Chaos Controlling On Simulink Model Of Absence Seizure

Epilepsy is a common refractory disease in Neurology. Research in its mechanism has not made much progress. In recent years, development in chaos control theory and nerve stimulation (especially transcranial magnetic stimulation, TMS) offer hope for those people who suffer from epilepsy.By adding control to epilepsy simulation system, we are try to answer the question what kind of stimulation will direct epilepsy to normal condition and how to provide it. The absence seizure model we used was the work of Dr. Suffczynski, it was simulated on the platform of Simulink.First, the typical chaotic system--Lorenz system was simulated. Then aperturbation was added to Lorenz system to see how it would affect the dynamics of Lorenz system and prepare it for epilepsy control system. After added periodic perturbation, the Lorenz system can either become stable or become more chaotic. This controlling method belongs to nonfeedback controlling method.Then we study how perturbation affect absence seizure model. According to TMS's affection to nerve system, two kind of perturbation was designed: periodic, random perturbations, and they were used to control absence seizure model. We compared the model output'(derivatives of postsynaptic potentials which is corresponding to EEG) plot, power spectrum, phase portrait, and correlation dimension with the original output'(no perturbation is added). We found that when a low-frequency perturbation (less than 1 Hz) is added to sensory input or a random perturbation is added to sensory input or cortex input, the dynamics of the system can be changed greatly (the correlation dimension is increased), when a high-frequency perturbation is added to model' input, how the dynamics of the system will change is unclear.Because low-frequency perturbation and random perturbation can make the absence seizure model more chaotic. These results may help to give proper magnetic stimulation to epileptic animals in our further experiment.