Design of Electrocardiography Signal Acquisition and Processing Software Module
Duong Trong Luong,
Nguyen Duc Thuan,
Nguyen Minh Duc,
Dang Huy Hoang,
Nguyen Ngoc Xuan
Issue:
Volume 3, Issue 2, April 2015
Pages:
11-17
Received:
10 March 2015
Accepted:
23 March 2015
Published:
28 March 2015
Abstract: This paper presents the design of electrocardiography (ECG) signal acquisition and processing using graphic programming language LabVIEW 2012. The module software is designed towards applying in researches, monitoring and diagnosing cardiovascular diseases. The module software includes several main functions such as acquiring and displaying ECG signals in real time; filtering common artifacts in ECG signal using different algorithms and techniques; reading, displaying, analyzing and processing available ECG database; computing heart rate; saving ECG signals before and after noises filtering in data and graphs format; analyzing ECG signals before and after noises filtering by spectral analysis method. The designed module software is tested with arrhythmia ECG database and 12-lead ECG database from physionet.org and experimented with measuring from volunteer in the lab. The experimented results show that this module could support for researches, monitoring and diagnosing cardiovascular diseases.
Abstract: This paper presents the design of electrocardiography (ECG) signal acquisition and processing using graphic programming language LabVIEW 2012. The module software is designed towards applying in researches, monitoring and diagnosing cardiovascular diseases. The module software includes several main functions such as acquiring and displaying ECG sig...
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Analysis by Computer Simulation of Factors Affecting the Extracellular Slow Wave Features of the Human Colon
Nicola Mirizzi,
Giuseppe Riezzo
Issue:
Volume 3, Issue 2, April 2015
Pages:
18-24
Received:
9 March 2015
Accepted:
25 March 2015
Published:
31 March 2015
Abstract: The study reported in this paper analyses, by computer simulation, factors affecting the features (amplitude, frequency and phase lag) of the slow waves of the extracellular myoelectrical activity of the human ascending colon. It takes into account both the anatomic and functional aspects of the colon haustra, the myoelectrical dynamics of the cells and the geometric modification of haustra’ configuration. The variable sacculated geometry of the colon wall, segmented into typical haustra, has been represented by a sequence of truncated round ellipsoids. According to the propagation of the front of depolarization-repolarization of the cells, slow waves are simulated by the cyclic movement of an annular band polarized by electrical dipoles oriented perpendicularly with respect to the surface of the ellipsoids and activated by a pacemaker. The simulation highlighted that the amplitude of the slow waves physiologically depends on the dipole moment of cells, and the frequency depends on the velocity of the polarized annular band. In addition, the amplitude, the frequency and the phase lag also depend on the dynamic modification of the geometrical factors (colon length and haustrum radius). Furthermore, the simulation results showed that the shape of the slow wave and the amplitude of its peaks depend on the inter-electrode distance and on the electrode positioning with respect to the lower edge of ellipsoids.
Abstract: The study reported in this paper analyses, by computer simulation, factors affecting the features (amplitude, frequency and phase lag) of the slow waves of the extracellular myoelectrical activity of the human ascending colon. It takes into account both the anatomic and functional aspects of the colon haustra, the myoelectrical dynamics of the cell...
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Coherence Function in Noisy Linear System
Issue:
Volume 3, Issue 2, April 2015
Pages:
25-33
Received:
12 March 2015
Accepted:
25 March 2015
Published:
2 April 2015
Abstract: The coherence function provides a measure of spectral similarity of two signals, but measurement noise decreases the values of measured coherence. When the two signals are the input and output of a linear system, any system noise also decreases the measured coherence values. In digital computations, useful coherence values require some degree of averaging to increase the degrees of freedom to more than two. These fundamental issues are presented with application to system input-output coherence and two random signals with a common component. Finally, estimated coherence of the two random signals, with varying degrees of freedom, are shown with empirical adjustments that can improve the estimate of coherence. Coherence has a wide range of biomedical applications, but this article focuses on the fundamental properties of the coherence function.
Abstract: The coherence function provides a measure of spectral similarity of two signals, but measurement noise decreases the values of measured coherence. When the two signals are the input and output of a linear system, any system noise also decreases the measured coherence values. In digital computations, useful coherence values require some degree of av...
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