The Gaussian mixture model (GMM), k-nearest neighbor (k-NN), quadratic discriminant analysis (QDA), and linear discriminant analysis (LDA) were compared to classify wrist motions using surface electromyogram (EMG). Ef...The Gaussian mixture model (GMM), k-nearest neighbor (k-NN), quadratic discriminant analysis (QDA), and linear discriminant analysis (LDA) were compared to classify wrist motions using surface electromyogram (EMG). Effect of feature selection in EMG signal processing was also verified by comparing classification accuracy of each feature, and the enhancement of classification accuracy by normalization was confirmed. EMG signals were acquired from two electrodes placed on the forearm of twenty eight healthy subjects and used for recognition of wrist motion. Features were extracted from the obtained EMG signals in the time domain and were applied to classification methods. The difference absolute mean value (DAMV), difference absolute standard deviation value (DASDV), mean absolute value (MAV), root mean square (RMS) were used for composing 16 double features which were combined of two channels. In the classification methods, the highest accuracy of classification showed in the GMM. The most effective combination of classification method and double feature was (MAV, DAMV) of GMM and its classification accuracy was 96.85%. The results of normalization were better than those of non-normalization in GMM, k-NN, and LDA.展开更多
目的:探索帕金森病伴冻结步态患者胫骨前肌和腓肠肌在直线行走过程中表面肌电(surface electromyogram,sEMG)的改变及其与临床特征之间的相关性。方法:选取符合入选标准的12例帕金森病伴冻结步态患者、13例帕金森病不伴冻结步态患者和1...目的:探索帕金森病伴冻结步态患者胫骨前肌和腓肠肌在直线行走过程中表面肌电(surface electromyogram,sEMG)的改变及其与临床特征之间的相关性。方法:选取符合入选标准的12例帕金森病伴冻结步态患者、13例帕金森病不伴冻结步态患者和11例健康对照受试者接受临床特征、步态时空参数和直线行走sEMG评估。分析步态周期各时段中重症侧胫骨前肌和腓肠肌内侧头的sEMG信号特征改变,指标选用标准化均方根振幅(root mean square,RMS)值和共激活比值。同时,探索sEMG改变与临床特征之间的相关性。结果:与健康受试者和非冻结步态患者相比,冻结步态患者的步速减慢、步幅缩短、摆动相减少、步态变异性增加(P<0.05)。在步态周期的单支撑相阶段,冻结步态患者胫骨前肌标准化RMS较健康对照降低(P<0.05);在摆动前期,冻结步态患者胫骨前肌标准化RMS较非冻结步态患者显著下降(P<0.01),但非冻结步态患者胫骨前肌标准化RMS较健康对照增加(P<0.01)。对于腓肠肌标准化RMS,冻结步态患者在摆动前期较非冻结步态患者和健康对照均显著降低(P<0.05)。此外,冻结步态患者的胫骨前肌-腓肠肌共激活比值在摆动相较非冻结步态患者降低(P<0.05)。冻结步态患者摆动前期腓肠肌标准化RMS与冻结步态严重程度(r=-0.758,P=0.007)、摆动相共激活比值和步幅变异性(r=0.716,P=0.013)显著相关。结论:直线行走步态周期中摆动前期胫骨前肌和腓肠肌的sEMG活动下降、摆动相胫骨前肌-腓肠肌共激活比值降低是帕金森病冻结步态患者的重要特征。展开更多
目的:探讨变频相位干涉电场刺激(temporal interference electrical fields stimulation,TIs)对人体肌肉力量和神经肌肉募集能力的影响。方法:16名健康成年人受试者均完成两次测试,两次测试至少间隔48小时。两次测试仅干预方案不同,分...目的:探讨变频相位干涉电场刺激(temporal interference electrical fields stimulation,TIs)对人体肌肉力量和神经肌肉募集能力的影响。方法:16名健康成年人受试者均完成两次测试,两次测试至少间隔48小时。两次测试仅干预方案不同,分别为变频TIs真刺激和假刺激,刺激目标靶区均为左侧初级运动皮层,测试任务为手部第一骨间背侧肌的最大自主收缩(maximal voluntary contraction,MVC),包括3 s和20 s两种条件。在采集20 s MVC的同时采集表面肌电信号,并利用表面肌电信号分解技术分析。结果:3 s MVC的峰值肌力表现出时间(干预前后)与干预条件(真假刺激)的显著交互作用(P<0.05);与刺激前相比,变频TIs后3 s MVC的峰值肌力显著提升,而假刺激后下降。20 s MVC的峰值肌电振幅表现出时间与干预条件的显著交互作用(P<0.05);与刺激前相比,变频TIs后峰值肌电振幅增加而假刺激后下降。结论:变频TIs能够有效增强3 s MVC的峰值肌力和20 s MVC时的运动单位同步放电水平,具有显著提升运动表现的潜力。展开更多
