FNS肢体多关节运动轨迹跟踪的实验研究

本文着重对功能神经电刺激（FNS）肢体多关节运动刺激脉冲的控制算法进行了比较实验研究。首先介绍了FNS系统的基本组成及原理,然后借助多功能FNS肢体运动控制平台,分别采用常规控制算法和自适应控制算法,以人体肘关节和腕关节的屈曲运动为控制目标,将体表电极分别置于肱二头肌和掌长肌运动点上,通过FNS运动状态测量装置,获取肘关节和腕关节运动角位移随时间的变化曲线。实验结果表明,与常规控制算法比较,基于人体生理特点的自适应控制算法使屈肘和屈腕运动获得了最佳的轨迹跟踪性能,并且刺激波形变化稳定、平滑,受试者无任何不良生理反应。     

神经肌肉电刺激模拟肌肉力量训练的生物力学研究

基于对电刺激模拟肌肉力量训练的理论与实践研究，结果表明：神经肌肉电刺激（NMES）的训练效果显著优于肌肉直接电刺激（MES），肌肉力量素质的增长与电刺激方式和刺激源的电特性有关；NMES能以较低的体能消耗完成肌肉力量的训练，适合作为常规训练前，中、后的辅助训练手段，NMES模拟肌肉力量训练的方式能满足肌肉功能群协调能力的同步发展。     

中枢神经的无创性磁刺激技术及其应用

无创性磁刺激技术在中枢神经功能检测和神经肌肉功能恢复的应用是生物医学工程和神经电生理研究的一个新热点,文章从理论上对磁刺激的发生发展,物理原理,特性,磁刺激与标准电刺激的差别,外周磁刺激技术的多信道磁刺激对电刺激模型等最新发展,以及临床上磁棘刺激在肌肉功能恢复的作用做了全面介绍。     

牵伸状态下深层肌肉刺激在脑卒中偏瘫患者中的效果评价

目的:探究牵伸状态下深层肌肉刺激在脑卒中偏瘫患者中的效果评价.方法:选取我院2019年1月至2021年2月105例脑卒中偏瘫患者为研究对象,依据康复方式不同分为常规组和刺激组.两组均予常规康复训练,常规组52例行肱二头肌牵伸训练,刺激组53例予牵伸状态下深层肌肉刺激,对比两组上肢痉挛程度,肱二头肌张力、弹性及硬度,上肢运动功能.结果:刺激组干预2月末改良Ashworth痉挛量表(Modified ashworth scale,MAS)水平优于常规组;振动频率、动态刚度、对数衰减水平低于常规组;Fugl-Meyer量表上肢肩肘部分(Fugl-Meyer assessment of upper extremity,FMA-UE)、功能独立性评定量表(Functional independent measure,FIM)评分高于常规组(P<0.05).结论:牵伸状态下深层肌肉刺激调节脑卒中偏瘫患者上肢痉挛程度,调控上肢运动功能,改善肱二头肌张力、弹性及硬度.     

肢体近端肌肉记录的磁刺激运动诱发电位在格林──巴利综合征中的应用

对１２例格林─巴利综合征患者进行磁刺激运动诱发电位（ＭＥＰ）测定，记录电极分别放置在肢体近端肌肉（三角肌、肱二头肌、股四头肌）及远端肌肉（小指展肌、胫前肌）上，将二者的结果相比较，并与同时进行的肌电图、神经传导速度、Ｆ波进行比较，发现ＭＥＰ阳性率最高，利于早期发现病变；肢体近远端记录的ＭＥＰ阳性率相近，但近端ＭＥＰ对以近端无力为主的ＧＢＳ患者更为敏感。     

肱二头肌不同模式运动任务刺激下的颈髓功能磁共振成像研究

目的 探究肱_二头肌不同模式运动任务刺激下的颈髓激活区分布及是否存在运动刺激-颈髓激活强度的同侧优势性.方法 9例健康右利手受试者行双上肢的肱二头肌负荷任务和屈肘运动仟务试验.采用GE 1.5T磁共振系统运用GRE-EPI扫描序列行颈髓功能磁共振成像(Fmri),行BOLD图像分析,对激活区的信号强度变化进行统计学分析.结果 (1)肱二头肌不同模式运动任务刺激下的颈髓激活区主要分布于C5～C6节段,邻近C7～C8节段亦出现少量激活;(2)单侧上肢运动条件下,脊髓双侧激活现象多见;(3)运动肢体同侧的脊髓激活区信号强度变化显著大于对侧(P<0.05).结论 肱二头肌不同模式运动任务诱发颈髓激活的节段分布与主要收缩肌——肱二头肌的脊髓支配节段(C5、C6)相符合,存在运动刺激-颈髓激活强度的同侧优势性.     

