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精密生物电信号频率与占空比测量电路的设计及其在神经阈值刺激仪中的应用 总被引:1,自引:0,他引:1
介绍了结构简单、测量准确的精密生物电信号频率与占空比测量电路的原理及其在神经阈值刺激仪中的应用。 相似文献
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便携式心电检测放大电路设计 总被引:2,自引:1,他引:2
目的:为便于日常心电监护,开发了一种便携式心电检测系统,介绍这种便携式心电检测系统中放大电路的设计。方法:该心电放大电路以AD620、OPA4277和TLC2254作为放大电路核心元件,针对心电信号的特殊信号和干扰频率范围,进行了分析,对由电极采集到的心电信号,通过前置放大部分,将微弱的心电信号高保真放大,并通过低通滤波、高通滤波及50Hz陷波滤除干扰。结果:差模电压增益为1000,共模抑制比为90dB,输入阻抗大于10GQ,通频带为0.035~110Hz。结论:系统具有高输入阻抗、高共模抑制比、低噪声、低温漂和高信噪比等优点,而且成本低、体积小、耗电少、携带方便。 相似文献
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肌电信号(EMG)是一种伴随肌肉运动而产生的生物电信号,对表面EMG的分析研究可发现它与肌肉生理状态和肢体运动模式之间的对应关系。基于生物反馈技术研制肌电信号生物反馈仪采用AT-MEGA16 AVR单片机为核心元件,通过信号调理电路消除表面EMG工频干扰和噪声,并利用声光报警反馈肌肉紧张程度信息。本文介绍了肌电信号生物反馈仪的基本构成及其特点,并对肌电生物信号的特点和提取方法进行了分析,采用均方根值(RMS)法实时反映肌肉活动状态,试验结果表明本系统能有效缓解肌肉的紧张程度,在康复医学方面有较好的应用前景。 相似文献
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仪器设备检修中,直流电压(包括电源及电路工作点)是最基本的测量项目。作为其检测工具,应该说有万用表和示波器可选,但由于二者功能上的侧重点不同,万用表侧重于电压、电流、电阻的数值测量,示波器侧重于电信号形态的监视(当然也包括信号频率及峰值的检测等功能)... 相似文献
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邵长菁 《中国医疗器械杂志》1994,18(5):269-271
该系统不仅利用通过传感器获得的肌电信号作反馈调节自我治疗,而且用单片机对生物电信号进行频谱分析,作为对人体病变进行辅助诊断的客观依据。 相似文献
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便携式心电监护仪的研制 总被引:5,自引:0,他引:5
本文主要介绍了便携式心电监护仪的系统设计原理。该监护仪由89S516单片机为控制中心,实现了对心电信号病态信号的实时采集、分析、存储、显示和报警等功能。其光电隔离电路能够有效的提高电路的线性度,改善电路的稳定性和频率特性。 相似文献
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在单导心电图机中心电信号输入到标准12导联选择是采用威尔逊网络而获得。而一种小型智能化心电图机———ECG-8110K型,打破使用威尔逊网络获取标准12导联方法的常规,采用微机处理系统控制进行加减组合运算而获得标准12导联心电图波形的手段,从而提高自动分析的可靠性。和单导心电图机一样,多导心电图机从人体表面获得的心电信号通过高压和中压保护电路、高频滤波电路后进入输入电路。单导心电图机则进入威尔逊网络获得标准12导联心电图波形,而ECG-8110K型心电图机则首先由人体上接收到的心电信号经导联线分别送… 相似文献
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Mehdi Rajabioun Ali Motie Nasrabadi Mohammad Bagher Shamsollahi 《Australasian physical & engineering sciences in medicine / supported by the Australasian College of Physical Scientists in Medicine and the Australasian Association of Physical Sciences in Medicine》2017,40(3):675-686
Effective connectivity is one of the most important considerations in brain functional mapping via EEG. It demonstrates the effects of a particular active brain region on others. In this paper, a new method is proposed which is based on dual Kalman filter. In this method, firstly by using a brain active localization method (standardized low resolution brain electromagnetic tomography) and applying it to EEG signal, active regions are extracted, and appropriate time model (multivariate autoregressive model) is fitted to extracted brain active sources for evaluating the activity and time dependence between sources. Then, dual Kalman filter is used to estimate model parameters or effective connectivity between active regions. The advantage of this method is the estimation of different brain parts activity simultaneously with the calculation of effective connectivity between active regions. By combining dual Kalman filter with brain source localization methods, in addition to the connectivity estimation between parts, source activity is updated during the time. The proposed method performance has been evaluated firstly by applying it to simulated EEG signals with interacting connectivity simulation between active parts. Noisy simulated signals with different signal to noise ratios are used for evaluating method sensitivity to noise and comparing proposed method performance with other methods. Then the method is applied to real signals and the estimation error during a sweeping window is calculated. By comparing proposed method results in different simulation (simulated and real signals), proposed method gives acceptable results with least mean square error in noisy or real conditions. 相似文献
