什么叫做心电图导联?

答:心脏的周围有组织液,而组织液为电流的良好导体,故整个人体可以比作一个容积导体,体表面各处的电位分布情况在不断变化。由于体表电位分布不同,如将2个金属小板的电极安置于体表任何部位,再用导线连接到心电图机中正负两极,     

电烧伤研究现状及临床治疗分析

电烧伤是一种电流通过人体造成人体组织受损的特殊烧伤,它会造成人体血管、神经、肌肉、皮肤及骨骼等组织的损伤。本文笔者就电烧伤研究的现状及临床治疗进行简要阐述,仅供参考。     

儿童血液微量元素与血铅的关系

铅广泛存在于人们生活环境的方方面面,属于一种多亲和性的物质,能够经过体表皮肤、消化道、呼吸道进人人体内,并分散到人体的各个的组织器官,对人体的神经、造血、泌尿、免疫、消化等多个系统造成不同程度的损害。特别是神经系统的损害。损     

新型多通道双相体外肌肉刺激器的设计

功能性电刺激（functional electrical stimulation,FES）是神经肌肉功能恢复与重建的新途径．其工作原理是通过人工产生电脉冲微量电流．经由皮肤．刺激由于高位中枢障碍引起信号传输通路受阻而失去中枢神经控制的骨骼肌．使相应的肌肉产生收缩．带动关节按一定的规律运动．从而完成相应的运动功能，实现康复的目的。     

实用重症监护护理

监护技术1心电监护心肌组织与身体其他组织一样,细胞在活动期间有电流产生。由于人体是一个导电体,心脏活动所产生的电位变化可以反映在体表的任何一个部位,由体表部位记录到的心脏电位变化波形即心电图。心脏的病变可以引起心肌电活动的变化,而心肌电活动的变化可引起心电图波相应的改变。在ICU中,心电监护作为心功能监护的重要组成部分,是观察病情变化必不可少的手段。1.1操作方法在ICU中,危重患者需要进行持续心电监护。心电监护仪会动态显示心电图的波形,必要时可以记录及储存心电图,出现异常时能自动报警。ICU内一般采用胸壁综合监…     

皮下结节型脂膜炎MRI表现1例

患者男,37岁,主因“右上臂三角区肿块3个月,局部皮肤桔皮样改变1个月”就诊.查体:右上肢三角肌区见类圆形肿块,质硬,活动度差,表面皮肤桔皮样改变.血常规及肿瘤标记物正常.右上肢X线片:右侧肱骨骨质及周围软组织未见明显异常(图1).右上肢MR:右侧肱骨三角肌外侧缘皮下脂肪组织内见边界清楚的类圆形肿块,与表皮组织粘连明显,T1WI、T2WI于略低信号基础上见絮状稍高信号(图2),考虑为纤维瘤.行右上肢体表肿物切除术.术后病理诊断:脂膜炎.     

康复医学领域的表面肌电应用研究

表面肌电（sulface electromyography，sEMG）信号是神经肌肉系统在进行随意性和非随意性活动时的生物电变化经表面电极引导、放大、显示和记录所获得的一维电压时间序列信号，其振幅约为0—5000μV，频率30—350Hz，信号形态具有较强的随机性和不稳定性。与传统的针式肌电图（needle electromyography，NEMG）相比，sEMG的空间分辨率相对较低，但是探测空间较大，重复性较好。基础研究表明，sEMG信号源于大脑运动皮层控制之下的脊髓α运动神经元的生物电活动，形成于众多外周运动单位电位在时间和空间上的总和，信号的振幅和频率特征变化取决于不同肌肉活动水平和功能状态下的运动单位活动同步化、肌纤维募集，以及和肌纤维兴奋传导速度下降等生理性因素以及探测电极位置、信号串线（crosstalk）、皮肤温度、肌肉长度，以及肌肉收缩方式等测量性因素的共同作用。在控制良好的条件下，上述sEMG信号活动的变化在很大程度上能够定量反映肌肉活动的局部疲劳程度、肌力水平、肌肉激活模式、运动单位兴奋传导速度、多肌群协调性等肌肉活动和中枢控制特征的变化规律，因而对于康复医学临床和基础研究等具有重要的学术价值和应用意义。     

