Papers by Keyword: Action Potential

Abstract: Because volleyball athletes’ lower body and tendon strength all carry out overload operation in the intense training process, its long time exercise will bring pain for volleyball athletes. Therefore, to carry out lower body muscle dynamics research and its electromyography on volleyball players' muscle EMG changes analysis. While the establishment of volleyball players' lower body muscle kinetic model equations, to analyze of the muscle state characteristics from the dynamic perspective on the volleyball player batting process. And to establish the interaction between the lower body muscle and tendon, which can provide reference for protecting volleyball athletes’ lower body muscles.

Abstract: Cardiac short-term memory which reflects the influence of pacing history is an intrinsic property of paced myocardium. It has been observed that premature ventricular contractions (PVCs) facilitate initiation of reentrant tachyarrhythmias. However, little is known about effects of pacing history on electrical behaviors of postextrasystolic beats. In the paper, by incorporating endo-, mid-, and epi-cardial myocytes, we developed a one-dimensional heterogeneous fiber to examine effects of the number of regular stimulations before PVCs on postextrasystolic depolarizations (PEDs). OpenMP parallel algorithm was performed on a four-core personal computer to accelerate the calculation. The results showed that for any type of myocytes, APDs for PEDs became longer for 500 than for 100 regular driven beats. The calculated ECGs reflected that repolarisation of the tissue was also lengthened for the fast long time pacing. Therefore, it was suggested that because of accumulation of memory, prolonged APDs and repolarisation after PVCs could provide sites for unidirectional block in the tissue and increase the risk of reentrant arrhythmias.

Abstract: Biomedical computer simulation can help researchers to recognize the regularities of living systems, In the paper, The modeling and simulation of ventricular cell action potentials, Purkinje fiber action potentials and pacemaker activities of sino-atrial node cells were performed. Reconstruction and analysis to the changes of the electrical activities in myocardial cells by modulating the environment factors.

Abstract: Computer simulation is an important method in the study of cardiac electrophysiology. However, complicated studies in tissues are difficult because of the long computation time. In order to speed up the simulation, in this paper a parallel algorithm based on OpenMP was studied on a multi-core computer. The Noble 91 mathematical model was used to develop a two-dimensional tissue. By initiating a reentrant wave, properties of the conventional sequential program, programs of the data parallelism and functional parallelism were analyzed and compared. The results showed that the execution time of the data parallelism was only about one-fourth of the sequential execution time and its efficiency was high, however, the execution time of the functional parallelism was approximately ten times of the sequential execution time and its efficiency became low. Therefore, the method of the data parallelism could significantly reduce the computation time and was suggested to be a good choice in the myocardial simulation.

Abstract: The Fitzhugh-Nagumo (fn) mathematical model characterizes the action potential of the membrane. The dynamics of the Fitzhugh-Nagumo model have been extensively studied both with a view to their biological implications and as a test bed for numerical methods, which can be applied to more complex models. This paper deals with the dynamics in the (FH) model. Here, the dynamics are analyzed, qualitatively, through the stability diagrams to the action potential of the membrane. Furthermore, we also analyze quantitatively the problem through the evaluation of Floquet multipliers. Finally, the nonlinear periodic problem is controlled, based on the Chebyshev polynomial expansion, the Picard iterative method and on Lyapunov-Floquet transformation (L-F transformation).