【作者】 李金香；

【导师】 王江；

【作者基本信息】 天津大学 ， 控制理论与控制工程， 2004， 硕士

【摘要】 肌电图的研究和肌电信号的分析一直是医学界一个重要的研究课题，尤其是表面肌电信号，由于其无损性和易测性，更是被广为关注。对于神经肌肉失调者，运动单元结构的变化是最主要的病因。这些结构的变化可通过研究肌肉活组织直接观察到。这需要研究者去观察在新陈代谢过程中肌肉纤维的分布情况、纤维的减少、以及纤维尺寸的改变。但活组织研究不能给出单个运动单元的信息。这些信息必须从肌电信号研究中给出。本文在了解了与肌肉纤维有关的生物知识的基础上，首先弄清楚了细胞跨膜电位及动作电位的产生机理；然后又在前人胞外电位容积导体模型的基础上，提出肌肉单纤维的点电流源模型。即从跨膜电流角度出发，将兴奋性单纤维看作是一连续产生的线性点电流源，且该电流源自运动终板以一定的传导速度传向纤维终端。首先根据电磁场理论得出独立点电流源在各向异性介质中任一点的电位解的形式（即权函数），然后根据中心导体模型计算出跨膜电流的计算表达式，最后计算兴奋性纤维外任一点的动作电位，则此动作电位就可表示为跨膜电流与权函数的卷积。同时本文还就模型中的各参数进行了分析。主要针对纤维直径、记录点与纤维的距离两个方面分别介绍了对权函数、跨膜电流及最后对胞外电位的影响。进一步，在单纤维胞外电位的计算模型基础上，讨论了运动单元动作电位及表面肌电信号的计算模型。同时通过与前人试验结果的比较，验证了本文提出的肌肉纤维点电流源模型在精确度满足要求的前提下，与前人的容积导体理论模型相比，计算模型简单，易于计算机仿真。更多还原

【Abstract】 The study of EMG (electromyography) is a subject of great interest inelectrophysiology, especially SEMG (surface electromyography), because of itsnoninvasive and testability. In neuromuscular disorders, the motor unit structure is altered by diseaseprocesses. These changes can be recognized by direct observations of the muscletissue in muscle biopsy studies. This allows one to look at the distribution of fibersaccording to the metabolic properties, loss of fibers, and change in fiber size. Thebiopsy does not give any information about individual MUs. Such information isobtained from electromyography (EMG) studies. This paper proposes a linear point current source model, namely, regarding thesingle active fiber as a series of continuous point current sources which start off fromend-plate and conduct to tendons with a constant velocity. First, we calculate theessential solution of the independent point current source in an anisotropic mediumwith the theory of electromagnetic field, and then calculate the transmembrane currentcomputing model from linear core conductor model. Finally, calculate the actionpotential of any point outer of the active fiber. The potential is defined as theconvolution of the transmembrane current and a weight function. At one time, in this paper, we analyzed the parameters of the model. Mostlyaimed at the fiber diameter, distance between the fiber and recording point, introducedthe influences for the weight function, transmembrane current and extracellularpotential resistively. Furthermore, this paper discussed the computing model of motorunit action potential and EMG. through the compare with the former testing result,testified the precision and validity of proposed model.更多还原