纵行神经束内电极与周围神经生物相容性的实验研究

目的　研究纵行神经束内电极长期植入家兔坐骨神经神经束中的生物相容性 ,并探讨应用纵行神经束内电极记录的周围神经束的信号对电子假手控制的可能性。方法　将纵行神经束内电极长期植入 12只新西兰大白兔坐骨神经的神经束内 ,分别作为记录和刺激电极 ,通过经颅刺激系统 ,在术后不同时间记录运动诱发电位 (MEP)和皮层体感诱发电位 (CSEP) ,观察电极长期植入神经束内所记录到的信号的变化 ;术后 6个月信号记录结束后 ,取电极植入处的神经束进行组织学检查 ,了解电极对神经束的影响。然后 ,将纵行神经束内电极植入一名前臂残肢志愿受试者残肢的三条主要神经的神经束中 ,记录志愿受试者在意识控制中完成不同手的动作时的信号 ,并将其应用于电子假肢的实时控制。结果　不同时间记录的MEP和CSEP潜伏期间的差异均具有显著性意义 (方差分析 ,均P <0 .0 0 1)。经组间比较 ,MEP和CSEP的潜伏期在术后 1个月内无明显变化 ,以后明显延长 ,但 3个月以后趋于稳定 ;不同时间记录的MEP峰间波幅间的差异有显著意义 (方差分析 ,P <0 0 0 1)。经组间比较 ,在术后 1个月内变化不明显 ,以后明显降低 ,3个月后又趋于平稳。不同时间记录的CSEP峰间波幅虽然随时间延长有下降的趋势 ,但其间的差异无显著意义 (方差分析 ,P >0 0

Experimental study of biocompatibility of LIFEs in peripheral fascicles

Objective To study the biocompatibility of longitudinally implanted intrafascicular electrodes (LIFEs) in a rabbit sciatic nerve model. And to discuss the possibility of peripheral fascicular signals as a new signal source to control an electronic prosthetic hand. Methods LIFEs were implanted chronically into sciatic peripheral fascicles of rabbits as recording and stimulating electrodes. Motor-evoked potentials (MEP) and cortical somatosensory-evoked potentials(CSEP) were recorded by using a transcranial stimulation system (TCS) over six-month period to observe the change of the signals recorded. At the end of the experiments, the fascicles at the electrodes implanted site were anatomized for histological examination under light microscope and transmission electron microscope. In human test, LIFEs were implanted into radial nerve, ulnar nerve and medial nerve of an amputee volunteer. Signals were detected when the volunteer was asked to do different movements of his missing hand, and the signals recorded by LIFEs were used to control an electronic prosthetic hand. Results The difference of onset latency (OL) of MEP and CSEP recorded at different time has remarkable statistical significance (one way ANOVA, P<0.001). After multiple comparisons, onset latency (OL) of MEP and CSEP had no obvious change during 1 month, but significantly increased in the later time, and then became stable after 3 months after implantation. The difference of the interpeak amplitudes (IPAs) of MEP recorded at different time has remarkable statistical significance (one way ANOVA, P<0.001). The interpeak amplitudes (IPAs) of MEP had no distinct change during 1 month, but significantly decreased over the next period, and then became stable after 3 months. Though the interpeak amplitudes (IPAs) of CSEP decreased slowly over six-month period of the study, the difference has no statistic significance (one way ANOVA, P>0.05). At the end of experiment, histological examination indicated that a typical foreign body reaction developed and electrodes caused a mild damage to fascicles. But inflammatory cells and neuroma were not seen around the electrodes. Signals recorded by LIFEs planted in proximal radial, ulnar and median nerve of the amputated arm were different when the amputee volunteer was ordered to do some different movements with his mind. Some signals could be used to control the seven-freedom electronic prosthetic hand. Conclusions Longitudinally implanted intrafascicular electrodes (LIFEs) have excellent biocompatibility with peripheral fascicles. They can be implanted chronically into fascicles and record signals. Furthermore, LIFEs can record physiological signals of peripheral fasciculi when hand moves, and these signals could be used to control an electronic prosthetic hand through further research.