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Dissertation submitted in compliance with the requirements for Masters Degree in Technology in the Department of Electrical Engineering, Technikon Natal, 2000. / The purpose of this study is the development of an affordable computer-based electrocardiogram, heart rate and temperature monitoring system, that would complement those that are available on the market and contribute to the reduction of the shortage of these medical instruments in South African hospitals and clinics. Electrocardiogram (ECG) refers to the graph that results from time versus voltage in a patient's chest. It reflects the rhythmic activity of the heart. For this reason the electrocardiogram has a diagnostic value that can be used by medical personnel to examine the biological (hence, clinical) behavior of the heart. The electrocardiogram can also be used to get the heart rate. This thesis explained how to acquire ECG signals from the patient and also how to achieve a cheaper way of providing galvanic isolation, which is required for sensors that are attached to the human body. It also explains computer interfacing using the parallel port and computer-based processing of these ECG signals to determine the instantaneous value of the heart rate and also to reduce the interference that contaminates these signals. In reducing interference, the performance of traditional IIR notch and adaptive filters, as noise cancelers, has been analyzed and compared. Least Mean Squares (LMS) and Normalized Least Mean Squares (NLMS) algorithms are the two algorithms that were considered in this study for adaptive noise canceling and their performance is evaluated and is compared based on their convergence rate, complexity and noise reduction. / M

近年，研究發現許多心臟衰竭患者的左室射血分數在正常範圍內。這種類型的心臟衰竭，已被稱為“射血分數保持的心臟衰竭（HFPEF）。研究還發現，HFPEF患者往往是老年女性，有高血壓病史，其預後比射血分數降低的心衰更好。 / 然而，很少人研究過中國人中HFPEF患者的死亡率。同時，經治療后HFPEF患者長期的生活質量是否改善沒有得到很好的研究，特別是在老年HFPEF患者中。此外，到目前為止，一直沒有一個風險評分系統用於預測HFPEF患者的預後。 / 我們從2006年至2010年在一所大學附屬醫院建立的心臟衰竭注冊研究中，前瞻性納入了847 名HFPEF的患者進行研究。此外，我們通過國際疾病分類第九版臨床修正（ICD-9- CM）代碼428進行數據檢索，回顧性分析了2001年至2005年入住我院的心臟衰竭的患者。其中170名射血分數超過50的患者納入本研究。爲了消除兩組病人基線差異對臨床終點的影響，我們計算出傾向性得分。在建立風險評分方面，所有HFPEF患者隨機分為推導組和驗證組。從推導組中，我們得到了風險評分，然後我們再在驗證組中測試評分系統是否可行。本研究中，生活質量是通過明尼蘇達州心力衰竭問卷（MLHFQ）進行評估。 / 我們研究的主要發現包括： / 1、與2001-2005年納入的HFPEF患者比，2006-2010年納入的HFPEF患者，一年生存率有顯著提高（76.9%比65.5%，P = 0.001），心臟衰竭的再次住院率也顯著下降（33.3%比50.6%，P <0.001）。傾向得分匹配調整後1年生存率提高（78.9%比68.1%，P = 0.02）和心衰再次住院率降低（34.3&比51.2%，P = 0.002）仍然顯著。 / 2、各個年齡組基線（32±16比30±15比34±11，P = 0.12）和12個月（16±14比16±12比19±13，P = 0.62）的MLHFQ得分均沒有顯著。HFPEF患者12個月時生活質量得到改善的比例在年齡組之間相似（84.0%比80.2%比87.5%，P = 0.68）。 / 3、我們通過Cox多因素回歸分析得到了了6個獨立的預測HFPEF患者1年死亡率的預後因素。每個因素根據其回歸系統獲得一個分數：低蛋白血症（5分），不使用鈣通道阻滯劑（3分），充血性心臟衰竭病史（2.5分），腦血管疾病病史（2.5分），尿素氮> 10mmol / L（2.5分），年齡> 78歲（2分）。每一個患者根據風險分數而被分為三個危險人群：低風險（0至5.5分），中等風險（10.5分）和高風險（11至17.5分）。在推導隊列，這三組的1年死亡率分別為10.5%，22.3%和48.7%分別。在驗證隊列，相應的死亡率分別為15.4%，25.3&和39%。 / 4、低蛋白血症為HFPEF患者1年死亡率的最有力的預測指標。 / 綜上所述，我們發現，近年來，HFPEF患者一年的死亡率和心臟衰竭再次住院率有所下降。與相對年輕的HFPEF患者相比，老年HFPEF患者經歷了類似的生活質量的改善。從臨床常用的變量得到的風險評分可用於預測HFPEF患者1年死亡率。低蛋白血症為HFPEF患者1年死亡率的最有力的預測指標。 / Recently, many studies have found that many patients presenting with clinical heart failure (HF) had a left ventricular ejection fraction in the normal range. This entity has been termed “heart failure with preserved ejection fraction (HFPEF). Previous studies have indicated that patients who have HFPEF tend to be older, female, and to have a history of hypertension. / However, little was known about the clinical outcome and related predictors of HFPEF patients in Chinese population. Long term quality of life (QOL) after treatment in HFPEF patients have not been well studied, especially in very elderly HFPEF. Furthermore, there has been no a risk score used HFPEF patients. / We