隨著時代與科技的發展，生醫電子越來越受到人們的重視，其中功能性電刺激被研究出可以用來治療許多身體的殘疾或是神經方面疾病，而仰賴半導體技術的提升，這一方面的醫療器材得以積體化成植入式裝置來取代受損部位或隨時監控並治療神經方面疾病。深層腦部刺激就是其中一種用來以電刺激來抑制腦部不正常放電的治療方式，可以用來治療帕金森氏症或癲癇等腦神經相關疾病。
而近年來，在電刺激的刺激波形的研究方面，有別於以往常見的方波波形刺激，許多團隊開始研究該種刺激的效益並與非方波式刺激的比較，許多研究成果都得出或提到指數下降式電流刺激在能成功誘發神經動作電位的情況下能有較好的能量效益表現。

本論文提出一個可應用在深層腦部刺激的高能量效益指數電流刺激電路，使用1V供給電壓並可輸出最大300uA指數電流至20kohm等校阻抗的電極。有別於常見之固定高電壓供給輸出電流路徑方式，本研究在第一版中提出一個回授架構使得升壓電路的輸出電壓會隨著輸出的刺激電流大小調整以減少在輸出電流非峰值時所浪費的功耗而達到高能量效益。而在第二版本設計中提出了可以操作在此種變動高電壓下的耐高壓開關電路及其控制、偏壓電路。而在實際情形，電極的阻抗可能並非理想值，所以如何因應該阻抗變化以避免輸出電流失真或能量效益不理想的問題也在本研究的第二版本設計中考量並提出解決方式。所提出的電路架構皆以標準TSMC 0.18um CMOS製程來模擬並實現，而電路方面也設計了一些方式來使標準的電晶體可以承受高壓，而在第二版本的設計中可以完整的輸出雙相指數電流刺激，並且降低40%的能量消耗。

關鍵字：、、

With the development of technology, Bio-medical Electrics has drawn more attention then before. Researches had shown that Functional electrical stimulation(FES) can be used to cure or replace function loss of human body and can even treat some neuron-related diseases. And thanks to the improvement of semi-conductor technology, these bio-medical devices can be integrated into small implant devices, which can replace damaged function on human body in daily life or detect and cure neuron-related problems whenever necessary. In recent years, many research groups has started to compare conventional rectangular stimuli with non-rectangular ones, and most groups has mentioned or concluded the high energy-efficiency of exponentially deceasing current stimuli.

A high energy-efficiency current stimulator that can be applied to deep brain stimulation(DBS) has been proposed in this study. A maximum 300uA output stimulation can be generated to electrode of 20kohm equivalent impedance with 1V supply voltage. In order to reduce energy consumption while delivering stimulation, exponential current pulses are used due to their higher energy-efficiency when inducing action potential on tissue than conventional rectangular pulses. However, conventional exponential stimulators use a fixed high voltage source to drive the output stimulation path, this causes energy waste while exponential stimulation is not at its peak current.Therefore, a technique is proposed to make the output high voltage tracing the output stimulation current to reach high energy-efficiency. A high voltage tolerant switch array is also proposed to sustain the mentioned varying high voltage. The proposed work is simulated and fabricated using standard TSMC 0.18 um process and the circuit is designed with consideration of high voltage issue on transistors. The second proposed design is measured to have 40\% of energy consumption reduction and can generate a full biphasic exponential pulse.

誌謝. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
中文摘要. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii
ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
目錄. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi
圖目錄. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x
表目錄. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
第1 章緒論. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 研究背景. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 研究動機. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 章節簡介. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
第2 章文獻回顧. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1 植入式刺激器電路研究與應用. . . . . . . . . . . . . . . . . . . . . 4
2.2 非方波式刺激波形研究. . . . . . . . . . . . . . . . . . . . . . . . . 6
2.3 指數電流刺激器電路研究. . . . . . . . . . . . . . . . . . . . . . . 8
第3 章第一版設計. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.1 電路設計目標. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2 電路架構. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2.1 指數電流產生電路與電流式數位類比轉換器. . . . . . . . . 14
3.2.2 輸出級. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2.3 電荷幫浦迴路. . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.2.4 輸出電流追蹤電路. . . . . . . . . . . . . . . . . . . . . . . 19
3.3 模擬結果. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.3.1 晶片佈局. . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.4 第一版量測. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.4.1 電流式數位類比轉換器. . . . . . . . . . . . . . . . . . . . 26
3.4.2 指數電流輸出. . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.4.3 功耗量測. . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.5 結果討論. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
第4 章第二版設計. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.1 電荷幫浦電路. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
4.2 電流輸出追蹤及負載適應之刺激電路. . . . . . . . . . . . . . . . . 37
4.3 耐高壓開關電路. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.4 模擬結果及佈局圖. . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.4.1 耐高壓開關電路模擬. . . . . . . . . . . . . . . . . . . . . . 47
4.4.2 具負載適應力輸出追蹤電路模擬及整體功耗. . . . . . . . . 48
4.4.3 晶片佈局. . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4.5 第二版量測. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
4.5.1 耐高壓開關電路量測. . . . . . . . . . . . . . . . . . . . . . 52
4.5.2 具負載適應力之輸出追蹤電路量測. . . . . . . . . . . . . . 54
4.5.3 功耗量測. . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.5.4 結果討論. . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
第5 章結論. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
5.1 總結. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
5.2 未來工作. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
參考文獻. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

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