千赫兹经皮脊髓电刺激下腰段神经纤维激活的仿真研究  

A simulation study of nerve fiber activation in the lumbar segment under kilohertz-frequency transcutaneously spinal cord stimulation

作　　者：徐琦[1] 李欣茹 鲁芷鑫 吴永超[2] XU Qi;LI Xinru;LU Zhixin;WU Yongchao(School of Artificial Intelligence and Automation,Huazhong University of Science and Technology,Wuhan 430074,P.R.China;Department of Rehabilitation,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology,Wuhan 430022,P.R.China)

机构地区：[1]华中科技大学人工智能与自动化学院,武汉430074 [2]华中科技大学同济医学院附属协和医院康复科,武汉430022

出　　处：《生物医学工程学杂志》2025年第2期300-307,共8页Journal of Biomedical Engineering

基　　金：国家自然科学基金(61771210)。

摘　　要：临床试验证实,千赫兹经皮脊髓电刺激(TSCS)可用于促进脊髓损伤后患者的感觉运动功能恢复,但脊髓纤维激活机制尚不明确,刺激参数选择大多依赖于经验。本文采用TSCS有限元模型仿真人体脊髓T_(12)至L_2节段的电场分布,使用神经元双电缆模型计算得到脊髓纤维的激活阈值,改变载波波形、相间延迟、调制波频率、脉宽等刺激参数,得到脊髓纤维激活阈值的变化规律。与正弦载波相比,采用方波载波可显著降低背根纤维的激活阈值;改变调制波频率所引起的背根纤维激活阈值变化不超过1V,背根纤维的激活阈值随调制波脉宽增加而降低。采用矩形脉冲(频率50Hz、脉宽1ms)调制10kHz方波的刺激波形,背根和背柱纤维的激活阈值最低(分别为27.6V和55.8V);添加载波相间延迟(5μs)可将背根纤维激活阈值降至20.1V。该仿真结果可为临床刺激参数选择提供理论依据。Clinical trials have demonstrated that kilohertz-frequency transcutaneous spinal cord stimulation(TSCS) can be used to facilitate the recovery of sensory-motor function for patients with spinal cord injury,whereas the neural mechanism of TSCS is still undetermined so that the choice of stimulation parameters is largely dependent on the clinical experience.In this paper,a finite element model of transcutaneous spinal cord stimulation was used to calculate the electric field distribution of human spinal cord segments T_(12) to L_2,whereas the activation thresholds of spinal fibers were determined by using a double-cable neuron model.Then the variation of activation thresholds was obtained by varying the carrier waveform,the interphase delay,the modulating frequency,and the modulating pulse width.Compared with the sinusoidal carrier,the usage of square carrier could significantly reduce the activation threshold of dorsal root(DR) fibers.Moreover,the variation of activation thresholds was no more than 1V due to the varied modulating frequency and decreases with the increased modulating pulse width.For a square carrier at 10kHz modulated by rectangular pulse with the frequency of 50Hz and the pulse width of 1ms,the lowest activation thresholds of DR fibers and dorsal column fibers were 27.6V and 55.8V,respectively.An interphase delay of 5μs was able to reduce the activation thresholds of the DR fibers to 20.1V.The simulation results can lay a theoretical foundation on the selection of TSCS parameters in clinical trials.

关 键 词：千赫兹频率 经皮脊髓电刺激 神经元模型 脊髓神经纤维 

分 类 号：R651.2[医药卫生—外科学]