Leong Hok Chong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 87-103). / Abstract also in Chinese. / Chapter 1. --- Abstract --- p.5 / Chapter 2. --- Introduction --- p.8 / Chapter 3. --- Noninvasive Methodology in Pulse Wave Assessment --- p.20 / Chapter 3.1 --- Applanation Tonometry --- p.20 / Chapter 3.2 --- The Instrument: Sphygmocardiograph --- p.20 / Chapter 3.3.0 --- Reproducibility of Sphygmocardiograph --- p.27 / Chapter 3.3.1 --- Background --- p.27 / Chapter 3.3.2 --- Study Aims --- p.28 / Chapter 3.3.3 --- Subjects and Methods --- p.28 / Chapter 3.3.4 --- Statistical Analysis --- p.29 / Chapter 3.3.5 --- Results --- p.31 / Chapter 3.3.6 --- Discussion --- p.35 / Chapter 4. --- Radial Artery-Derived Aortic Augmentation Indexin Normotensive Subjects --- p.36 / Chapter 4.1 --- Background --- p.36 / Chapter 4.2 --- Study Aims --- p.36 / Chapter 4.3 --- Subjects and Methods --- p.38 / Chapter 4.4 --- Statistical Analysis --- p.38 / Chapter 4.5 --- Results --- p.39 / Chapter 4.6 --- Discussion --- p.52 / Chapter 5. --- Changes of Arterial Pulses in Normotensive Subjects with Family History of Hypertension --- p.56 / Chapter 5.1 --- Background --- p.56 / Chapter 5.2 --- Study Aims --- p.58 / Chapter 5.3 --- Subjects and Methods --- p.58 / Chapter 5.4 --- Statistical Analysis --- p.59 / Chapter 5.5 --- Results --- p.59 / Chapter 5.6 --- Discussion --- p.65 / Chapter 6. --- Radial Artery-Derived Aortic Augmentation Indexin Hypertensive Subjects --- p.67 / Chapter 6.1 --- Background --- p.57 / Chapter 6.2 --- Study Aims --- p.68 / Chapter 6.3 --- Subjects and Methods --- p.68 / Chapter 6.4 --- Statistical Analysis --- p.69 / Chapter 6.5 --- Results --- p.69 / Chapter 6.6 --- Discussion --- p.70 / Chapter 7. --- Changes of Arterial Pulses in Antihypertensive Therapies: Comparison between Diuretic and Long-Acting Calcium Antagonist --- p.72 / Chapter 7.1 --- Background --- p.72 / Chapter 7.2 --- Study Aims --- p.73 / Chapter 7.3 --- Subjects and Methods --- p.73 / Chapter 7.4 --- Statistical Analysis --- p.74 / Chapter 7.5 --- Results --- p.74 / Chapter 7.6 --- Discussion --- p.76 / Chapter 8. --- General Remarks and Conclusion --- p.80 / Chapter 9. --- Acknowledgments --- p.86 / Chapter 10. --- References --- p.87

臂叢阻滯麻醉可以阻斷同側正中神經，尺神經，橈神經和肌皮神經，故其經常被用於上肢手術中麻醉和/或鎮痛。臂叢阻滯麻醉也可以阻滯同側交感神經，導致同側上肢血管擴張（動脈和靜脈）和血流增加。脈沖多普勒超聲技術可以檢測到這些局部的血流動力學變化。文獻回顧表明迄今為止發表的大部分報道片面地評估了臂叢阻滯麻醉後上肢的局部血流動力學變化缺乏全面而系統的研究，並且報道中關於脈沖多普勒超聲技術用於上肢局部血流動力學測量的可靠性和可重復性的數據也很有限。此外，上肢的局部血流動力學變化是否與測量的位置或者使用的臂叢阻滯麻醉技術有關尚且未知。 / 我假設脈沖多普勒超聲是壹種可靠的測量上肢血流動力學變化的方法，它可以系統地定量測定臂叢阻滯麻醉後上肢的局部血流動力學變化，確定這些變化在上肢不同部位的差異，以及確定不同臂叢阻滯麻醉技術後局部血流動力學變化的差異。以下的部分列舉了本博士課題中開展的壹系列研究來證實我的假設。 / 第壹，我們在12個健康年輕誌願者中（年齡21-34歲）用脈沖多普勒超聲在上肢肱動脈和指掌側總動脈進行血流動力學測量，評估其在觀察者內和觀察者間的差異性。兩個觀察者獨立進行了測量。測量的指標包括收縮期峰值血流速度（厘米/秒），舒張末期血流速度（厘米/秒），收縮期峰值血流速度和舒張末期血流速度比值，平均速度（厘米/秒），時均速度（厘米/秒），阻力指數，搏動指數，動脈直徑（厘米），和血流量（毫升/分鐘）。結果顯示脈沖多普勒超聲是壹種可靠的方法，可用來重復測量上肢的局部血流動力學參數（組內相關系數>0.9）. / 第二，我們在8個病人中（年齡24-70歲）系統地評估了超聲波引導下的腋路臂叢神經阻滯後同側肱動脈的局部血流動力學變化。結果表明臂叢神經阻滯後最早的變化是脈沖多普勒頻譜波形的變化，其波形由三相變為單相，舒張期血流曲線擡升。隨著時間推移，收縮期峰值血流速度，舒張末期血流速度，平均速度，時均速度，動脈直徑，和血流量均顯著增加，收縮期峰值血流速度和舒張末期血流速度比值，阻力指數，搏動指數顯著降低。大部分變化發生在神經阻滯後5分鐘。在所有的局部血流動力學指標中，舒張末期血流速度表現出最顯著的變化（3.7倍），其增加超過收縮期峰值血流速度（1.5倍）和平均速度（2.8倍）。 / 第三，利用15個病人（年齡23-70歲），我們評估了超聲波引導下的鎖骨上臂叢神經阻滯後上肢近端動脈（肱動脈）和遠端動脈（指掌側總動脈）血流動力學變化的差異。臂叢神經阻滯之後，在能量多普勒圖像上，指掌側總動脈表現出更明顯的血管擴張。在脈沖多普勒頻譜波形中，兩個動脈均出現舒張早期的反流消失以及舒張期曲線擡升。另外，收縮期峰值血流速度，舒張末期血流速度，平均速度，時均速度，動脈直徑，和血流量增加，收縮期峰值血流速度和舒張末期血流速度比值，阻力指數，搏動指數顯著降低。這些指標的相對變化在指掌側總動脈比肱動脈更顯著。此研究中，4個病人出現對側手部溫度的增加，以此推測局部麻醉藥的雙側擴散。 / 第四，我們開展了壹項前瞻性隨機對照研究來比較腋路和鎖骨上臂叢神經阻滯引起的局部血流動力學變化的不同。兩組病人人口統計學資料類似。兩種臂叢神經阻滯技術均引起肱動脈和指掌側總動脈收縮期峰值血流速度，舒張末期血流速度，平均速度，時均速度，動脈直徑，和血流量的顯著增加，收縮期峰值血流速度和舒張末期血流速度比值，阻力指數，搏動指數顯著降低。跟腋窩方法相比，鎖骨上技術能夠引起肱動脈時均速度和血流量更顯著的增加。然而，在感覺神經阻滯起效方面，腋窩方法比鎖骨上方法更快。 / 總之，脈沖多普勒超聲可重復地測量肱動脈和指掌側總動脈的血流動力學參數及其變化。臂叢阻滯麻醉引起肱動脈和指掌側總動脈脈沖多普勒頻譜形態的變化，血流速度的增加和血流量的增加。這些局部血流動力學變化在指掌側總動脈中比肱動脈更顯著。鎖骨上臂叢神經阻滯比腋窩方法引起更顯著的局部血流動力學變化。臨床醫生可以利用上肢遠端動脈的局部血流動力學變化來評價臂叢阻滯麻醉的交感神經阻滯效應。