studied 847 HFPEF patients who were prospectively enrolled into a HF Registry from 2006 to 2010 at a teaching hospital. In addition, a historical cohort of patients admitted in our hospital from 2001 to 2005 was retrospectively retrieved and data searched using the ICD-9-CM code 428. Among this, 170 with HFPEF were selected for study. To adjust for the impact of baseline differences between the 2 cohorts on clinical outcomes, we calculated a propensity score. To establish a risk score, HFPEF patients were randomly divided into derivation group and validation group. We got a risk score from the derivation group and then checked in the validation one. QOL was assessed by the Minnesota Living with Heart Failure Questionnaire (MLHFQ) instruments. / Main findings of our study included: / 1. 1-year survival rates improved (65.5% vs. 76.9%, p=0.001) and HF re-hospitalization rates decreased (50.6% vs. 33.3%, p<0.001 in HFPEF patients admitted between 2001-2005 and 2006-2010, respectively). The improvement in 1-year survival (68.1% vs. 78.9%, p=0.02) and HF re-hospitalization (51.2% vs. 34.3%, p=0.002) remained significant after propensity score matching. / 2. Baseline (30±16 vs. 28±16 vs. 29±16, p=0.87) and 12-months (15±14 vs. 16±14 vs. 15±12, p=0.92) MLHFQ score showed no significant differences with advancing age. Proportion of patients who experienced improvement in QOL at 12-months were similar among age groups (84.0% vs. 80.2% vs. 87.5%, p=0.68). / 3. Six independent prognostic factors were identified, and each was assigned a number of points proportional to its regression coefficient: hypoalbuminemia (5 points), not use of CCB (3 points), history of HF (2.5 points), history of CVD (2.5 points), BUN>10mmol/L (2.5 points), age>78 years (2 points). Wecalculated risk scores for each patient and defined three risk groups: low risk (0 to 5.5 points), intermediate risk (6 to 10.5 points) and high risk (11 to 17.5 points). In the derivation cohort, the 1-year mortality rates for these three groups were 10.5%, 22.3%, and 48.7% respectively. In the validation cohort, the corresponding mortality rates were 15.4%, 25.3% and 39%. / 4. Hypoalbuminemia was the most powerful predictor of 1 year mortality for HFPEF patients. / In summary, we found that the mortality of HFPEF patients in the first year decreased over time. Elderly HFPEF patients experienced similar improvements in QOL compared to younger ones. The clinical based risk score can be used to predict mortality of HFPEF patients. Hypoalbuminemia was the most powerful predictor of 1 year mortality for HFPEF patients. / 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. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Liu, Ming. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 124-150). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Declaration of originality --- p.i / Acknowledgement --- p.ii / List of abbreviations --- p.iv / Publications --- p.vii / Full paper --- p.vii / Abstracts --- p.viii / Abstract --- p.ix / 中文摘要 --- p.xii / Table of Contents --- p.xiv / List of Tables --- p.xx / List of Figures --- p.xxi / Chapter SECTION I --- LITERATURE REVIEW --- p.1 / Chapter CHAPTER 1 --- DEFINITION, PATHOPHYSIOLOGY AND DIAGNOSIS OF HFPEF --- p.1 / Chapter 1.1 --- Definition of HFPEF --- p.2 / Chapter 1.2 --- Pathophysiology of HFPEF --- p.3 / Chapter 1.2.1 --- Structure abnormality in HFPEF --- p.3 / Chapter 1.2.2 --- Diastolic dysfunction in HFPEF --- p.10 / Chapter 1.2.3 --- Systolic function in HFPEF --- p.12 / Chapter 1.2.4 --- Left atrial dysfunction in HFPEF --- p.14 / Chapter 1.2.5 --- Peripheral factors in HFPEF --- p.15 / Chapter 1.3 --- Diagnosis of HFPEF --- p.16 / Chapter 1.3.1 --- Clinical features --- p.17 / Chapter 1.3.2 --- Echocardiographic features of HFPEF