电刺激对军人血浆褪黑激素昼夜节律的影响

人体的生理与行为节律是由内源性昼夜节律钟产生与调控的。我们通过监测人体体核温度 ,就电针与光照肌对军人血浆褪黑激素节律的影响进行了研究 ,以探索电针调节人体节律的相位反应规律。实验结果显示 ,电针对军人血浆中的褪黑激素节律相位的影响具有明显的依时相性 ,其相位反应曲线呈光性模式。这一发现为治疗睡眠与节律混乱性疾病提供了新的思路。     

基于小波包-交叉频率相干性的肌间耦合特性

人体运动控制系统具有高度的非线性特性,通过量化评价表面肌电(sEMG)信号间的非线性耦合强度,可以得到运动相关肌肉的功能状态,进而探究人体运动控制的机制。本文将小波包分解和n∶m相干性分析相结合,构建基于小波包-n∶m相干性的肌间交叉频率耦合分析模型,探究肌电信号间的非线性耦合关系。在维持30%最大自主收缩力(MVC)的肘部屈伸状态下,采集20名健康成年人的sEMG信号,首先基于小波包分解获取子带分量,然后将子带信号进行n∶m相干性计算,分析肌间耦合特征。结果表明:30%MVC的肘部屈曲运动下,协同肌对和拮抗肌对的线性耦合(频率比为1∶1时)强度高于非线性耦合(频率比为1∶2、2∶1和1∶3、3∶1时);对于肌间非线性耦合,随着频率比的增大,耦合强度随之降低,且频率比为n∶m和m∶n之间没有明显的耦合强度差异;beta和gamma频段内的肌间耦合主要体现在协同肌对之间的线性耦合(1∶1)和低频率比的非线性耦合(1∶2、2∶1)以及拮抗肌对之间的线性耦合上。以上说明:小波包-n∶m相干性方法可以定性、定量地描述肌间非线性耦合强度,为深入揭示人体运动控制机制和运动功能障碍患者的康复评价提供理论参考。     

功能电刺激腕关节运动的自适应控制技术研究

针对功能电刺激(FES)康复技术中肌肉的时变和高度非线性的特点,提出一种实时调整FES系统输出,实现康复患者自适应训练的方法。考虑到患者间和康复各阶段肌肉对电刺激响应能力的差异,利用神经网络良好的非线性逼近能力,采用神经网络辨识器辨识相关运动肌肉的FES模型,并在此基础上,利用神经网络控制器在线调节控制策略及刺激参数,提高FES系统的自适应能力。通过人体腕关节运动控制的FES实验,验证该方法具有较高的轨迹跟踪控制精度和较强的自适应能力。     

基于加速度信号的人体爬行与步行过程中多关节协同运动模式对比

基于人体运动协同控制理论提出人体爬行过程中四肢关节的协同运动模式与步行过程中四肢协同运动模式具有相似性是其能促进步行功能康复重要运动生理基础的假设。为了证明该假设，本研究首先基于MPU9250加速度传感器收集了5名受试者爬行和步行过程中双侧肘、腕、膝、踝关节等8处关节在运动过程中的加速度信号；然后，依次对信号进行预处理、周期分割、矢量化等处理；最后，利用非负矩阵分解算法提取爬行和步行运动过程中肢体间多关节运动的协同运动模式，并计算爬行与步行运动关节协同模式之间的相关系数。结果显示5名受试者爬行及步行过程中均能提取2种关节姿势协同模式，并且对应协同模式的相似系数分别为0.76和0.72，说明爬行运动与步行运动过程中肢体运动协同模式具有一定的相似性。本研究可以为爬行运动用于儿童步行功能康复提供一定的参考。     

经颅磁声电刺激影响大鼠工作记忆中局部场电位的相位幅值耦合分析EI北大核心CSCD

经颅磁声电刺激是一种新型无创的神经调控手段,其利用超声与静磁场耦合作用产生的感应电场调节相应脑区神经节律振荡活动。本文旨在探讨经颅磁声电刺激对记忆过程中神经元集群信息传递与交流的影响。实验中,将20只健康成年维斯塔尔(Wistar)大鼠随机分为对照组(5只)和刺激组(15只),对刺激组施加0.05~0.15 T、2.66~13.33 W/cm2的经颅磁声电刺激,对照组不施加刺激;采集大鼠执行T迷宫工作记忆任务中前额叶皮层的局部场电位信号,比较不同参数刺激组大鼠与对照组大鼠delta节律相位、theta节律相位与gamma节律幅值之间的耦合差异性。实验结果显示,刺激组delta节律与gamma节律的耦合强度明显低于对照组(P<0.05),theta节律与gamma节律的耦合强度明显高于对照组(P<0.05);随着刺激参数的增加,delta节律与gamma节律、theta节律与gamma节律耦合程度分别呈现减小、增大的趋势。本文初步研究结果表明,经颅磁声电刺激能够抑制前额叶皮层中delta节律神经活动,增强theta节律与gamma节律振荡活动,从而促进了不同空间范围内神经元集群之间的信息交流与传递,这为进一步探索经颅磁声电刺激调节大脑记忆功能的作用机制奠定了基础。     