麻醉醫師還可以根據這些發現為術後需要較好血流灌註的上肢血管手術選取臂叢神經阻滯方法。 / Brachial plexus block (BPB), which produces sensory and motor blockade of the ipsilateral median, ulnar, radial and musculocutaneous nerves, is frequently used for anesthesia and/or analgesia during surgical procedures of the upper extremity. BPB also produces ipsilateral sympathetic nerve blockade that is characterized by vasodilatation (venous and arterial), and an increase in blood flow to the ipsilateral upper extremity. Pulsed wave Doppler (PWD) ultrasound (US) has been used to evaluate these regional hemodynamic changes. A review of the literature shows that most published reports to date have only partially evaluated the regional hemodynamic changes in the upper extremity after a BPB. There are also limited data demonstrating that PWD US is a reliable or reproducible method of quantifying the regional hemodynamic changes in the upper extremity. Moreover, it is also not known whether the regional hemodynamic changes vary with the site of measurement or the technique of BPB used. / I hypothesized that PWD US is a reliable method for measuring regional hemodynamic parameters in the upper extremity. It can be used to comprehensively quantify the regional hemodynamic changes after a BPB and to determine the extent of these changes at different sites in the upper extremity and after different techniques for BPB. The following section outlines a series of studies that I undertook during this PhD project to corroborate my hypothesis. / Firstly, we sought to assess the intra-observer and inter-observer variability of measuring regional hemodynamic parameters, in the brachial and common palmar digital arteries of the upper extremity, using PWD US in 12 healthy young volunteers aged 21-34 yrs. The measurements were performed independently by two observers. Measured hemodynamic parameters included peak systolic velocity (PSV, cm/s), end diastolic velocity (EDV, cm/s), ratio of PSV and EDV (S/D), mean velocity (Vmean, cm/s), time-averaged mean velocity (TAVM, cm/s), resistance index (RI), pulsatility index (PI), the arterial diameter (d, cm), and blood flow (mL/min). The results showed that PWD US is a reliable and reproducible method of measuring regional hemodynamic parameters in the upper extremity (ICC>0.9). / Secondly, we comprehensively evaluated the regional hemodynamic changes in the ipsilateral brachial artery after an ultrasound guided (USG) axillary BPB in eight adult patients aged 24-70 yrs. Our results suggested that the earliest change after the BPB was a change in the morphology of the PWD spectral waveform from a triphasic to a monophasic waveform and an elevation in the diastolic blood flow velocity. Over time, there was also a significant increase in PSV, EDV, Vmean, TAVM, d, and blood flow, and a decrease in S/D ratio, RI, and PI. Most of these changes were seen as early as 5 minutes after the block. The increase in EDV (3.7-fold) was the most notable change, and it was significantly greater than the increase in PSV (1.5-fold) and Vmean (2.8-fold). / Thirdly, the regional hemodynamic changes in the proximal (brachial artery) and distal (common palmar digital artery) artery of the upper extremity after an USG supraclavicular BPB was investigated in 15 adult patients aged 23-70 yrs. After the block, the common palmar digital artery showed more obvious vasodilatation on the power Doppler US scan. In the PWD spectral waveform, and in both arteries studied, the protodiastolic blood flow disappeared and there was an elevation of the diastolic curve. Also there was a significant increase in PSV, EDV, Vmean, TAVM, d, and blood flow, and a significant reduction in S/D ratio, PI and RI in both arteries. Relative changes of these parameters were greater in the common palmar digital artery than in the brachial artery. In this study, bilateral spread of local anesthetic was