【摘要】：基于刺入式電極的視神經(jīng)視覺假體,為盲人的視覺修復(fù)提供了新的可能性。為了對該視神經(jīng)假體的電刺激策略和微電極設(shè)計(jì)提供理論支持,基于真實(shí)的電極結(jié)構(gòu),在COMSOL軟件中建立刺入式微電極的外部電場仿真模型,并將其與利用NEURNO軟件實(shí)現(xiàn)的神經(jīng)纖維雙層電纜模型結(jié)合,系統(tǒng)地研究電極與視神經(jīng)纖維的相對位置、電刺激脈沖寬度以及電極幾何結(jié)構(gòu)的改變對視神經(jīng)纖維興奮閾值的影響。不同電極位置、刺激脈寬刺激下閾值變化規(guī)律的仿真結(jié)果,與以往報道的動物實(shí)驗(yàn)和仿真實(shí)驗(yàn)結(jié)果相符,證明了所建模型的有效性。根據(jù)仿真結(jié)果,對刺入式視神經(jīng)假體中刺激脈寬的選擇和電極幾何結(jié)構(gòu)的設(shè)計(jì),建議如下:窄脈寬刺激有利于降低能量消耗;電極錐度的設(shè)計(jì)要在滿足電極力學(xué)特性及易于植入視神經(jīng)的基礎(chǔ)上,盡可能地減小,以降低纖維興奮的閾值;電極的暴露面積越小,纖維興奮所需的電流閾值越低,但電荷密度閾值越高;較低的電流閾值有利于減少能量消耗,但過高的電荷密度閾值卻容易造成組織損傷,因此電極暴露面積的設(shè)計(jì)需要在耗能與安全性之間進(jìn)行綜合考慮。電極絕緣層厚度的改變對視神經(jīng)纖維的興奮閾值沒有明顯的影響,但從電極插入的難易考慮,應(yīng)盡可能減小絕緣層厚度。以上結(jié)果對人體其他部位神經(jīng)纖維的電刺激同樣具有參考價值。
[Abstract]:The optic nerve visual prosthesis based on punctured electrode provides a new possibility for visual repair of blind people. In order to provide theoretical support for the electrical stimulation strategy and microelectrode design of the optic nerve prosthesis, based on the real electrode structure, the external electric field simulation model of the punctured microelectrode was established in COMSOL software. Combined with the double-layer cable model of nerve fiber realized by NEURNO software, the effects of the relative position of electrode and optic nerve fiber, the width of electrical stimulation pulse and the geometric structure of electrode on the excitation threshold of optic nerve fiber were studied systematically. The simulation results of threshold variation under different electrode positions and stimulation pulse width are consistent with the results of animal experiments and simulation experiments reported in the past, which proves the effectiveness of the model. According to the simulation results, the selection of stimulation pulse width and the design of electrode geometry in punctured optic nerve prosthesis are suggested as follows: narrow pulse width stimulation is beneficial to reduce energy consumption; The design of electrode taper should be reduced as much as possible on the basis of satisfying the mechanical properties of electrode and easy to be implanted into optic nerve, in order to reduce the threshold of fiber excitation. The smaller the exposure area of the electrode is, the lower the current threshold needed for fiber excitation is, but the higher the charge density threshold is. Lower current threshold is beneficial to reduce energy consumption, but excessive charge density threshold is easy to cause tissue damage, so the design of electrode exposure area needs to be considered comprehensively between energy consumption and safety. The change of the thickness of the electrode insulation layer has no obvious effect on the excitation threshold of the optic nerve fiber, but it is difficult to consider from the electrode insertion, so the thickness of the insulation layer should be reduced as much as possible. The above results also have reference value for electrical stimulation of nerve fibers in other parts of human body.
【作者單位】： 上海交通大學(xué)生物醫(yī)學(xué)工程學(xué)院;北京大學(xué)工學(xué)院生物醫(yī)學(xué)工程系;
【基金】：國家重點(diǎn)基礎(chǔ)研究發(fā)展計(jì)劃(973計(jì)劃)(2011CB7075002/5,2011CB013304) 國家自然科學(xué)基金(61171174)
【分類號】：R318.18;TP391.9

【相似文獻(xiàn)】

相關(guān)期刊論文 前3條

1 高潔;喬清理;解楠;;基于實(shí)驗(yàn)數(shù)據(jù)計(jì)算機(jī)仿真大鼠視神經(jīng)纖維對于胞外點(diǎn)電極刺激的響應(yīng)與影響[J];中國組織工程研究與臨床康復(fù);2010年09期

2 徐亮,陳瑛瑛;視神經(jīng)纖維分析儀的調(diào)制參數(shù)在青光眼診斷中的作用[J];眼科;1999年01期

3 遲啟民,富田剛司,稻積幸介,早川友康,井戶忠美;應(yīng)用激光偏光掃描測量儀評價正常人視網(wǎng)膜神經(jīng)纖維層厚度與年齡的關(guān)系[J];中華眼科雜志;1998年03期

相關(guān)重要報紙文章 前2條

1 黃山;借芯片復(fù)明不靠“視力”靠運(yùn)算[N];大眾科技報;2002年

2 英文化;微型機(jī)器醫(yī)生執(zhí)行重大醫(yī)療任務(wù)[N];科技日報;2004年

，

本文編號：2488192