经颅电刺激技术用于运动表现提升的研究进展

经颅电刺激(TES)包括经颅直流电刺激、经颅交流电刺激和经颅随机噪声刺激,是一种非侵入的脑刺激技术。通过不同尺寸的电极将特定模式的低强度电流作用于特定的脑区,调节大脑皮质神经活动和/或兴奋性,增强大脑与神经、肌肉的连接,达到改善运动表现的作用。目前TES技术正在实现从实验室研究到运动科学应用研究的转变。首先阐述TES作用于大脑皮质的神经机制,着重评述近20年来TES在人类运动表现提升方面的研究进展,包括身体平衡、耐力表现、运动疲劳、肌肉力量和运动学习能力等5个方面;然后综述TES在脑网络功能连通性中应用的相关研究,并探讨该领域对TES改善运动表现的重要意义; 最后对TES在运动表现提升中的应用研究进行展望。     

电刺激在脑瘫治疗中的应用

脑性瘫痪是中国人群疾病谱中最主要的致残因素之一,近年来的发病率呈显著上升趋势。经过40多年的研究表明,电刺激疗法能成功地恢复脑瘫患者的部分运动功能,且具有无创、操作简便、适应症广等优点,它是现代康复工程领域很有应用前景的一项新技术。本文综述了当前应用于电刺激治疗脑性瘫痪的两类电刺激即神经肌肉电刺激（NMES）和阈值电刺激（TES）的治疗原理、临床疗效、适应症及并发症等,并介绍了与之相关的治疗技术和研究进展。     

神经电刺激下的人体增强研究进展

近年来,许多研究探索人类记忆、学习、情绪调控等认知功能、感知功能、运动功能的神经电刺激增强。脑机接口可用作更精细化的神经电刺激,它的信息读写性能提升也得到研究。非侵入式刺激以经颅直流电刺激(tDCS)为代表,实施较为便捷,但是在长期有效性和刺激精度方面需要进一步提升。侵入式刺激方式以脑深部电刺激(DBS)、迷走神经刺激(VNS)为代表,已经在临床上取得了广泛的认可和应用,刺激具备高精度特性,但是在增强方面的研究与应用上存在限制。对以上研究进展进行综述,并对人体增强研究的局限和发展趋势进行评论。     

服务于功能性电刺激的双足步态实验

背景：功能性电刺激利用低频弱电流脉冲刺激失去神经控制的肌肉已经在截瘫行走的临床应用中取得了小范围成功,但现有的电刺激模式存在不灵活、不易操作、且稳定性不高的缺点。 目的：基于步态分析方法,研究涉及到步行动作的各肌肉群的协同动作关系,将肌肉电刺激模式简化为无需患者操作的规律性控制策略,并验证该策略在功能性电刺激实验中的有效性。 方法：针对双足步行的特点,提出一种基于关节角变化趋势及肌电信号强度变化的步态研究方法,旨在服务于功能性电刺激的设计,为下肢肌肉提供理想的电刺激模式,使人体产生相应的肌肉群协同动作,从而使受试者最终实现非自主控制的行走运动。 结果与结论：实验结果一方面验证了基于步态分析的电刺激模式设计是可行的,对今后加入更复杂的控制方式提供了依据,另一方面也为未来开展的瘫痪患者临床康复实验研究打下了基础。     

Effect of joint angle on mechanomyographic amplitude during unfused and fused tetani in the human biceps brachii muscle