超声诊断黏液性恶性纤维组织细胞瘤1例

患者男,57岁,四年前发现右上臂肿块,其间肿块逐渐增大,无肩臂疼痛及麻木感。查体于右上臂可触及一5.0cm×6.0cm的肿块,质中等,边界欠清,表面欠光整,活动度尚可,无压痛,同侧腋窝淋巴结未见肿大。超声检查:右上臂肌层内探查见3.8cm×2.3cm的低回声区,境界欠清,边缘不规则,内部回声不均匀,内部及周边可探及点条状血流信号,阻力指数(RI)为0.79(图1);超声提示右上臂实质性包块,考虑来源于肌层。术中所见:肿物约4.0cm×3.0cm,无包膜,与周围组织分界不清,位于脂肪层,质中等。术后病理诊断:右上臂黏液性多形性细胞恶性肿瘤,局部肌肉纤维组织中少量…     

含损耗神经脉冲传输的耦合孤波特性

孤波是一种能在长距离保持无形变传输的特殊行波.文章旨在分析神经信息传输的孤波特性,建立了包含损耗的描述耦合神经孤波传输的非线性薛定谔方程组;利用变分法导出神经孤波传输过程中的参数演化方程组,分析同地和异地耦合孤波的相互作用特性以及损耗对相互作用的影响.发现传输过程中孤波的振幅呈指数型衰减,异地耦合孤波的相互作用为吸引力并且损耗能减弱相互作用力,同地耦合孤波的相互作用较大并且难以计算出准确值.结果表明,传输过程中孤波能描述神经脉冲的一些传输和相互作用特性,实验结果可为神经脉冲传输模型的建立以及深入研究提供理论依据.     

声衰减系数中的相位对消假象

本文首先分析了测量声衰减的信号接收装置特性。在此基础上,用直径0.06、0.5和1.4cm的三种压电接收换能器,在1～6MHz的频率范围内,测量超声在猪的心、肝、肌肉和脂肪组织中的声衰减系数,以研究这类换能器的相位对消效应对声衰减值造成的“假象”。经过实验证明:在测得的声衰减系数值中,确实潜在着压电换能器相位对消效应造成的“假象”此种效应对声衰减数据的影响,与接收换能器的面积大小相对应,同理论分析相一致:当使用小面积的换能器时,衰减系数与频率之间接近为线性关系。因此,要提高测量组织声衰减的精度,应采用小面积的压电换能器,或聚焦换能器。如果选用电声换能器、辐射力法和热学方法测量,可完全避免相位对消效应造成的“假象”。     

The potential for utilizing inter-limb coupling in the rehabilitation of upper limb motor disability due to unilateral brain injury

Purpose. Symmetry tendencies in human movement have generally been regarded as a constraint to upper limb motor performance. However, several recent studies have suggested that this phenomenon might be utilized in the rehabilitation of individuals with motor disability due to unilateral brain injury. In this paper the efficacy of such a rehabilitative approach is explored by reviewing: (i) examples of symmetry tendencies in healthy individuals, (ii) the potential neurophysiological mechanisms responsible for inter-limb coupling, and (iii) recent studies which have directly assessed the effects of inter-limb coupling on individuals with unilateral brain injury.

Method. A thorough review of current published evidence was conducted utilizing various electronic search engines (Medline, PreMedline, Embase and Cinahl). Studies included those that focused on symmetry tendencies and/or inter-limb coupling in the upper limbs with a particular emphasis placed on studies of individuals with unilateral brain injury.

Results. Based on the current literature it seems that motor function of the affected upper limb in individuals with unilateral brain injury can be improved through a rehabilitation approach that incorporates inter-limb coupling.

Conclusion. This approach should be considered as an adjunct to more common rehabilitation strategies with future research aimed at determining the most effective means of employing this paradigm.     

智能下肢假肢传感器的应用

背景:下肢运动是一种复杂的运动,采用合适的传感器获取人体运动生理信息,成为智能假肢控制的前提.国际上现有的下肢假肢控制信息源为与运动信息有关的物理量,这类信息可以直接反映人体运动的生物力学特性,采集比较简单,非常适合实时控制.现有智能下肢假肢产品根据采用的控制方法不同选择一种或几种传感器测量人体运动信息.目的:研究一种能够采集智能下肢假肢控制所需人体运动信息的传感器系统.方法:对智能下肢假肢带固定式气缸阻尼器的四连杆机械机构进行运动分析,得出四连杆后臂下轴电位计输出信号与膝关节弯曲角度的对应关系,同时,选取合适的霍尔传感器安装位置,解决了其中存在的双值问题.设计了传感器输出信号采集实验,通过跑步机速度调节来保证步行速度安全可控,测量不同步速下脚尖离地时刻膝关节弯曲角度,分析采集结果找到了它们之间的对应关系.结果与结论:脚尖离地时刻膝关节弯曲角度随着步行速度增大而增大,采用二次曲线拟合取得了较好效果.实验结果显示,水平步行状态下,采用电位计和霍尔传感器作为检测手段能够检测下肢假肢的步速,也能区分支撑期和摆动期.     

