背景:束内电刺激已被广泛采用以实现截肢者的感觉反馈。具有有希望的柔性和空间选择性指数(SSI)的轴突状碳纳米管纱(CNTy)电极可以是产生人工体感的迷人替代品。
方法:在这里,我们系统地公开了通过束内CNTy电极进行人工体感的客观神经调节基础。使用具有不同暴露长度的CNTy电极对12只大鼠的胫神经进行电刺激。使用硬膜外三十通道电极阵列同步记录体感诱发电位(SEP)。SEP的时空特性分析为电流脉冲幅度(PA),脉冲宽度(PW)和脉冲频率(PF)变化。
结果:与大多数CNTy电极的4和8Hz的电流阈值相比,1Hz的电流阈值显示出最低的平均值(20/28)。对于所有的电极,SEP的振幅和感知场的激活区域随着PWs和PAs的增加而增加,并且在PFs从1到8Hz时显著降低。随着PWs和PAs的推进,SEP峰值的P1和N1的延迟逐渐减少。考虑到高SSI,相对稳定的电流阈值,更宽的感觉幅度变化范围和感知场的最佳稳定性,L-200μm电极对于具有1-8Hz的PF的神经调节是优选的,PWs为100-800μs,PAs为2-64μA。
方法:与其他神经接口相比,新型CNTy电极具有良好的灵活性和SSI。我们首次通过CNTy电极系统地探索了人工体感的客观神经调节基础。
结论:SSIs显著升高,与其他周围神经界面相比,CNTy电极的电流和电荷阈值较低。这项研究可以,第一次,为CNTy电极实现精细的感觉反馈奠定坚实的神经调节基础。
BACKGROUND: Intrafascicular electrical stimulation has been extensively adopted to achieve sensory feedback for limb amputees. Axon-like carbon nanotube yarn (CNTy) electrodes with both promising flexibility and spatial selectivity index (SSI) can be fascinating alternatives to generate artificial somatosensation.
METHODS: Here we systematically disclose objective neuromodulation basis for artificial somatosensation through intrafascicular CNTy electrodes. CNTy electrodes with different exposed lengths were utilized for electrically stimulating tibial nerves in twelve rats. Somatosensory evoked potentials (SEPs) were recorded synchronously using an epidural thirty-channel electrode array. Spatiotemporal characteristics of SEPs were analyzed as current pulse amplitude (PA), pulse width (PW) and pulse frequency (PF) varied.
RESULTS: The current thresholds at 1 Hz exhibit the lowest means when compared with those at 4 and 8 Hz for most CNTy electrodes (20/28). For all the electrodes, amplitudes of SEPs and activated areas of perceptive fields increase with PWs and PAs rising, and decrease remarkably with PFs from 1 to 8 Hz. Latencies of P1 and N1 of SEP peaks gradually reduced with PWs and PAs advancing. Considering high SSIs, relatively stable current thresholds, wider variation ranges of sensory magnitudes and optimal stability of perceptive fields, the L-200 µm electrodes are preferable for neuromodulation with PFs of 1 - 8 Hz, PWs of 100 - 800 μs and PAs of 2 - 64 μA.
METHODS: New-type CNTy electrodes possess both promising flexibility and SSI when compared with other neural interfaces. We systematically explore objective neuromodulation basis for artificial somatosensation through CNTy electrodes for the first time.
CONCLUSIONS: Significantly higher SSIs, lower current and charge thresholds exist for CNTy electrodes in comparison with other peripheral-nerve interfaces. This study can, for the first time, lay a solid neuromodulation foundation for CNTy electrodes to achieve fine sensory feedback.