The influence of muscle length-dependent changes in contractile properties on the mechanomyogram (MMG) was investigated during evoked contractions of the biceps brachii muscle. The biceps of nine healthy subjects was stimulated by single twitches, unfused (10 Hz), and fused (30 Hz) frequencies at elbow joint angles of 75, 90, 105, 120, 135, and 150°. During evoked contractions, the longitudinal movement was estimated by the fluctuation of torque signal, and the lateral movement was detected by MMG. Contraction time and half relaxation time were calculated from the single twitches. For repetitive stimulations, followed by eliminating DC component from torque signals, the root mean square values calculated from the torque and MMG signals, which were torque fluctuation and RMS–MMG, respectively. For the 10 Hz stimulation condition, reductions in the torque fluctuation and RMS–MMG were concomitantly observed with increasing elbow angle, and there was a significant correlation between the torque fluctuation and RMS–MMG. On the other hand, for 30 Hz stimulation, there were no significant differences in the torque fluctuation and RMS–MMG over all elbow angles, and no significant correlation between the two parameters. Moreover, the torque fluctuation and RMS–MMG for 10 Hz stimulation were correlated with the contraction time and half relaxation time obtained at each elbow angle, while there were no correlations for the 30 Hz condition. These data suggest that MMG could be a reliable tool to study the development of fusion and the changes in muscle contractile properties during repetitive unfused contractions.     

Mapping from motor cortex to biceps and triceps altered by elbow angle

This experiment used cortical microstimulation to probe the mapping from primary motor cortex to the biceps and triceps muscles of the arm in monkeys. The mapping appeared to change depending on the angle at which the elbow was fixed. For sites in the dorsal part of the arm and hand representation, the effects of stimulation were consistent with initiating a movement of the elbow to an extended angle. Stimulation evoked more triceps activity than biceps activity, and this difference was largest when the elbow was fixed in a flexed angle. For sites in the ventral part of the arm and hand representation, stimulation had the opposite effect, consistent with initiating a movement of the elbow to a flexed angle. For these sites, stimulation evoked more biceps activity than triceps activity, and the difference was largest when the elbow was fixed in an extended angle. For sites located in intermediate positions, stimulation evoked an intermediate effect consistent with initiating a movement of the elbow to a middle, partially flexed angle. For these sites, when the elbow was fixed at a flexed angle, the evoked activity was largest in the triceps, and when the elbow was fixed at an extended angle, the evoked activity was largest in the biceps. These effects were obtained with 400-ms-long trains of biphasic pulses presented at 200 Hz and 30 microA. They were also obtained by averaging the effects of individual, 30-microA pulses presented at 15 Hz. How this stimulation-evoked topography relates to the normal function of motor cortex is not yet clear. One hypothesis is that these results reflect a cortical map of desired joint angle.     

Proprioceptive control of multijoint movement: unimanual circle drawing

The present experiments addressed whether proprioception is used by the central nervous system (CNS) to control the spatial and temporal characteristics of unimanual circle drawing. Circle drawing is a multijoint movement, in which the muscles crossing the elbow and the shoulder are sequentially activated. The spatial and temporal characteristics of circle drawing depend on the precise coordination of these sequential activation patterns, and proprioception is ideally suited to support this coordination. Blindfolded human subjects produced a counterclockwise circular drawing motion (diameter = 16 cm) with the dominant arm at a repetition rate of 1/s. In some trials, 60–70 Hz vibration was applied to the tendons of the biceps brachii and/or the anterior deltoid. Spatial parameters measured from hand-movement data included the x- and y-axis diameters, circularity, and drift of the hand in the workspace. Vibration of either the biceps brachii or the anterior deltoid caused subjects to draw circles with decreased diameter, with changes in circularity, and with a systematic drift of the hand. These distortions to circle drawing by tendon vibration demonstrate that the CNS uses proprioceptive information to accomplish the spatial characteristics of this motor task. Simultaneous vibration of both muscles produced a drift that exceeded the individual vibration effects, which suggests that the CNS combined proprioceptive information related to elbow and shoulder rotation to control the movement of the hand. The temporal characteristics of circle drawing were quantified from joint angle data. While vibration did not significantly influence the relative phase between elbow and shoulder rotation, the variability of the phase relationship increased significantly, which suggests that proprioception contributes to phase stabilization. During circle drawing, elbow flexion-extension movements were produced with limited activation of the biceps. Nevertheless, biceps vibration distorted the circle metrics, suggesting that a muscle’s significance as a sensory transducer is independent of its activity level. Received: 29 November 1997 / Accepted: 16 February 1999     