基于表面肌电非负矩阵分解与一致性的肌间协同耦合关系研究

肌肉协同模型是神经产生并控制运动的低维度结构,探讨不同动作任务下的表面肌电信号(sEMG)间的相干性分析,可以体现相应肌群的协同耦合关系,进而能从神经控制运动与肌肉相互配合协调的角度揭示运动产生与执行规律。组织8名年轻健康受试者(男女均半、20～24岁)进行上肢腕部屈、伸实验,采集动作时相应肌群的sEMG数据,引入非负矩阵分解(NMF)方法分析肌间协同性,并进一步对协同性较高的肌群采用一致性分析方法,研究信号beta(15~35 Hz)和gamma(35～60 Hz)频段的耦合强度关系,探讨腕部伸屈动作下不同受试者之间的协同耦合性差异。结果表明:腕伸动作下,主动肌桡侧腕短伸肌(ECR)、指伸肌(ED)、尺侧腕伸肌(ECU)、肱桡肌(B)在协同模块W₅中具有协同关系,且肌间耦合强度显著(P<0.05),beta频段与gamma频段一致性显著面积相差较大(1.261±0.966);腕屈动作下,分别在协同模块公式中存在具有协同关系的肌肉对,且肌肉间耦合强度显著(P<0.001),在beta和gamma频段一致性显著面积相差较小(0.412±0.163),但主动肌桡侧腕屈肌、指浅屈肌间不具有协同性,耦合关系较弱。以上说明:神经控制运动的方式不同,体现为肌肉协同耦合关系有所差异;在同一协同模块中,协同性较高的肌肉间耦合关系较强,揭示神经控制运动规律与肌肉相互配合方式;运用此方法进行肌间协同耦合联合分析,可望深入揭示中枢神经模块化协同控制运动机制,进一步为运动障碍患者功能分析和评价提供科学依据。     

自然步态摆动期动力学协调模式的研究

建立了包含肌肉一肌腱动力特性和神经兴奋一肌肉收缩动力学方程在内的人体下肢生物力学模型，并针对自然步态摆动期的运动过程，采用最优控制方法进行了计算分析。计算结果与实验测量结果在运动学、肌电信号和肌肉活性参数等方面均具有很好的一致性；同时利用模型分析了肌肉协调运动模式，结果表明在自然步态摆动期运动过程中，神经系统将肌肉结成不同的协同肌群，并按照特定的时序结构控制不同肌群实现步行运动的加速、制动和姿态控制。     

一种基于T-S模糊辨识的人体站立平衡系统建模方法

为了使被动平衡康复训练系统可以制定安全的训练强度和训练方式,本论文采用T-S模糊辨识方法建立了一种新的人体站立平衡系统数学模型。该模型以多维运动平台的运动加速度为模型输入,人体关节角度为模型输出。采用人工蜂群寻优算法改进模糊C-均值聚类算法,提高了辨识前件参数的效率。通过试验,采集了9位健康成年人的被动站立平衡调节数据,用于模型参数训练和模型结果验证。采用仿真结果和测量数据的均方差及互相关度,证明了所建模型是准确和合理的。     

H-R神经元的正弦函数-延迟反馈反控制

目的研究单个Hindmarsh-Rose(H-R)神经元模型从周期动力学模式转向混沌模式的自适应反控制问题。方法利用施加正弦函数延迟自反馈方法进行数值模拟分析,分别将耦合强度和时间延迟作为控制参数。结果通过大量的数值模拟计算,给出神经元的膜电位变量随耦合强度和时间延迟两个参数变化的分岔图,发现在耦合强度值和时间延迟两个参数组合的一些范围内,本来是3峰周期动力学模式的H-R神经元运动可被反控制成混沌模式及其他周期模式的运动。结论对H-R神经进行反控制的正弦延迟自适应反馈法是有效的,耦合强度和时间延迟均为反控制的重要参数。控制过程反映了神经独有的自适应的信息识别的动力学特性。     

