【作者】 韩晴；

【导师】 梁国壮； 贺银方；

【作者基本信息】 河北科技大学 ， 生物医学工程， 2011， 硕士

【摘要】 随着电刺激技术在临床应用的蓬勃发展,磁刺激技术也越来越受到研究者的关注和重视。近年来,在临床诊断及疾病治疗中,磁刺激技术不断被证实具有较高的应用价值和应用前景,因此一直受到各国研究人员的广泛关注。相对于电刺激技术,磁刺激技术具有无创伤、无痛、有效、易于重复操作及操作简单等明显优点。目前应用于临床的磁刺激系统基本分为两类:高频强磁场的磁刺激系统(如:经颅磁刺激transcranial magnetic stimulation, TMS)和超低频磁场磁刺激系统(extremely low frequency, ELF)。高频强磁场的磁场强度可以达到2.5特斯拉甚至更高,一般采用电容充放电产生交变电流,既而产生磁场。超低频磁场磁刺激系统的磁场强度一般在几十mT甚至更小。本文设计一款由AT89S52型单片机控制的超低频磁场刺激系统,单片机程序均由汇编语言开发。与现有的磁刺激系统不同,本文设计的磁刺激系统是一款由单片机控制,产生磁场的频率强度可调的磁刺激系统。系统硬件由AT89S52型单片机、数码管显示模块、D/A转换模块、功率放大模块、按键控制模块、电源电路模块和电极线圈组成。7位数码管实现了治疗时间、刺激强度/频率和功能状态的实时显示;按键控制模块实现了磁场频率、强度的调节。本设计采用Proteus单片机仿真软件对系统硬件和单片机程序进行了仿真,均达到了设计要求。应用Ansoft电磁场有限元仿真软件对三维线圈模型进行了磁场仿真,磁感应强度达到20mT左右。此外采用Protel 99SE绘制磁刺激系统电路原理图,并绘制系统的印刷板电路,完成了样机的焊接与调试。在白求恩国际和平医院的睡眠障碍研究中心,应用本系统对正常成年人和嗜睡病人进行了睡眠障碍患者的临床试验。采集刺激前后的脑电信号,并对脑电信号进行了功率谱分析和脑电地形图显示与分析。测试表明,磁刺激系统对嗜睡病人进行治疗,磁场刺激可以提高脑电信号的幅值,在清醒闭目状态下,进入轻度睡眠的时间有所增加,额部脑电信号幅度有所增加,眼动期缩短,表明磁刺激能够有效改善嗜睡病人的症状,提高睡眠质量。更多还原

【Abstract】 With booming development of electrical stimulation technology in the clinical application, researchers pay more and more attentions at magnetic stimulation technology. The magnetic stimulation technology which used in clinical diagnosis and treatment of diseases proofed that it has a high application value and tempting prospects for the development, therefore, it has been hit by a wide attention of scholars. Relative to the electrical stimulation technology, the magnetic stimulation technology have the advantage at painless, easy to repeat operation, no wound, effective and easy to operate.At present, the magnetic stimulation system used in clinically research is basically divided into two classes: high-frequency magnetic field of magnetic stimulation system (such as, transcranial magnetic stimulation, TMS) and extremely low frequency magnetic stimulation system (ELF).The magnetic field strength of high-frequency magnetic field can reach 2.5 tesla’s or higher, which generally use the capacitor recharge to produce alternating current, then produce a magnetic field. The magnetic field strength of extremely low frequency magnetic stimulation system is in commonly several millitesla’s or even smaller. A type of low frequency magnetic stimulation system based on the AT89S52 SCM is designed in the paper, and I develop the all microcontroller program by assembly language.Different from the existing magnetic stimulation system, the magnetic stimulation system designed in the paper is controlled by SCM, and the SCM sent out the pulse waveform for magnetic stimulation system. This system hardware consists of the AT89S52 SCM, digital pipe display module, D/A conversion module, power amplifier module, button control module, power supply module and electrode coil etc. The treatment time, stimulate strength/frequency and functional status are displayed by Seven digital tube. The frequency and amplitude are adjusted by button control module, and which realized the innovation of the magnetic field frequency stimulation system that can not be adjusted. The system hardware and microcontroller program are simulated by the Proteus single-chip microcomputer simulation software in the design, which reached the design requirements. The three-dimensional electromagnetic field coil model is simulated by ansoft fem simulation software, and the magnetic field strength reach to 20 millitesla’s. This article have used Protel 99SE software to map the magnetic stimulation system of the circuit principle diagram, and developed the printing plate circuit, completed the prototype of welding and debugging.In Bethune international peace hospital’s sleep disorders research center, we did research to compare the normal adults and sleepiness patients when they underwent stimulation, compare EEG before and after stimulation, and analysis the EEG by power spectrum. Tests show that the magnetic stimulation inhibits certain parts of the brain cortex, and sleepiness patient have stronger effect than normal adult.更多还原