Modeling The Epilepsy And Neuromodulation By A Closed-loop Disturbance Rejection Approach

In recent years,low-intensity transcranial focused ultrasound stimulation is a new adjuvant treatment for epilepsy.It not only has higher spatial resolution,but also can achieve non-invasive neuromodulation.However,at present,the mechanism of ultrasound stimulation on epilepsy has not been fully clarified.Related research mainly explores the effective ultrasound stimulation parameter range via animal experiments in open-loop stimulation mode.It lacks individual adaptability.In order to improve the neuromodulation,this thesis proposes a closed-loop neuromodulation scheme based on improved linear active disturbance rejection control(LADRC).The research on closed-loop neuromodulation of the epilepsy is carried out from four aspects: optimization of the control algorithm,establishment of a mouse epileptic model,closed-loop control simulations and animal experiments.First of all,two kinds of modified LADRC schemes have been proposed to overcome deficiencies of the LADRC and reduce the difficulties in neuromodulation of the epilepsy.Stability analyses are given to prove the improved algorithms.Secondly,a multi-coupling neural mass model(NMM)is employed to model the mouse seizures.Then,based on the established mouse epileptic model,neuromodulation of the improved LADRC,PI,and LADRC are compared.Finally,through a group of animal experiments with ultrasound stimulations,it is verified that ultrasound stimulation with certain parameters can effectively suppress epilepsies in mouse.Numerical results of neuromodulation show that the proposed scalable observer bandwidth and phase lead active disturbance rejection control(SOB-PLADRC)has the advantage of little dependence on the model.Rely on inputs and outputs,epilepsies can be quickly and effectively suppressed.It shows that,by the SOB-PLADRC,modeling the complex physiological phenomena can be avoided and desired neuromodulation can be obtained.It is effective and feasible.Results of animal experiments show that choosing appropriate ultrasound stimulation parameters can effectively suppress epilepsies in mouse.Results of the thesis also lay a theoretical foundation for design of the closed-loop ultrasound neuromodulation system for epilepsies,and it provides a theoretical basis for future animal experiments or even clinical treatments.