本研究之目的為開發心率變異度(heart rate variability, HRV)即時分析系統，以之探討呼吸調控對心率變異度之影響。即時分析系統包含: (一) 心電圖擷取模組，以雙電極式獲取類比心電圖訊號；(二) 即時演算分析模組，將類比心電圖訊號轉換成數位形式，偵測並計算心跳間期，經重新取樣及快速傅立葉轉換將心電圖由時域轉換成頻域，更於同時計算心跳間期之標準差(standard deviation of normal to normal, SDNN)；(三) 顯示介面模組，以之將所擷取之訊號與演算結果繪圖呈現，並可將分析結果傳輸至電腦儲存。以市售心電圖模擬機產生之訊號作為輸入源進行系統驗證，結果顯示心跳間期偵測誤差率與誤差值分別為3.77 %與0.33 %，HRV的頻域分析的結果與市售心電圖分析儀CheckMyHeart (達楷生醫科技公司)雷同。在呼吸調控的探討上，每組實驗量測10位受試者，使其進行特定呼吸模式，項目含頻率、時間及姿勢。結果顯示高頻呼吸調控對自律神經有抑制作用，長時間低頻呼吸調控則有提升自律神經活性之效果，躺姿較坐姿能有效輔助呼吸調控達到人體放鬆狀態。總言之，本研究已研發完成心率變異度即時分析雛型系統，並以之量測計算調控呼吸對改變自律神經狀態的探討，相信此系統有朝一日可成為一項非侵入式監測吾人日常生活自律神經狀態的工具。

The goal of this work is to develop a real-time analysis system for studying heart rate variability (HRV) in response to respiratory regulation. This system is comprised of three components: an acquisition module of electrocardiogram (ECG), a calculating module for real-time analysis and a liquid-crystal display (LCD) module. The acquisition module is used for acquiring analog ECG signals. The calculation module converts the analog ECG to digital form, detects R-waves of ECG, calculates R-R intervals (RRI), re-samples RRI and then transforms the re-sampled RRI to frequency domain via fast Fourier transform software. Standard deviation of normal to normal intervals was calculated in time-domain by the calculation module at the same time. All the information including the acquired ECG, calculated statistics and plots were displayed on the LCD and stored in a computer through universal asynchronous receiver/transmitter. To verify the developed system, a commercial ECG generator, FLUKE MPS450, was used to produce normal ECG. The results show that the standard error and the standard deviation of RRI measured by the real-time analysis system were 3.77 % and 0.33 %, respectively. The ECG from MPS450 and human subjects were analyzed by the developed system and a commercial system (CheckMyHeart, DailyCare Biomedical). The HRV of the acquired ECG were calculated and then converted to frequency domain. The HRV frequency spectra for both systems were very similar. For the studies of autonomic nervous system (ANS) activity upon respiratory regulation, three factors were taken into account: respiratory rate (6 and 20 breathing/minute) and elapse time (2 and 5 minutes) of respiration regulation and lying/sitting position of subjects. Each study involved ten subjects. The results show that the ANS activity was inhibited by the fast respiratory rate (i.e. 20 breathing/minute) and was activated by the long elapse time (i.e. 5 minutes) with the 6 breathing/minute respiratory rate. It is obvious that the parasympathetic system of the subjects in lying position was activated by the respiratory regulation compared to those sitting on a chair. In conclusion, a prototype real-time analysis system for HRV measurement is accomplished; and it is capable of automatically providing information for analyzing ANS activity in response to respiratory regulation. The system has potential to provide a non-invasive mean to analyze ANS activity in our daily life.

目錄
摘要 I
Abstract II
致謝 IV
目錄 V
圖索引 VII
表索引 IX
第一章 緒論 1
1.1 研究背景 1
1.2 文獻回顧 2
1.2.1 呼吸與自律神經系統 2
1.2.2 自律神經系統與心率變異度 2
1.2.3 心率變異度與身心狀態 3
1.3 研究動機與目的 4
1.4 論文架構 4
第二章 理論基礎 6
2.1 心電圖簡介 6
2.2 自律神經系統 10
2.3 呼吸性竇性心律不整 11
2.4 心率變異度 11
2.4.1 心率變異度與自主神經系統 11
2.4.2 心率變異度分析方法 12
2.4.3 心率變異頻譜意義 12
2.5 心跳間期重新取樣(Berger algorithm) 14
2.6 快速傅立葉轉換原理 15
第三章 材料與方法 17
3.1 心率變異度即時分析系統架構 18
3.2 心電圖擷取模組 18
3.2.1 儀表放大器 20
3.2.2 類比主動濾波器 21
3.3 即時演算分析模組 24
3.3.1 動態閥值演算法 26
3.3.2 重新取樣 26
3.3.3 位元反轉 27
3.3.4 快速傅立葉轉換 29
3.3.5 心率變異度分析 31
3.4 顯示介面 31
3.4.1 直線演算法 32
3.5 呼吸調控實驗之方法與步驟 34
第四章 結果與討論 36
4.1 心電圖擷取功能驗證 36
4.2 即時演算分析模組驗證 38
4.2.1 R波偵測結果 38
4.2.2 重新取樣驗證 39
4.2.3 快速傅立葉轉換驗證 39
4.2.4 HRV分析準確度驗證 41
4.3 調控呼吸與心率變異度探討 44
第五章 結論與未來展望 54
5.1 結論 54
5.2 未來展望 55
5.2.1 韌體模組與顯示介面之改良 55
5.2.2 實驗設計之改良 56
參考文獻 57
附錄A 受測者同意書 60
附錄B 壓力知覺量表 61
附錄C 原始分析結果 62