基金Project(NIPA-2012-H0401-12-1007) supported by the MKE(The Ministry of Knowledge Economy), Korea, supervised by the NIPAProject(2010-0020163) supported by Key Research Institute Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology, Korea
文摘The Gaussian mixture model (GMM), k-nearest neighbor (k-NN), quadratic discriminant analysis (QDA), and linear discriminant analysis (LDA) were compared to classify wrist motions using surface electromyogram (EMG). Effect of feature selection in EMG signal processing was also verified by comparing classification accuracy of each feature, and the enhancement of classification accuracy by normalization was confirmed. EMG signals were acquired from two electrodes placed on the forearm of twenty eight healthy subjects and used for recognition of wrist motion. Features were extracted from the obtained EMG signals in the time domain and were applied to classification methods. The difference absolute mean value (DAMV), difference absolute standard deviation value (DASDV), mean absolute value (MAV), root mean square (RMS) were used for composing 16 double features which were combined of two channels. In the classification methods, the highest accuracy of classification showed in the GMM. The most effective combination of classification method and double feature was (MAV, DAMV) of GMM and its classification accuracy was 96.85%. The results of normalization were better than those of non-normalization in GMM, k-NN, and LDA.
文摘目的:探索帕金森病伴冻结步态患者胫骨前肌和腓肠肌在直线行走过程中表面肌电(surface electromyogram,sEMG)的改变及其与临床特征之间的相关性。方法:选取符合入选标准的12例帕金森病伴冻结步态患者、13例帕金森病不伴冻结步态患者和11例健康对照受试者接受临床特征、步态时空参数和直线行走sEMG评估。分析步态周期各时段中重症侧胫骨前肌和腓肠肌内侧头的sEMG信号特征改变,指标选用标准化均方根振幅(root mean square,RMS)值和共激活比值。同时,探索sEMG改变与临床特征之间的相关性。结果:与健康受试者和非冻结步态患者相比,冻结步态患者的步速减慢、步幅缩短、摆动相减少、步态变异性增加(P<0.05)。在步态周期的单支撑相阶段,冻结步态患者胫骨前肌标准化RMS较健康对照降低(P<0.05);在摆动前期,冻结步态患者胫骨前肌标准化RMS较非冻结步态患者显著下降(P<0.01),但非冻结步态患者胫骨前肌标准化RMS较健康对照增加(P<0.01)。对于腓肠肌标准化RMS,冻结步态患者在摆动前期较非冻结步态患者和健康对照均显著降低(P<0.05)。此外,冻结步态患者的胫骨前肌-腓肠肌共激活比值在摆动相较非冻结步态患者降低(P<0.05)。冻结步态患者摆动前期腓肠肌标准化RMS与冻结步态严重程度(r=-0.758,P=0.007)、摆动相共激活比值和步幅变异性(r=0.716,P=0.013)显著相关。结论:直线行走步态周期中摆动前期胫骨前肌和腓肠肌的sEMG活动下降、摆动相胫骨前肌-腓肠肌共激活比值降低是帕金森病冻结步态患者的重要特征。
文摘目的:探讨变频相位干涉电场刺激(temporal interference electrical fields stimulation,TIs)对人体肌肉力量和神经肌肉募集能力的影响。方法:16名健康成年人受试者均完成两次测试,两次测试至少间隔48小时。两次测试仅干预方案不同,分别为变频TIs真刺激和假刺激,刺激目标靶区均为左侧初级运动皮层,测试任务为手部第一骨间背侧肌的最大自主收缩(maximal voluntary contraction,MVC),包括3 s和20 s两种条件。在采集20 s MVC的同时采集表面肌电信号,并利用表面肌电信号分解技术分析。结果:3 s MVC的峰值肌力表现出时间(干预前后)与干预条件(真假刺激)的显著交互作用(P<0.05);与刺激前相比,变频TIs后3 s MVC的峰值肌力显著提升,而假刺激后下降。20 s MVC的峰值肌电振幅表现出时间与干预条件的显著交互作用(P<0.05);与刺激前相比,变频TIs后峰值肌电振幅增加而假刺激后下降。结论:变频TIs能够有效增强3 s MVC的峰值肌力和20 s MVC时的运动单位同步放电水平,具有显著提升运动表现的潜力。