穿戴式下肢外骨骼对人体步态特性的影响研究

本文拟探明穿戴式下肢外骨骼对人体下肢相应关节参数与肌肉运动学、动力学参数的影响变化,进而为优化其结构、提高其系统性能提供科学依据。本文通过采集受试者的行走数据,以人体下肢各关节在矢状面上的关节角度作为下肢外骨骼仿真分析的驱动数据,运用人体生物力学分析软件Anybody分别建立了人体模型(即未穿戴下肢外骨骼的人体模型)和人-机系统模型(即穿戴下肢外骨骼后的模型),并对比分析了两种情况下人体下肢运动时的运动学参数(关节力、关节力矩)及肌肉参数(肌肉力、肌肉激活程度、肌肉收缩速度、肌肉长度)的变化情况。实验结果表明,人体穿戴下肢外骨骼后行走的步态满足正常步态,但会出现个别肌肉力突增的现象;下肢主要肌肉的最大肌肉激活程度均未超过1,说明肌肉均未出现疲劳或损伤状况;股直肌的最大肌肉激活程度增加最多(0.456),半腱肌的最大肌肉激活程度增加最少(0.013),提示下肢外骨骼最容易引起股直肌疲劳或损伤。通过本文研究结果说明,为避免出现个别肌肉力突增导致人体下肢损伤,在设计下肢外骨骼时,要特别注意人体体段长与下肢外骨骼杆长的一致性和运动的平稳性。     

Stroke-induced synergistic phase shifting and its possible implications for recovery mechanisms

Among other diminished motor capabilities, survivors of a stroke often exhibit pathological joint synergies. With respect to the upper limbs, these deficits diminish coordination in reaching, pointing, and daily task performance. Past research on pathological synergies suggests that the synergistic relationship between joints is different for flexion than in extension. One explanation for different flexion and extension synergies is that there exists a time difference between the joint being volitionally moved and the joint that moves in synergy. The goal of this research was to measure these synergistic time differences. The experiment included 11 hemiparetic subjects who performed rhythmic elbow motions at five different frequencies. A motion capture system was used to record the resulting shoulder synergies. Synergistic shoulder rotations were found to exhibit frequency-dependent phase lags (delays) and leads (advances) in the paretic arm. Furthermore, the synergistic leads and lags varied with frequency and were subject specific. We found that timing differences between joints in pathological movements are comparable to differences that were observed by other researchers for normal, able-bodied movement synergies. Moreover, the fact that pathological synergies were evident in rhythmic motion suggests that they are spinal in origin. A significant amount research exists relating to able-bodied spinal synergies. Thus, the supposition that pathological synergies are an expression of normal synergies would tie disabled movement into a larger body of work related to able-bodied synergies. The rehabilitation implications of this possible connection are discussed.     

Rhythmic affects on stroke-induced joint synergies across a range of speeds

Joint synergies are one among several diminished motor capabilities that are associated with stroke. These synergies are characterized by a stereotypical combination of involuntary joint coactivations. This research measured the synergistic rotations of the shoulder in response to voluntary rhythmic motion of the elbow across a range of speeds. The experimental protocol included a total of 22 subjects divided into two groups: (1) stroke survivors and (2) neurologically intact controls. Rhythmic motion in stroke survivors resulted in comparable synergies to discrete movement. It was found that hemiparetic subjects had greater synergy than neurologically intact individuals for all speeds. Synergy was quantified using a synergy ratio. This ratio uses elbow rotation as an input in the denominator and shoulder rotation as an output in the numerator. The amount of shoulder synergy varied with the subject’s level of impairment as measured by a modified Fugl-Meyer assessment. As rhythmic speeds increased, the synergy ratios became higher for stroke subjects. This effect was especially pronounced for subjects with higher impairment. The relationships between synergies that arise from rhythmic and discrete movements are also discussed. The results of this study may have implications for therapeutic interventions, robotic rehabilitation approaches, and for the design of orthotic devices. More generally, these results shed light on the role of central pattern generators in hemiparetic motion.     

