Examinando por Materia "ELECTROCARDIOGRAPHY ( ECG )"

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  • Miniatura
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    Desarrollo de un Holter digital con grabación de eventos y software de visualización
    (2014-04-24) Villa-Rodríguez, L. (Leonardo); Lemos-Duque, J. D. (Juan Diego)
    The ambulatory monitoring of electrocardiographic signals, “Holter”, represents a decisive tool in the diagnostic evaluation of patients with cardiac arrhythmias involved in pathological processes like cardiomyopathies, post-infarct stages, injuries of the cardiac autonomous system, among others, as well as in the monitoring of implanted pacemakers. There are few devices of this kind available in Colombia and most of them are very specialized and expensive for the majority of patients. We built a cardiac monitoring and cardiac events registering system prototype that processes the ECG signals (amplification, filtration and DC elevation), and stores the data acquired from the three main derivations DI, DII and DIII in an SD (Security Digital) memory using the FAT (File Allocation Table) standard, which allows the reading of this information in any computer. Moreover, we developed a software program that allows for the visualization of the registries previously stored in the SD memory for their review and analysis. Using an ECG simulator, the frequencies 30 BPM, 120 BPM and 300 BPM and the amplitudes 0,5 mV, 1 mV and 2 mV were calibrated. It was found that the prototype errors were smaller than 1% for frequency and 6% for amplitude.
  • Miniatura
    PublicaciónAcceso abierto
    Modelo paramétrico de la actividad eléctrica celular cardiaca estimado a partir de registros electrocardiográficos estándares
    (2014-05-05) Illanes, A. (Alfredo); Sérandour, G. (Guillaume)
    The main purpose of this paper is to relate cellular cardiac electrical activity with the cardiac electrical activity measured in only one electrocardiogram (ECG) lead, through a cellular action potential (AP) parametrical model. This is performed by relating known dynamics, which can be mathematically modeled, existing at a cardiac cell level, to dynamics which can be obtained from a standard ECG recording. The main cellular dynamic used for relating with the ECG is the one known as three dimensional cellular restitution curve, which relates the action potential duration (APD) with its preceding diastolic interval and with the APD of the preceding cardiac cycle. Similar restitution curves were found in ECG signals recorded under the isometric handgrip test by relating the QT interval with its preceding TQ interval and with the QT interval of the preceding cardiac cycle. Following this similarity, a parametrical restitution curve, derived from a three ionic current cellular AP model was fitted to the ECG restitution relation for AP model parameter estimation. This model is finally simulated by stimulating it with an impulse train of frequency similar to the heart rate of the tested subject. The results show that the restitution curve experimentally obtained from the ECG is similar to the one obtained from de AP model simulation. Moreover the simulated APD follows satisfactorily the QT interval time variation of the tested subject. This opens new perspectives for the analysis of cellular cardiac electrical activity from standard ECG recordings.
  • Miniatura
    PublicaciónAcceso abierto
    Sistema de transmisión inalámbrica de señales ECG y de temperatura para ambientes hospitalarios (SINHO)
    (2014-04-24) Ballesteros, D. M. (Dora María); Melo, H. E. (Harvey Enrique); Maya-Quintero, A. J. (Ascanio José)
    This paper presents the design, development and testing of a multi-channel device for acquisition and transmission of ECG and temperature signals, using wireless transmission technologies (Bluetooth, ZigBee, RF), with a central monitoring user interface. We analyzed the system’s performance based on its availability (97%), connection time (6 seconds) and measurement’s accuracy (98%)