulation investigations are presented. The reported result shows that the proposed method could be used to estimate radial artery pulse wave, which could be further used in blood pressure (BP) computation.

Fapanni Tiziano, Emilio Sardini, Mauro Serpelloni
A Preliminary Study on Flexible Temperature Sensors for Eskin Medical Devices

In the latest years, the need of a renewed paradigm for healthcare arose promoting the research towards the idea of remote diagnosis, care and monitoring of physiological parameters. Thus, the wearable and eskin devices arose to be embedded in the standard medical equipment. In this work, a preliminary study on flexible AJP-printed temperature sensors is reported in order to propose a novel approach to evaluate infection sites, monitor the body temperature and compensate the effects of temperature on other on-body sensors. Two different geometries are proposed, designed, produced, evaluated and compared. The results shown a similar dependance on temperature (average TCR = 2.5 ∙ 10 - 3 °C-1) and the dependance on substrate deformation was enquired as well as the geometrical features of the sensors.

Claudio Nevoloso, Ciro Spataro, Rosario Miceli, Antonino Oscar Di Tommaso, Gioacchino Scaglione, Giuseppe Schettino
Cascaded H-Bridges Multilevel Inverter Drive: Active Power Analysis in Frequency Domain

The international standard IEC 61800-9-2 introduces energy efficiency classification for frequency converters or complete drive module (CDM) and provides instrumentation minimum requirements for accurate measurement of CDM input and output power valid for conventional pulse-width-modulated (PWM) voltage source inverter (VSI). This paper highlights the necessary improvements to update the standard with more detailed prescriptions according to the converter topologies and the modulation techniques adopted. In this framework, this paper address the power analysis in the frequency domain of a cascaded H-bridges-multilevel inverter (CHBMI) in an interior permanent magnet synchronous motor (IPMSM) drive for the identification of the minimum measurement bandwidth. The power spectrums are analyzed for different modulation strategies, different switching frequency values and IPMSM working conditions.

Daniel Belega, Dario Petri, Dominique Dallet
Iterative Interpolated DFT-based Frequency Estimator for Electrical Waveform Affected by Decaying DC Offset

An iterative Interpolated Discrete Fourier Transform (IpDFT)-based frequency estimator of a sinewave affected by decaying dc offset is proposed in this paper. The accuracies of the proposed procedure and the classical IpDFT algorithm are compared with each other under different steady-state and dynamic testing conditions suggested in the IEC/IEEE 60255-118.1:2018 - Synchrophasors for power systems – Measurements. A decaying dc offset is added to the test signals suggested in the Standard and off-nominal frequency is considered. Procedure accuracy is analyzed through simulations by considering the maximum of the absolute value of the frequency error. Comparison with the frequency error thresholds proposed in the Standard is also performed.

Arthur Silva Souza, Raimundo Carlos Silveiro Freire, Luiz Augusto M. M. Nobrega, Felipe Alexandre Da Silva Bento, George Victor Rocha Xavier, Marlo Andrade
Antennas Comparison Applied to Detect Partial Discharges Coupled via Dielectric Window and Oil Valve in Power Transformers

Considering increasing the reliability of electrical systems, continuous equipment maintenance is essential, thus ensuring longevity and avoiding failures that can cause irreparable damage to the equipment. Partial discharges are physical phenomena that cause short circuits in power equipment. There are techniques that use the detection of partial discharges as a condition monitoring techniques for electrical equipment. One of these techniques is the detection of partial discharges in power transformers by means of antennas. Thus, different antennas were analyzed for different coupling to the sensor into the high voltage equipment, either via dielectric window or oil valve. In comparison, the L-probe antenna obtained the best result, at −10 dB, while at −5 dB the log spiral performed better, for insertion via the dielectric window. For coupling via oil valve, the monopole obtained the best result, at −10 dB, considering the bandwidth at −5 dB the conical 70mm did better.

Jakub Svatos, Jan Fischer, Jan Holub
Increasing of Sampling Rate of Internal ADC in Microcontrollers by Equivalent-Time Sampling

The paper describes the Equivalent-Time Sampling (ETS) in Software-Defined Instruments (SDI) - typically oscilloscopes. It introduces a possible solution of the microcontrollers drawback caused by the maximal sampling frequency and its limitations in digitizing quick transient responses. The principle of ETS used in microcontrollers is explained, and the jitter effect is taken into account. Analog-to-digital converter input model and real properties of softwaredefined oscilloscope from ETS point of view are introduced and explained. In the system for circuit behavior analysis as a step response, where a microcontroller with internal peripherals (pulse-width modulation and analog-to-digital converter) is used for a test signal generation and data digitization, the use of ETS may increase the equivalent sampling rate of the internal analog-to-digital converter up to tens of MSa/s.

Sioma Baltianski
Bias-induced Impedance of Current-carrying Conductors: Measurements Simulation Using FRA

The paper presents mainly the simulation of impedance measurements utilizing a frequency response analyzer (FRA) for the study of the currentcarrying conductors under the influence of bias. It is vital to have confidence in the results of impedance spectroscopy because one of the informative quantities has very little impact on the resulting impedance. During the passage of an electric current, the studied objects have an additional low-frequency impedance called the bias-induced impedance effect (ZBI-effect) [1]. An emphasis was placed on explaining how the ZBIeffect acts as an amplifier for temperature modulation of a resistance caused by the test signal. A description of the investigated object is based on electrical models whose parameters provide useful information for further research. Several studies have been done to assess the consistency of electrical parameters. A silver wire was used in research as an object under study and as a representative of pure metals.

Krzysztof Musioł, Maciej Koszarny, Marian Kampik, Krzysztof Kubiczek, Adam Ziółek, Jolanta Jursza
A New Impedance Metrology Infrastructure at GUM

Collaboration of the Polish National Metrology Institute (GUM, Warsaw) with the Silesian University of Technology (SUT, Gliwice) and joint participation in international projects focused on the development of digital sources and digital impedance bridges contributed to the development of the impedance metrology infrastructure at GUM. The article presents current work related to expanding the current infrastructure with a new 4TP, mostly thermostated impedance standards terminated with MUSA connectors. Design solutions, results of thermal stability measurements and results of the comparison of new impedance standards made with the currently implemented digital impedance bridge are presented in the paper.

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