The potential for utilizing inter-limb coupling in the rehabilitation of upper limb motor disability due to unilateral brain injury

Purpose. Symmetry tendencies in human movement have generally been regarded as a constraint to upper limb motor performance. However, several recent studies have suggested that this phenomenon might be utilized in the rehabilitation of individuals with motor disability due to unilateral brain injury. In this paper the efficacy of such a rehabilitative approach is explored by reviewing: (i) examples of symmetry tendencies in healthy individuals, (ii) the potential neurophysiological mechanisms responsible for inter-limb coupling, and (iii) recent studies which have directly assessed the effects of inter-limb coupling on individuals with unilateral brain injury.

Method. A thorough review of current published evidence was conducted utilizing various electronic search engines (Medline, PreMedline, Embase and Cinahl). Studies included those that focused on symmetry tendencies and/or inter-limb coupling in the upper limbs with a particular emphasis placed on studies of individuals with unilateral brain injury.

Results. Based on the current literature it seems that motor function of the affected upper limb in individuals with unilateral brain injury can be improved through a rehabilitation approach that incorporates inter-limb coupling.

Conclusion. This approach should be considered as an adjunct to more common rehabilitation strategies with future research aimed at determining the most effective means of employing this paradigm.     

A quasi-dynamic nonlinear finite element model to investigate prosthetic interface stresses during walking for trans-tibial amputees

BACKGROUND: To predict the interface pressure between residual limb and prosthetic socket for trans-tibial amputees during walking. METHODS: A quasi-dynamic finite element model was built based on the actual geometry of residual limb, internal bones and socket liner. To simulate the friction/slip boundary conditions between the skin and liner, automated surface-to-surface contact was used. Besides variable external loads and material inertia, the coupling between the large rigid displacement of knee joint and small elastic deformation of residual limb and prosthetic components were also considered. RESULTS: Interface pressure distribution was found to have the same profile during walking. The high pressures fall over popliteal depression, middle patella tendon, lateral tibia and medial tibia regions. Interface pressure predicted by static or quasi-dynamic analysis had the similar double-peaked waveform shape in stance phase. INTERPRETATION: The consideration of inertial effects and motion of knee joint cause 210% average variation of the area between the pressure curve and the horizontal line of pressure threshold between two cases, even though there is only a small change in the peak pressure. The findings in this paper show that the coupling dynamic effects of inertial loads and knee flexion must be considered to study interface pressure between residual limb and prosthetic socket during walking.     

膝下残肢界面应力准动态有限元模型研究

目的:为计算小腿截肢患者行走过程中残肢和接受腔之间的界面压力.方法:根据残肢、骨骼和假肢接受腔的真实几何形状建立了准动态有限元模型,采用了自动面面接触模型模拟皮肤和接受腔衬套之间的边界摩擦和滑动,并在考虑行走过程中外力和惯性载荷的同时,考虑了膝关节刚体位移和残肢弹性变形之间的耦合.结果:对一个步态周期内的残肢界面压力进行了仿真计算,结果表明界面压力主要分布在髌韧带区、腘窝区、胫骨内外侧.在站立相,除髌韧带区外,其他区域的压力具有与地面反力相似的变化规律.结论:本文所建立的准动态模型考虑了患者行走过程中膝关节位移,更接近于人体真实运动,能够用于假肢接受腔界面特性的预测和现代假肢的数字化设计.     

Interlimb neural coupling: Implications for poststroke hemiparesis

Interlimb coordination is essential to perform goal-directed daily tasks and purposeful locomotion. The coordination occurs due to spatiotemporal coupling of movements, which also comprises interactions in segmental kinematics, joint dynamics, and muscle activity. Neuroanatomical and neurophysiological linkages at the spinal and brain level are responsible for the coordination. The linkage is termed “neural coupling”. According to the task demand, the coupling may occur between two upper limbs or two lower limbs or all four limbs. Central pattern generators play a key role in interlimb coordination by regulating the rhythmic upper and lower limb movements. Neuroanatomically, multiple areas of both cerebral hemispheres via the corpus callosum interact and control the bimanual upper limb movements. There is an interhemispheric synchronization and disinhibition to control the coupled bimanual upper and lower limb movements. Movement of the upper limb also enhances neuromuscular recruitment of the lower limb. In stroke, bimanual motor impairments exist in the form of asymmetry and reduced coordination, which may be related to weakness of the ipsilateral body side lesser than the contralateral side. The aim of the present review was to understand the interlimb coordination and neural coupling and its implication in stroke rehabilitation. The review suggests incorporating the movements of bilateral upper and lower limbs either simultaneously or consecutively for hemiparetic subjects. Further, the conventional and contemporary rehabilitation methods need to be reconsidered while utilizing the coupling concept.     

