基于肌电信号的人手运动状态的辨识

研究的目的在于利用人体前臂的肌电信号进行人手动作模式的识别。根据采集的肌电信号，判断动作始末状态并对该肌电信号进行小波降噪预处理，利用小波变换的高频细节系数极值构造特征矢量，经过学习矢量量化（LVQ）神经网络训练，能够有效地识别握拳、展拳、手腕内旋和手腕外旋4种动作模式。和前馈型神经网络比较，LVQ神经网络具有更高的识别准确率和更稳定的再现性。     

一种基于表面肌电信号映射人体下肢运动意图的方法

智能膝关节假肢是截肢患者恢复日常运动的重要辅具。对人体下肢运动意图的识别是实现下肢假肢控制的关键。该文针对此问题,提出了一种通过表面肌电信号预测膝关节角度的方法。对表面肌电提取时域特征,通过 BP 神经网络模型建立平地行走过程中表面肌电信号和膝关节角度的映射关系,预测膝关节角度。     

大腿截肢患者的残肢肌电运动识别

目的研究利用大腿残肢肌电信号进行下肢运动模式识别的方法,探讨肌电信号控制下肢假肢的可能性。方法采集15名大腿截肢者残肢侧股直肌、股外侧肌、阔筋膜张肌、股二头肌、半腱肌、臀大肌6块肌肉的表面肌电信号,提取肌电信号的6种时域、频域特征,利用支持向量机对平地行走、上楼梯、下楼梯、坐下、起立5种下肢运动模式进行识别。结果利用残肢肌电信号可以实现5种下肢运动模式的在线识别,对同一受试者同次测试数据识别率为94%,同一受试者的多次混合数据识别率为85%,对不同受试者混合数据识别率为74%。通过特征优化,仅利用3块肌肉的2个特征,对同一受试者的同次测试数据识别率仍可达92%。对平地行走、上楼梯、下楼梯3种动作的识别,同一受试者同次测试数据识别率为100%,同一受试者的多次混合数据识别率为98.33%,对不同受试者混合数据识别率为93.33%。结论仅仅利用残肢肌电信号能够实现运动意图的在线识别,通过对同一患者使用前的多次数据训练,有望达到较高的识别率。研究结果为肌电运动识别用于下肢假肢控制奠定了基础。     

基于肌电信号的膝关节跨越障碍角度预测方法

为解决人体跨越障碍物时膝关节角度输出的问题,针对性设计一种穿戴式信号获取实验台,对下肢运动姿态进行运动分析,将肌肉电信号及关节角度信号作为运动数据,对信号进行处理后利用BP神经网络预测跨越障碍时输出角度,提出一种利用BP神经网络算法,根据不同大腿抬起高度,分析膝关节运动主动肌与被动肌发力程度,预测输出人体跨越障碍时膝关节角度的方法,能够有效帮助假肢膝关节或康复机器人实现跨越障碍的复杂动作。     

基于小波分析与神经网络相结合的表面肌电信号识别的研究

表面肌电信号是从人体骨骼肌表面通过电极记录下来的神经肌肉活动发放的生物电信号，具有非平稳性和复杂性的特点。本研究通过使用小波分析与神经网络相结合的方法，识别正常肌电信号与疲劳肌电信号。实验表明，将小波分解后的肌电信号代替原始肌电信号，能明显提高神经网络对肌电信号的识别准确率。     

基于BP神经网络的手势动作表面肌电信号的模式识别

手势语言在日常生活中有着广泛的应用,本研究利用手势动作时从前臂4块肌肉上获取的4路表面肌电(SEMG)信号,经特征提取并采用BP神经网络,对8种手势动作模式进行了识别.鉴于BP网络具有较强的模式分类能力,而特征提取(幅度绝对值均值、AR模型系数、过零率)又利用了多路肌电信号的信息,实验结果取得了较高的识别正确率,表明所采用的方法是有效的.     

独立分量分析和小波熵在动作模式分类中的应用

在表面肌电信号(electromyography,EMG)中,各类动作的识别是一个重要研究方向.本文采用独立分量分析independent component analysis,ICA)对肌电信号进行处理,消除各动作信号之间的相互线性耦合叠加,并采用信号的小波熵作为特征向量进行模式识别.试验表明,在对信号进行先期ICA处理以后,动作模式的识别效果较好.此方法也可应用于其他生理信号的识别分类.     

基于灰色系统理论的表面肌电分类

为提高假肢分类的准确率和速度 ,提出采用灰色系统理论中的灰关联法进行动作辨识。首先用小波变换方法对表面肌电信号进行分析 ,通过对小波系数奇异值分解提取信号特征 ,根据待分类动作与各标准动作模式间特征矢量的灰关联系数做出判断。从掌长肌和肱桡肌采集的两道表面肌电信号中识别四种运动模式 ,准确率达87.5 %。与神经网络等识别方法相比 ,此方法不需大量训练样本数量 ,运算量小 ,在识别率相近的情况下 ,辨识速度大大提高。     

基于小波包熵的与动作相关表面肌电信号的分类

目的:对与动作相关的表面肌电信号进行分类识别.材料与方法:与动作相关的表面肌电信号是从右手前臂肌群表面采集而来.用小波包变换将信号分解成16个等频带宽的的子空间.之后,计算每个子空间的相对小波包能量和每个信号的小波包熵.结果:正确识别率达到100%.结论:小波包熵能够作为与动作相关的表面肌电信号的特征值来识别不同的动作表面肌电模式.     

