食指力量对指浅屈肌运动单元募集模式的影响

目的检测不同食指力量水平下指浅屈肌运动单元的募集模式。方法设计食指20%、40%、60%最大随意收缩力量(maximum voluntary contraction,MVC)3个单指力量输出任务,采用8×1(行×列)阵列电极采集8名受试者的指浅屈肌sEMG信号,利用快速独立分量分析算法提取sEMG信号中运动单位动作电位(motor unit action potential,MUAP)信息,分析不同类型MUAP发放模式与力量的相关性。结果在原始信号中成功提取4种MUPA,且随力量水平的增加,MUAP总数目呈现递增趋势;不同力量水平下,4种类型MUAP所占比重不同,且随力量变化趋势不同。结论不同力量水平下,指浅屈肌改变运动单元募集模式以产生相应肌力。     

指浅屈肌变异一例

在解剖一老年男性尸体时发现双侧指浅屈肌异常，报道如下。该指浅屈肌有2个肌腹。尺侧肌腹起于肱骨内上髁和尺骨上端的前面，肌腹中部宽1．9cm(左侧)，1．8(右侧)：厚0．6cm(左侧)，0．8cm(右侧)，     

掌长肌伴有指浅屈肌中指肌腱缺如1例

掌长肌起自肱骨内上髁以及前臂深筋膜,肌腹很小而腱细长,止于掌腱膜。掌长肌缺如较常见,但掌长肌伴有指浅屈肌中指（第3指）肌腱缺如尚未见文献报道。作者在解剖尸体中,发现1例掌长肌伴有指浅屈肌中指肌腱缺如,现报告如下,     

小指指浅屈肌变异1例

在制作上肢肌肉标本过程中,见小指指浅屈肌变异1例。查文献,未见此类型变异报道,现报道如下。在标本前臂前群肌中,桡侧腕屈肌尺侧、指浅屈肌桡侧浅面见一细长的变异肌束(图1)。     

人指屈肌和指伸肌的肌纤维型构成及年龄差异

用尸检取材(死后24小时内),肌球蛋白ATP酶染色法,检测了不同年龄组(共18例,3～69岁)指浅屈肌、指深屈肌和指伸肌的肌纤维型构成.结果表明:中青年组各肌的Ⅰ型纤维比例分别为指浅屈肌47.2%,指深屈肌44.7%,指伸肌47.7%,各肌之间无明显差异.肌纤维型构成随年龄增加而明显变化,各肌Ⅰ型纤维比例均表现为少儿组较高,中青年组较低,而老年组又明显增高,三组之间具有显著差异.文中还讨论了肌纤维型构成与年龄的关系.     

人指屈肌和指胂肌的肌纤维型构成及年龄差异

用尸检取材，肌球蛋白ＡＴＰ酶染色法，检测了不同年龄组（共１８例，３－６９岁）指浅屈肌、指深屈肌和指伸肌的肌纤维型构成。结果表明：中青年组各肌的Ｉ型纤维比例分别为指浅屈肌４７．２％，指深屈肌４４．７％，指伸肌４７．７％，各肌之间无明显差异。     

儿童旋前圆肌及指浅屈肌的肌内神经分布模式:为BTX-A的注射提供解剖定位

目的探索儿童旋前圆肌和指浅屈肌的肌内终末神经密集区的分布范围,为注射BTX-A治疗脑瘫患儿前臂肌痉挛提供解剖定位。方法使用改良的Sihler`s肌内神经染色法观察儿童旋前圆肌和指浅屈肌的肌内神经分支分布模式。结果旋前圆肌的神经入肌点有上、下两个,下部的神经支较粗大、分布更广,其肌内神经分支呈扫帚状,相邻各神经分支末端可见明显的"O"和"Y"型吻合,该肌的肌内终末神经密集区位于肌腹中部;指浅屈肌的神经入肌点有上、中、下3个,肌内终末神经密集区可分上、中、下3部,其中以中部最为密集,各终末神经间可见"Y"、"O"吻合。结论鉴于两肌的肌内终末神经密集区均位于肌腹中部,当脑瘫患儿旋前圆肌、指浅屈肌痉挛时,使用BTX-A治疗肌痉挛的最佳注射靶区应选择在肌腹中部。     

拇长屈肌变异2例

在制作上肢肌肉标本时,发现拇长屈肌变异2例,此类变异少见,现报道如下: 变异1标本1为一成年男性左侧上肢肌肉标本.分开其肌间隙后,见指浅屈肌、指深屈肌、拇长屈肌均正常,在深层指深屈肌与拇长屈肌之间见一异常肌束.     