基于统计参数映射分析跑鞋跟掌落差对下肢关节负荷的影响

目的 探讨在相同跑速下穿着不同落差跑鞋对下肢关节负荷的影响,为跑鞋设计和跑步者选购跑鞋提供依 据。 方法 18 名男性跑步者分别穿着零落差和 10 mm 落差跑鞋以(4. 0±0. 2) m/ s 速度完成测试,使用红外高速运 动捕捉系统和三维测力台同步采集下肢运动学参数和地面反作用力( ground reaction force, GRF)。 使用统计参数 映射法(statistical parameter mapping,SPM)分析跑鞋跟掌落差对支撑期垂直 GRF、下肢关节三维力矩的影响。 结 果 跑鞋跟掌落差对垂直 GRF 无影响,对下肢关节部分力矩-时间序列影响显著。 与穿着零落差跑鞋相比,穿着 10 mm 落差跑鞋在 27% ~ 38% 支撑期髋关节内旋力矩增加,在 47% ~ 75% 支撑期膝关节伸展力矩增加,在 16% ~ 33% 、25% ~ 30% 、12% ~ 25% 支撑期踝关节跖屈力矩、外翻力矩和外旋力矩降低。 结论 与穿着零落差跑鞋相比,穿 着 10 mm 落差跑鞋在支撑前期髋关节负荷增加,踝关节负荷降低,在支撑中期膝关节负荷增加。 建议跑步者结合 自身特点及跑鞋跟掌落差对下肢关节负荷特征的影响,选择适合自己的跑鞋。     

排球运动起跳过程中踝关节的生物力学特性

文题释义： 急停起跳：在激烈的排球比赛中,急停起跳动作是运动员比赛过程中出色完成扣球、拦网、跳发球、跳传球等技术所必不可少的关键阶段,也是运动员获得较好起跳高度的关键实施环节。 踝关节的活动范围：研究发现长期从事举重项目的人比正常人的踝关节活动度要小,长期从事游泳项目的人比正常人的踝关节活动度要大。踝关节的活动范围往往还跟运动成绩相关联,如短跑、速滑等竞速性项目运动成绩好的运动员踝关节的活动度也相对较好。 背景：目前对踝关节的生物力学特性研究多集中于方法学的探讨,对复合动作模式下踝关节生物力学特征的研究较少。 目的：分析对排球运动员起跳落地时踝关节的运动学和动力学特性。 方法：研究选取天津体育学院排球专项运动的学生男女各20名。主要采用Vicon三维运动捕捉系统和Kistler三维测力台,同步采集受试者在起跳落地时踝关节运动学与动力学参数,总共获得3次有效数据,利用统计学方法对数据进行对比分析。研究方案的实施符合天津体育学院的相关伦理要求,所有受试者均为自愿参加,并对试验过程完全知情同意。 结果与结论：①发现在该动作模式中,踝关节跖屈角度男性明显小于女性,在起跳阶段踝关节处于内翻和内旋状态,在落地缓冲阶段踝关节处于内翻和外旋状态,且角度男性组略大于女性,此时极易造成踝关节损伤;②三维方向的峰力矩和力值男性组均大于女性;三维方向峰值力矩和力出现的时间男性组晚于女性,而且存在双腿力量不均衡以及双脚不同时着地情况。 ORCID: 0000-0003-4584-148X(鲍春雨) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

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。     

Phase relationships between segmentally organized oscillators in the leech heartbeat pattern generating network

Motor pattern generating networks that produce segmentally distributed motor outflow are often portrayed as a series of coupled segmental oscillators that produce a regular progression (constant phase differences) in their rhythmic activity. The leech heartbeat central pattern generator is paced by a core timing network, which consists of two coupled segmental oscillators in segmental ganglia 3 and 4. The segmental oscillators comprise paired mutually inhibitory oscillator interneurons and the processes of intersegmental coordinating interneurons. As a first step in understanding the coordination of segmental motor outflow by this pattern generator, we describe the functional synaptic interactions, and activity and phase relationships of the heart interneurons of the timing network, in isolated nerve cord preparations. In the timing network, most (approximately 75%) of the coordinating interneuron action potentials were generated at a primary spike initiation site located in ganglion 4 (G4). A secondary spike initiation site in ganglion 3 (G3) became active in the absence of activity at the primary site. Generally, the secondary site was characterized by a reluctance to burst and a lower spike frequency, when compared with the primary site. Oscillator interneurons in G3 inhibited spike activity at both initiation sites, whereas oscillator interneurons in G4 inhibited spike activity only at the primary initiation site. This asymmetry in the control of spike activity in the coordinating interneurons may account for the observation that the phase of the coordinating interneurons is more tightly linked to the G3 than G4 oscillator interneurons. The cycle period of the timing network and the phase difference between the ipsilateral G3 and G4 oscillator interneurons were regular within individual preparations, but varied among preparations. This variation in phase differences observed across preparations implies that modulated intrinsic membrane and synaptic properties, rather than the pattern of synaptic connections, are instrumental in determining phase within the timing network.     

