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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A novel cuffless technique for non-invasive blood pressure measurement under post-exercise conditions. / CUHK electronic theses & dissertations collection

January 2008 (has links)
Cardiovascular diseases (CVD) are the leading cause of death. It is also one of the major factors resulting sudden deaths in exercises. Blood pressure (BP) is one of the vital diagnostic parameters to reflect the functionality of cardiovascular system and evaluate the conditions of CVD. However, current BP measuring devices usually require the occlusion of cuff that causes inconvenience to users during measurement. They are neither suitable nor practical for long-term monitoring. Pulse transit time (PTT), the duration for a pressure pulse wave to travel from one arterial site to another, has been proposed as a potential parameter for cuffless BP measurement in recent decades. Because of its cuffless and non-invasive measuring features, the aim of the present study is to develop a novel PTT-based BP estimation for cuffless and non-invasive monitoring of BP under resting and exercise conditions. / The accuracy of proposed method for continuous BP monitoring has been evaluated on seventeen subjects during cycling. Brachial BP was measured by FinapresRTM (Fin. BP) and a trained nurse (Nur. BP). In approximate 22000 beats, the differences between predictions and Fin. BP were 1.3+/-13.0 mmHg for SBP and -1.5+/-6.1 mmHg for DBP respectively. The intermittent BP measurements using the proposed method were compared to the readings from FinapresRTM and nurse separately. The differences between proposed method and Nur. BP were 0.9+/-9.9 mmHg for SBP and -1.2+/-5.2 mmHg for DBP respectively. The differences between proposed method and Fin. BP were -0.1+/-12.6 mmHg for SBP and -1.4+/-5.9 mmHg for DBP respectively. The predictions using the proposed method were more consistent with the nurse readings. Furthermore, thorax impedance signal was proposed for cuffless BP estimation and it was examined on twenty-two subjects. The results illustrated that proposed parameters, measured from Q wave of electrocardiogram to the peaks of thorax impedance signal and its derivative, were highly correlated with BP. They were potential parameters to provide non-invasive and cuffless BP estimation. / To conclude, the accuracy of proposed method was comparable to the cuff-based approaches under resting and exercise conditions. This work is potential to solve the problems due to prevalence of CVD and rising aging population. (Abstract shortened by UMI.) / Wong, Yee Man. / Adviser: Y. T. Zhang. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3650. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / 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, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
2

A model-based calibration method for the design of wearable and cuffless devices measuring arterial blood pressure.

January 2008 (has links)
Liu, Yinbo. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 74-79). / Abstracts in English and Chinese. / Abstract --- p.i / List of Figures --- p.iv / List of Tables --- p.viii / Introduction --- p.1 / Chapter 1.1 --- Current status of Blood Pressure Management --- p.1 / Chapter 1.2 --- Current Status of Noninvasive Blood Pressure Measurement Techniques --- p.4 / Chapter 1.3 --- Motivations and Objectives of This Thesis --- p.9 / Chapter 1.4 --- Organization of This Thesis --- p.9 / Backgrounds --- p.11 / Chapter 2.1 --- Principle of the Pulse Transit Time-based Approach for BP Measurement --- p.11 / Chapter 2.1.1 --- General Descriptions --- p.11 / Chapter 2.1.2 --- Pressure Wave Propagation in Cylindrical Arteries --- p.13 / Chapter 2.1.3 --- Determining the PTT for BP Measurement --- p.14 / Chapter 2.2 --- Backgrounds for Pressure Related Elastic Properties of Artery --- p.17 / Chapter 2.2.1 --- Transmural Pressure and Its Components --- p.17 / Chapter 2.2.2 --- Volume-pressure Models --- p.19 / Chapter 2.2.3 --- Types and Structure of the Artery and Its Properties --- p.20 / Chapter 2.3 --- Literature Review on the Calibration Methods for Cuffless Blood Pressure Measurements --- p.22 / Chapter 2.4 --- Section Summary --- p.25 / Investigations on Factors Affecting PTT or BP --- p.26 / Chapter 3.1 --- The Effects of External Pressure --- p.26 / Chapter 3.1.1 --- Background --- p.26 / Chapter 3.1.2 --- Experimental protocol --- p.28 / Chapter 3.1.3 --- Analysis for the Effects of External Pressure on PTT --- p.30 / Chapter 3.1.4 --- Section Discussions --- p.31 / Chapter 3.2 --- The Effects of Hydrostatic Pressure --- p.32 / Chapter 3.2.1 --- Experimental protocol --- p.33 / Chapter 3.2.2 --- Analysis for the Effects of Hydrostatic Pressure on PTT --- p.34 / Chapter 3.2.3 --- Section Discussions --- p.37 / Chapter 3.2.4 --- Section Summary --- p.38 / Modeling the Effect of Hydrostatic Pressure on PTT for A Calibration Method --- p.39 / Chapter 4.1 --- Current Status of Hydrostatic Calibration Approaches --- p.39 / Chapter 4.2. --- Modeling Pulse Transit Time under the Effects of Hydrostatic Pressure for A Hydrostatic Calibration Method: --- p.40 / Chapter 4.2.1 --- Basic BP-PTT model --- p.40 / Chapter 4.2.2 --- V-P relationship Represented by a Sigmoid Curve --- p.40 / Chapter 4.2.3 --- Relating PTT with Hydrostatic Pressure --- p.41 / Chapter 4.2.4 --- Implementing the Hydrostatic Calibration Method for BP Estimation --- p.43 / Chapter 4.3. --- Preliminary Experiment --- p.44 / Chapter 4.3.1. --- Experimental Protocol and Methodology --- p.44 / Chapter 4.3.2. --- Experimental Analysis --- p.46 / Chapter 4.4. --- Section Discussions --- p.48 / Chapter 4.5. --- A Novel Implementation Algorithm of Hydrostatic Calibration Method for Cuffless BP Estimation --- p.49 / Chapter 4.6. --- Section Summary --- p.50 / Experimental Studies for the Hydrostatic Calibration Approach --- p.51 / Chapter 5.1 --- Experimental Analysis --- p.51 / Chapter 5.1.1 --- Experimental Protocol --- p.51 / Chapter 5.1.2 --- Methodology --- p.53 / Chapter 5.1.3 --- Preparations --- p.54 / Chapter 5.1.4 --- Experimental Results --- p.56 / Chapter 5.2 --- Section Discussions --- p.63 / Chapter 5.3 --- Section Summary --- p.70 / Conclusions and Suggestions for Future Works --- p.71 / Chapter 6.1 --- Conclusions --- p.71 / Chapter 6.2 --- Suggestions for Future Works --- p.72 / Reference --- p.71
3