observed in 4 patients, as evidenced by an increase of skin temperature on the contralateral hand. / Fourthly, a prospective and randomized study was conducted to compare the regional hemodynamic changes in the upper extremity after an axillary and supraclavicular BPB. The two study groups were similar with respect to demographic data. Both axillary and supraclavicular BPB caused a significant increase in PSV, EDV, Vmean, TAVM, d, and blood flow, and a significant reduction in S/D ratio, PI and RI in both the brachial and common palmar digital arteries. Compared with the axillary approach, the supraclavicular approach produced significantly greater increases in TAVM and blood flow in the brachial artery. However, the onset of sensory blockade was faster after the axillary BPB than with the supraclavicular BPB. / In conclusion, PWD US is a reliable and reproducible method for quantifying the regional hemodynamic parameters in both the brachial and common palmar digital arteries. BPB produces a change in the morphology of the PWD spectral waveform, arterial vasodilatation, an increase in blood flow velocity, and an increase in blood flow in both the ipsilateral brachial and common palmar digital arteries. These changes in regional hemodynamic parameters were more profound in the common palmar digital artery than in the brachial artery. Also these changes were more significant after a supraclavicular BPB than after an axillary BPB. These findings will allow clinicians to evaluate the sympathetic effect of a BPB using regional hemodynamic changes in the distal arteries of the upper extremity. These findings will also allow anesthesiologists to make an evidence-based choice on the techniques of BPB for vascular surgery of the upper extremity when good tissue perfusion is desirable postoperatively. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Li, Jiawei. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 182-192). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / TABLE OF CONTENTS / ABSTRACT / 中文摘要 / STATEMENT OF WORK / ACKNOWLEDGMENTS / PUBLICATIONS AND PRESENTATIONS / LIST OF ABBREVIATIONS / LIST OF TABLES / LIST OF FIGURES / Chapter CHAPTER 1 --- Introduction / Chapter 1.1 --- Introduction / Chapter 1.2 --- Aims of the project / Chapter 1.3 --- Outline of the thesis / Chapter CHAPTER 2 --- Literature Review / Chapter 2.1 --- Introduction / Chapter 2.2 --- Why regional hemodynamic changes occur after a BPB / Chapter 2.2.1 --- Anatomy of the sympathetic nervous system in the upper extremity / Chapter 2.2.2 --- The anatomic relationship between the sympathetic nerves and the brachial plexus / Chapter 2.2.3 --- Sympathetic efferents to blood vessels in the upper extremity / Chapter 2.3 --- Methods used to measure regional hemodynamic changes / Chapter 2.3.1 --- Skin and muscle blood flow / Chapter 2.3.2 --- Regional hemodynamic measurements using PWD US / Chapter 2.3.2.1 --- Basics of Doppler ultrasound / Chapter 2.3.2.2 --- Principles of blood flow / Chapter 2.3.2.3 --- Spectral analysis of blood flow using PWD US / Chapter 2.4 --- Published data on regional hemodynamic changes after BPB / Chapter 2.4.1 --- Skin temperature / Chapter 2.4.2 --- Cutaneous and muscular blood flow / Chapter 2.4.3 --- Regional hemodynamic measurements on major arterial branches of the upper extremity / Chapter 2.5 --- Introduction of BPB / Chapter 2.5.1 --- Anatomy of the brachial plexus / Chapter 2.5.2 --- Techniques for performing BPB / Chapter 2.5.3 --- USG BPB / Chapter 2.5.3.1 --- History / Chapter 2.5.3.2 --- Advantages of ultrasound guidance for peripheral nerve blockade / Chapter CHAPTER 3 --- Methodology / Chapter 3.1 --- Introduction / Chapter 3.2 --- Patient preparations / Chapter 3.3 --- Regional hemodynamic measurement / Chapter 3.3.1 --- Ultrasound equipment / Chapter 3.3.2 --- Patient position / Chapter 3.3.3 --- Regional hemodynamic