【作者】 贾晓枫；

【导师】 陈中伟；

【作者基本信息】 复旦大学 ， 外科学， 2003， 博士

【摘要】 目　的1、探讨神经束内电极不同埋入方式长期留置后家兔坐骨神经电生理表现的规律以及改良形状和埋入方式对神经束内电极的存留和神经电信号的影响。2、探索神经束内电极留置后家兔坐骨神经组织学变化及与电生理表现的相关性。3、在残肢志愿受试者上臂尺、桡、正中神经植入神经束内电极，研究三大主要神经的神经信息和神经信息控制假肢的可行性。方　法18只家兔随机分成两组，实验组14只分组进行不同时期实验，每只家兔双侧后肢同体对照分成两组，一侧埋入直型神经束内电极（直型组，Z组），另一侧埋入改良神经束内电极（改良组，T组）。其余4只作为病理研究的对照组。以外部绝缘的直径60μm95%铂5%铱合金丝制成直型神经束内电极及头端弹簧状的改良神经束内电极。用显微外科操作技术将直型或改良神经束内电极分别插入家兔两侧坐骨神经一神经束中作为记录电极。用显微缝线将神经束内电极固定至神经外膜。以神经束外一直电极作参考电极，远端连接肌电图仪，分别在植入点近端（顺向神经干传导，A组）和远端（逆向神经干传导，B组）的神经束中插入同心针电极刺激，记录神经束电信号。在家兔第一趾脱毛后置2个环状表面电极刺激，观察记录感觉神经动作电位（C组）。再以神经束内电极作刺激电极，同心针电极刺入该侧腓肠肌处，记录观察电信号。术后即时及间隔不同的时间段检测坐骨神经电信号，记录潜伏期、波幅和神经传导速度。同体对照比较改良组和直型组之间在神经束内电极不同留置时限A、B、C各组电信号以及神经束内电极的有效存留个体数和有效存留时间的差异。比较在电极不同留置时限随时间延长A、B、C各组电信号的改变。<WP=5>电信号检测结束后，采用HE染色和氨银染色法光镜下观察电极埋入点及其近端、远端坐骨神经的显微结构、透射电镜观察其超微结构并以IMS图像分析系统定量测定有髓神经轴索直径的改变，探索与电生理表现之间的相关性。动物实验证实长期植入自制神经束内电极具有良好的组织相容性以及稳定的传导和记录神经信号的特性后，应用神经束内电极直接插入志愿受试者残肢上臂三大神经一神经束中作为记录电极采集神经信号。以神经外电极作参考电极，远端连接肌电图仪，记录受试者在清醒状态下用脑意识控制幻想已失去手的各种动作时中枢神经发出运动指令的神经信息，并在幻想指伸和指屈动作时实时用电极引出信息控制7自由度神经信息控制假肢模拟装置，观察假肢的动作。将记录到的幻想手不同动作时三大神经内的信息进行识别及分析，探讨应用神经信息作为假肢控制信息源的可能性。结　果 1、①动物实验表明：神经束内电极作为记录电极可稳定地记录到周围神经的电信号。A组电信号波型具有典型的运动神经动作电位特征，B组波型具有感觉神经动作电位特征，C组波型具典型的感觉神经动作电位特征。以神经束内电极作刺激电极可见该侧腓肠肌处肌肉出现收缩，同心针电极可以记录到肌电信号。②改良组和直型组之间不同时期坐骨神经电信号特征基本一致，潜伏期、波幅和传导速度的差异均无显著性（P均>0.05）；而神经束内电极的有效存留个体数（P<0.05）和有效存留时间（P <0.01）的差别均有统计学意义。③不同时期A、B组电信号波型大体稳定，潜伏期和传导速度的差别没有统计学意义（P均>0.05），波幅的差别在Ａ组即时电信号组和1月后电信号组之间（P<0.05），以及6－9月电信号组和即时电信号组（P<0.01）、1月后电信号组（P<0.01）、2月后电信号组（P<0.01）、3－6月电信号组（P<0.05）之间均有统计学意义。B组波幅的差别在即时电信号组和6－9月电信号组之间，以及3－6月电信号组和6－9月电信号之间均有统计学意义（P均<0.05）。2、组织学、超微结构研究显示：①家兔坐骨神经标本在神经束内电极埋入处未见明显急慢性炎症反应。在电极植入处周围可见薄层同心圆排列的胶原、成纤维细胞，未见巨噬细胞，少数标本可找到个别淋巴细胞。②在电极的埋入点实验组有髓轴索的直径较正常对照组相应位置略细，平均减少10.8%（P<0.01），在埋入点近端和远端数值基本正常（P均>0.05）。在电极埋入点，电极留置时间1-2月组、3-6月组、6-9月组和对照组4组两两之间，轴索直径的差异均有显著的统计学意义（P<0.01）。3、受试者用脑意识控制幻想已失去手的各种动作时，可用神经束内电极稳定地<WP=6>记录到三大神经的电信号。将桡神经的神经束内电极和参考电极直接与7自由度神经信息控制假肢模拟装置相连，能够成功触发假肢指伸动作，但无法实现闭合。对嘱受试者幻想已失去手的各种动作时所记录到的32组神经信息所进行的时域分析表明桡神经的信息发放强度要大于尺神经和正中神经的信息发放强度。频域分析也证实了这点。此外，它还显示①同一神经内不同纤维的神经信息频谱形状一致，发放模式相同；②执行同一动作时，同一功能神经纤维束发放的频谱具有一定的稳定性；③作用力增大时，神经信息的低频成分减少，高频成分增加；④不同神经控制肢体运动时，“各主其职、协调合作”；⑤不同神经在同时协调同一动作时，频谱不同。 结　论 1、 建立了家兔周围神经电信号检测的更多还原

