共查询到20条相似文献,搜索用时 15 毫秒
1.
Broman Holger Bilotto Gerardo De Luca Carlo J. 《IEEE transactions on bio-medical engineering》1985,(5):341-344
Average muscle action potential conduction velocity values were obtained during isometric constant-force contractions by a cross-correlation technique. To minimize the bias introduced by nondelayed activity appearing on the two myoelectric derivations, the signals were doubly differentiated. This arrangement effectively reduced the nondelayed activity and increased the accuracy of the estimate. 相似文献
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The Measurement of Muscle Fiber Conduction Velocity Using a Gradient Threshold Zero-Crossing Method 总被引:2,自引:0,他引:2
Masuda Tadashi Miyano Hisao Sadoyama Tsugutake 《IEEE transactions on bio-medical engineering》1982,(10):673-678
The conduction velocity of myoelectric potential along muscle fiber is known to be an index of the degree of muscular fatigue or muscular disease. When detecting the myoelectric potential by means of surface electrodes, the conduction velocity must be extracted from an apparently random wave of a myoelectric signal. In this paper, a method for determining conduction velocity is proposed based upon a zero-crossing time delay measurement with reference to the derivative of a myoelectric signal. The slope value of the input signal provides an effective criterion for rejecting undesired zero crossing caused by noise. This method needs no spectral analysis nor correlation calculation. Compared to another previously reported zero-cossing approach using digital filter preprocessing, it shows a more accurate and rapid estimation of velocity. 相似文献
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Direct On-Line Estimation of Muscle Fiber Conduction Velocity by Surface Electromyography 总被引:1,自引:0,他引:1
A new approach to the measurement of muscle fiber conduction velocity by surface electromyography (EMG) is developed, based upon a triple surface-electrode configuration. Unlike previously reported methods, it does not require the Fourier transformation of raw EMG data, and can be implemented on-line on a simple digital computer. Although programmed here on a PDP-11 machine, the algorithms developed are equally suited to a 16-bit microprocessor, without any need for hardware multiplication or floating-point facilities. Accurate conduction velocity estimates may be obtained every few seconds. 相似文献
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The measurement of the average conduction velocity of action potentials along muscle fibers has important applications in muscle fatigue study and ergonomics. A cross-correlation-based method for the estimation of this velocity from surface electromyography (EMG) is presented. It is implemented on a standard low-cost 8-bit microprocessor. The use of cross correlation for such an on-line application has been made possible by the use of an efficient polarity correlation algorithm. 相似文献
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该文介绍了频率步进信号处理的基本原理,分析了相对运动速度对频率步进信号的影响,在此基础上提出了一种新的频率步进信号的速度估计方法,通过计算机仿真验证了上述方法的有效性。 相似文献
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Solomonow Moshe Baratta Richard Shoji Hiromu D''Ambrosia Robert D. 《IEEE transactions on bio-medical engineering》1986,(8):735-745
The myoelectric profile of an electrically stimulated muscle with separate and simultaneous control of firing rate and recruitment was determined. The signal consists of low amplitude, desynchronous discharge at low recruitment levels and exhibits monotonic, distinct compound action potentials at moderate to full recruitment. The myoelectric signal-force model is described by sigmoidal function when the signal is represented by its median frequency (MF), rms, or mean absolute value (MAV) at firing rates inducing just above fused force response (~28 pps). At firing rates corresponding to the maximal tetanic force of the muscle (~51 pps) the MES-force model is represented by a second-order polynomial for MF, rms, and MAV. Dynamic tracking of force induced by a sinusoidal recruitment/derecruitment of the muscle's motor unit pool at frequencies in the range of 0-1 Hz show that the MAV is independent, whereas the rms and MF are dependent on tracking frequency. The linearized MAV-force model was found superior for use as a sensorless force feedback measurement in a closed-loop control scheme aimed at restoration of regulated movement to a paralyzed limb joint. 相似文献
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线性调频信号参数快速估计 总被引:1,自引:0,他引:1
线性调频(LFM)信号参数检测是对SAR对抗的一个重要问题,本文在对用Radon-Wign er变换、快速解线调和最大似然(ML)估计和分析LFM信号的基础上,给出一种消除ML估计带来旁瓣的方法,进一步提出了一种局部快速搜索的最大似然估计法,并用于LFM信号的起始频率和调频斜率等参数的估计。最后给出了三种快速算法的计算机模拟结果。 相似文献
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部分样本雷达信号的参数估计 总被引:1,自引:0,他引:1
线性调频信号参数检测是SAR对抗的一个重要问题 ,其估计参数的方法有多种 ,但对于分析部分样本LFM信号而言 ,绝大多数估计方法的误差很大。在用快速相关解线调估计和分析部分样本LFM信号存有误差的基础上 ,提出了一种改进的快速相关解线调算法运用于部分样本LFM信号的起始频率和调频斜率参数的估计 ,减小了误差。最后对改进的算法进行了仿真 ,证实了改进后的有效性。 相似文献
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Nonstationary myoelectric signal processing is considered. A midpoint moving average estimator for the signal variance is developed. The performance of the estimator is analyzed and optimum window size criteria are derived. Comparison of the theoretical performance to experimental performance shows good agreement. The resultant estimation error is only moderately (2-3 percent) degraded from the equivalent stationary case. Finally, the developed estimator is compared to a typical squarer followed by a low-pass filter myoelectric processor. Provided that the low-pass filter has a linear phase characteristic in the passband, the two systems have essentially the same error performance. 相似文献
11.
