目前對於帕金森氏症及癲癇等腦神經失調疾病的治療方式仍以藥物控制為主，但是藥效會隨著時間而遞減且藥物容易產生其他的副作用。隨著積體電路技術的發展，目前已發展出許多用於治療神經疾病的可植入式微系統。像是利用植入式微系統記錄神經訊號並根據記錄到的神經訊號來控制義肢。深層腦刺激可用於治療帕金森氏症及癲癇等神經失調疾病。然而，目前大部份的腦機介面微系統會記錄多個通道的神經訊號並進行訊號處理。一般會採取多個記錄放大器共用一個類比數位轉換器的做法。此做法會使得腦機介面無法在記錄到特定訊號後立刻給予神經刺激訊號。本論文提出將記錄電路與刺激電路構成一個閉迴路控制細胞刺激系統，以達到即時刺激細胞的目的。閉迴路控制細胞刺激系統主要以像素類比數位轉換器取代傳統的類比數位轉換器。每個記錄通道都有獨立的像素類比數位轉換器，而像素類比數位轉換器以脈衝訊號作為輸出訊號，此輸出訊號可以直接控制腦機介面系統的刺激電路，形成一個閉迴路控制刺激電路的系統。如此一來，可以在記錄神經訊號後即時地給予神經細胞電刺激訊號，並建立細胞與細胞之間額外的連結。閉迴路控制細胞刺激系統的主要兩個電路部份是像素類比數位轉換器與可調電壓腦機介面刺激器。本論文針對這兩個電路做設計，採用TSMC CMOS 0.18μm製程實現晶片，並量測晶片以驗證電路功能。

The treatments for Parkinson’s disease, epilepsy and other brain disorders have relied mainly on medication, while medication is found to have degenerative or even adverse effects. Following the rapid development of integrated circuits, various implantable microsystems have been developed for neural rehabilitation. For example, neural activities of the motor cortex can be recorded for controlling external prosthetic devices. Deep-brain stimulation is also found useful for treating neural disorders such as the Parkinson’s diseases or epilepsy. However, most brain-machine-interface (BMI) microsystems have multiple recording channels share the same analogue-to-digital converter (ADC), and the recordings are processed in a digital core. This would hinder the possibility of stimulating neurons right after a specific pattern of neural activities is recorded. This thesis proposes the recording and stimulation circuits that facilitate closed-loop control on the neural stimulation. Pixel-level ADCs that convert neural recordings into digital pulses are used to replace the traditional ADCs. Each recording channel has its own pixel ADC whose pulse output can control the stimulators directly. A stimulator circuit that can set its output voltage automatically by feedback control is also designed. The proposed circuit would enable BMI microsystem to stimulate neurons in real time and in accordance with neural recordings. This feature allows brain to build extra connections between neurons. The proposed circuits have been designed and fabricated with the TSMC 0.18μm process. The measurement results are presented and discussed in this thesis.

誌謝 I
摘要 III
Abstract V
目錄 VII
圖目錄 IX
表目錄 XIII
第一章　緒論 1
1.1　研究動機 1
1.2　論文貢獻 2
1.3　論文章節概述 2
第二章　文獻回顧 5
2.1　腦機介面系統簡介 5
2.2　閉迴路控制細胞刺激系統 8
2.3　應用於腦機介面之類比數位轉換器介紹 9
2.3.1　循續漸近式類比數位轉換器 9
2.3.2　正回授式類比數位轉換器 12
2.3.3　類比時間轉換器 18
2.4　應用於腦機介面之升壓電路介紹 20
2.4.1　Cockcroft-Walton升壓電路 20
2.4.2　Dickson升壓電路 22
2.4.3　改良型對稱Cockcroft-Walton升壓電路 23
2.5　討論 25
2.6　總結 26
第三章　像素類比數位轉換器研究與晶片實現 27
3.1　像素類比數位轉換器運作原理與系統架構 27
3.2　各子電路介紹與電路模擬結果 32
3.2.1　電壓電流轉換器 32
3.2.2　電流模式取樣與維持電路 36
3.2.3　電流控制可調頻率振盪器 38
3.2.4　計數器與閂鎖器 42
3.2.5　總電路模擬結果 44
3.3　晶片佈局與規格 47
第四章　可調電壓之腦機介面刺激器研究與晶片實現 49
4.1　可調電壓之腦機介面刺激器系統架構介紹 49
4.2　各子電路介紹與電路模擬結果 52
4.2.1　升壓電路 52
4.2.2　電壓比較器 57
4.2.3　數位類比轉換器 59
4.2.4　總電路模擬結果 61
4.3　晶片佈局與規格 62
第五章　晶片量測結果 65
5.1　晶片量測平台 65
5.2　晶片功能驗證 67
5.2.1　像素類比數位轉換器晶片功能驗證 67
5.2.2　可調電壓之腦機介面刺激器晶片功能驗證 76
第六章　結論及未來研究方向 81
6.1　結論 81
6.2　未來研究方向 82
參考文獻 83

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