采用表面阵列电极的人体前臂电刺激仿真研究

表面阵列电极在改进刺激选择性和控制能力方面具有优越性能,而触点大小和间距是对刺激范围和深度影响最大的因素。针对手功能康复需求,在建立前臂同心圆柱层次模型的基础上,利用有限元仿真得到直流阴极表面电刺激下前臂组织内神经纤维的胞外电势分布,采用神经纤维激励函数表征外加电场对神经轴突电活动的影响。通过仿真研究不同触点尺寸和排列方式的阵列电极设计,采用激励函数峰值和半宽度评价刺激效果。结果表明,当阵列电极触点尺寸由12 mm增大到14 mm,间距由6 mm减小到2 mm时,被激活的靶组织区域面积增大了169.36 mm2,使得刺激选择性变差;而大小触点交叉排列的结构设计能使激活的靶组织区域面积减小至少89.52mm2,有助于提高刺激选择性能,从而为表面阵列电极的优化设计提供理论指导。     

采用表面阵列电极的神经肌肉电刺激系统设计与优化

表面阵列电极在改进刺激选择性和控制能力方面具有优越性能,其中电极设计和刺激波形对于神经肌肉电刺激效果具有重要影响.针对手功能康复需求,采用大小电极触点交叉排列的表面阵列电极,对人体前臂组织实施直流阴极刺激；基于人体前臂的简化层次模型,通过有限元法仿真人体前臂组织的电场分布,使用神经纤维激励函数表征外加电场对神经轴突电活动的影响.在此基础上,选择前臂深层神经纤维激励函数的峰值和半宽度乘积之比作为靶向性能评价函数,利用粒子群算法对表面阵列电极的触点尺寸和间距进行优化设计.结果发现,当大、小触点尺寸分别为9.80和10.72 mm时,阵列电极的靶向性能最优,靶向性能评价函数最大值为11 252.68 V/m4.对比不同刺激波形作用下随时间变化的人体前臂深层神经纤维激励函数最大值,发现矩形波刺激下神经纤维激励函数最大值可达3.448 V/m2,稍高于其他刺激波形,有利于神经纤维的激活,从而为表面阵列电极设计和制定刺激处方提供理论指导.     

有源电极用于表面肌电信号的检测

表面肌电信号的研究对康复医学、运动医学和临床诊断等具有重要意义，信号的正确检测是定量分析表面肌电信号的前提。本文探讨了如何减小表面肌电信号检测中可能遇到的噪声及电极单元的设计要点，并采用仪用放大器AD620设计了双极性的有源电极用于信号检测。实验表明，采用有源电极可以提高信噪比，减小噪声，有效地提取出表面肌电信号。     

基于多尺度最大李雅普诺夫指数的表面肌电信号模式识别

为了提高动作表面肌电信号的识别率,提出一种将最大李雅普诺夫指数和多尺度分析结合的方法。从非线性和非平稳的角度出发,引入多尺度最大李雅普诺夫指数特征,并应用到人体前臂6类动作表面肌电信号的模式识别中。首先利用希尔伯特-黄变换,对原始信号进行经验模态分解,即多尺度分解;然后利用非线性时间序列分析方法,计算多尺度最大李雅普诺夫指数;最后将多尺度最大李雅普诺夫指数作为特征向量,输入支持向量机进行识别。平均识别率达到97.5%,比利用原始信号的最大李雅普诺夫指数进行识别时提高了3.9%。结果表明,利用多尺度最大李雅普诺夫指数对动作表面肌电信号进行模式识别效果良好。     

适于脑功能活动检测的便携式近红外光谱仪的研制

研制一种新型的可用于研究脑功能活动的16通道便携式近红外光谱仪(NIRS)。系统探头柔软性强,与待测部位有良好贴附性,可探测面积为4.4cm×15cm的前额叶区域。选用集成化探测器、光源及其驱动芯片和基于USB接口的掌上型数据采集卡,使整机重量控制在1kg以内。用Visual C 6.0平台开发配套软件,系统的时间分辨率可通过软件设置,最高达100ms。监测Valsalva手法诱导脑血流调节过程的结果表明,系统能够实时测量人脑前额叶皮层血氧和血容量变化情况,从而反映出待测区域功能活动的强弱,为研究大脑认知神经活动提供了条件。     

Adaptations of Walking Pattern on A Compliant Surface to Regulate Dynamic Stability