patients --- p.18 / Chapter 1.3.3 --- BNP AND N-pro BNP assays --- p.18 / Chapter CHAPTER 2 --- EPIDEMIOLOGY OF HFPEF --- p.28 / Chapter 2.1 --- Prevalence of HFPEF among HF patients --- p.28 / Chapter 2.2 --- Demographic features and comorbid conditions --- p.29 / Chapter 2.2.1 --- Age --- p.30 / Chapter 2.2.2 --- Gender --- p.31 / Chapter 2.2.3 --- Hypertension --- p.31 / Chapter 2.2.4 --- Coronary artery disease --- p.32 / Chapter 2.2.5 --- Atrial fibrillation --- p.33 / Chapter 2.2.6 --- Diabetes Mellitus --- p.34 / Chapter 2.2.7 --- Renal Dysfunction --- p.34 / Chapter 2.2.8 --- Body Mass Index --- p.35 / Chapter 2.2.9 --- Anemia --- p.35 / Chapter 2.2.10 --- Chronic Obstructive Pulmonary Disease --- p.35 / Chapter 2.3 --- Mortality of HFPEF patients --- p.36 / Chapter 2.3.1 --- Mortality rates --- p.36 / Chapter 2.3.2 --- Pattern of death --- p.37 / Chapter 2.4 --- Prognostic predictors --- p.38 / Chapter 2.5 --- Health related quality of life in HFPEF patients --- p.40 / Chapter CHAPTER 3 --- TREATMENT OF HFPEF PATIENTS --- p.42 / Chapter 3.1 --- Non-pharmacologic Therapy --- p.42 / Chapter 3.2 --- Medical and Surgical Therapy --- p.43 / Chapter 3.2.1 --- Clinical Studies --- p.43 / Chapter 3.2.2 --- Randomized Controlled Clinical Trials --- p.43 / Chapter 3.2.3 --- Current Therapeutic Recommendations --- p.45 / Conclusions --- p.46 / Chapter SECTIONS II --- STUDIES ABOUT HFPEF --- p.47 / Chapter CHAPTER 4 --- OBJECTIVES AND HYPOTHESIS --- p.47 / Chapter 4.1 --- Objectives of the study --- p.47 / Chapter 4.2. --- Hypothesis --- p.48 / Chapter CHAPTER 5 --- METHODOLOGY --- p.49 / Chapter 5.1 --- Patient population --- p.49 / Chapter 5.2 --- Definition of HFPEF patients --- p.49 / Chapter 5.3 --- Baseline patient data --- p.50 / Chapter 5.4 --- Echocardiogram --- p.50 / Chapter 5.5 --- Health related quality of life assessment --- p.51 / Chapter 5.6 --- Follow-up and clinical outcome --- p.51 / Chapter 5.7 --- Statistical analysis --- p.52 / Chapter CHAPTER 6 --- IMPROVED 12 MONTH SURVIVAL OF PATIENTS ADMITTED WITH HFPEF OVER THE LAST DECADE --- p.54 / Chapter 6.1 --- Introduction --- p..54 / Chapter 6.2 --- Methods --- p.54 / Chapter 6.2.1 --- Patient population --- p.54 / Chapter 6.2.2 --- Baseline patient data --- p.55 / Chapter 6.2.3 --- Study endpoints --- p.56 / Chapter 6.2.4 --- Statistical analysis --- p.56 / Chapter 6.3 --- Results --- p.57 / Chapter 6.3.1 --- Baseline patient characteristics --- p.57 / Chapter 6.3.2 --- Unadjusted clinical outcomes --- p.57 / Chapter 6.3.3 --- Propensity score adjusted clinical outcomes --- p.58 / Chapter 6.4 --- Discussion --- p.58 / Chapter 6.5 --- Conclusions --- p.61 / Chapter CHAPTER 7 --- QUALITY OF LIFE IN ELDERLY PATIENTS WITH HFPEF --- p.67 / Chapter 7.1 --- Introduction --- p.67 / Chapter 7.2 --- Methods --- p.68 / Chapter 7.2.1 --- Patient population --- p.68 / Chapter 7.2.2 --- Health related quality of life assessment --- p.69 / Chapter 7.2.3 --- Follow-up --- p.69 / Chapter 7.2.4 --- Statistical analysis --- p.69 / Chapter 7.3 --- Results --- p.70 / Chapter 7.3.1 --- Baseline patient characteristics --- p.70 / Chapter 7.3.2 --- Mortality --- p.71 / Chapter 7.3.3 --- Health-related quality of life --- p.71 / Chapter 7.3.4 --- Therapy --- p.71 / Chapter 7.3.5 --- Predictors of HRQoL improvement in HFPEF patients --- p.72 / Chapter 7.4 --- Discussions --- p.72 / Chapter 7.5 --- Conclusions --- p.75 / Chapter CHAPTER 8 --- A RISK SCORE TO PREDICT 1 YEAR MORATALITY IN PATIENTS WITH HFPEF --- p.83 / Chapter 8.1 --- Introduction --- p.83 / Chapter 8.2 --- Methods --- p.84 / Chapter 8.2.1 --- Patient population --- p.84 / Chapter 8.2.2 --- Candidate Predictor Variables --- p.84 / Chapter 8.2.3 --- Statistical analysis --- p.85 / Chapter 8.3 --- Results --- p.86 / Chapter 8.3.1 --- Patient Characteristics and Outcomes --- p.86 / Chapter 8.3.2 --- Predictors of Mortality --- p.87 / Chapter 8.3.3 --- Generation of the Risk score --- p.87 / Chapter 8.3.4 --- Validation of the risk score --- p.88 / Chapter 8.4 --- Discussions --- p.88 / Chapter 8.5 --- Conclusions --- p.91 / Chapter CHAPTER 9 --- ALBUMIN LEVELS PREDICT SURVIVAL IN PATIENTS WITH HFPEF --- p.97 / Chapter 9.1 --- Introduction --- p.97 / Chapter 9.2 --- Methods 97 --- p.xviii / Chapter 9.2.1 --- Patient population --- p.97 / Chapter 9.2.2 --- Baseline measurement --- p.98 / Chapter 9.2.3 --- End points --- p.99 / Chapter 9.2.4 --- Statistical analysis --- p.99 / Chapter 9.3 --- Results --- p.100 / Chapter 9.3.1 --- Baseline patient characteristics --- p.100 / Chapter 9.3.2 --- Hypoalbuminemia and Cardiac Events --- p.101 / Chapter 9.3.3 --- Albumin and body mass index (BMI) --- p.102 / Chapter 9.3.4 --- Causes of hypoaluminemia in HFPEF patients --- p.102 / Chapter 9.4 --- Discussion --- p.103 / Chapter 9.4.1 --- Liver dysfunction --- p.104 / Chapter 9.4.2 --- Hemodilution --- p.105 / Chapter 9.4.3 --- BMI and hypoalbuminemia --- p.105 / Chapter 9.4.4 --- Renal failure --- p.106 / Chapter 9.4.5 --- B-type Natriuretic Peptides and albumin --- p.107 / Chapter 9.5. --- Conclusions --- p.109 / Chapter CHAPTER 10 --- GENERAL SUMMARY --- p.117 / Chapter 10.1 --- Main findings of our study --- p.117 / Chapter 10.2 --- Clinical implications --- p.119 / Chapter 10.3 --- Potential for final development of research --- p.120 / Chapter CHAPTER 11 --- CONCLUSIONS --- p.123 / References --- p.124

The Spiral Vortex (SV) ventricular assist device (VAD) was investigated by 2-component laser Doppler anemometry (LDA) while pumping a refractive index-matched blood analogue fluid. The VAD was operated under physiological conditions corresponding to 75% assist (4 litres/minute) or weaning from assist (2 litres/minute). Data were sampled on a 5-mm grid throughout most of the interior of the blood chamber, using two orthogonal LDA configurations from which 3D velocity data were synthesised. Data were subjected to statistical analysis of quasistatic time intervals and approximation by Fourier series. The velocity vector fields were explored statically (via 2D plots) and dynamically (using 3D animations of the reduced data). Reynolds stresses were computed and visualised in 2D. Fluid pathlines were simulated and plotted in 3D. The flow was found to be dominated by an irrotational vortex that accelerated and precessed in phase with the pumping diaphragm. Two unexpected flow structures, a rising, swirling near-wall layer in diastole and a reflection of the outflow vortex upon valve closure, enhanced washing of the walls. The thickness of the boundary layer was estimated to be 2 mm. Fluid velocities were generally lower than those reported in steady-flow studies on the SV VAD, although turbulence was comparable. Under the weaning mode, the coherence of the main vortex was degraded and flow recirculation was observed distal to the inflow port; this operating mode must be regarded as an indication for anticoagulation. In both pumping modes, turbulence was elevated in association with asymmetric buckling of the pneumatically driven diaphragm. Suboptimal orientation of the tilting-disc inlet valve gave rise to augmented turbulence production and skewing of the main vortex; similar results were obtained for an axisymmetric polymer (Jellyfish) valve, despite its advantageous haemodynamics. Flow stagnation was apparent where the inflow stream impinged on the wall, opposite the inflow port. The overall design of the SV VAD appears to almost ideal, in the context of current technology. However, elimination of recirculation/stagnation zones, especially in the weaning mode, remains a priority for the ultimate optimisation of haemocompatibility. Pulsatile VADs will probably never be entirely free of flow recirculation or stagnation, and published claims to the contrary probably reflect study limitations.

