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

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.

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Digital Finite Impulse Response Notch Filter with Non-Zero Initial Conditions, Based on an Infinite Impulse Response Prototype Filter

Metrology and Measurement Systems ◽

10.2478/v10178-012-0068-x ◽

2012 ◽

Vol 19 (4) ◽

pp. 767-776 ◽

Cited By ~ 6

Author(s):

Sławomir Kocoń ◽

Jacek Piskorowski

Keyword(s):

Impulse Response ◽

Narrow Band ◽

Finite Impulse Response ◽

Initial Conditions ◽

Notch Filter ◽

Infinite Impulse Response ◽

Fir Filters ◽

Ecg Signals ◽

Prototype Filter ◽

Power Line Noise

Abstract In this paper a concept of finite impulse response (FIR) narrow band-stop (notch) filter with non-zero initial conditions, based on infinite impulse response (IIR) prototype filter, is proposed. The filter described in this paper is used to suppress power line noise from ECG signals. In order to reduce the transient response of the proposed FIR notch filter, optimal initial conditions for the filter have been determined. The algorithm for finding the length of the initial conditions vector is presented. The proposed values of the length of initial conditions vector, for several ECG signals and interfering frequencies, are calculated. The proposed filters are tested using various ECG signals. Computer simulations demonstrate that the proposed FIR filters outperform traditional FIR filters with initial conditions set to zero.

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A Variational Approach for Designing Infinite Impulse Response Filters With Time-Varying Parameters

IEEE Transactions on Circuits and Systems I Regular Papers ◽

10.1109/tcsi.2017.2746747 ◽

2018 ◽

Vol 65 (4) ◽

pp. 1303-1313 ◽

Cited By ~ 3

Author(s):

Karel Toledo de la Garza ◽

Jorge Torres Gomez ◽

Rodrigo C. de Lamare ◽

Maria Julia Fernandez-Getino Garcia

Keyword(s):

Impulse Response ◽

Variational Approach ◽

Infinite Impulse Response ◽

Time Varying ◽

Varying Parameters ◽

Infinite Impulse Response Filters ◽

Time Varying Parameters ◽

Impulse Response Filters

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ECG Signal Processing

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.749.394 ◽

2013 ◽

Vol 749 ◽

pp. 394-400

Author(s):

Lukas Smolarik ◽

Dusan Mudroncik ◽

Lubos Ondriga

Keyword(s):

Notch Filter ◽

Electric Activity ◽

Infinite Impulse Response ◽

Measured Signal ◽

Point System ◽

Pass Filter ◽

Low Pass Filter ◽

Ecg Signals ◽

Useful Signal ◽

Contact Sensing

Electrocardiography (ECG) is a diagnostic method that allows sensing and record the electric activity of heart [. The measurement of electrical activity is used as a standard twelve-point system. At each of these leads to measure the useful signal and interference was measured. The intensity of interference depends on the artefacts (electrical lines, brum, motion artefacts, muscle, interference from the environment, etc.). For correct evaluation of measured signal there is a need to processing the measured signal to suitable form. At present, the use of electrocardiograms with sensors with contact scanning are difficult to set a time so we decided to use the principle of non-contact sensing. Such a device to measure the ECG was constructed under the project. The disadvantage of such devices is a problem with a high level of noise, which degrades a useful signal. The aim of this article is to pre-process the signals obtained from non-contact sensing. The contactless devices are powered from the network and battery. The electrodes were connected by way of Eithoven bipolar leads. Signals were pre-treated with suitable filters so that they are also appropriate for their subsequent analysis. In the filtration ECG signals was used as a method of linear (low pass filter, high pass, IIR (Infinite Impulse Response) peak, notch filter. The results of many signals clearly demonstrate removing noise in the ECG signals to the point that is also suitable for their analysis.

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Control System Design for Retinal Imaging Adaptive Optics Systems Using Orthonormal Basis Functions

Microelectromechanical Systems ◽

10.1115/imece2006-16037 ◽

2006 ◽

Author(s):

Maurizio Ficocelli ◽

Foued Ben Amara

Keyword(s):

Control System ◽

System Design ◽

Impulse Response ◽

Adaptive Optics ◽

Finite Impulse Response ◽

Retinal Imaging ◽

Basis Functions ◽

Infinite Impulse Response ◽

Control System Design ◽

Time Varying

This paper presents a solution to control system design issues for membrane mirrors used in retinal imaging adaptive optics systems. Such systems allow for the early diagnosis of eye diseases through high resolution imaging of the retina. Optical defects in the eye, known as aberrations, distort the retinal images, hence reducing their resolution. A retinal imaging adaptive optics system makes use of a deformable mirror whose shape is adjusted in real time to cancel the aberration effects. Due to the unknown and time-varying nature of the aberrations in the eye, the main control problem addressed in this paper is the tracking of an unknown and time-varying shape for the membrane mirror. Since the desired shape of the mirror is unknown and time-varying, it is proposed in this paper to design a multivariable controller that is tuned online to converge to the controller needed to achieve regulation. This is done iteratively, by taking advantage of the Q-parameterization of stabilizing controllers, so that the controller will converge to the ideal controller. Most often, finite impulse response (FIR) filters are used to represent the Q-parameter. It is proposed in this paper to represent the Q-parameter using orthonormal infinite impulse response filter basis functions. Such basis functions yield faster convergence rates during parameter estimation, and a Q-parameter representation that is less sensitive to parameter variations from the desired parameters. This is particularly crucial for the proposed application, where small errors in a typical FIR representation for the Q-parameter can lead to significant performance degradation. Simulation results are presented to illustrate the performance of the proposed adaptive controller design approach.

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