老年人左、右手喝水动作的运动特性研究

目的通过采集和分析人体三维运动数据,研究老年人左、右手喝水动作的运动学特性。分析左、右手动作的差异,为镜像康复设备的设计和精准康复训练方案的制定提供数据支持和理论基础。方法选取16名右利手的老年人为实验对象,实验对象分别用左、右手完成喝水动作。应用运动捕捉系统采集实验者上肢的三维运动轨迹,分析实验对象在喝水动作中,左、右肩、肘、腕关节的三维运动角度和角速度的相关性。结果左、右手在肩关节的矢状轴角度、肘关节的屈伸角度、肩关节的旋内旋外角度、肘关节旋内旋外的角度上具有高度相关性(相关系数r0.8);在肩关节冠状轴的角度、腕关节掌屈背伸的角速度上具有低度相关性(0.3r0.5);在肩关节冠状轴的角速度上具有微弱相关性(0.1r0.3);在其余上肢的关节角度和角速度上具有显著相关性(0.5r0.8)。结论健康老年人在完成喝水动作中,主要利用肩关节的旋内旋外活动和肘关节的屈伸、旋内旋外活动。右手在关节屈伸角度的运动幅度上大于左手,而在关节旋内旋外角度的运动幅度方面小于左手。在镜像康复机器人设计和康复轨迹规划中,应尊重左、右手的差异,实现精准康复的目的。     

Development of computer-based environment for simulating the voluntary upper-limb movements of persons with disability

Upper-limb orthotic systems have been designed for restoring the upperlimb functions of individuals with disabilities resulting from spinal cord injury (SCI), stroke and muscular dystrophy. These systems employ either functional electrical stimulation or external power. It is proposed that, instead of time-consuming and complicated monitoring using sensors and motion analysis, a software simulator with both angular displacement and acceleration parameters can facilitate the design of a control strategy for an orthosis. Reaching movements of three cervical SCI subjects are used to verify the simulator. A motion analysis system is used to measure the range of motion and joint angles during hand reaching. Results indicate that quaternion and spline curve techniques are suitable for interpolation of the hand reaching movements. The information needed for good simulation only compress the shoulder and elbow joint angles in a few key postures. Stimulated acceleration signals on the upper-arm segment have a high correlation coefficient (>0.9) and a small root mean squared error (<0.11 g) with a real bi-axial accelerometer.     

Human motor unit activity during the onset of muscle fatigue in submaximal isometric isotonic contraction

Summary The onset of fatigue has been studied by relating motor unit activity and surface myoelectric activity during constant force isometric contraction in man.The surface (global) EMG of the biceps brachii was recorded using bipolar electrodes. The global EMGs of the other elbow flexors were also recorded. Motor unit activity was recorded simultaneously at three points of the biceps brachii by using wire electrodes.The time course of the integrated surface EMG showed that fatigue occurred right at the beginning of the contraction. The increase of the integrated EMG was especially important when the value of the force maintenance was high. The time course of this increase was close to that of the output of the spikes recorded by the wire electrodes.No matter what the value of the force maintenance, MU recruitment occurred throughout the contraction. The existence of an increase in the MU firing frequency depended on the value of this force.Contractile element fatigue is believed to provide the explanation of these results, while neuromuscular junction fatigue may perhaps be more important near the time limit.     

Assessment of muscle fatigue using sonomyography: muscle thickness change detected from ultrasound images

Muscle fatigue is an exercise-induced reduction in maximal voluntary muscle force. As the surface electromyography (SEMG) can be used to estimate the features of neuromuscular activations associated with muscle contractions, it has been widely employed as an objective tool to evaluate muscle fatigue. On the other hand, ultrasound imaging can inherently provide the morphological information of individual muscle, thus the architectural changes of muscles during fatigue can be obtained. In this study, we demonstrated the feasibility of using the dimensional change of muscles detected by ultrasound images, named as sonomyography (SMG), to characterize the behavior of muscles when they were in fatigue. The SEMG signals of the muscles were also recorded simultaneously and used for comparison. The right biceps brachii muscles of 8 normal young male adult subjects were tested for 30s under 80% of the maximal voluntary isometric contraction. The muscle fatigue was indicated by the change of the root-mean-square (RMS) and median frequency (MDF) of the SEMG signals. The results showed that the SEMG RMS had a linear increase with time with a rate of 2.9+/-1.9%/s (mean+/-S.D.), while the MDF decreased linearly with a rate of -0.60+/-0.26Hz/s. The muscle thickness, detected from the ultrasound images, continuously increased during the muscle fatigue but with a nonlinear increase with time, which was rapid during the initial 8.1+/-2.1s with a mean deformation rate of 0.30+/-0.19%/s and then became slower with a rate of 0.067+/-0.024%/s up to 20s after the contraction. The muscle deformation at 20s was 3.5+/-1.6%. The results demonstrated that the architectural change of muscles detected using SMG could potentially provide complementary information for SEMG for the muscle fatigue assessment.     

