基于Parylene-C柔性视网膜金微电极的电化学特性及植入可行性研究
发布时间：2019-04-12 12:13
【摘要】：视觉假体作为失明患者视力最有潜力的修复方案之一,现已是国内外学者研究的热点。视觉假体中视网膜假体对外层感光细胞受损引起的视网膜退行性病变的功能性修复已取得了一定成果。视网膜微电极阵列作为视网膜假体关键性部件,通过刺激视网膜内层细胞产生电信号,经视神经传递至大脑皮层,形成视觉。其电学特性和体内植入的可行性是保证视网膜假体安全稳定工作的前提条件。本研究针对视网膜微电极阵列的结构特点和植入要求,设计制作以Parylene-C为衬底,金作为电极材料,直径为200μm的圆形柔性视网膜微电极,用于视网膜表层刺激,并通过体外电化学测试和眼内植入可行性测试对其性能进行评估。视网膜微电极表面形貌在扫描电镜下呈现出良好的粗糙度,有助于电极呈现较低的电化学阻抗和较高的电荷注入能力。微电极阵列进行体外电化学测试采用三电极测试系统,搭建眼内仿真环境进行测试,实验方法包括电化学阻抗谱、循环伏安法、瞬时电压法,分别测试并计算得出微电极电化学阻抗、电荷储存能力和电荷注入能力。本研究测试得到微电极的电化学阻抗在1KHz时的阻抗为36.54±0.88 kΩ,相位角为-73.52±1.3°,电荷储存能力为103.33±15μC/cm2,电荷密度为22.3μC/cm2。视网膜微电极成功植入大鼠眼内,自然弯曲,贴合于视网膜上,展现出了良好的柔韧性。结果表明,本文采用的微电极,在降低成本、简化工艺的基础上,无论柔韧性还是电学特性都符合视网膜植入电极的要求,可用作动物实验的视网膜植入电极。
[Abstract]:As one of the most potential visual restoration schemes for blind patients, visual prosthesis has become a hot research topic both at home and abroad. Some achievements have been achieved in the functional repair of retinal degeneration caused by photoreceptor cell damage in visual prosthesis. Retinal microelectrode array, as a key component of retinal prosthesis, produces electrical signals through optic nerve to form vision by stimulating inner layer cells of retina. Its electrical properties and the feasibility of implantation in vivo are the prerequisite to ensure the safety and stability of the retinal prosthesis. According to the structural characteristics and implantation requirements of retinal microelectrode array, a flexible circular retinal microelectrode with Parylene-C as substrate, gold as electrode material and 200 渭 m in diameter was designed and fabricated for retinal surface stimulation. The performance was evaluated by in vitro electrochemical test and intraocular implantation feasibility test. The surface morphology of retinal microelectrode shows good roughness under scanning electron microscope, which is helpful for the electrode to show lower electrochemical impedance and higher charge injection ability. The microelectrode array was tested in vitro by a three-electrode test system. The experimental methods included electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and transient voltage method (IVA), and an in-eye simulation environment was set up for the test. The electrochemical impedance, charge storage capacity and charge injection capacity of the microelectrode were measured and calculated respectively. The electrochemical impedance of the microelectrode at 1KHz is 36.54 卤0.88 k 惟, the phase angle is-73.52 卤1.3 掳, and the charge storage capacity is 103.33 卤15 渭 C / cm2, charge density 22.3 渭 C / cm2.. The retinal microelectrode was successfully implanted into the eyes of the rats, naturally bent, attached to the retina, showing good flexibility. The results show that the microelectrode used in this paper can be used as an implanted electrode in animal experiments on the basis of reducing the cost and simplifying the process. Both the flexibility and the electrical properties of the microelectrode can meet the requirements of the retinal implantation electrode.
【学位授予单位】：北京协和医学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R318.18
本文编号：2457004
[Abstract]:As one of the most potential visual restoration schemes for blind patients, visual prosthesis has become a hot research topic both at home and abroad. Some achievements have been achieved in the functional repair of retinal degeneration caused by photoreceptor cell damage in visual prosthesis. Retinal microelectrode array, as a key component of retinal prosthesis, produces electrical signals through optic nerve to form vision by stimulating inner layer cells of retina. Its electrical properties and the feasibility of implantation in vivo are the prerequisite to ensure the safety and stability of the retinal prosthesis. According to the structural characteristics and implantation requirements of retinal microelectrode array, a flexible circular retinal microelectrode with Parylene-C as substrate, gold as electrode material and 200 渭 m in diameter was designed and fabricated for retinal surface stimulation. The performance was evaluated by in vitro electrochemical test and intraocular implantation feasibility test. The surface morphology of retinal microelectrode shows good roughness under scanning electron microscope, which is helpful for the electrode to show lower electrochemical impedance and higher charge injection ability. The microelectrode array was tested in vitro by a three-electrode test system. The experimental methods included electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and transient voltage method (IVA), and an in-eye simulation environment was set up for the test. The electrochemical impedance, charge storage capacity and charge injection capacity of the microelectrode were measured and calculated respectively. The electrochemical impedance of the microelectrode at 1KHz is 36.54 卤0.88 k 惟, the phase angle is-73.52 卤1.3 掳, and the charge storage capacity is 103.33 卤15 渭 C / cm2, charge density 22.3 渭 C / cm2.. The retinal microelectrode was successfully implanted into the eyes of the rats, naturally bent, attached to the retina, showing good flexibility. The results show that the microelectrode used in this paper can be used as an implanted electrode in animal experiments on the basis of reducing the cost and simplifying the process. Both the flexibility and the electrical properties of the microelectrode can meet the requirements of the retinal implantation electrode.
【学位授予单位】：北京协和医学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R318.18
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