Browsing by Author "Frank, Alejandro"

Now showing 1 - 2 of 2
  • Artículo
    Enhancement of early warning properties in the Kuramoto model and in an atrial fibrillation model due to an external perturbation of the system
    (2017-07-28) García Gudiño, David; Landa, Emmanuel; Mendoza Temis, Joel; Albarado Ibañez, Alondra; Toledo Roy, Juan C.; Morales, Irving O.; Frank, Alejandro; García Gudiño, David; 0000-0002-8696-6169; Mendoza Temis, Joel; 0000-0002-4164-2881; Albarado Ibañez, Alondra; 0000-0002-4725-7714
    "When a complex dynamical system is externally disturbed, the statistical moments of signals associated to it can be affected in ways that depend on the nature and amplitude of the perturbation. In systems that exhibit phase transitions, the statistical moments can be used as Early Warnings (EW) of the transition. A natural question is thus to wonder what effect external disturbances have on the EWs of system. In this work we study the impact of external noise added to the system on the EWs, with particular focus on understanding the importance of the amplitude and complexity of the noise. We do this by analyzing the EWs of two computational models related to biology: the Kuramoto model, which is a paradigm of synchronization for biological systems, and a cellular automaton model of cardiac dynamics which has been used as a model for atrial fibrillation. For each model we first characterize the EWs. Then, we introduce external noise of varying intensity and nature to observe what effect this has on the EWs. In both cases we find that the introduction of noise amplified the EWs, with more complex noise having a greater effect".
  • Artículo
    The role of the autonomic nervous system on cardiac rhythm during the evolution of diabetes mellitus using heart rate variability as a biomarker
    (2019-05-09) Albarado Ibañez, Alondra; Arroyo Carmona, Rosa Elena; Sánchez Hernández, Rommel; Ramos Ortiz, Geovanni; Frank, Alejandro; García Gudiño, David; Torres Jácome, Julián; Albarado Ibañez, Alondra; 0000-0002-4725-7714; Arroyo Carmona, Rosa Elena; 0000-0002-0471-994X; Sánchez Hernández, Rommel; 0000-0002-4008-4179
    "Heart rate variability (HRV) is highly influenced by the Autonomic Nervous System (ANS). Several illnesses have been associated with changes in the ANS, thus altering the pattern of HRV. However, the variability of the heart rhythm is originated within the Sinus Atrial Node (SAN) which has its own variability. Still, although both oscillators produce HRV, the influence of the SAN on HRV has not yet been exhaustively studied. On the other hand, the complications of diabetes mellitus (DM), for instance, nephropathy, retinopathy, and neuropathy, increase cardiovascular morbidity and mortality. Traditionally, these complications are diagnosed only when the patient is already suffering from the negative symptoms these complications implicate. Consequently, it is of paramount importance to develop new techniques for early diagnosis prior to any deterioration on healthy patients. HRV has been proved to be a valuable, noninvasive clinical evidence for evaluating diseases and even for describing aging and behavior. In this study, several ECGs were recorded and their RR and PP intervals were analyzed to detect the interpotential interval (ii) of the SAN. Additionally, HRV reduction was quantified to identify alterations in the nervous system within the nodal tissue via measuring the SD1/SD2 ratio in a Poincaré plot".