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The paper deals with the functional diagnosis based on the synchronous analysis of a spirogram and a cardiac intervalogram (CIG) by evaluating respiratory sinus arrhythmia (RSA). A method based on the calculation of R-R interval differences in separate breathing cycles is used for automated reckoning of RSA. A band-pass filter is employed to separate out a respiratory constituent of CIG. The programmed algorithmic use of the method is based on a linear selective transformation that is a general procedure for morphological analysis of cardiac signals in real time. 相似文献
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Tianning Li Peng Wen Sophie Jayamaha 《Australasian physical & engineering sciences in medicine / supported by the Australasian College of Physical Scientists in Medicine and the Australasian Association of Physical Sciences in Medicine》2014,37(2):431-437
This paper applies the nonlocal mean (NLM) method to denoise the simulated and real electroencephalograph signals. As a patch-based method, the NLM method calculates the weighted sum of a patch. The weight of each point is determined by the similarity between the points of the own patch and its neighbor. Based on the weighted sum, the noise is filtered out. In this study, the NLM denoising method is applied to signals with additive Gaussian white noise, spiking noise and specific frequency noise and the results are compared with that of the popular sym8 and db16 Wavelet threshold denoising (WTD) methods. The outcomes show that the NLM on average achieves 2.70 dB increase in improved signal to noise ratio (SNRimp) and 0.37 % drop in improved percentage distortion ratio compared with WTD. The moving adaptive shape patches-NLM performs better than the original NLM when the signals change dramatically. In addition, the performance of combined NLMWTD denoising method is also better than original WTD method (0.50–4.89 dB higher in SNRimp), especially, when the signal quality is poor. 相似文献
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使用独立元分析方法,提出了一种以独立元对各电极点投影系数的离散度为噪声独立元选取准则,设计了一套心外膜标测电位去噪新方法。实验结果表明,该方法可有效地去除心外膜电位标测信号中的电极间串扰和外界干扰等噪声,突出电极点上检测到的除极信号。因此,该方法适用于心外膜电位标测系统的去噪工作。 相似文献
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在微电极导向的立体定向手术治疗帕金森病中,依据神经元的自发放电特征,对微电极定位,由于细胞放电信号频率成份复杂,噪声干扰严重,基线漂移大,从微电极记录中很难识别出神经元的放电。为此提出一种新的非线性方法提取神经元放电,利用多分辨小竣变换对信号分解,对有用信息分量系数平方,再对信号重构。对112个病人的放电记录处理结果表明,该方法能有效地提取出细胞放电波形,剔除噪声。 相似文献
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心率变异性信号基于小波变换的分解 总被引:1,自引:0,他引:1
在对心率变异性(HRV)信号及类似的信号进行分析时往往希望把其中具有分形性质的1/f成份和非1/f成份分解开分别处理。然而,由于1/f成份和非1/f成份在频域上相互重叠,不容易简单地用频域滤波的方法来分解。因此有人根据1/f成份的特点提出了所谓粗粒化谱分析的频域分解方法。由于该方法存在一些缺点,本文根据1/f成份的特点提出了基于小波变换的HRV信号的时域分解算法。对仿真的HRV信号和实际HRV信号的分解的结果证实本文提出的方法优于粗粒化谱分析法。 相似文献
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目的:探讨子宫肌瘤的低场MRI表现及诊断价值。方法:回顾性分析29例子宫肌瘤患者的低场MRI表现,并与手术病理结果作对照。结果:本组29例患者中,有22例多发肌瘤,7例单发肌瘤,MRI共检出60个病灶。所有病灶均呈圆形或类圆形,在T1WI上表现为等或低信号,在T2WI上表现为低信号或混杂信号。本组29例患者中,有27例患者的MRI诊断与手术病理结果相符,诊断符合率为93.1%。结论:低场强MRI对子宫肌瘤能作出正确诊断,可作为B超检查的重要补充手段。 相似文献