基于有限元-神经元模型的大鼠硬膜外脊髓电刺激仿真研究

doi:10.3969/j.issn.0258-8021. 2015. 03.007

摘要
图/表
参考文献
相关文章 (5)

全文: PDF (1760 KB) HTML (1 KB)
输出: BibTeX | EndNote (RIS)

摘要临床研究证实，硬膜外脊髓电刺激（ESCS）能促进脊髓损伤后的运动功能恢复，但基本神经机制则需通过动物实验进行研究。在建立大鼠ESCS有限元-神经元组合模型的基础上，仿真L2节段单阴极刺激条件下脊髓组织内的电势分布，确定L1到S2节段背根、腹根纤维和不同深度背柱纤维激活阈值的变化规律，分析纤维位置和刺激脉宽对神经纤维激活阈值的影响。仿真结果发现，距电极最近的背根纤维激活阈值最低为041 V，浅层背柱纤维的激活阈值略高为047 V，最近腹根纤维的激活阈值最高为078 V，减小电极-纤维距离有利于脊髓纤维的选择性激活；不同深度背柱纤维的激活阈值随刺激脉宽增加而减小，但脉宽过大导致背柱纤维激活阈值的降幅变小，过长的脉宽使得激活阈值的降幅趋缓，合理选择刺激脉宽有利于激活深层背柱纤维，增加脊髓组织的激活区域，提高ESCS对于深层背柱纤维的募集能力。该仿真结果可为动物实验研究中合理选择刺激参数、提高刺激选择性能提供理论指导。

	服务

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	陈清阳¹徐琦^1*王熠钊²孟勇¹

关键词 ：有限元模型, 神经元模型, 硬膜外脊髓电刺激, 大鼠, 脊髓纤维

Abstract：Clinical research demonstrated that epidural spinal cord stimulation (ESCS) was able to facilitate motor function recovery after spinal cord injury, but the underlying neural mechanism must be explored by animal experiments. In this paper, based on the construction of finite element and neuron model of ESCS, the distribution of electric potentials was simulated in the rat spinal cord with a stimulating cathode located at the midpoint of L2 spinal segment. The excitation thresholds of typical spinal fibers were calculated to analyze the influence of the fiber location and pulse width on the recruitment of nerve fibers. The simulation results showed that the dorsal root fiber entering the spinal cord at the cathode level had the lowest excitation threshold of 041 V, whereas the excitation threshold of the ventral root fiber at the same level was 078 V and much higher than that of the most superficial dorsal column fiber with the excitation threshold of 047 V. The decrease of the fiberelectrode distance was able to improve the selectivity of fiber activation. It was also shown that the excitation threshold of dorsal column fibers at different depths within the midsagittal plane of spinal cord decreased with the increase of pulse width, whereas too long pulse width corresponded to the decreased slope of the varied activation threshold for dorsal column fibers. Therefore, the choice of an appropriate pulse width is essential to the activation of deep dorsal column fibers and the increasing activated area of the stimulated tissue. Our simulation results would offer guidance for the selection of stimulation parameters and the improvement of the stimulation selectivity during animal experiments.

Key words： finite element model neuron model epidural spinal cord stimulation rat spinal cord fiber

基金资助:国家自然科学基金（60874035）；国家重点基础研究（973）项目（2013CB329500）

引用本文:

陈清阳¹徐琦^1*王熠钊²孟勇¹. 基于有限元-神经元模型的大鼠硬膜外脊髓电刺激仿真研究[J]. 中国生物医学工程学报, 2015, 34(3): 308-314.

链接本文:

http://cjbme.csbme.org/CN/10.3969/j.issn.0258-8021. 2015. 03.007 或 http://cjbme.csbme.org/CN/Y2015/V34/I3/308

［1］夏楠, 侯文生, 章毅, 等. 经硬脑膜电刺激对视皮层神经活动影响的仿真研究［J］. 中国生物医学工程学报, 2011, 30(5):725-730.
［2］徐飞, 张定国, 许恒. 电触觉的皮肤神经机理仿真及实验验证［J］. 中国生物医学工程学报, 2014, 33(1):22-27.
［3］Holsheimer J, Wesselink WA. Optimum electrode geometry for spinal cord stimulation:the narrow bipole and tripole ［J］. Medical and Biology and Engineer and Computing, 1997, 35(5):493-497.
［4］Rattay F, Minassian K, Dimitrijevic MR. Epidural electrical stimulation of posterior structures of the human lumbosacral cord: 2. quantitative analysis by computer modeling ［J］. Spinal Cord, 2000, 38(9):473-489.
［5］Gerasimenko YP, Lavrov IA, Courtine G, et al. Spinal cord reflexes induced by epidural spinal cord stimulation in normal awake rats ［J］. Journal of Neuroscience Methods, 2006, 157(2): 253-263.
［6］Zhou Hui, Xu Qi, He Jiping, et al. A fully implanted programmable stimulator based on wireless communication for epidural spinal cord stimulation in rats ［J］. Journal of Neuroscience Methods, 2012, 204(2): 341-348.
［7］Senqul G, Watson C, Tanaka L, et al. Atlas of spinal cords of the rat, mouse, marmoset, macaque, and human ［M］. San Diego: Elsevier Academic Press, 2012:15-72.
［8］Lee D, Hershey B, Bradley K, et al. Predicted effects of pulse width programming in spinal cord stimulation: a mathematical modeling study ［J］. Medical and Biology and Engineering and Computing, 2011, 49(7):765-774.
［9］杨安峰, 王平. 大鼠的解剖和组织［M］. 北京: 科学出版社, 1985: 159-161.
［10］McIntyre CC, Richardson AG, Grill WM. Modeling the excitability of mammalian nerve fibers:influence of afterpotentials on the recovery cycle ［J］. Journal of Neurophysiology, 2002, 87(2): 995-1006.
［11］Raspopovic S, Capogrosso M, Micera S. A computational model for the stimulation of rat sciatic nerve using a transverse intrafascicular multichannel electrode ［J］. IEEE Transaction on Neural Systems and Rehabilitation Engineering, 2011, 19(4): 333-344.
［12］Suh YS, Chung K, Goggeshall RE. A study of axonal diameters and areas in lumbosacral roots and nerves in the rat ［J］. The Journal of Comparative Neurology, 1984, 222(1): 473-481.
［13］Ladenbauer J, Minassian K, Hofstoetter US, et al. Stimulation of the human lumbar spinal cord with implanted and surface electrodes: a computer simulation study ［J］. IEEE Transaction on Neural Systems and Rehabilitation Engineering, 2010, 18(6): 637-645.
［14］Struijk JJ, Holsheimer J, Spincemaille GH, et al. Theoretical performance and clinical evaluation of transverse tripolar spinal cord stimulation ［J］. IEEE Transactions on Rehabilitation Engineering, 1998, 6(3): 277-285.
［15］Struijk JJ, Holsheimer J, Boom HBK. Excitation of dorsal root fibers in spinal cord stimulation: a theoretical study ［J］. IEEE Transactions on Bimomedical Engineering, 1993, 40(7): 632-639.
［16］Butterwick A, Vankov A, Huie P, et al. Tissue damage by pulsed electrical stimulation ［J］. IEEE Transactions on Bimomedical Engineering, 2007, 54(12): 2261-2267.