Helical axis calculation based on Burmester theory: experimental comparison with traditional techniques for human tibiotalar joint motion

In prosthetics and orthotics design, it is sometimes necessary to approximate the multiaxial motion of several human joints to a simple rotation about a single fixed axis. A new technique for the calculation of this axis is proposed, originally based on Burmester’s theory. This was compared with traditional approaches based on the mean and finite helical axes. The three techniques were assessed by relevant optimal axis estimation in in vitro measurements of tibiotalar joint motion. A standard jig and radiostereometry were used in two anatomical specimens to obtain accurate measurements of joint flexion. The performance of each technique was determined by comparing the motion based on the resulting axis with the experimental data. Random noise with magnitude typically similar to that of the skin motion was also added to the measured motion. All three techniques performed well in identifying a single rotation axis for tibiotalar joint motion. Burmester’s theory provides an additional method for human joint motion analysis, which is particularly robust when experimental data are considerably error affected.     

人工腰椎间盘植入后小关节应力分布的比较研究

目的:通过三维有限元的方法研究正常椎间盘、髓核摘除、人工腰椎间盘三组小关节的应力分布,探讨人工腰椎间盘植入小关节应力分布的影响.方法:利用有限元软件MSC.MARK,建立正常椎间盘、髓核摘除、人工腰椎间盘及L4～5运动节段的三维模型,然后模拟腰椎节段的运动,进行小关节应力分布的比较研究.结果:在各种运动状态下髓核摘除组小关节的应力最大,人工腰椎间盘组的小关节应力比正常椎间盘高,但明显小于髓核摘除组,但在旋转状态下,人工腰椎间盘小关节的中心部位承受的应力最大.结论:人工腰椎间盘植入后与髓核摘除组相比可降低小关节的应力,但仍高于正常的腰椎间盘组;人工腰椎间盘组的抗旋转能力明显低于正常腰椎间盘组和髓核摘除术后组,由此可见,目前的人工腰椎间盘具有腰椎间盘大部分的力学功能,与真正的腰椎间盘仍有差别.     

Use of multiple wearable inertial sensors in upper limb motion tracking

This paper presents a new human motion tracking system using two wearable inertial sensors that are placed near the wrist and elbow joints of the upper limb. Each inertial sensor consists of a tri-axial accelerometer, a tri-axial gyroscope and a tri-axial magnetometer. The turning rates of the gyroscope were utilised for localising the wrist and elbow joints on the assumption that the two upper limb segment lengths are known a priori. To determine the translation and rotation of the shoulder joint, an equality-constrained optimisation technique is adopted to find an optimal solution, incorporating measurements from the tri-axial accelerometer and gyroscope. Experimental results demonstrate that this new system, compared to an optical motion tracker, has RMS position errors that are normally less than 0.01 m, and RMS angle errors that are 2.5-4.8 degrees .     

Disruptions in joint control during drawing arm movements in Parkinson’s disease

Impairments in control of multi-joint arm movements in Parkinsons Disease (PD) were investigated. The PD patients and age-matched elderly participants performed cyclical arm movements, tracking templates of a large circle and four differentially oriented ovals on a horizontal table. The wrist was immobilized and the movements were performed with shoulder and elbow rotations. The task was performed with and without vision at a cycling frequency of 1.5 Hz. Traces of the arm endpoint, joint-motion parameters represented by range of motion and relative phase, and joint-control characteristics represented by amplitude and timing of muscle torque were analyzed. The PD patients provided deformations of the template shapes that were not observed in movements of elderly controls. The deformations were consistent for each shape but differed across the shapes, making quantification of impairments in the endpoint movement difficult. In contrast, the characteristics of joint control and motion demonstrated systematic changes across all shapes in movements of PD patients, although some of these changes were observed only without vision. A specification of the PD influence was observed at the level of joint control and it was not distinguishable in joint and endpoint motion, because of the property of multi-joint movements during which control at each joint influences motion at the other joints. The results suggest that inability of PD patients to provide fine muscle torque regulation coordinated across the joints contributes to the altered endpoint trajectories during multi-joint movements. The study emphasizes the importance of the torque analysis when deficits in multi-joint movements are investigated, because specific impairments that can be detected in joint-control characteristics are difficult to trace in characteristics of joint and endpoint kinematics, because of interactions between joint motions.