Digital notch filter with time-varying quality factor for the reduction of powerline interference

2010 ◽  
Author(s):  
Jacek Piskorowski
Keyword(s):  
Quality Factor ◽  
Notch Filter ◽  
Time Varying ◽  
Digital Notch Filter ◽  
Powerline Interference

scholarly journals Time-Varying IIR Notch Filter with Reduced Transient Response Based on the Bézier Curve Pole Radius Variability

2019 ◽  
Vol 9 (7) ◽  
pp. 1309
Author(s):  
Sławomir Kocoń ◽  
Jacek Piskorowski
Keyword(s):  
Impulse Response ◽  
Transient Response ◽  
Narrow Band ◽  
Notch Filter ◽  
Infinite Impulse Response ◽  
Time Varying ◽  
Parametric Curve ◽  
Ecg Signals ◽  
Powerline Interference ◽  
Time Invariant

In this paper a concept of the second order digital infinite impulse response narrow band-reject filter with reduced transient response is proposed. In order to suppress the transient response of the considered infinite impulse response (IIR) notch filter its pole radius is temporarily varied in time using the Bézier parametric curve. Computer simulations verifying the effectiveness of the proposed pole-radius-varying notch filter are presented and compared to the performance of the traditional time-invariant filter using ECG signals distorted by unwanted powerline interference.

Intracranial pressure waves: characterization of a pulsation absorber with notch filter properties using systems analysis

2008 ◽  
Vol 2 (1) ◽  
pp. 83-94 ◽  
Author(s):  
Rui Zou ◽  
Eun-Hyoung Park ◽  
Erin McCormack Kelly ◽  
Michael Egnor ◽  
Mark E. Wagshul ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cerebrospinal Fluid ◽  
Intracranial Pressure ◽  
Transfer Function ◽  
Input Signal ◽  
Systems Analysis ◽  
Notch Filter ◽  
Time Varying ◽  
Cardiac Frequency ◽  
Arterial Blood

Object The relationship between the waveform of intracranial pressure (ICP) and arterial blood pressure can be quantitatively characterized using a newly developed technique in systems analysis, the time-varying transfer function. This technique considers the arterial blood pressure as an input signal composed of multiple frequencies represented in the output ICP according to the transfer function imposed by the intracranial system on the input signal. The transfer function can change with time and with physiological manipulations. The authors examined data obtained from canine experiments involving manipulations of ICP. Methods The authors analyzed 11 experiments from 3 normal mongrel dogs under conditions of normal ICP and with changes in ICP made by bolus injection, infusion, or withdrawal of cerebrospinal fluid by using time-varying transfer function. Results During normal ICP periods, the gain of the transfer function displayed a deep notch (≥ 1 log unit) centered at or near the cardiac frequency. In systems terms, the intracranial compartment under normal conditions appears to act as a notch filter attenuating the cardiac frequency input relative to other frequencies. Epochs of ICP elevation showed suppression of the notch, and the notch was restored when ICP returned to normal. Conclusions The intracranial system in these animals could be considered to include a pulsation absorber for which the target frequency appears to be close to the cardiac frequency. One possible source for such an absorber mechanism might be the free movement of cerebrospinal fluid, implying that impairment of this motion may have important clinical implications in various neurological conditions such as hydrocephalus.

Time-varying AR modeling and adaptive IIR notch filter for anti-jamming DSSS receiver

2010 ◽  
Vol 27 (4) ◽  
pp. 465-473
Author(s):  
Jining Feng ◽  
Xiaobo Yang ◽  
Zhejun Diao ◽  
Siliang Wu
Keyword(s):  
Notch Filter ◽  
Time Varying ◽  
Ar Modeling

scholarly journals An approach of adaptive notch filtering design for electrocardiogram noise cancellation

2021 ◽  
Vol 22 (3) ◽  
pp. 1303
Author(s):  
Rahmad Hidayat ◽  
Ninik Sri Lestari ◽  
Herawati Herawati ◽  
Givy Devira Ramady ◽  
Sudarmanto Sudarmanto ◽  
...  
Keyword(s):  
Notch Filter ◽  
Ecg Signal ◽  
Least Mean Square ◽  
Heart Activity ◽  
Frequency Range ◽  
Biomedical Signal ◽  
Nlms Algorithm ◽  
Digital Notch Filter ◽  
Notch Filtering ◽  
Electrocardiogram Ecg

An electrocardiogram (ECG) is a means of measuring and monitoring important signals from heart activity. One of the major biomedical signal issues such as ECG is the issue of separating the desired signal from noise or interference. Different kinds of digital filters are used to distinguish the signal components from the unwanted frequency range to the ECG signal. To address the question of noise to the ECG signal, in this paper the digital notch filter IIR 47 Hz is designed and simulated to demonstrate the elimination of 47 Hz noise to obtain an accurate ECG signal. The full architecture of the structure and coefficient of the IIR notch filter was carried out using the FDA Tool. Then the model is finished with the help of Simulink and the MATLAB script was to filter out the 47 Hz noise from the signal of ECG. For this purpose, the normalized least mean square (NLMS) algorithm was used. The results indicate that before being filtered and after being filtered it clearly shows the elimination of 47 Hz noise in the signal of the ECG. These results also show the accuracy of the design technique and provide an easy model to filter out noise in the ECG signal.

scholarly journals Metaheuristic Regression Equations for Split-Ring Resonator Using Time-Varying Particle Swarm Optimization Algorithm

Electronics ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 300
Author(s):  
Muhammad Mughal ◽  
Tahir Ejaz ◽  
Arshad ◽  
Ashiq Hussain
Keyword(s):  
Particle Swarm Optimization ◽  
Resonant Frequency ◽  
Quality Factor ◽  
Ring Resonator ◽  
Particle Swarm ◽  
Split Ring Resonator ◽  
Regression Equations ◽  
Time Varying ◽  
Split Ring ◽  
Swarm Optimization

This article presents a new technique for determining accurate values of resonant frequency and quality factor pertaining to the split-ring resonator. Different conducting shield materials have been used around a copper split-ring. The split-ring has been designed to operate at about 2.1 GHz. Various equations were worked out earlier to determine the values of resonant frequency and quality factor. However, these equations yielded different solutions. Therefore, simulations were used to obtain the values of the resonant frequency and quality factor of the split-ring resonator with different five-shield materials, using High-Frequency Structure Simulator (HFSS) software. In this work, a novel method has been introduced for obtaining values of resonant frequency which provides results with negligible error. An optimal technique, namely time-varying particle swarm optimization (TVPSO), was then performed to obtain two sets of equations for resonant frequency and quality factor. The two sets of equations, optimized using TVPSO, were compared for their effectiveness in matching the actual frequency and quality factor for each of the five materials. It was found that the TVPSO was significant in achieving the frequency and quality factor regression equation to accurately resemble the actual values portrayed by the low mean absolute error.

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