Surface EMG (electromyography) signal is a complex nonlinear signal with low signal to noise ratio (SNR). This paper is aimed at identifying different patterns of surface EMG signals according to fractal dimension. Tw...Surface EMG (electromyography) signal is a complex nonlinear signal with low signal to noise ratio (SNR). This paper is aimed at identifying different patterns of surface EMG signals according to fractal dimension. Two patterns of surface EMG signals are respectively acquired from the right forearm flexor of 30 healthy volunteers during right forearm supination (FS) or forearm pronation (FP). After the high frequency noise is filtered from surface EMG signal by a low-pass filter, fractal di-mension is calculated from the filtered surface EMG signal. The results showed that the fractal dimensions of filtered FS surface EMG signals and those of filtered FP surface EMG signals distribute in two different regions, so the fractal dimensions can rep-resent different patterns of surface EMG signals.展开更多
提出用 Levenberg-Marquardt 算法改进 BP 神经网络识别表面肌电信号的方法。采用多尺度小波变换对肌电信号进行 分析,提取各尺度下小波系数幅值的最大和最小值构造特征矢量,输入 BP 神经网络可进行模式识别,经过训练能够成 功地从...提出用 Levenberg-Marquardt 算法改进 BP 神经网络识别表面肌电信号的方法。采用多尺度小波变换对肌电信号进行 分析,提取各尺度下小波系数幅值的最大和最小值构造特征矢量,输入 BP 神经网络可进行模式识别,经过训练能够成 功地从表面肌电信号中识别展拳、握拳、前臂内旋、前臂外旋四种运动模式。实验表明,LM 算法在响应时间和识别 精度上都比标准的 BP 算法有了很大提高。展开更多
基金Project supported by the National Natural Science Foundation of China (No. 60171006)the National Basic Research Program (973) of China (No. 2005CB724303)
文摘Surface EMG (electromyography) signal is a complex nonlinear signal with low signal to noise ratio (SNR). This paper is aimed at identifying different patterns of surface EMG signals according to fractal dimension. Two patterns of surface EMG signals are respectively acquired from the right forearm flexor of 30 healthy volunteers during right forearm supination (FS) or forearm pronation (FP). After the high frequency noise is filtered from surface EMG signal by a low-pass filter, fractal di-mension is calculated from the filtered surface EMG signal. The results showed that the fractal dimensions of filtered FS surface EMG signals and those of filtered FP surface EMG signals distribute in two different regions, so the fractal dimensions can rep-resent different patterns of surface EMG signals.
文摘提出用 Levenberg-Marquardt 算法改进 BP 神经网络识别表面肌电信号的方法。采用多尺度小波变换对肌电信号进行 分析,提取各尺度下小波系数幅值的最大和最小值构造特征矢量,输入 BP 神经网络可进行模式识别,经过训练能够成 功地从表面肌电信号中识别展拳、握拳、前臂内旋、前臂外旋四种运动模式。实验表明,LM 算法在响应时间和识别 精度上都比标准的 BP 算法有了很大提高。