Experimental Research Of The Induced Electric Field Measurement In The Organism Tissue

Transcranial magnetic stimulation (TMS) generates the induced magnetic field when thepulse current flows though the stimulation coils, the induced magnetic field affects the brainand generates the induced electric field which stimulates the brain to achieve the goals of thediagnosing and treatment of nervous system diseases. TMS has been applied widely by itsincomparable advantages of non-intrusive and pain-free and so on. The most importantresearch on the TMS is the investigation on its induced electromagnetic field. The mainresearch content is as follows:In order to compare with the measured values, the induced magnetic field of the roundcoils and the figure-eight coils is calculated perspectively. Then the deformed bending roundcoils and figure-eight coils are designed and their magnetic field is calculated. The resultsshow that the two kinds of the deformed coils can improve the magnetic focusing and get thebest bending angles and the best bending coils of the induced magnetic field.The induced electric field of the deformed bending figure-eight coils is calculated, andthe best bending angles of the induced electric field are obtained. The results show that thedeformed bending figure-eight coils can effectively improve the electric field focusing. Themeasuring methods of the electromagnetic field are compared. The electromagnetic inductionmethod is adopted to measure electromagnetic field. The theory of the electromagnetic fieldmeasuring field which is adopted is deduced. The measurement of electromagnetic field isachieved by using the electromagnetic induction method.The induced electric field acquisition and display device based on the micro-programmed controller unit (MCU) is made, which includes the making of MCU minimumsystem and AD acquisition system, and the data display interface on the host computer byusing LabVIEW software. The MCU uses STC89C52RC, AD conversion chip uses AD0804.The printed circuit boards are drawn by using Altium Designer software and the hardware iscompleted. After that the induced electric field of the coils is measured by using the inducedelectric field acquisition and display device. The results show that the device can measure partof the valid data under the experimental conditions.