基于柔顺机构的减振神经电极的设计与评估

Physical Design Concepts and Biomechanical Evaluations of a Novel Neural Electrode Abutment with Micromotion-Attenuation Capability Based on Compliant Mechanisms

为了提高神经电极长期稳定性,提出基于柔顺结构的新型减振神经电极的设计思路,对其柔性铰链进行建模分析,并采用有限元方法对电极-脑组织界面的微动进行静态分析和模态分析,研究了不同方向微振对电极-脑组织界面力学状态的影响,对新型减振电极与原电极的力学性能进行对比评估.结果显示,新型减振电极可以有效改善微振动环境下的应力状态：在横向微振环境下,有效降低最大应力6.64%;纵向微振环境下,有效降低最大应力4.47%;其二、三阶固有频率为3~8Hz,可避开微振的频率范围.新型减振电极可显著提高电极的减振能力,预期可有效提高电极工作寿命.

Micromotion is one of the most important factors that influence the long-term stability of neural electrodes.In order to improve the long-term stability of brain-implanted electrodes,a neural electrode abutment which has the capability of vibration attenuation was developed to control different modes of micromotion in a more effective way.The compliant hinge was studied with the mechanics modeling analysis,and the static and modal mechanical states of neural electrode-brain tissue interface were investigated with finite element methods.The results of the finite element analysis confirmed that the novel neural electrode abutment had the anticipated micromotion-attenuation capability.The proportion of decline of von Mises stress was 4.47% on the longitudinal direction and 6.64% on the lateral direction.The results show that the novel neural electrode abutment is effective in reducing vibration,which has potential capabilities for improving the stability of neural electrodes in a long term.