Comparison of methods of measuring the brachial systolic pressure in determining the ankle/brachial index

O'Flynn, Ellen Ivy January 1991 (has links)
This study was designed to determine which method of measuring the systolic blood pressure is more accurate when determining the ankle/brachial index (ABI), which is an important tool in assessing graft patency for patients who have had peripheral vascular surgery. The accuracy of the stethoscope diaphragm was compared with the stethoscope bell and Doppler methods used to measure the brachial systolic pressure. These pressures were then used in the calculation of the ABI and then the ABI was compared by method and time since surgery. The theoretical framework for this study was drawn from theories on sound generation, transmission and measurement. This study used a two-repeated measures design in which the subjects served as their own control. The results were then analyzed using an ANOVA specific to a two-repeated measures design. The sample consisted of 31 subjects which comprised 80% of all peripheral vascular surgery patients admitted over a two month period to a large tertiary care hospital in Western Canada. The subjects ranged in age from 47 to 82 years, the majority had at least one other medical condition in addition to peripheral vascular disease, were on a variety of medications, and 35% had had previous vascular surgery. The subjects had their brachial systolic blood pressure measured by the three methods on the third, fourth and fifth postoperative day. At the same time they also had their dorsalis pedis and posterior tibial pressures measured by the Doppler method. There was no significant difference in the brachial systolic blood pressure related to the methods used to take the blood pressure, the postoperative day that the blood pressure was measured, nor was there any interaction between method and occasion. Also, there was no significant difference in either the dorsalis pedis or posterior tibial ankle/brachial indices related to method used to measure the brachial systolic blood pressure, the postoperative day the measurement was taken, nor any interaction between method and occasion. The findings suggest that peripheral vascular surgery patients often have systolic pressures that differ between the right and left arm which would make a major difference in the calculation of the ABI. Therefore, the pressures should be measured in both arms, followed by documentation and consistent use of the arm with the highest pressure when determining the ABI. The findings also suggest that inservice education and periodic skill checking be implemented when the nurse is required to employ the Doppler method owing to the number of variables to consider when operating this instrument. / Applied Science, Faculty of / Nursing, School of / Graduate
4

A noninvasive and cuffless method for the measurements of blood pressure.

