João Evangelista Neto

New approach for T-wave end detection on electrocardiogram: Performance in noisy conditions

BackgroundThe detection of T-wave end points on electrocardiogram (ECG) is a basic procedure for ECG processing and analysis. Several methods have been proposed and tested, featuring high accuracy and percentages of correct detection. Nevertheless, their performance in noisy conditions remains an open problem.MethodsA new approach and algorithm for T-wave end location based on the computation of Trapeziums areas is proposed and validated (in terms of accuracy and repeatability), using signals from the Physionet QT Database. The performance of the proposed algorithm in noisy conditions has been tested and compared with one of the most used approaches for estimating the T-wave end point: the method based on the threshold on the first derivative.ResultsThe results indicated that the proposed approach based on Trapeziums areas outperformed the baseline method with respect to accuracy and repeatability. Also, the proposed method is more robust to wideband noise.ConclusionsThe trapezium-based approach has a good performance in noisy conditions and does not rely on any empirical threshold. It is very adequate for use in scenarios where the levels of broadband noise are significant.

ENERGY MANAGEMENT SYSTEM. CASE STUDY: HOSPITAL OF HEARTH DISEASE

Copyright ©2016 by authors and Institute of Technology Galileo of Amazon (ITEGAM). This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ ABSTRACT In this article is to describe the steps in the implementation of an energy management system and its application to a case study, this case was a hospital for cardiovascular diseases. The implementation of the energy management system in this center has been validated previously by the authors in many companies with different missions whether the productive sector and services. This method is result of several approach complementations from other existing methods, adding thermodynamics and mathematical-statistical tools. The aims of the method is to provide a tool that allows diagnose the energy management stage in enterprise or services center and at the same time address the enterprise energy management to achieving an efficient use of the energy carriers. The most important result of the implementation of the method in a hospital were the followings: Areas and equipment Higher Energy consumers, percentage of electricity not associated with patients serving directly, the ratio between the number of assist patients per month and the energy efficiency. These results allow know the potential savings in the hospital and establish an action plan.

Two solutions for the processing of ambulatory electrocardiogram

The Electrocardiogram (ECG) ambulatory monitoring has three stages: acquisition, processing and analysis, in each one, the information on ECG signal itself or the time series extracted from it are affected by noises, interferences and artifacts. The analysis of the duration and variability of heart intervals establishes rules for the selection of valid beats and to determine with accuracy the fiducially points, especially the T wave end. This paper describes two problems and their solutions involved in the processing stage. First, a method is described to identify the valid beats for heart rate variability analysis, and then another one is presented for the determination of T wave end point, based on the calculation of trapezes areas. The validation of both methods exhibits excellent performance indexes in comparison with other approaches.