Thirty-seven outpatients (M=34, F=3) undergoing rehabilitative exercise in two community-based programs were evaluated for smoking behavior using three separate measures. The specific objective of the study, i.e., to compare concurrent measures of smoking exposure via end-tidal carbon monoxide (F_{ET_CO} ), saliva thiocyanate (SCN) and questionnaire responses, were initially concealed from the subjects to avoid experimental bias that might alter smoking behavior or questionnaire responses. Questions on smoking status and topography were intermingled with a variety of other coronary risk items to further mask the objectives. Triangulation of data for the F_{ET_CO} and SCN responses and the smoking admission/denial item on the questionnaire, led to acceptance of biochemical thresholds for smoking detection (F_{ET_CO} =9ppm, SCN=55 umol•1^-1 ). Twelve subjects (32%) evidenced F_{ET_CO} levels high enough to be designated as smokers (9-37 ppm) and each was an admitted smoker. Of the 12 admitted smokers, 11 demonstrated SCN levels between 58-278 umol•1^-1. Among the 25 who denied smoking, only 3 patients revealed SCN levels higher than 55 umol/1^-1. Multiple linear regression analyses showed that responses to a few smoking topographic items among the admitted smokers explained much of the variance in biochemical exposure (71-87%). These results show the efficacy of smoking status and topography questionnaire items for identification of current smokers and determination of those who have an increased coronary risk factor. / M.S.

by Leung Sze-wing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 79-84). / Abstracts in English and Chinese. / ACKNOWLEDGEMENT --- p.II / ABSTRACT --- p.III / 摘要 --- p.V / CONTENTS --- p.VI / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Objectives --- p.1 / Chapter 1.2 --- Prevalence of Heart Diseases --- p.1 / Chapter 1.3 --- Importance of ECG Monitoring --- p.2 / Chapter 1.4 --- Wireless Electrode --- p.2 / Chapter 1.5 --- Analogue-to-Digital Converters --- p.3 / Chapter 1.6 --- Organization of Thesis --- p.4 / Chapter CHAPTER 2 --- LITERATURE REVIEW --- p.5 / Chapter 2.1 --- Telemetry --- p.5 / Chapter 2.1.1 --- "Definitions of ""Telemetry “" --- p.5 / Chapter 2.1.2 --- Advantages of Telemetry --- p.6 / Chapter 2.1.3 --- History of Telemetry --- p.7 / Chapter 2.1.4 --- Special Considerations on Telemetry System --- p.10 / Chapter 2.2 --- Sigma-Delta Converter --- p.12 / Chapter 2.2.1 --- Conventional Digitizing Circuitry --- p.12 / Chapter 2.2.2 --- "Single, Dual-Slope A/D Converters" --- p.13 / Single-Slope A/D Converter --- p.13 / Dual-Slope Converter --- p.75 / Chapter 2.2.3 --- Successive Approximation (SAR) --- p.17 / Chapter 2.2.4 --- Flash Converters --- p.18 / Chapter 2.2.5 --- Sigma-Delta Converter --- p.18 / Chapter 2.3 --- Conclusion --- p.20 / Chapter CHAPTER 3 --- WIRELESS ELECTRODE --- p.21 / Chapter 3.1 --- """Single Electrode"" Measurement" --- p.21 / Chapter 3.2 --- VSE (Virtual Single Electrode) --- p.21 / Concentric Electrode --- p.21 / Chapter 3.3 --- WE (Wireless Electrode) --- p.24 / Chapter 3.4 --- Discussion --- p.29 / Chapter CHAPTER 4 --- SIGMA-DELTA CONVERTER FOR ECG SIGNALS --- p.30 / Chapter 4.1 --- Motivations --- p.30 / Chapter 4.2 --- Baseband Application --- p.31 / Chapter 4.2.1 --- Simulation Results --- p.31 / Chapter 4.2.2 --- Experimental Results --- p.48 / Chapter 4.3 --- Wireless Application --- p.58 / Chapter 4.3.1 --- General Description --- p.58 / Chapter 4.3.2 --- Simulation Results --- p.59 / Chapter 4.3.3 --- Scenario 1 (Analogue Decoding) --- p.70 / Chapter 4.3.4 --- Scenario II (Digital Decoding) --- p.73 / Chapter 4.4 --- Discussion and Conclusion --- p.76 / Chapter CHAPTER 5 --- CONCLUSION AND FUTURE WORK --- p.77 / Chapter 5.1 --- General Conclus ion --- p.77 / Chapter 5.2 --- Future Work --- p.78 / BIBLIOGRAPHY --- p.79 / LIST OF ABBREVIATIONS --- p.85

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.

