首页|基于小波降噪和时序数据图像化的表面肌电信号识别

基于小波降噪和时序数据图像化的表面肌电信号识别

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表面肌电信号(sEMG)是人体肌肉收缩时发出的信号,能很好地反映人体肌肉功能,因此被广泛应用在临床、假肢控制、康复评估等领域.由于受采集器、佩戴位置和环境等因素的影响,电脑接收的信号包含随机噪声,严重影响信号的分析和研究.因此,本文提出了一种基于新的小波阙值降噪和时序数据图像化的表面肌电信号识别方法.首先,本文采集五种基本上肢运动的sEMG,并采用小波分解对其降噪.提出了一种新的阈值函数以弥补传统小波分解任务中软阈值函数的失真现象和硬阈值函数会产生振荡的缺陷,并在理论上证明了该函数在阈值处的连续性和与原小波系数的无偏差性.然后,受计算机视觉中卷积神经网络成功应用的启发,本文利用短时傅里叶变换将时序数据转换成图像数据.随后,在原始数据集和不同阈值函数降噪后的数据集上的实验表明,本文方法降噪后的数据集上分类性能更优;在降噪后的数据集上,使用二维卷积神经网络(Two Dimensional Convolutional Neural Networks,2DCNN)模型在四个动作的数据上准确率最高、一个次高.说明本文方法可以有效提高sEMG的识别率,具有较好泛化能力.
Surface Electromyography Recognition Based on Wavelet Denoising and Time-series Imaging
Surface Electromyography(sEMG)is the signal sent by human muscle contraction,which can well reflect human muscle function,so it is widely used in clinical,prosthesis control,and rehabilitation evaluation etc.However,due to the influence of collec-tor,wearing position,environment and other factors,the signal received by the computer contains random noise,which seriously af-fects the analysis and research of the signal.In this article,we proposed a sEMG recognition method based on a new wavelet thresh-old denosing and time sequence data visualization.Firstly,sEMG of five basic upper limb movements were collected and denoised by improved wavelet decomposition.A new threshold function was proposed to make up for the distortion of soft threshold function and the vibration of hard threshold function in traditional wavelet decomposition,and it was proved that the function was continuous at the threshold and non-deviation from original wavelet coefficient.Then,inspired by the successful application of convolutional neural networks in computer vision,we transformed time-series data into image data using Short-time Fourier Transform.Finally,the experimental results on both the original datasets and the datasets denoised by different methods show that the model obtains su-perior classification results on the datasets denoised by the proposed method.The Two-dimensional Convolutional Neural Networks(2DCNN)model has highest accuracy on four action datasets and second highest accuracy on one action datasets.Therefore,the pro-posed method can effectively improve the recognition rate of sEMG and has good generalization.

surface electromyographywavelet denoisingtime-series dataimage datashort-time Fourier transform

菅小艳、韩素青、杨红菊

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太原师范学院 计算机科学与技术学院,山西 晋中 030619

山西大学 计算机与信息技术学院,山西 太原 030006

山西大学 计算智能与中文信息处理教育部重点实验室,山西 太原 030006

表面肌电信号 小波降噪 时序数据 图像数据 短时傅里叶变换

国家自然科学基金山西省教育厅项目山西省教育科学规划课题(十四五)

619761282022-008GH-220176

2024

山西大学学报(自然科学版)
山西大学

山西大学学报(自然科学版)

CSTPCD北大核心
影响因子:0.287
ISSN:0253-2395
年,卷(期):2024.47(1)
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