measurements using PWD US / Chapter 3.3.3.1 --- Optimizing settings for B-Mode US / Chapter 3.3.3.2 --- Optimizing settings for PWD US / Chapter 3.3.3.3 --- Measurement of regional hemodynamic parameters / Chapter 3.3.4 --- Measurement of diameter (d) and blood flow (Q) / Chapter 3.4 --- USG BPB / Chapter 3.4.1 --- USG axillary BPB / Chapter 3.4.1.1 --- Scout scan / Chapter 3.4.1.2 --- Aseptic precautions / Chapter 3.4.1.3 --- USG axillary BPB / Chapter 3.4.2 --- USG supraclavicular BPB / Chapter 3.4.2.1 --- Scout scan / Chapter 3.4.2.2 --- Aseptic precautions / Chapter 3.4.2.3 --- USG supraclavicular BPB / Chapter 3.5 --- Outcome data after the BPB / Chapter CHAPTER 4 --- Measurement of Regional Hemodynamic Parameters in the Upper Extremity Using Pulsed Wave Doppler Ultrasound: A Reliability Study / Chapter 4.1 --- Introduction / Chapter 4.2 --- Methods / Chapter 4.2.1 --- Subjects / Chapter 4.2.2 --- Study design / Chapter 4.2.3 --- Data acquisition / Chapter 4.2.4 --- Statistical analysis / Chapter 4.3 --- Results / Chapter 4.4 --- Discussion / Chapter 4.4.1 --- Summary of main findings / Chapter 4.4.2 --- Compared with previous studies / Chapter 4.4.3 --- Sources of measurement variability / Chapter 4.4.4 --- Explanation for the variation in the changes in various regional hemodynamic parameters / Chapter 4.5 --- Conclusion / Chapter CHAPTER 5 --- Regional Hemodynamic Changes after an Axillary BPB: A Pulsed Wave Doppler Ultrasound Study / Chapter 5.1 --- Introduction / Chapter 5.2 --- Methods / Chapter 5.2.1 --- Patient enrollment / Chapter 5.2.2 --- Patient preparation / Chapter 5.2.3 --- Measurement of baseline regional hemodynamic parameters / Chapter 5.2.4 --- USG axillary BPB / Chapter 5.2.5 --- Outcome data after the BPB / Chapter 5.2.6 --- Sensory and motor assessments after the BPB / Chapter 5.2.7 --- Statistical Analysis / Chapter 5.3 --- Results / Chapter 5.4 --- Discussion / Chapter 5.4.1 --- Summary of main findings / Chapter 5.4.2 --- Limitations / Chapter 5.4.3 --- Changes in PWD spectral waveform / Chapter 5.4.4 --- Changes in regional hemodynamic parameters / Chapter 5.4.5 --- Increase in skin temperature / Chapter 5.4.6 --- Effects of local anesthetic / Chapter 5.5 --- Conclusion / Chapter CHAPTER 6 --- Does a Supraclavicular Brachial Plexus Block Induce Comparable Hemodynamic Changes in the Proximal and Distal Arteries of the Upper Extremity? / Chapter 6.1 --- Introduction / Chapter 6.2 --- Methods / Chapter 6.2.1 --- Patient recruitment / Chapter 6.2.2 --- Patient preparation / Chapter 6.2.3 --- Measurement of baseline regional hemodynamic parameters, arterial diameter and blood flow / Chapter 6.2.4 --- USG supraclavicular BPB / Chapter 6.2.5 --- Outcome measurements after the BPB / Chapter 6.2.6 --- Statistical analysis / Chapter 6.3 --- Results / Chapter 6.4 --- Discussion / Chapter 6.4.1 --- Summary of the main findings / Chapter 6.4.2 --- Limitations / Chapter 6.4.3 --- Changes in the PWD spectral waveform / Chapter 6.4.4 --- Explanation of the differences in regional hemodynamic changes in the distal and proximal arteries after BPB / Chapter 6.4.5 --- Increase in skin temperature and its relation to blood flow / Chapter 6.4.6 --- Bilateral sympathetic effect after supraclavicular BPB / Chapter 6.4.7 --- Other findings of this study / Chapter 6.5 --- Conclusion / Chapter CHAPTER 7 --- Does a Supraclavicular Brachial Plexus Block Induce Greater Changes in Regional Hemodynamics than an Axillary Brachial Plexus Block? / Chapter 7.1 --- Introduction / Chapter 7.2 --- Methods / Chapter 7.2.1 --- Sample size estimation / Chapter 7.2.2 --- Exclusion criteria / Chapter 7.2.3 --- Randomized allocation / Chapter 7.2.4 --- Preparations before the ultrasound scan / Chapter 7.2.5 --- Measurement of baseline regional hemodynamic parameters, diameter and blood / Chapter 7.2.6 --- USG axillary and supraclavicular BPB / Chapter 