BACKGROUND Increasingly, it is recognised that the unique needs of people from culturally and linguistically diverse backgrounds (CaLDB) should be addressed within a framework of cultural competence. To date, there are limited data on the issues facing CaLDB patients in the Cardiac Rehabilitation (CR) setting. Appreciation of an individual???s values, attitudes and beliefs underpins negotiation of behaviour change in the CR setting. Therefore an understanding of patient and professional interactions is of key importance. OBJECTIVES The focus of this study has been to undertake an exploration of CR service delivery to people from culturally and linguistically diverse backgrounds, using Arabic speaking people as an exemplar of a CaLDB group. More broadly, this research project has sought to identify factors, which influence the practice of health professionals towards CaLDB patients, and to develop a model for evaluation of culturally competent health care in the CR setting. The study sought to achieve these aims by addressing the following research questions: 1. In what way do health practitioners in CR adjust their treatment and support to accommodate the perceived needs of CaLDB communities? 2. In what way do factors (such as individual and organisation perspectives) influence the adjustment of clinical practice and service delivery of CR practitioners; and what are practitioners??? and patients??? perception of barriers and facilitators to service delivery? 3. To what level are CaLDB patients satisfied with CR services? This study design is comprised of the following elements: (1) interviews with health practitioners and Arabic speaking background patients as an exemplar of CaLDB patients; (2) review of policy and procedure documents and medical records; and (3) field observation. METHOD This thesis embraces a qualitative approach as the primary method of investigation to align with the exploratory and descriptive nature of the study. The main methods used in the study were: in depth interviews with health professionals and patients; field observations; appraisal of relevant documents and consultation with expert panels. Study samples were selected through a purposive sampling strategy.Data were analysed using the method of content analysis, guided by the research questions. FINDINGS In total, 25 health professionals (20 female and 5 male) and 32 patients (21 male and 11 female) were interviewed. The method of qualitative content analysis was used for data analysis. Data analysis revealed four major themes: 1) The challenging context; 2) Tuning practices; 3) Influencing factors; and 4) Goodness of fit. The study demonstrated a challenging context for CR delivery, both from the perspective of patients and health professionals. Data reveal a process of reflection, negotiation, and navigation of care by CR health professionals in an effort to understand and meet the diverse needs of CALDB patients. CONCLUSION On the basis of the study findings, a process-oriented model of tuning practice to achieve cultural competence in CR delivery is proposed to inform policy, research and clinical practice.

No description available.

(Uncorrected OCR) Abstract Many studies have been conducted in Caucasian populations on the optimal body mass index cut-off for obesity, as well as the relationship between body mass index and percentage body fat and their associations with cardiovascular risk factors. However, few studies of this kind have been conducted in the Hong Kong Chinese population, This research is deemed to be important due to ethnic differences between Asians and Caucasians, Therefore, this dissertation aims to determine any ethnic differences from a sample of the local Hong Kong Chinese population, in order to advance health care policies controlling known cardiovascular risk factors. A total of 800 subjects were randomly selected from a pool of subjects participated in a Hong Kong Cardiovascular Risk Factor Prevalence study conducted in 1994-1996. These subjects were contacted and 453 disease-free subjects (210 males and 243 females) consented to participate in the current study, Data collected included serum and blood pressure measurements, body mass index, percentage body fat measured by bioelectrical impedance analysis, and a self-completed cardiovascular risk factor questionnaire, The mean age of the 453 subjects was 51.64 years (SD=12.3). When obesity was defined as percentage body fat ~ 25 and 2: 30 in males and females respectively, 23 kg/m2 was found to be the optimum cut-off value, with 78% correct classification (95% CI = 69%-87%). The corresponding sensitivity and specificity were 88% (95% CI = 81 %-95%) and 67% (95% CI = 57%-77%) respectively. On the other hand, if obesity was defined as percentage body fat ~ 25 and 2: 35 in males and females respectively, then 25 kg/m2 was found to be the best cut-off value with 82% correct classification (95% CI = 74%-90%). The corresponding sensitivity and specificity were 78% (95% CI = 69%-87%) and 85% (95% Cl = 78%-92%) respectively. Moreover, body mass index was found to be quadratically body fat. The quadratic relationship did not appear two genders, except that the percentage body fat of of females by 9.97 (SE=0.33). Finally, except for total cholesterol, high density lipoprotein cholesterol, and fasting glucose, body mass index did not provide any substantial information additional to percentage body fat on serum and blood pressure measurements. was the only measure on which percentage body fat did additional to body mass index. When waist-hip body mass index and percentage body fat,. except for body mass index did not have additional information on measurements when percentage body fat or/and [n conclusion, the optimal body mass index cut-off for obesity in Hong Kong Chinese was lower than the 30kg/m2 recommended by the World Health Organization, a clear reflection of ethnic difference between Asians and Caucasians. The quadratic relationship between percentage body fat and body mass index was similar in Hong Kong Chinese as in Caucasians and Blacks. Moreover, percentage body fat together with waist-hip-ratio were found to be better indicators of cardiovascular risk factors in Hong Kong. This was the first time such findings were found in the Hong Kong Chinese population. II / abstract / toc / Medical Sciences / Master / Master of Medical Sciences

