脉络膜上腔视觉假体刺激参数的选择

发布时间：2018-03-13 11:18

本文选题：电刺激　切入点：电极　出处：《眼科新进展》2014年02期 　论文类型：期刊论文

【摘要】：目的探讨脉络膜上腔电刺激参数优化的组合方式,指导实际应用中脉络膜上腔视觉假体刺激方案的选择。方法将带有不同尺寸刺激点(50μm、150μm、350μm、500μm)的薄膜电极植入白兔脉络膜上腔,进行跨视网膜电刺激,于动物的视觉皮层硬脑膜外记录电诱发电位(electrical evoked potential,EEP)。实验中采用的刺激脉冲波形为先负后正或先正后负的双相脉冲,脉冲宽度分别为0.25 ms、0.50 ms、0.75 ms和1.00 ms,刺激频率为1 Hz、2 Hz和4 Hz。结果实验中无论采用哪种尺寸的电极进行刺激,整体上诱发EEP所需的阈电流均随着脉冲宽度的增加而减小,随着刺激频率的增加而增加。当刺激频率从1 Hz增加到4 Hz时,阈电流增加的幅度在短脉冲宽度(0.25 ms)刺激时为77%(500μm电极)和170%(150μm电极);在长脉冲宽度(1.0 ms)刺激时,增加的幅度较低,约为38%(500μm电极)和131%(150μm电极)。与此同时先负后正的刺激脉冲所需的阈电流总是低于先正后负的刺激脉冲所需的阈电流。结论由于采用大尺寸的电极伴以长脉冲宽度刺激时,诱发EEP所需的阈电流强度随刺激频率增加的幅度较小,此外先负后正的刺激脉冲所需的阈电流也相对较低,因此这些都将成为脉络膜上腔视觉假体未来应用中优先选择的刺激方案。
[Abstract]:Objective to explore the optimal combination of electrical stimulation parameters in suprachoroidal cavity and to guide the choice of suprachoroidal visual prosthesis stimulation in practical application. Methods the membrane electrodes with 50 渭 m (150 渭 m) or 350 渭 m (500 渭 m) of different size were implanted into the superior choroidal cavity of white rabbits. The electric evoked potential (EEP) was recorded in the epidural dura mater of the visual cortex of animals by tranretina electrical stimulation. The stimulus pulse waveform used in the experiment was first negative and then positive or negative after negative biphasic pulse. The pulse width was 0.50 Ms 0.75 Ms and 1.00 Ms, respectively, and the stimulation frequency was 1 Hz and 4 Hz. Results in the experiment, the threshold current required to induce EEP decreased with the increase of pulse width, regardless of the electrode size. When the stimulation frequency increased from 1 Hz to 4 Hz, the amplitude of threshold current increased from 1 Hz to 4 Hz, the amplitude of threshold current increased from 77 to 500 渭 m electrode at short pulse width (0.25 Ms) and 150 渭 m electrode from 170 to 150 渭 m electrode at short pulse width. At the same time, the threshold current required for positive and negative stimulus pulses is always lower than the threshold current required for positive and negative stimulus pulses. Conclusion because of the use of large electrodes with long pulse width stimulation, The threshold current intensity required to induce EEP is smaller with the increase of stimulus frequency, in addition, the threshold current required for the first negative and then positive stimulus pulses is also relatively low. Therefore, these will be the priority for suprachoroidal visual prosthesis in the future.
【作者单位】：哈尔滨医科大学附属第四医院眼科;哈尔滨医科大学附属第二医院心外科;上海交通大学激光与光子医学生物研究所;
【基金】：黑龙江省卫生厅科研课题(编号:2011-164)~~
【分类号】：R77

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