The behavior of neurons can be modeled by the FitzHugh-Nagumo oscillator model, consisting of two nonlinear differential equations, which simulates the behavior of nerve impulse conduction through the neuronal membrane. In this work, we numerically study the dynamical behavior of two coupled FitzHugh-Nagumo oscillators. We consider unidirectional and bidirectional couplings, for which Lyapunov and isoperiodic diagrams were constructed calculating the Lyapunov exponents and the number of the local maxima of a variable in one period interval of the time-series, respectively. By numerical continuation method the bifurcation curves are also obtained for both couplings. The dynamics of the networks here investigated are presented in terms of the variation between the coupling strength of the oscillators and other parameters of the system. For the network of two oscillators unidirectionally coupled, the results show the existence of Arnold tongues, self-organized sequentially in a branch of a Stern-Brocot tree and by the bifurcation curves it became evident the connection between these Arnold tongues with other periodic structures in Lyapunov diagrams. That system also present multistability shown in the planes of the basin of attractions.

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Introduction: Amyotrophic Lateral Sclerosis (ALS) is a progressive and degenerative motor disease of the nervous system. Symptoms are variable, the main one being muscle weakness. Treatment is based on medication and monitoring by a multidisciplinary team to maintain quality of life (QoL) and autonomy. There are barriers, like mobility, and telehealth (TH) can be a possibility of care. Objectives: To identify evidence of the use of TH in patients with ALS to improve symptoms and QoL. Design and settings: Study carried out at Centro Universitario São Camilo. Methodology: Literature review in the PubMed, Lilacs and PEDro, between 2011 and 2021, in Portuguese, English or Spanish, with “ALS”, “telemedicine”, “TH”. Results: Of the 14 studies found, 13 were selected after review. The majority (93%) made use of video and telephone calls for monitoring and new orientations, after face-to-face evaluation; but all showed the possibility of remote assessment, associated or no with technological resources (such apps, accelerometers, smartwatches). 31% of the studies reported indication of TH for respiratory care in critically ill patients. In general, 93% of the papers demonstrated that TH brought benefits in maintaining QoL and improving respiratory parameters. Conclusion: Use of TH in patients with ALS seems to be to viable, safe and beneficial for assessment and monitoring, especially in advanced stages and for respiratory symptoms.