基于手臂表面肌电信号的智能小车控制系统

研究一种基于手臂表面肌电信号的智能小车控制系统。当左臂做出曲臂、左勾、右勾、自然下垂四种动作时,小车将完成前进、左转、右转、停止四种运动状态。手臂表面肌电信号采集模块通过三个单通道肌电信号传感器采集左臂四种动作下的肌电信号并进行预处理;在信号识别及指令编码模块对肌电信号进行分类识别,识别出手臂的不同动作,并编码出对应的控制指令。通过无线传输模块把控制指令传输给智能小车控制模块;智能小车控制模块根据控制指令驱动电机转动,从而实现对小车运动状态的调控。实验证明,本智能小车控制系统信号识别率高,延迟小。     

基于表面肌电信号的手势识别与分析

目的 研究利用前臂及手部表面肌电( surface electromyography,sEMG)信号进行手势识别的方法,以及不同 手势下拇指、食指的关节角度,探讨 sEMG 信号控制外骨骼手的可行性。 方法 采集 20 名健康右利手受试者右侧 前臂及手部 6 块肌肉 sEMG 信号。 提取 sEMG 信号的时域特征值,对比人工神经网络( artificial neural network, ANN)、K-近邻(K-nearest neighbor, KNN)、决策树(decision tree, DT)、随机森林( random forest, RF)和支持向量机(support vector machine, SVM)等多种分类器对 6 种日常手势进行识别。 同时,采用 Vicon 摄像机跟踪系统捕捉右手拇指、食指运动轨迹,计算拇指、食指关节角度。 结果 利用前臂及手部 sEMG 信号可以实现 6 种手势的模式识别,其中 ANN 分类器的分类预测效果最好,测试集预测精度可达 97. 9% ,Kappa 系数可达 0. 975。 同时,计算得到不同手势下拇指、食指的关节角度,并进行不同手势下关节角度相关性分析。 结论 利用前臂及手部 sEMG 信号进 行手势识别,能够实现具有几乎完全一致的分类预测结果。 研究结果证明了 sEMG 信号手势识别应用于外骨骼手 控制的可行性。     

An exploratory study to design a novel hand movement identification system

Electromyogram signal (EMG) is an electrical manifestation of contractions of muscles. Surface EMG (sEMG) signal collected from the surface of skin has been used in diverse applications. One of its usages is in pattern recognition of hand prosthesis movements. The ability of current prosthesis devices has been generally limited to simple opening and closing tasks, minimizing their efficacy compared to natural hand capabilities. In order to extend the abilities and accuracy of prosthesis arm movements and performance, a novel sEMG pattern recognizing system is proposed. To extract more pertinent information we extracted sEMGs for selected hand movements. These features constitute our main knowledge of the signal for different hand movements. In this study, we investigated time domain, time-frequency domain and combination of these as a compound representation of sEMG signal's features to access required signal information. In order to implement pattern recognition of sEMG signals for various hand movements, two intelligent classifiers, namely artificial neural network (ANN) and fuzzy inference system (FIS), were utilized. The results indicate that our approach of using compound features with principle component analysis (PCA) as dimensionality reduction technique, and FIS as the classifier, provides the best performance for sEMG pattern recognition system.     

基于改进机器学习算法的步态识别与预测研究EI北大核心CSCD

针对人体下肢不同步态过程的个体差异和行走过程中步幅随机变化等问题,本文提出一种利用运动姿态信号进行步态识别与预测的方法。研究采用基于免疫粒子群算法(IPSO)优化门控循环单元(GRU)网络算法,建立以人体姿态变化数据为输入,以下一阶段姿态变化数据及准确率为输出的网络模型,以期实现对人体姿态变化的预测。本文首先明确概述IPSO优化GRU算法的过程,采集多名受试者分别执行平地行走、蹲起、坐姿腿屈伸等动作的人体姿态变化数据,通过对比分析IPSO优化的循环神经网络(RNN)、长短期记忆网络(LSTM)、GRU网络识别与预测情况,以验证所建模型的有效性。试验结果显示,优化后的算法可较好预测人体姿态变化,其中平地行走和蹲起动作的均方根误差(RMSE)可精确到10^(-3),坐姿腿屈伸的RMSE可精确到10^(-2);各种动作的R^(2)值均可达0.966以上。以上研究结果表明,优化后的算法可应用于实现康复治疗中人体步态运动评价和步态趋势预测、假肢和下肢康复设备设计等研究,对今后提高患者肢体功能、活动水平和生活独立能力的研究提供参考。     

