Narcis Iulian Adochiei

Heart rate variability monitoring due to 50 Hz electromagnetic field exposure and statistical processing

This study investigates the influence of the 50 Hz electromagnetic exposure on heart rate variability (HRV). Thus, we recorded and preceded the ECG signals for 44 volunteers both in high and normal field exposure. The acquisition system and the QRS detection algorithm were developed by the authors with the view to be used in this study. Spectral measurements of the HRV revealed a significant increase (Students t-test: Pt=0.00l; Mann-Whitney U-test Pu=0.00l; average difference D=16.857) in the power of the HF components and significant reduction in the power of the low-frequency (Students t-test: Pt=0.003; Mann-Whitney U-test Pu=0.003; average difference D=-14.906) on volunteers exposed compared with unexposed one conditions.

LMS algorithm derivatives used in real-time filtering of ECG signals: A study case on performance evaluation

The paper presents two derivatives of the Least Mean Square (LMS) algorithm, which can be utilized in real-time processing of the electrocardiographic (ECG) signals: (i) the Normalized LMS (NLMS), and (ii) Sign based LMS (S-LMS) algorithms. The algorithms are suitable for implementation on Digital Signal Processors (DSPs) or on Field Programmable Gates Arrays (FPGAs), and the practical implementations of their equations are presented. The implementation of the iterative steps can be done in an easy manner with low computational complexity with good effect on the filtering process, for both types of perturbations, electronic noises and power line interference signals, which can occur on ECG signals.

FPGA approach of an adaptive filter for ECG signal processing

The paper presents an implementation of an proposed adaptive filter structure, which use as running support a circuit like Field Programmable Gate Array (FPGA). The proposed method can be used to clean the electrocardiographic (ECG) signals from power line interference in real-time. The Least Mean Square (LMS) algorithm is used to update up to twelve coefficients from filters structure. The design was developed using DE2 platform (Development and Education Board), which include one circuit FPGA type Cyclone II. The provided results concludes that the FPGA approach of proposed LMS adaptive filter structure, which is intended to process in real-time the ECG signal, presents better performances.

An innovative design and mathematical implementation of an electrical model of the human circulatory system under ESD stress

In order to observe the impact of the electrostatic charges on human body, the paper investigates the mathematical modeling of the human circulatory system and the equivalent electrical circuit, modeled as an electrical net. The mathematical implementing and the modeling of the equivalent electrical circuit that simulates the electrical activity of the human circulatory system has a maj or importance not only for analyzing the electrostatic discharge phenomena in engineering applications but also in getting information about different means of detecting various human diseases. The analyses of the whole circulatory system were performed, using the software programs MAT LAB and Cadence.