Design And Analysis Of Adjustable Multi-parameter Transcranial Magnetic Stimulation System

Non-invasive brain modulation has become an effective means of diagnosis and treatment of neuropsychiatric disorders.Transcranial magnetic stimulation technology has been widely used for its non-invasive features.Although various forms of stimulation have been proposed,the design of the corresponding stimulation device lags behind the theoretical research,and the current device is relatively simple and cannot meet the clinical needs.Therefore,this paper developed a new stimulation device from the perspective of designing flexible adjustment of stimulation parameters.First of all,in the stimulation system proposed in this paper,the adjustable parameters included the current form in the coil,the stimulation intensity and the stimulation coil.The overall structure of the system was described in detail.Based on the theory of electromagnetic field,the realization of monophasic,biphasic or burst stimulating currents,the adjustment of stimulus intensity and the control of coil selection were all given the corresponding circuit simulations to verify the feasibility of the scheme.At the same time,the control of multi-coil array also gives a brief design.Secondly,the design of the magnetic stimulation system was realized by the hardware circuit,including the power supply circuit,the control circuit,the inverter circuit and the coil control circuit.The specific parameters of the circuit were all given in this paper.Based on the designed stimulation circuit,the corresponding experimental results was compared with the results of circuit simulation.Finally,the coils and brain models were constructed based on the finite element analysis method.The model parameters were given and the evaluation criteria for stimulus effects were defined: stimulus depth and focus.The inductive electric field distribution and the stimulating effect of two kinds of commercial coils were analyzed briefly.Then the influence of the variation of the diameter and angle of the stimulating coil on the stimulating effect was analyzed emphatically.The regularity in the changing process was quantitatively and qualitatively analyzed.This paper gives the design and theoretical analysis of the magnetic stimulation device from the aspects of stimulating current waveform design,circuit simulation,hardware system realization,electromagnetic field distribution,which provides a new idea for the design and application of new transcranial magnetic stimulation device.