Coronary Heart Disease (CHD) accounts for almost 20% of all deaths in the United States and is a leading cause of premature death and disability. The cost for this disease includes not only lost work years, but billions of health care dollars. Women account for almost half of the deaths from CHD and rates for the death of young women have risen 30% from 1988 to 1998. For the two-thirds of women who survive the initial coronary event, the risk of future events and disability increases. Cardiac rehabilitation (CR) is a multi-disciplinary program designed to reduce this risk. Unfortunately, only 25% of eligible women attend the program. Few studies have analyzed the factors that influence women's CR enrollment choices making a careful examination of these factors particularly relevant. The purpose of this study was to qualitatively explore the factors associated with a woman's decision to enroll, or not enroll, in CR from the perspectives of the patient and her support person. Twenty-five women (15 enrolled in CR, 10 not enrolled in CR) and 24 matched support persons (one person's supporters refused to participate) were interviewed using a semi-structured format from September, 1999 to January, 2001. Questions addressed the beliefs, affect, social referents, past experiences/habits, and facilitating/constraining conditions related to CR enrollment choices. Support persons were asked to respond to these questions from their perception of their loved one's attitudes, beliefs and health care seeking behaviors. Information from the interviews was transcribed verbatim, entered into NUD*IST, and coded using the components of the Expanded Theory of Reasoned Action (Triandis, 1977) as a framework. Descriptive analyses was done on basic demographic information, including perceptions of health and depression. There were specific factors identified in each of the primary categories of affect, beliefs, facilitating/constraining factors, and social referents and information. The key findings indicated that a lack of information on CR, feelings related to the perceived necessity of CR, transportation, finances, and accessibility were primary factors in enrollment behavior. Overall agreement between the cardiac female and her support person existed in most categories, except affect, where a minimum number of emotions was stated by the supporter. Cardiologists are a preferred source for CR information and they and primary care physicians need to increase the amount of positive support they provide to post-coronary event women. Emphasis on the necessity of attending CR as well as solutions for transportation and finances may increase enrollment. More research should be completed on the context of depression related to CR, importance of factors identified as having an impact on CR decision making, and the role of support persons in the enrollment choices of women. / Graduation date: 2002

Thesis (M. D.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 229-273). Also available in print.

Thesis (Ph.D.)--York University, 2008. Graduate Programme in Psychology. / Typescript. Includes bibliographical references (leaves 142-164). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NR38999

Thesis (Ph. D.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains vii, 123 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 59-66).

Thesis (Ph. D. in Biomedical Engineering)--Vanderbilt University, 2003. / Title from PDF title screen. Includes bibliographical references.

published_or_final_version / Community Medicine / Master / Master of Philosophy