应用于肌电信号探测的放大器设计

发布时间：2018-06-16 09:17

本文选题：功能电刺激 + 运算跨导放大器　；参考：《东南大学》2017年硕士论文

【摘要】：相关数据显示,我国有2000多万各类肢体截瘫患者,其中有200多万因脊髓损伤导致的截瘫或四肢瘫痪患者。患者生活自理能力受限甚至丧失,严重影响了生活质量。采用微电子技术和神经系统理论相结合的方法,采集正常人体四肢的体表肌电(Surface Electromyographic,SEMG)信号,对瘫痪肢体进行功能电刺激,从而实现瘫痪肢体协调和运动功能重建的目标。体表肌电信号的采集与放大对于整个神经信号探测前端来说非常重要。本论文主要研究体表肌电信号放大器电路的设计。本设计采用两级滤波器级联的结构,将噪声与信号摆幅分开考虑,使用基于gm/id的设计方法分别设计两级运算跨导放大器(Operational Transconductance Amplifier,OTA),采用有源晶体管来实现大阻值的反馈电阻,从而实现选频功能。将充当有源电阻的晶体管的栅极电压单独引出,调节此电压可以控制电阻值以确保精确选频。整个设计采用TSMC0.18μmCMOS工艺,供电电压为1.8V,根据后仿结果显示,整个肌电信号放大器增益为60dB,可以实现50～1500HZ的选频,静态功耗为7.2μW,在50-1000HZ的频带内,积分噪声为2.03μVrms,电压输出摆幅达到±0.92V,噪声效率因子(Noise Efficiency Factor,NEF)为 4.86。整个芯片尺寸为 2mm×3mm。根据仿真结果,肌电信号放大器能够有效地探测并放大微弱的体表肌电信号,为接下来信号的数字化处理和传递打下了良好的基础,也为从分立元器件设计转向微电子化设计积累了经验。
[Abstract]:The related data show that there are about 20000000 kinds of limb paraplegia in our country, of which about 2000000 of the patients with paraplegia or limb paralysis caused by spinal cord injury. The patient's self-care ability is limited or even lost, which seriously affects the quality of life. A combination of microelectronics and neural system theory is used to collect the body surface of the normal body. Surface Electromyographic (SEMG) signals are used to perform functional electrical stimulation of paralyzed limbs to achieve the objective of paralyzed limb coordination and movement function reconstruction. The acquisition and amplification of the body surface EMG signal is very important for the whole nerve signal detection front end. This paper mainly studies the design of the body surface EMG signal amplifier circuit. The design adopts a cascade of two stage filter, which divides the noise from the signal swing separately. Using the gm/id based design method, the two level operational transconductance amplifier (Operational Transconductance Amplifier, OTA) is designed respectively. The active transistor is used to realize the feedback resistance of the large blocking value, thus the frequency selection function is realized. The gate voltage of the resistive transistor is extracted separately, adjusting this voltage to control the resistance value to ensure accurate frequency selection. The whole design uses TSMC0.18 micron mCMOS technology and the power supply voltage is 1.8V. According to the post simulation results, the whole EMG amplifier gain is 60dB, which can achieve 50 to 1500HZ frequency selection, static power consumption is 7.2 u W, 50-1000HZ In the frequency band, the integral noise is 2.03 mu Vrms, the voltage output swing is + 0.92V, the noise efficiency factor (Noise Efficiency Factor, NEF) is 4.86. whole chip size 2mm * 3mm. based on the simulation results. The EMG signal amplifier can effectively detect and amplify the weak body surface muscle electrical signal, for the digital processing and transmission of the next signal. It has laid a good foundation, and has accumulated experience for the design of discrete components to microelectronics.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN722

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