Several Issues Studied In Magnetic Stimulation Design

As a noninvasive clinical and research technique in medical field, now magnetic stimulation plays an important role in the word-wide research field. Currently, there exist two major problems in magnetic stimulation systems: 1. the magnetic focusing of the coil. 2. The high power dissipation of the system.Presently, the magnetic stimulation researched and developed in our country can only be used in the system with single stimulation and single capacitance. Thus, the issue of controlling repeat stimulation comes out. It includes three main problems, one problem is the charge and discharge from capacitance to inductance, another problem is whether the speed of charge in capacitance can keep up with that of discharge of induction, the third problem is how to control the switchover automatically in multi-capacitance power supply system. Besides, one of the essential techniques of magnetic stimulation is focusing. Whether all kinds of model, or optimization of coil, the purpose of both is to find out the distribution of electric field, confirm the area of field, in that case, the magnetic stimulation can be carried out selectively, which is called focus. The confirmed inclusion at present is that the main factors that influence focus include the shape and dimension of coil, the conductivity of organ on which the magnetic stimulation is operating, and also where we put the coil during stimulation.In this Graduation Project, I have made some improvement on the magnetic stimulation. Firstly, the design of automatic switchover in multi-capacitance power supply system comes true. I used single chip, keyboard, LCD and RLC circuit in logic control of digit circuit. When we input stimulation frequency from the keyboard, we get the display of frequency on LCD, and can also control the break or connection of silicon as well as the charge or discharge of three capacitances both by using single chip. Secondly, I introduce the modeling and simulation of eight coil and multi-circle coil, from that we get the results of magnetic distribution of eight coil, and we also get the result of the focus of multi-circle. The comparison between these results with the circle ones provides hopefully efficient evidences and directions of the future work. After introducing the background of the Graduation Project such as the development of the magnetic field, the newly development of the field and so on, the paper carefully and systematically illustrate the throughway of the project, the work of the project as well as the result and discussion.