Dynamic stability can be threatened by various travel surface changes that humans encounter on a daily basis. The central nervous system (CNS) must acquire appropriate information about upcoming surface changes and provide necessary proactive and reactive changes to maintain stability. The purpose of this study was to examine stability control by characterizing adaptations in step patterns, center of mass (COM) trajectory, and lower limb muscle activity when stepping onto and walking on a compliant surface. Eight young adults walked under two conditions: baseline ground walking and while walking on a large foam mat (compliant surface). Optotrak system was used to collect 3D-full body kinematics and electromyography was collected for the rectus femoris, biceps femoris, tibialis anterior, medial gastrocnemius, and soleus bilaterally. Vertical COM decreased on the compliant surface while medio-lateral COM was not affected. This lowering of the vertical COM peak would provide a more stable posture when walking on the surface. Toe trajectory during the swing phase was elevated to avoid tripping on the deformable compliant surface. Step width and length increased on the compliant surface which would increase base of support and provide better control of COM. Increases in gastrocnemius and soleus activity during push-off accounted for increases in step length seen on the compliant surface. Dynamic stability margin in the anterior–posterior direction demonstrated a constant overcompensation and subsequent correction in COM control. These proactive and reactive changes in motor patterns show how the CNS actively coordinates all body segments while traveling on a compliant surface in order to maximize stability.An erratum to this article can be found at     

Algorithm for the Detection of Muscle Activation in Surface Electromyograms During Periodic Activity

A simple surface electromyography (EMG) activation detection algorithm was developed for improved numerical definition of initiation and deactivation of muscle activity during periodic motion when maximum voluntary contractions are impractical to obtain. For the encapsulation of activation/deactivation periods of a signal as percentages of normal cycle parameters, two interrelated and variable thresholds of percent amplitude and duration of a normalized cycle were the analyzed inputs into an algorithm. Outputs for statistical analysis were total percent activation per cycle, standard deviation of activity per cycle, and temporal indices of where the signal turned on and off. Percent activity per cycle had a coefficient of variance of 0.24 (0.11). After the user chose whether to consider the signal for either encompassing all non-base-line activity or peak activity only, resulting coefficients of variation for percent activity were reduced to 0.16 (0.08). The results indicated the feasibility of a mathematically simple algorithm for repeatable decomposition of EMG activity. The need for a modifiable threshold parameter to incorporate varying needs of salient activity levels was also substantiated. © 2002 Biomedical Engineering Society. PAC02: 8719Nn, 8719Ff, 8780-y     

握力刺激强度与运动皮层激活相关性的fMRI研究

目的研究握力刺激强度与运动皮层激活程度的相关性。方法16例正常右利手受试者根据视觉刺激提示右手进行固定频率的三种不同握力运动,同时进行BOLD fMRI扫描,用spm5计算得到不同握力的脑激活区并比较差异。结果在三种不同握力运动中,对侧主运动区、对侧躯体感觉区、对侧辅助运动区(SMA)和对侧运动前区(PMC)明显激活;同侧激活区较小或者未见激活区;同侧小脑激活区较对侧明显激活。随着握力强度的增高,M1和S1激活强度、范围都提高;小脑激活程度有所降低。结论正常人手握力运动时脑皮质运动网络被激活,握力刺激强度与M1、S1的激活程度呈正相关。     

基于虚拟气体传感器阵列的新型肺癌检测电子鼻实验研究

本研究介绍了一种新型的基于虚拟气体传感器阵列及图象识别方法的新型无创肺癌检测与诊断电子鼻。该电子鼻包含一个由固相微萃取和毛细管柱组成的前处理装置实现病人呼吸气体中有机气体成分的浓缩吸附、脱附和分离,通过一个表面涂覆聚异丁稀薄膜差动结构的声表面波传感器对分离后的有机气体成分进行定量检测。此外,采用由毛细管柱方法实现的虚拟气体传感器阵列及改进的人工神经网络算法实现对肺癌呼吸气味图像的有效识别。通过临床实验验证,表明该电子鼻仪器可以有效地识别出肺癌患者、肺癌疑似病人和健康人,因此将有望在包括肺癌等疾病的早期诊断仪器中发挥重要的作用。     

Another Look at the Relationship of Electrodermal Activity to Electrode Contact Area

The present study was undertaken lo reexamine the hypothesis that the relationship between skin conductance and electrode size is monotonic and linear. Skin conductance activity was recorded from 48 right-handed male subjects using 6 different sixes of electrode collars ranging in exposed surface area from .131 cm² to .786 cm². The dependent measures were skin conductance level (SCL); skin conductance response (SCR) amplitude to a series of 8 loud tones; latency, rise time, and recovery half-time of the first tone elicited response; (he largest self-generated SCR; and the number of nonspecific responses. The results indicated a significant linear relationship between contact area and SCL, stimulus and self-generated SCR amplitude, and the number of nonspecific responses. Latency was not affected by electrode size although the other time-based measures were. Differences in skin conductance activity were found among different palmar recording sites. The observed linear relationship between electrode size and electrodermal measures has implications for current models of electrodermal activity and for the comparison of results across studies in which different electrode contact areas are used.