【Abstract】 OBJECTIVE1、To investigate long-term electrophysiological manifestation after implantation of intrafascicular electrode by different implantation modes in sciatic nerve of rabbits, the influence upon surviving of intrafascicular electrode and electric signals of nerve with modified form and implantation mode. 2、To investigate histological changes of sciatic nerve after implantation of intrafascicular electrode and the relationship with electrophysiology. 3、To study the information of 3 major nerves and the feasibility of nerve-signal controlled prosthesis after implantation of intrafascicular electrodes in the ulnar, radial, median nerve of upper arm in amputee volunteer. METHODS18 rabbits were divided into 2 groups. 14 of them were divided as experimental group by different experimental periods. Both hind limbs of each rabbit were divided into 2 groups by isobody control researches: one side was implanted with straight intrafascicular electrode (straight group, Z group); another side was implanted with modified intrafascicular electrode (modified group, T group). The rest 4 rabbits belonged to control group for pathologic study. Intrafascicular electrode fabricated from external insulated wire 60μm in diameter (95%Pt-5%Ir alloy), and spring-structure made in the head end as modified intrafascicular electrode. Intrafascicular electrode was implanted as recording electrode directly by microsurgery technique into the fascicle of the sciatic nerve in<WP=8>rabbit and fixed to epineurium with microsuture. Straight intrafascicular electrode was implanted at one side and modified intrafascicular electrode at the other side in the same rabbit respectively. Another straight electrode was placed outside the fascicle as reference electrode. Both distal ends were coupled to electromyogram. Stimulating with concentric pin electrode inserted at a proximal point (Along-nerve-trunk conduction, Group A) or a distal point (Contra-nerve-trunk conduction, Group B) from the point which the recording electrode threaded the fascicle, the signal of the fascicle was recorded. Stimulating with 2 superficial ringed electrodes at depilated 1st toe of rabbit, sensory nerve action potential (SNAP) (Group C) was recorded. Then threaded concentric pin electrode into gastrocnemius with intrafascicular electrode as stimulating electrode, the signal was recorded. As electric signals of the sciatic nerve be harvested at different intervals, the latent period, amplitude and nerve conduction velocity were recorded. Isobody control researches were performed within modified group and straight group at different intervals: the differences of electric signals of group A, B, C, the surviving individual number and the surviving period of intrafascicular electrodes. The electric signals of group A, B, C were compared respectively during different period after implantation of electrodes.As detection of electric signals completed, microstructural changes in sciatic nerve at the level of implant, the levels proximal and distal to the implant zone were studied with Hematoxylin and Eosin (HE) staining, Ammonia Silver staining, and the ultrastructural changes were studied with transmission electron microscope. The diameters of myelinated axons were quantitatively determined by Image Analysis System. The relationship with electrophysiology was investigated. As animal experiments confirmed that long-term implanted self-made intrafascicular electrode has good compatibility, stably conducting and recording characters, signals of nerves were harvested by intrafascicular electrodes which were inserted directly as recording electrodes into the fascicles of the three major nerves of upper arm in the amputation stump of amputee volunteer. An electrode was placed outside the fascicle as reference electrode. All distal ends were coupled to electromyogram. When the volunteer in wakefulness imaged various kinds of actions of the lost hand with consciousness, the nerve information sent out by central nerve system to control motions was recorded. Th更多还原