基于肌电信号的手臂运动状态的辨识

本研究的目的是利用人体上肢肌肉的肌电信号辨识人体肘关节运动状态。当人体手臂做屈伸运动时，采集肱二头肌和肱三头肌的肌电（EMGs）信号和肘关节角度信号，对EMGs进行处理和特征提取。提取的特征值作为一个四层的神经网络模型的输入信号，运用改进后的误差反传学习算法最优化网络各层权值，映射出人体表面肌电信号和手臂运动状态间的非线性关系，并将处理后的肌电信号转换为相应时刻的肘关节运动角度。试验结果表明神经网络预测出的肘关节运动角度与测角仪测出的实际运动角度最大误差小于1度。     

Prior experience and current goals affect muscle-spindle and tactile integration

We previously have shown that reports of illusory elbow extension from biceps vibration can be attenuated by touching a stationary cue-surface with the index fingertip of a vibrated arm. However, this was not the case if the subject had previously felt genuine motion of the cue-surface without biceps vibration. Two potential explanations for this are that the sense of elbow orientation results from tactile and muscle stretch cues that are integrated based on (1) an awareness of the tactile cue’s mobility or (2) specific patterns of tactile and muscle spindle activity resembling the elbow motion during previous interactions with the tactile cue. We tested these hypotheses by comparing how touching the cue-surface attenuated the reports of arm movement during biceps vibration after a demonstration of the cue- surface mobility without involving any elbow motion versus simultaneously touching the cue-surface as it moved and extending the elbow to correspond exactly to the elbow extension illusion during vibration. Touching the cue-surface stopped attenuating the reports of elbow extension during biceps vibration only after experiencing actual cue-surface motion while moving the elbow . This supports the second hypothesis that tactile and muscle stretch feedback that are integrated based on specific patterns of tactile and muscle spindle activity recalled from previous interactions with the tactile cue. We also tested the influence of motor set on the sense of elbow position in this paradigm. We found that even after touching the stationary cue-surface had ceased to attenuate illusory elbow motion during biceps vibration, illusory elbow motion during vibration still could be attenuated. This was possible if the subjects intended to actively use their wrists rather than the elbow to maintain fingertip contact. We conclude that muscle stretch and tactile cues are integrated to locate the arm within a highly specific context associated with tactile and proprioceptive feedback from prior experience and current movement goals.     

Surface EMG recordings during maximum static shoulder forward flexion in different positions

Summary This study investigated how position in the range of motion influences the power spectral density function during static shoulder forward flexion. 23 healthy females (20–30 years) volunteered as subjects. They performed maximum static shoulder forward flexions in three positions: 45, 65 and 90° of shoulder flexion. An isokinetic dynamometer was used and the subjects were seated in a specially constructed chair to enable adequate fixation. The elbow was extended and the hand pronated. Electromyographic (EMG) signals (using surface electrodes) were obtained from the descending part of the right trapezius, the anterior portion of the right deltoid, the right infraspinatus and the common belly of the right biceps brachii. The four EMG-signals and the torque and shoulder angle were analyzed by computer. For each 256 ms, mean power frequency, root mean square value and mean torque were calculated. At each of the three positions four 256 ms periods were analyzed and the data are presented as their means. In the trapezius and the biceps brachii the mean power frequency did not change between the three positions. Deltoid and infraspinatus had significantly higher mean power frequencies at 90° than at 45° of flexion. Different factors behind the change in mean power frequency are discussed. The need to standardize the range of motion when studying dynamic fatiguing contractions is emphasised.