7.2.7 --- Outcome measurements after the BPB / Chapter 7.2.8 --- Statistical analysis / Chapter 7.3 --- Results / Chapter 7.4 --- Discussion / Chapter 7.4.1 --- Summary of the main findings / Chapter 7.4.2 --- Limitations / Chapter 7.4.3 --- Change in the PWD spectral waveform / Chapter 7.4.4 --- Differences in regional hemodynamic changes between the 2 study groups / Chapter 7.4.5 --- Differences in sensory and motor blockade between the 2 study groups / Chapter 7.4.6 --- Changes in skin temperature / Chapter 7.5 --- Conclusion / Chapter CHAPTER 8 --- Summary and Conclusions / APPENDIX / REFERENCES

Alan George Miller. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (p. 204-230). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.

1. An explicit mathematical description of PEP in terms of DBP was proposed, which in the first time quantitatively clarified the ventricular and arterial effects on PEP timing. / 2. A nonlinear pressure-volume relationship which reflected the natural arterial wall properties was introduced into the asymmetric T-tube arterial model, which effectively and quantitatively described the effect of pulsatile BP on arterial parameters, e.g., compliance, PTT etc. / 3. A mathematical relationship between PAT and BP was firstly proposed as a result of the heart-arterial interaction, which simulated a significantly strong and negative relationship between PAT and SBP and between PAT and MBP but a much weaker negative relationship between PAT and DBP during exercise. The hypothesis was supported by the experiment data. To our knowledge, it is the first study describing the quantitative relation of PAT and BP by both model-based study and experimental data. / 4. A novel wearable measurable CO parameter, PTRR, was proposed and it successfully showed a significantly high and positive correlation with CO during exercise both in model simulation and in the experiments. / 5. Linear prediction models using PAT to estimate MBP and using PTRR to estimate CO were proposed and evaluated in two exercise experiments conducted on 84 subjects with different ages and cardiovascular diseases. Results showed the proposed method could achieve the accuracy required for medical diagnosis. / 6. Taken the findings in 3, 4 and 5 together, this study in the first time provided both the theoretical basis and experimental verifications of developing a wearable and direct measurement technique of CPO in dynamic exercise using multiple physiological signals measured on body surface. / Cardiac power output (CPO) is defmed as the product of mean arterial blood pressure (MBP) and cardiac output (CO), and CPO measured during peak dynamic exercise (i.e. peak CPO) has been shown as a powerful predictor of death for heart failure patients. However, so far there has been no existing device which directly measures CPO, and CPO is acquired from simultaneous measurement of MBP and CO. Further, simultaneous MBP and CO measurement during dynamic exercise is a challenge for current BP and CO methods. Therefore, there is an urgent need to develop new devices which are fully wearable and unobtrusive for monitoring of CPO during dynamic exercise. Since the core problem in most wearable devices is how to estimate the target cardiovascular parameter, e.g. CPO in this study, through physiological signals measured from body surface, this thesis focus on developing a direct measurement technique of CPO in dynamic exercise using multiple physiological signals measured on body surface, specifically, electrocardiogram (ECG) and photoplehtysmogram (PPG). / Finally, based on the theoretical and experimental verifications, linear prediction models were proposed to estimate MBP from PAT and estimate CO from PTRR. The results showed that PAT can estimate MBP with a standard deviation of 7.42 mmHg, indicating PAT model has the potential to achieve the accuracy required