呼吸中枢驱动增加时呼吸力学改变以及对吸气开始信号的影响

目的探讨呼吸中枢增加所造成的呼吸力学改变及其对吸气开始信号的影响。方法以10例正常志愿者为研究对象,采用CO2重复呼吸的方法,使呼气末CO2分压(PCO2-ET)增高到最大耐受水平,观察呼吸中枢驱动增加时的呼吸力学和吸气开始时相关信号的动态变化。结果正常志愿者重复呼吸试验最大可以耐受的PCO2-ET值为(81.2±6.6)mm Hg。随着PCO2-ET逐渐升高,膈肌肌电图的均方根(RMSdi)、跨膈压(Pdi)和潮气量(VT)进行性增高,而呼吸周期(Ttot)逐渐缩短,PCO2-ET水平从基础值[PCO2-ET(level-0)]到最大值[PCO2-ET(level-4)],RMSdi从(17.17±12.41)μV增加到(147.99±161.64)μV,Pdi和VT分别由(7.5±1.7)cm H2O和(0.68±0.27)L增加到(26.13±11.51)cm H2O和(2.21±0.37)L,而Ttot从(2.91±0.85)s减少到(1.92±0.39)s,RMSdi、Pdi、VT和Ttot与PCO2-ET的动态变化呈高度线性相关(r值分别为0.956、0.973、0.956和0.89,P均<0.001)。吸气开始时,最早出现吸气信号改变为RMSdi,其次为口腔压(Pm),再次为吸气流量(Flow);随着PCO2-ET增加,Pm和Flow滞后于RMSdi的时间逐渐延长,而Flow滞后于Pm的时间不变。结论膈肌肌电图信号的出现先于其他吸气相关信号,随着呼吸中枢驱动的增加,传统的吸气同步信号口腔压和吸气流量滞后于膈肌肌电图时间延长,提示膈肌肌电图可作为更加敏感的吸气开始的信号,可以用于呼吸机的人机同步触发,改善同步性,尤其是适合在中枢驱动异常增高的条件下。     

肌电控制康复机器人协助的脑卒中患者肘关节康复训练的多参数评价

摘要 目的：探索在肌电控制机器人协助的脑卒中偏瘫患者肘关节康复训练中,有关肘关节电生理﹑动力学﹑运动学等多项参数的变化情况,并为脑卒中评估提供更加全面的定量评估方法。 方法：本研究募集了8例偏瘫患者,对其分别进行了20次肌电控制机器人辅助的肘关节康复训练,在实验过程中记录了肱二头肌与肱三头肌的肌电信号,肘关节力矩信号和角度信号。 结果：训练后Fugl-Meyer上肢功能评测值显著大于训练前（P<0.05）,Ashworth量表值显著小于训练前（P<0.05）;在最大自主等长收缩（MVC）实验中,肘关节屈曲与伸展的MVC力矩显著大于训练前（P<0.01）;三头肌的力矩-肌电比显著大于训练前（P<0.05）;在无辅助跟踪运动中肘关节运动角度和目标角度均方根误差（RMSE）显著小于训练前（P<0.05）。 结论：肌电控制康复机器人肘关节康复训练从关节力矩、肌肉效率、运动精度等多个方面改善偏瘫患者的运动功能。以上参数从多角度定量反映了偏瘫患者运动功能状态,具有应用于临床运动功能评估的潜在价值。     

The relationship between anaerobic threshold and electromyographic fatigue threshold in college women

Summary The purpose of this study was to investigate the relationship between anaerobic threshold (Th_an) and muscle fatigue threshold (EMG_FT) as estimated from electromyographic (EMG) data taken from the quadriceps muscles (vastus lateralis) during exercise on a cycle ergometer. The subjects in this study were 20 female college students, including highly trained endurance athletes and untrained sedentary individuals, whose fitness levels derived from their maximal oxygen consumption ranged from 24.9 to 62.2 ml · kg^–1·min^–1. The rate of increase in integrated EMG (iEMG) activity as a function of time (iEMG slope) was calculated at each of four constant power outputs (350, 300, 250, 200 W), sufficiently high to bring about muscle fatigue. The iEMG slopes so obtained were plotted against the exercise intensities imposed, resulting in linear plots which were extrapolated to zero slope to give an intercept on the power axis which was in turn interpreted as the highest exercise intensity sustainable without electromyographic evidence of neuromuscular fatigue (EMGF_FT). The Th_an was estimated from gas exchange parameters during an incremental exercise test on the same cycle ergometer. The mean results indicated that oxygen uptake (VO₂) at Th_an was 1.391·min^–1, SD 0.44 andVO₂ at EMG_FT was 1.33 1·min^–1, SD 0.57. There was no significant difference between these mean values (P>0.05) and there was a highly significant correlation betweenVO₂ at Th_an andVO₂ at EMG_FT (r=0.823,P<0.01). These data supported the concept of Th_an on the basis that Than was associated with the highest exercise intensity that could be sustained without evidence of neuromuscular fatigue and thus suggested that EMG_FT may provide an attractive alternative to the measurement of Th_an.     