基于遗传算法的sEMG至SFAP的分解算法

本研究提出了一种表面肌电信号(Surface Electromyogram，sEMG)至单纤维动作电位(Single Fiber Action Potential，SFAP)新的分解算法。由于sEMG分解的复杂性，本研究将sEMG分解问题转化为SFAP三基函数参数的优化问题和同一SFAP参数的聚类问题。在算法中，运用改进的遗传算法(Genetic Algorithm，GA)进行参数的优化，运用无监督学习的Kohonen神经网络进行参数的聚类。遗传算法的运用加强了算法的搜索能力，提高了分解的正确率，加快了算法的收敛速度。本分解算法的运用使得医疗诊断和假肢控制等领域可以通过非侵入式测量得到SFAP随时间的变化规律。     

基于多模态信息融合的肘关节连续运动估计

目的 针对目前上肢康复训练设备多为被动式、训练方式单一、患者主动参与度较低等问题,提出一种基于多模态信息融合的上肢连续运动估计算法,实现对肘关节力矩的准确估计。方法 首先,在4种角速度下,采集受试者的表面肌电信号和姿态信号,提取信号的时域特征并利用主成分分析方法进行特征融合;其次,通过附加动量法和自适应学习率对反向传播神经网络(back propagation neural network, BPNN)进行改进,使用粒子群算法(particle swarm optimization, PSO)对神经网络进行优化,构建基于PSO-BPNN的连续运动估计模型;最后,以第2类拉格朗日方程计算的关节力矩作为准确值,对模型进行训练,并与传统BPNN模型进行性能对比。结果 传统BP神经网络模型均方根误差为558.9 mN·m,R²系数为77.19%,优化模型后的均方根误差和R²系数分别为113.6 N·m、99.12%,力矩估计准确度进一步提高。结论 本文提出的肘关节连续运动估计方法能够准确地识别运动意图,为上肢外骨骼康复机器人的主动控制提供切实可行的方...     

Several practical issues toward implementing myoelectric pattern recognition for stroke rehabilitation

High density surface electromyogram (sEMG) recording and pattern recognition techniques have demonstrated that substantial motor control information can be extracted from neurologically impaired muscles. In this study, a series of pattern recognition parameters were investigated in classification of 20 different movements involving the affected limb of 12 chronic stroke subjects. The experimental results showed that classification performance could be improved with spatial filtering and be maintained with a limited number of electrodes. It was also found that appropriate adjustment of analysis window length, sampling rate, and high-pass cut-off frequency in sEMG conditioning and processing would be potentially useful in reducing computational cost and meanwhile ensuring classification performance. The quantitative analyses are useful for practical myoelectric control toward improved stroke rehabilitation.     

Ant colony optimization-based feature selection method for surface electromyography signals classification

This paper presented a new ant colony optimization (ACO) feature selection method to classify hand motion surface electromyography (sEMG) signals. The multiple channels of sEMG recordings make the dimensionality of sEMG feature grow dramatically. It is known that the informative feature subset with small size is a precondition for the accurate and computationally efficient classification strategy. Therefore, this study proposed an ACO based feature selection scheme using the heuristic information measured by the minimum redundancy maximum relevance criterion (ACO-mRMR). The experiments were conducted on ten subjects with eight upper limb motions. Two feature sets, i.e., time domain features combined with autoregressive model coefficients (TDAR) and wavelet transform (WT) features, were extracted from the recorded sEMG signals. The average classification accuracies of using ACO reduced TDAR and WT features were 95.45±2.2% and 96.08±3.3%, respectively. The principal component analysis (PCA) was also conducted on the same data sets for comparison. The average classification accuracies of using PCA reduced TDAR and WT features were 91.51±4.9% and 89.87±4.4%, respectively. The results demonstrated that the proposed ACO-mRMR based feature selection method can achieve considerably high classification rates in sEMG motion classification task and be applicable to other biomedical signals pattern analysis.     

Surface EMG based hand gesture identification using semi blind ICA: validation of ICA matrix analysis

Surface electromyogram (sEMG) has numerous applications. It has been widely used in various biosignal and neuro rehabilitation applications. There is an urgent need for establishing a simple yet robust system that can be used to identify subtle complex hand actions and gestures for control of prosthesis and other computer assisted devices. Earlier work to identify the hand actions and gestures based on sEMG suffers from limitation that these are suitable for gross actions where there is only one prime-mover muscle involved and not suitable for small subtle and complex muscle contraction. This paper presents the hand gesture identification using sEMG decomposed using semi-blind independent component analysis combined with neural network based classifier. The aim was to provide reliable and natural control for rehabilitation and human computer interaction applications. We have proposed a model based approach where the hand muscle anatomy is known. The system was tested on 5 subjects and with experiments repeated on different days. The system was compared with raw sEMG as used by other researchers. The system is able to classify the different hand actions 100%. In comparison, the classification of the traditional ICA and raw sEMG for the same experiments and similar features was a poor 65% and 60% respectively. This research demonstrates that sEMG can be decomposed to the individual muscle activities using semi-blind ICA. The muscle activity after decomposition can be used to accurately identify small and subtle hand actions and gestures. Finally the ICA source separation was validated with mixing matrix analysis.