The purpose of this study is to develop a pulmonary model and determine the frequency response sensitivity of mechanical parameters such as impedance, dynamic compliance, and dynamic resistance as a function of individual airway properties. Computer simulations of a three compartment model of various physiological cases were used to determine lung parameters as a function of frequency, peripheral airway contribution to total airway resistance, and relative percent obstruction of the peripheral airways. Provided our present concepts of the lung are valid and adequately incorporated into the present model, our results indicate the utility of frequency dependence as a measure of airway obstruction. 相似文献
12.
提出了一种对二相编码(BPSK)信号子脉冲宽度估计的新方法。通过获取BPSK信号的精确频率,构造相位相差π/2的正弦信号和BPSK进行混频,提取两次混频后信号的包络交叉点来对BPSK信号的相位跳变点进行估计,从而获得信号子脉冲宽度估计。仿真试验表明:在低信噪比(SNR)情况下可以较好地获得BPSK信号的子脉冲宽度估计值。 相似文献
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Kwatny Eugene Thomas Donald H. Kwatny Harry G. 《IEEE transactions on bio-medical engineering》1970,(4):303-313
This paper describes the use of power spectral density and cumulative power functions in the examination of the electromyogram (EMG). The EMG signals were obtained with surface electrodes from two muscles, the flexor pollicis brevis and the extensor digitorum, in four subjects. Each muscle was studied at two levels of contraction, both before and during fatigue. The power spectral density functions are compared, using a cumulative power difference function and the mean frequency of the spectrum, to determine differences between loading conditions in an individual muscle, before and during fatigue, between different muscles, between individuals (same muscle), and combinations of these conditions. 相似文献
18.
数字场强仪具有准确、耐用、方便等优点,因而得到了广泛应用,但是在实际使用中如果方法不当也会出现一些问题。 某村广播电视室新购一台VS900数字场强仪,测得机房各频道输出电平正常,但发现严重的过调现象,怀疑场强仪有问题,但到县局校对时却正常。在这种情况下,笔者到该村电视室检查,发现该村使用的是非锁相环调制器,频率出现偏差。有些技术人员习惯于用厂家预置标准频道频率测量,未考虑调制器的频率偏差,因而所测量的值与实际电平值不同,故出现上面的现象。测量值与实际值如表1。 表中数据表明,偏差值有大有小,大的可… 相似文献
19.
姜维正 《信息技术与信息化》2006,(4):63-65
本文给出了一种利用单片机进行控制的精密测频方法,以及该方法克服测量误差的原理。并对传统的测频方法中存在的精度低的问题进行了简单分析。 相似文献
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A method was proposed for detecting and rejecting motion artifacts superimposed on myoelectric (ME) signals which are used in the estimation of muscular activity, in the control of powered prostheses, and in other applications. The method is based on the propagation characteristics of motor unit action potentials derived with multiple surface electrodes placed along the muscle fibers. The contamination of artifacts was detected by the decrease of the normalized correlation coefficient calculated at the time shift corresponding to the potential propagation. The product of two correlated signals was found to be less affected by the artifacts and was a better estimate of muscular activity than the root mean square of the ME signal which is conventionally used in the applications of ME signals. 相似文献