近幾年來生醫電子領域已逐漸被人們重視並投入發展。已有許多研究指出功能性電刺激可用來治療許多神經性疾病、恢復部分器官功能、修補因神經受損造成的殘疾…等可為人們帶來更健康、更方便的生活。而這種功能性電刺激即是由刺激電路所產生的。
一般而言，在許多的植入式裝置裡，刺激電路由於是最靠近神經的IC電路，所以在設計上對於安全的需求是最為重視的。而在安全上通常是以「經過刺激後，殘留在電極/神經上的殘餘電荷」這個指標為基本要求。我們希望此值能越低越好，以避免刺激器後端的電極陣列在長期運作後產生像是電解的質變，進而傷害到神經；如同我們對於神經的基本生理認知，神經需要足夠的閥值電荷才能被刺激。而已有研究指出刺激器若能輸出「非對稱式刺激波形」這種特殊的功能性電刺激的話，有助於壓低神經刺激時所需要的閥值電荷，並可使刺激器的能量利用率及運作時間皆有進步；然而在輸出非對稱式波形下，又要能夠達到夠低的殘餘電荷，在設計電路角度上是非常困難的。
本論文即是觀察到了上面的設計困境，並以過去文獻的方法為基礎改進，成功地達到了能在輸出非對稱式波形的情況下同時兼顧低殘餘最後電荷。在模擬上達到了能在輸出400μA的非對稱式刺激波形下，其殘餘電荷佔總輸出電荷誤差比降低至0.1％以下。

Bio-medical field has drawn more and more attention in recent years. Functional electrical stimulation (FES) has been researched and applied to treat neuron disease, repair the physiological function of patients suffering from neuron damage. The stimulator is very close to neuron in all implantable devices, so safety is the critical point. Usually, residual charge on electrode/neuron interface after once stimulation is estimated as safety standard. We wish the residual charge can be reduced as low as possible. Because lower residual charge means the electrode electrolysis probability is smaller.
Besides, some researches have proven that the stimulator with asymmetric stimulation output waveform can reduce neuron stimulation threshold charge effectively. However, stimulator with asymmetric output waveform is hard to reduce residual charge because of its difficult calibration through circuit.
According to above design hard point, we use an improved current source control signal called sequential switching signal (S.S signal) to achieve lower residual charge when transferring asymmetric waveform. The stimulator has been fabricated using TSMC 0.18μm technology. Simulation result shows that stimulation current is up to 400μA and its residual charge mismatch percentage is less than 0.1%.

摘要
Abstract
致謝
目錄
圖目錄
表格目錄
第一章 序論
1.1 刺激器研究發展現況
1.2 神經及刺激器運作原理
1.3 神經刺激器系統架構及其設計要點
1.4 研究動機
1.5 本論文各章節簡介
第二章 文獻回顧
2.1 神經刺激器刺激方式及其相關架構
2.2 常見電荷平衡技巧文獻回顧
2.3 非對稱式波形刺激下的電荷平衡文獻回顧
第三章 電路實現技巧與電路架構
3.1 電路系統架構圖
3.2 電流鏡控制訊號改良
A. 一般電流鏡放大誤差
B. Williams式電流鏡控制訊號
C. 依序式分支電流鏡控制訊號
3.3 各子電路架構
A. 電流式數位類比轉換器DAC
B. 分支型電流鏡multi-branch current mirror
C. 運算放大器OPAMP
D. 開關陣列Switch array
第四章 模擬結果
4.1 晶片佈局圖
4.2 輸出波形圖
4.3 蒙地卡羅模擬：Williams式 V.S. 序列切換式
4.4 序列切換式訊號：Pre-sim V.S. Post-sim
4.5 規格表及文獻比較
4.6 模擬結果討論
第五章 結論
5.1 未來工作
參考文獻

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