BACKGROUND Increasingly, it is recognised that the unique needs of people from culturally and linguistically diverse backgrounds (CaLDB) should be addressed within a framework of cultural competence. To date, there are limited data on the issues facing CaLDB patients in the Cardiac Rehabilitation (CR) setting. Appreciation of an individual???s values, attitudes and beliefs underpins negotiation of behaviour change in the CR setting. Therefore an understanding of patient and professional interactions is of key importance. OBJECTIVES The focus of this study has been to undertake an exploration of CR service delivery to people from culturally and linguistically diverse backgrounds, using Arabic speaking people as an exemplar of a CaLDB group. More broadly, this research project has sought to identify factors, which influence the practice of health professionals towards CaLDB patients, and to develop a model for evaluation of culturally competent health care in the CR setting. The study sought to achieve these aims by addressing the following research questions: 1. In what way do health practitioners in CR adjust their treatment and support to accommodate the perceived needs of CaLDB communities? 2. In what way do factors (such as individual and organisation perspectives) influence the adjustment of clinical practice and service delivery of CR practitioners; and what are practitioners??? and patients??? perception of barriers and facilitators to service delivery? 3. To what level are CaLDB patients satisfied with CR services? This study design is comprised of the following elements: (1) interviews with health practitioners and Arabic speaking background patients as an exemplar of CaLDB patients; (2) review of policy and procedure documents and medical records; and (3) field observation. METHOD This thesis embraces a qualitative approach as the primary method of investigation to align with the exploratory and descriptive nature of the study. The main methods used in the study were: in depth interviews with health professionals and patients; field observations; appraisal of relevant documents and consultation with expert panels. Study samples were selected through a purposive sampling strategy.Data were analysed using the method of content analysis, guided by the research questions. FINDINGS In total, 25 health professionals (20 female and 5 male) and 32 patients (21 male and 11 female) were interviewed. The method of qualitative content analysis was used for data analysis. Data analysis revealed four major themes: 1) The challenging context; 2) Tuning practices; 3) Influencing factors; and 4) Goodness of fit. The study demonstrated a challenging context for CR delivery, both from the perspective of patients and health professionals. Data reveal a process of reflection, negotiation, and navigation of care by CR health professionals in an effort to understand and meet the diverse needs of CALDB patients. CONCLUSION On the basis of the study findings, a process-oriented model of tuning practice to achieve cultural competence in CR delivery is proposed to inform policy, research and clinical practice.

Thesis (M.S.)--University of Michigan, 1998. / Running title: CHD Web site. Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 1998. / Running title: CHD Web site. Includes bibliographical references.

Fifty percent of the diagnosed cases of coronary heart disease in the United States are of unknown etiology. This study proposed that five personality traits— achievement, dominance, aggression, succorance and Critical Parent—differentiate individuals with coronary heart disease manifestations. The ultimate goal of this research was to formulate a predictive profile of at-risk individuals of developing coronary heart disease. Cardiac rehabilitation units' participants from across the United States were recruited as subjects. Randomly selected cardiac rehabilitation units were sent an initial letter inquiring whether their staff would be willing to participate in the study by administering the instruments to their participants. Eight units from each of the 50 states were contacted. A total of fourteen units agreed to participate. One hundred sixty-nine subjects completed the Demographic Data Questionnaire and the Adjective Check List. Five scale scores, representing the five personality differentials, were analyzed. Comparison of the male subject population (n=135) and the male normative population (n=198) revealed no significant differences in terms of the five traits. Comparison of diagnostic subgroups of the subject population also revealed no significant differences. It was concluded that the subject population did not differ significantly from the normative population in terms of the five traits assess by the instrument used. The goal of a predictive profile was not realized due to this lack of findings. / Master of Science / incomplete_metadata