圖索引
圖 1-1 心率變異之功率頻譜圖 3
圖 2-1 心臟動作電位之傳導系統 7
圖 2-2 心肌細胞去極化步驟 7
圖 2-3 正常的心電圖圖解及其區間特徵 8
圖 2-4 Einthoven三角 9
圖 2-5 12導程心電圖-胸導程 10
圖 2-6 Berger重新取樣演算法示意圖 15
圖 3-1 心率變異度即時分析系統研究架構 17
圖 3-2 心率變異度即時分析系統架構 18
圖 3-3 心電圖擷取模組方塊圖 19
圖 3-4 ECG擷取電路實照圖 19
圖 3-5 ECG的功率頻譜分布圖 20
圖 3-6 INA128內部架構與接腳圖 21
圖 3-7 二階高通Sallen–Key主動濾波器電路架構 22
圖 3-8 四階低通Sallen–Key主動濾波器電路架構 22
圖 3-9 韋恩橋式帶拒濾波器 23
圖 3-10 後級放大減法電路 23
圖 3-11 韌體架構流程圖 24
圖 3-12 韌體程式流程圖 25
圖 3-13 動態閥值示意圖 26
圖 3-14 Berger重新取樣演算法流程圖 27
圖 3-15 快速傅立葉分解示意圖 28
圖 3-16 快速傅立葉位元反轉排序 28
圖 3-17 位元反轉演算法程式 29
圖 3-18 快速傅立葉演算法流程圖 30
圖 3-19 蝴蝶演算法示意圖 30
圖 3-20 FFT演算法之頻譜結果 31
圖 3-21薄膜電晶體液晶顯示器實照圖 32
圖 3-22 分析結果呈現配置 32
圖 3-23 Bresenham直線演算法結果呈現 33
圖 3-24 連點演算流程圖 33
圖 3-25 圖解Bresenham直線演算法結果 34
圖 3-26 實驗流程設計 35
圖 4-1 雙極式心電圖之頻寬增益與頻率響應圖 37
圖 4-2 雙極式心電圖擷取波形 37
圖 4-3 心率80 BPM之心電圖 38
圖 4-4 R-R interval暫存器存取結果之擷取畫面 39
圖 4-5 重新取樣驗證結果 39
圖 4-6 驗證單一頻率訊號頻譜分析 40
圖 4-7 驗證混和頻率訊號頻譜分析 40
圖 4-8 人體心電圖實際分析結果呈現 41
圖 4-9 心電圖模擬訊號於自製系統即時HRV分析結果 42
圖 4-10 心電圖模擬訊號於CheckMyHeart分析軟體之HRV分析結果 42
圖 4-11 心房顫動模擬訊號於自製系統即時HRV分析結果 43
圖 4-12 心房顫動模擬訊於CheckMyHeart分析軟體號之HRV分析結果 43
圖 4-13 即時分析系統準確度測試結果 44
圖 4-14 低頻呼吸調控之低頻高頻功率比趨勢 48
圖 4-15 高頻呼吸調控之低頻高頻功率比趨勢 49
圖 4-16 短時低頻呼吸調控之低頻高頻功率比趨勢 51
圖 4-17 躺姿短時低頻呼吸調控之低頻高頻功率比趨勢 53


表索引
表 2-1 心率變異頻譜意義 13
表 3-1 分析結果顯示配置表 32
表 3-2 呼吸調控實驗模式表 35
表 4-1 雙極式心電圖擷取模組之響應特性 37
表 4-2 低頻呼吸於心率變異度之立即效應-以自製系統分析 46
表 4-3 低頻呼吸於心率變異度之立即效應-以市售儀器分析 46
表 4-4 高頻呼吸於心率變異度之立即效應-以自製系統分析 47
表 4-5 高頻呼吸於心率變異度之立即效應-以市售儀器分析 47
表 4-6 受試者A~J對近一個月壓力感知之分數 48
表 4-7 短時低頻呼吸於心率變異度之立即效應-以自製系統分析 50
表 4-8 短時低頻呼吸於心率變異度之立即效應-以市售儀器分析 50
表 4-9 受試者K~T對近一個月壓力感知之分數 51
表 4-10 躺姿短時低頻呼吸於心率變異度之立即效應-以自製系統分析 52
表 4-11 躺姿短時低頻呼吸於心率變異度之立即效應-以市售儀器分析 52
表 4-12 受試者a~j對近一個月壓力感知之分數 53
表 C-1 低頻呼吸調控對心率變異度之影響-以自製系統分析 62
表 C-2 低頻呼吸調控對心率變異度之影響-以市售儀器分析 63
表 C-3 高頻呼吸調控對心率變異度之影響-以自製系統分析 64
表 C-4 高頻呼吸調控對心率變異度之影響-以市售儀器分析 65
表 C-5 短時低頻呼吸調控對心率變異度之影響-以自製系統分析 66
表 C-6 短時低頻呼吸調控對心率變異度之影響-以市售儀器分析 67
表 C-7 躺姿短時低頻呼吸調控對心率變異度之影響-以自製系統分析 68
表 C-8 躺姿短時低頻呼吸調控對心率變異度之影響-以市售儀器分析 70

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