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P300 are event related potentials that are widely used; however, the performance of systems based on it decrease drastically when they are transported outside a laboratory environment where the stimuli can be isolated. Since isolation of the stimulus is not always practical it is desirable to study P300 when the subjects are receiving stimuli in other senses besides sight. Thus this paper tested the...
This paper comprises the methodology followed to design and implement a wavelet packet based algorithm for QRS region detection and R/S wave identification. Validation is performed using electrocardiographic (ECG) records 100 to 109 of the MIT-BIH Arrhythmia database. The proposed algorithm reconstructs the ECG signal using two nodes from the wavelet packet decomposition. Sensitivity (Se) and positive...
Cardiovascular diseases are still number one cause of death in the world. Once the patients have had previous events that jeopardize their physical integrity or even their life it is indispensable to monitor them anytime. The present work describes the design and implementation of a portable system able to monitor the heart rate and alerts the patient and a relative when an sinus arrhythmia occurs...
This paper comprises the analysis of rats electrocardiogram (EKG) recorded within a toxicology study. Acquired signals are processed to assess changes in heart response to air pollution in Mexico City, by means of Heart Rate Variability (HRV) using the SDNN index. EKG records were acquired along 8 days from 12 rats, divided into control group, supplied with filtered air (FA), and exposed group, who...
Along the electroencephalography signal one may identify several frequency intervals as well as negative and positive potentials which are related to conscience states (e.g. awake and asleep) and to neuronal processes such as the response to a variety of stimuli and their interpretation. The P300 is among the latter. The fact that these potentials are the result of the sum of several neurons activation,...
In this work, an algorithm based on Wavelet Transform (WT) is developed for detecting QRS complex, J point and peak and end of T wave. The algorithm has been validated using different databases provided by Physionet [1]. It is presented an application of the algorithm in the study of the Heart Rate Variability (HRV) and the JT interval is proposed as a more appropriate measure of ventricular repolarization...
This study presents a method for baseline drift removal in the ECG signal by means of the discrete wavelet transform with the Daubechies-4, in where the central pseudo-frequency parameter is used. The sampling frequency of ECG record related to each decomposition scale of the transform is assessed. DWT is applied to the level of decomposition calculated with the above values; this makes the algorithm...
This work describes the design and operation of a electrocardiograph capable of acquiring simultaneous recordings of 12-lead for the study of the spatial variability of ventricular repolarization intervals. The electrocardiography system consists of an acquisition module with a dedicated channel for each lead with a circuit for detection of lead failure. Each channel has a gain of 1000, a CMRR of...
We evaluate the dispersions in ratios of ventricular repolarization intervals, in order to determine whether they improve the separation between 10 normal subjects and 10 patients with old myocardial infarction compared with dispersion of ventricular repolarization intervals. All the ratios dispersions were larger in OMI patients than in normal subjects and the best separation between groups was obtained...
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