Heriberto Zavala-Fernández

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T-wave alternans (TWA) allows for identification of patients at an increased risk of ventricular arrhythmia. Stress test, which increases heart rate in controlled manner, is used for TWA measurement. However, the TWA detection and analysis are often disturbed by muscular interference. The evaluation of wavelet based denoising methods was performed to find(More)
Event-related potentials (ERP) recorded by electroencephalography (EEG) are brain responses following an external stimulus, e.g., a sound or an image. They are used in fundamental cognitive research and neurological and psychiatric clinical research. ERPs are weaker than spontaneous brain activity and therefore it is difficult or even impossible to identify(More)
A combined MEG and EEG data vector was input into the standard TDSEP algorithm.As time delays the set was chosen in the TDSEP calculation and consequently a set of 101 time-lagged covariance matrices had to be simultaneously diagonalized. The calculation was performed for each of the subjects separately. t t = 1, 5, 10, 15, , 500 ... s M,E=0 (t) = W· x M(More)
231 Influence of Mobile Phones on the Quality of ECG Signal Acquired by Medical Devices T. Buczkowski, D. Janusek, H. Zavala-Fernandez, M. Skrok , M. Kania, A. Liebert Institute of Radioelectronics, Faculty of Electronics and Information Technology, Warsaw University of Technology, Nowowiejska Str., 15/19, 00-665, Warsaw, Poland, t.buczkowski@ire.pwe.edu.pl(More)
The application of Blind Source Separation (BSS) is now an accepted technique in the feld of biosignal processing. The reduction of noise (biological and technical artifacts) in body surface potential mapping recorded during exercise is a frequent goal. Two BSS methods (FastICA and temporal decorrelation) for removing noise are compared with respect to the(More)
All algorithms were capable of isolating the heart beat and most algorithms succeeded for the eye movements. Reduction of eye movement artifact is important in clinical applications as patients often cannot control their eye movements. The suggested comparative framework is of high practical value as demonstrated on a limited data set. Future work will(More)
Acquisitions of body surface potentials require in some studies that, patients perform exercise on cycle ergometer to increase their heart rate. Under this condition recordings are highly affected by the muscular activity derived from the pedalling (motion artefact). To reject this interference we propose the use of independent component analysis (ICA) by(More)
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