by AMMI standard (mean error within +/- 5 mmHg and SD less than 8 mmHg). The results also showed that PTRR can estimate CO with a percent error of 22.57%, showing an accuracy which was considered as clinically acceptable (percent error less than 30%). / Heart failure is the end stage of many cardiovascular diseases, such as hypertension, coronary heart disease, diabetes mellitus, etc. Around 5.8 million people in the United States have heart failure and about 670,000 people are diagnosed with it each year. In 2010, heart failure will cost the United States $30.2 billion, and the cost of healthcare services is a major component of this total. With the resultant burden on health care resources it is imperative that heart failure patients with different risk stages are identified, ideally with objective indicators of cardiac dysfunction, in order that appropriate and effective treatment can be instituted. / In order to verify the theoretical findings, two experiments were carried out. One was incremental supine bicycle exercise conducted on 19 young healthy subjects and the other was incremental to maximum supine bicycle exercise conducted on 65 subjects, including heart failure patients, cardiovascular patients and healthy elderly. PAT showed significantly high and negative correlation with SBP and MBP, but lower correlation with DBP. PTRR showed significantly high and positive correlation with CO. / In this thesis, a model based study is conducted to address the above problem. Firstly, we deduced the mathematical expression of PEP as a function of DBP by introducing the arbitrary heart rate into the exponential mathematical description of a pressure-source model. Secondly, an asymmetric T-tube model was modified by introducing a nonlinear pressure-volume relationship where PTT was expressed as a dependent variant of BP. Thirdly, we proposed the mathematical equation between PAT and BP by coupling the modified ventricular and arterial models. Then, the relationships between PAT with systolic blood pressure (SBP), MBP and DBP were simulated under changing heart contractility, preload, heart rate, peripheral resistance, arterial stiffness and a mimic exercise condition. The simulation results indicated significantly high and negative correlations between PAT and SBP and between PAT and MBP whereas the correlation between DBP and PAT was low. / Next, we developed a novel CO index, namely pulse time reflection ratio (PTRR), expressed in terms of MBP and mean aortic reflection coefficient (Gamma(0)), from the modified asymmetric T-tube model. PTRR was further expressed in terms of PAT and inflection point area (IPA), a surrogate of Gamma(0) from the shape feature of PPG. The simulation results suggested significantly and positive relationship between PTRR and CO and between IPA and Gamma(0) during dynamic exercise. / Recently, a wearable measurable parameter, pulse arrival time or PAT, has been developed for BP measurement. PAT is the time delay from the R peak of ECG to the systolic foot of PPG. PAT consists of two timing components, the pre-ejection period (PEP) of the heart and pulse transit time (PTT). PTT is related to BP by an arterial elastic model and thus can be used to estimate beat-to-beat BP. However, PTT is difficult to be measured through a wearable device, and thus PAT is usually used as a surrogate of PTT for BP estimation, under the assumption of a constant PEP. However, PEP is not a constant but changing with physiological conditions, which may alter the PAT-BP relationship. Thus, it is important to clarify the PAT-BP relationship and address the feasibility of MBP estimation using PAT during dynamic exercise. / To summarize, the original contributions of this thesis are: / Wang, Ling. / Adviser: Y.T. Zhang. / Source: Dissertation Abstracts International, Volume: 73-03, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.