肌营养不良征的肌电图分析

目的：探讨肌营养不良肌患的神经电生理改变。方法：对16例肌营养不良患进行常规肌电图(EMG)、神经电图(ENOG)检测，EMG检测四肢近端肌肉及腓肠肌等，观察静息状态时自发电位，测定运动单位电位(MUP)的时限、波幅、大力收缩时的募集相。测定运动、感觉神经的传导速度(MCV、SCV)及动作电位的末端潜伏期(ML)诱发电位波幅。结果：本组资料显示所检肌时限异常率占82％，波幅降低率占72％，大力收缩早募集占60％。结论：肌电图检测可以对肌营养不良和脊肌萎缩症提供很好的诊断和鉴别诊断依据。     

慢性脊髓性肌萎缩的电生理改变及肌活检

目的:探讨慢性脊髓性肌萎缩(SMA)患者的肌电图及肌活检的诊断价值。方法:对38例SMA病人进行肌电图和肌活检检查。结果:肌电图除3例正常外,其余表现为神经原性损害;光镜提示神经原性萎缩。结论:提示肌电图在SMA的确诊有重要价值。     

肌电图检查对颈椎间盘突出症的诊断价值

目的：颈椎间盘突出症为临床常见病,为准确定位依断,我们采用由单一脊神经后支支配的颈棘间肌等颈部深层肌群肌电图检查法,对颈椎间盘突出症患者进行定位诊断。方法：对３４例经临床和影学检查确认为颈椎间盘突出的患者,进行颈部深层肌肌电图测定。结果：与临床及影像学诊断的符合率９７％。颈部深层肌异常电位３３例,其中失神经电位２８例,阳性率８２．３％。Ｃ５－６椎间盘突出为其肌电图异常电位发生率也最高。结论：异常电     

Correlation between muscle metabolism and changes in M-wave and surface electromyogram: Dynamic constant load leg exercise in untrained subjects

In untrained subjects exercising on a cycle at constant work loads presented at a sub- or suprathreshold level, reduced M wave amplitude with lengthening of duration was measured in vastus lateralis muscle during and after suprathreshold exercise. M wave changes were correlated with increased blood lactate concentration. At the two work load levels, the increase in root mean square of EMG was rapidly closely adjusted to that of oxygen consumption, confirming the reality of adaptative reflex mechanisms in leg muscles during cycling. © 1997 John Wiley & Sons, Inc. Muscle Nerve 20:1197–1199, 1997     

Synergy matrices to estimate fluid wrist movements by surface electromyography

Although many efforts have been undertaken to develop an interface using surface electromyography (sEMG) to connect the gap between a human and a wrist prosthesis, most of these efforts have offered only static positioning (ON/OFF) of the prosthesis. This study introduced synergy matrices to extract fluid wrist movement intents by sEMG to allow individuals with wrist amputations to use wrist prostheses. A non-negative muscle synergy matrix was used to map muscle activities in the forearm into four predefined wrist movement intents (flexion/extension and radial/ulnar deviation). The directions of the predefined intents were constrained to two perpendicular axes, so each movement spanned only a one-dimensional space. A joint synergy matrix was used to span the whole two-dimensional space by combining the four wrist movement intents. Ten healthy subjects volunteered for a validation experiment, which was built as a virtual environment in which people with wrist amputation could receive myoelectric control training. The results showed that proportional two-degree-of-freedom (DOF) movements could be estimated by sEMG. This work could be useful not only for wrist prostheses but also for alternative computer interfaces and studies to examine motor adaptation by sEMG.     

旋前园肌综合征的电生理诊断分析

目的:寻找旋前园肌综合征的电生理诊断方法.方法:通过EMG检查及手术证实,共确诊患者20例,观察其支配肌电生理指标.结果:旋前园肌综合征病人20例均见自发电位,10例有前臂MNCV减慢,15例有潜伏期延长,17例支配肌波幅(AMP)下降,10例有神经干动作电位(NAP)降低.结论:电生理检查能够为旋前园肌综合征诊断和鉴别诊断提供可靠依据.