基于FPGA的TMS下脑电系统设计与研究

发布时间：2018-05-03 12:02

本文选题：经颅磁刺激 + 脑电信号　；参考：《燕山大学》2015年硕士论文

【摘要】：经颅磁刺激(Transcranial Magnetic Stimulation,TMS),是一种无痛、无创的绿色治疗方法,磁场可以无衰减地经过颅骨直接作用到大脑神经。在实际应用中,并不局限于对大脑组织的刺激,外周的神经肌肉也同样有效。目前,经颅磁刺激技术得到了广泛使用,通过改变磁刺激信号的刺激频率可以达到兴奋或抑制局部大脑皮质功能的目的。现有对TMS技术的使用发现其对脑电信号有显著的影响效果,但是需要一种在TMS环境下的脑电采集设备,来进一步了解TMS技术对于脑电采集及分析的影响。论文设计了一种基于FPGA(Field-Programmable Gate Array,现场可编程门阵列)的TMS刺激环境下的生物电信号采集设备。TMS刺激环境下,会在皮肤表层诱发一个很强的电场,可以使放大器在很长的持续时间内处于饱和状态,同时电源噪声也会被TMS刺激器引入信号采集设备中。针对上述噪声和放大器饱和问题,引入全带宽放大器的概念,对常规的生物电信号采集设备进行了改进,改进了常规采集设备的模拟电路,对引入信号采集设备中的直流分量进行衰减而不是滤波处理,使其能够采集到有效的低频及直流信号;并且将TMS刺激和脑电信号采集频率进行匹配,在TMS刺激后的作用有效时间内进行脑电信号采集,使得TMS刺激对采集的影响最小。论文介绍了包括前端放大器的设计、模拟/数字转换电路、数字处理部分、数据传输及上位机接收显示的完整硬件实现。此外,介绍了FPGA平台上的程序设计和核心的算法实现。包括数据采集、USB通信的基本原理和实现、相关滤波算法的实现等。同时讨论了程序设计和算法优化中的一些关键问题。
[Abstract]:Transcranial Magnetic stimulation is a painless and non-invasive green treatment method. Magnetic field can directly affect the brain nerve through the skull without attenuation. In practice, it is not limited to stimulation of brain tissue, peripheral neuromuscular is also effective. At present, transcranial magnetic stimulation (TMS) technology has been widely used. By changing the frequency of magnetic stimulation signals, we can achieve the purpose of stimulating or inhibiting the function of local cerebral cortex. The current use of TMS technology has found that it has a significant effect on EEG signals, but it needs a EEG acquisition equipment under the TMS environment to further understand the impact of TMS technology on EEG acquisition and analysis. In this paper, we design a bioelectric signal acquisition device based on FPGA(Field-Programmable Gate array (field programmable gate array) under TMS stimulation environment, which can induce a strong electric field in the skin surface. The amplifier can be saturated for a long time and the power noise will be introduced into the signal acquisition equipment by the TMS stimulator. Aiming at the above problems of noise and amplifier saturation, the concept of full bandwidth amplifier is introduced, and the conventional bioelectric signal acquisition equipment is improved, and the analog circuit of conventional acquisition equipment is improved. The DC component introduced in the signal acquisition device is attenuated rather than filtered so that it can collect effective low frequency and DC signals, and the frequency of TMS stimulation and EEG signal acquisition is matched. EEG signals were collected within the effective time after TMS stimulation, which made TMS stimulation have the least effect on acquisition. This paper introduces the design of the front-end amplifier, the analog / digital conversion circuit, the digital processing part, the complete hardware realization of the data transmission and the host computer receiving and displaying. In addition, the program design and core algorithm implementation on FPGA platform are introduced. It includes the basic principle and realization of USB communication of data acquisition device, the realization of relevant filtering algorithm and so on. At the same time, some key problems in programming and algorithm optimization are discussed.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R454;TN911.7

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