同种异体肢体移植中他克莫司的应用剂量

背景:他克莫司应用于同种异体肝移植的免疫耐受已多见报道.目的:探索他克莫司在异体肢体移植时的最佳应用剂量.方法:建立同种异体肢体移植大鼠模型,移植造模后设立给予不同他克莫司剂量的0.5,1,2 mg/(kg?d)组及对照组,对大鼠进行大体观察、组织学、淋巴细胞亚群测定.结果与结论:移植后出现排斥反应的时间分别是对照组(3.43±0.79) d、0.5 mg/(kg?d)组(5.68±0.97) d、1 mg/(kg?d)组(9.13±1.17) d、2 mg/(kg?d) 组(9.61±2.38) d,排斥反应的病理分级4组分别为(2.61±0.38),(1.57±0.43),(0.85±0.24),(0.71±0.19)级.移植后各给药组CD4+、CD8+检测值均明显下降,CD4/CD8比值轻度增加或在正常值范围内;对照组CD4+、CD8+无明显变化,CD4/CD8比值明显增加.提示,他克莫司的应用剂量在1 mg/(kg?d)时就能达到理想的抑制免疫排斥反应,提高用量后意义不大.     

基于表面肌电的步态分析

背景:步态分析在人体运动系统和神经系统疾病的病因分析,诊断,功能、疗效与残疾评定中是重要的评价手段,其中肌肉活动是影响步行动力的基础因素.目的:分析人体自然行走过程中下肢前后肌群的表面肌电变化,分析对应于步态周期不同时相前后肌群的表面肌电特征和机制.方法:采用德国zebris FDM 步态分析系统(6 m)配套的同步肌电仪采集7例健康人正常步态过程中下肢胫骨前肌和腓肠肌外侧表面肌电信号,利用Matlab软件进行消噪和归一化,得到完整步态周期不同时相对应的表面肌电信号图,观察其峰值变化.采用芬兰ME6000肌电仪测试15 m自由行走人体左右侧下肢胫骨前肌和腓肠肌外侧表面肌电信号,提取时域和频域特征参数.结果与结论:下肢胫骨前肌和腓肠肌外侧表面肌电信号在一个完整步态周期中呈特征性变化,即胫骨前肌表面肌电的峰值发生在后跟着地处,而腓肠肌外侧其峰值发生在中后支撑相处.进一步分析发现,人体在自由行走时其下肢肌肉优势侧与非优势侧差异有显著性意义(P＜0.05),且不同肌肉其差异趋势不同.     

人脑BOLD信号的有源仿真和成像

目的：脑功能磁共振成像(functional Magnetic Resonance Imaging ,fMRI)主要基于人脑血氧饱和水平依赖(Blood Oxygen Level Dependent,BOLD)信号在成像时的灰度幅值变化进行检测。对BOLD信号进行仿真并成像,可以作为金标准和标准信号,检测脑磁共振成像的质量和检出率。方法：设计了一种可以有源模拟人脑BOLD的激发电路,可以实现不同电流幅值、不同频率、不同占空比的稳定矩形波输出,在时间域内仿真人脑BOLD信号。结果：三台不同型号、不同场强的MR仪测皆有稳定的矩形波输入且检出率一致。结论：同一设备对本设计同一刺激模式均有相近的检出率,可以作为已知且确定信号的“金标准”定量分析磁共振系统对BOLD信号的检出率、一致性。     

基于有限状态机的智能下肢假肢控制

背景:传统的下肢假肢行走状态改变时膝关节阻尼不能随之改变,假肢跟随性差,变化范围小。目的:基于有限状态机的智能下肢假肢控制方法,实现假肢侧对健肢侧的实时跟踪和步速跟随。方法:智能下肢假肢采用带固定式气缸阻尼器的四连杆机构,采用有限状态机的控制方法,感知当前的步态事件,触发步态状态的转变,调整对应的步态模式,得到步态规划的输出动作。结果与结论:实验结果表明,智能下肢假肢能够进行步速识别和步态识别,控制器输出不同的控制策略,控制步进电机调整膝关节阻尼的大小,假肢侧能够对健肢侧进行实时跟踪和步速跟随。