本博士論文研究使用胸戴式標籤的自我注入鎖定(SIL)都普勒雷達，用於監測可移動人員的心血管活動。本論文設計的胸戴式標籤有兩種類型-有源標籤和無源標籤，使用有源標籤的雷達操作在5.8 GHz，由自我注入鎖定振盪器(SILO)標籤及調頻接收機所組成。第一個SILO標籤天線設計使用了超表面，並且應用在生命徵象偵測，該天線包括頻率選擇面及電磁能帶隙面，用以抑制移動雜波並消除身體鄰近效應。第二個SILO標籤天線設計使用了互補開口環諧振器，能藉由近場感應來監測心率變異性。為了提高指向心臟區域的天線方向性，第三個SILO標籤天線設計使用了部分反射面，該反射面由開口環諧振器陣列所組成。此外，提出了結合總體經驗模態分解及主成份分析的演算法，以去除提取心跳訊號過程中呼吸和身體移動造成的干擾，從而準確估算心臟活動時序。為使SILO標籤小型化以方便不同聽診部位的心音測量，第四個SILO標籤天線採用環形天線和同心環的疊層結構設計，並應用隱半馬爾可夫模型來分割心音信號。最後，將傳輸陣列透鏡設計為無源標籤，將來自遠程5.8 GHz SIL都普勒雷達的入射波在透入胸部後能聚焦在心臟的特定區域，以利於長期心率變異監測。

This dissertation presents the use of self-injection-locked (SIL) Doppler radars with chest-worn tags for monitoring the cardiovascular activities of a mobile person. There are two types of chest-worn tags used in this research-active tag and passive tag. The radar using the active tag operates at 5.8 GHz and consists of a self-injection-locked oscillator (SILO) tag and a frequency modulation (FM) receiver. The first SILO tag antenna is designed using metasurfaces for vital-sign detection. This antenna comprises a frequency selective surface (FSS) and an electromagnetic bandgap (EBG) surface to reject the moving clutter and eliminate the body-proximity effect. The second SILO tag antenna is designed with a complementary split ring resonator (CSRR) for near-field sensing to monitor heart rate variability (HRV). To improve the antenna directivity towards the heart area, the third SILO tag antenna is designed with a partially reflective surface (PRS) that is composed of an array of split ring resonators (SRRs). Moreover, the combined ensemble empirical mode decomposition (EEMD) and principal component analysis (PCA) algorithm is proposed to remove respiratory and body motion artifacts in the extraction of the heartbeat signal, yielding accurate estimates of cardiac timings. To miniaturize the SILO tag for the convenience of measuring heart sounds at different auscultation sites, the fourth SILO tag antenna is designed using a stacked structure of a loop antenna and a concentric loop. Furthermore, a hidden semi-Markov model (HSMM) is applied to segment the heart sound signal. Finally, a transmitarray lens is designed as the passive tag to focus the incident wave from a remote 5.8 GHz SIL Doppler radar on a specific area of the heart via penetration into the chest for long-term HRV monitoring.

Contents

論文審定書 i
摘要 ii
Abstract iii
List of Figures vi
List of Tables xi
Chapter 1 Introduction 1
1.1 Research Motivation 1
1.2 Remote Cardiovascular Activity Monitors 2
1.3 Wearable Cardiovascular Activity Monitors 4
1.4 Overview of Dissertation 6
Chapter 2 SIL Doppler Radar for Wearable Applications 8
2.1 Self-Injection-Locked Oscillator (SILO) Tag 8
2.2 Moving Clutter Rejection Using Circular Polarized Wave 11
2.3 Moving Clutter Rejection Using Signal Processing 15
2.3.1 Bandpass Filtering 15
2.3.2 Empirical Mode Decomposition 15
2.3.3 Variational Mode Decomposition 16
2.3.4 Variational Mode Extraction 19
2.3.5 Successive Variational Mode Decomposition 20
Chapter 3 Chest-Worn Heart Rate Variability Monitor 23
3.1 Tag Antenna Design 23
3.2 SILO Tag Implementation 30
3.3 Signal Processing and Results 32

Chapter 4 Chest-Worn Heart Sound Monitor 40
4.1 Human Heart Sound 40
4.2 SILO Tag Implementation 42
4.3 Signal Processing and Results 45
Chapter 5 Chest-Worn Transmitarray Lens for Remote HRV Monitoring 52
5.1 Transmitarray Lens Design and Test 53
5.2 HRV Monitoring Setup and Results 57
5.3 Comparison of Various Signal Processing Techniques 62
Chapter 6 Conclusion 71
Bibliography 73
Vita 83

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