January 2002 (has links)
Chan Ka Wing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references. / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Objectives --- p.1 / Chapter 1.2 --- Definitions --- p.2 / Chapter 1.2.1 --- Definition of blood pressure --- p.2 / Chapter 1.2.2 --- Definition of hypertension --- p.3 / Chapter 1.3 --- Problems related to hypertension --- p.4 / Chapter 1.4 --- The importance of measuring blood pressure --- p.4 / Chapter 1.4.1 --- Self-measurement of blood pressure --- p.5 / Chapter 1.4.2 --- Ambulatory blood pressure measurement --- p.5 / Chapter 1.5 --- Review of blood pressure measurement techniques --- p.7 / Chapter 1.5.1 --- The invasive method --- p.7 / Chapter 1.5.2 --- Noninvasive methods --- p.8 / Chapter 1.6 --- Review of currently available blood pressure meters --- p.15 / Chapter 1.7 --- Prevalence of hypertension --- p.19 / Chapter 1.7.1 --- Hong Kong --- p.19 / Chapter 1.7.2 --- Worldwide --- p.20 / Chapter 1.8 --- The market for blood pressure meters --- p.21 / Chapter 1.9 --- Organization of the thesis --- p.22 / References --- p.24 / Chapter Chapter 2 --- Measurement of the ECG-PPG interval --- p.30 / Chapter 2.1 --- Introduction --- p.30 / Chapter 2.1.1 --- Pulse transit time (PTT) --- p.30 / Chapter 2.1.2 --- Electrocardiogram (ECG) --- p.36 / Chapter 2.1.2.1 --- Measurement of the ECG signal --- p.37 / Chapter 2.1.3 --- Photoplethysmography (PPG) --- p.38 / Chapter 2.1.3.1 --- Measurement of the PPG signal --- p.41 / Chapter 2.1.4 --- Measurement of blood pressure by ECG-PPG interval --- p.43 / Chapter 2.2 --- Source of errors for measurement of the ECG-PPG interval --- p.44 / Chapter 2.2.1 --- Effects of variability of ECG-PPG intervals --- p.44 / Chapter 2.2.2 --- Effects of bending the arm --- p.49 / Chapter 2.2.3 --- Effects of an external force --- p.54 / Chapter 2.3 --- Conclusion --- p.60 / References --- p.62 / Chapter Chapter 3 --- Cuffless and Noninvasive Measurement of Blood Pressure --- p.68 / Chapter 3.1 --- Introduction --- p.68 / Chapter 3.2 --- Effects of subject-dependent calibration --- p.74 / Chapter 3.3 --- Effects of different time intervals --- p.81 / Chapter 3.4 --- The impact of using different Q-P intervals --- p.96 / Chapter 3.5 --- Real-time measurement of blood pressure --- p.104 / Chapter 3.6 --- Conclusion --- p.108 / References --- p.110 / Chapter Chapter 4 --- Motion Artifact Reduction from PPG Recordings in Ambulatory Blood Pressure Measurement --- p.114 / Chapter 4.1 --- Introduction --- p.114 / Chapter 4.2 --- Previous works --- p.115 / Chapter 4.3 --- Theory --- p.116 / Chapter 4.3.1 --- The adaptive filter --- p.117 / Chapter 4.3.2 --- Variation of step-size parameters --- p.119 / Chapter 4.3.3 --- Effects of filter length --- p.120 / Chapter 4.4 --- Experiment --- p.121 / Chapter 4.5 --- Results --- p.123 / Chapter 4.6 --- Discussion --- p.131 / Chapter 4.7 --- Conclusion --- p.133 / References --- p.135 / Chapter Chapter 5 --- Measurement of Blood Pressure using the PPG signal --- p.138 / Chapter 5.1 --- Introduction --- p.138 / Chapter 5.2 --- Theory --- p.138 / Chapter 5.3 --- Experiment --- p.142 / Chapter 5.3.1 --- Multiple linear regression (MLR) --- p.142 / Chapter 5.3.2 --- Artificial neural networks (ANNs) --- p.146 / Chapter 5.3.3 --- Results --- p.149 / Chapter 5.3.4 --- Discussion --- p.152 / Chapter 5.4 --- The implementation of the Q-P interval --- p.153 / Chapter 5.4.1 --- Results --- p.154 / Chapter 5.4.2 --- Discussion --- p.156 / Chapter 5.5 --- Conclusion --- p.157 / References --- p.158 / Chapter Chapter 6 --- Conclusion and Future Studies --- p.160 / Chapter 6.1 --- Major contributions --- p.160 / Chapter 6.2 --- Future studies --- p.162 / References --- p.165 / Appendix I --- p.166
5

Cuffless blood pressure measurement with temperature compensation.

January 2004 (has links)
Lee Chi Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 112-121). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Objectives --- p.1 / Chapter 1.2 --- Blood Pressure --- p.2 / Chapter 1.3 --- Hypertension --- p.3 / Chapter 1.3.1 --- Definition of Hypertension --- p.3 / Chapter 1.3.2 --- Causes and Symptoms of Hypertension --- p.3 / Chapter 1.3.3 --- Complication of Hypertension --- p.4 / Chapter 1.3.4 --- Prevalence of Hypertension --- p.4 / Chapter 1.4 --- Blood Pressure Measurement --- p.5 / Chapter 1.4.1 --- History --- p.5 / Chapter 1.4.2 --- Techniques and Methods --- p.7 / Chapter 1.4.3 --- Current Devices --- p.13 / Chapter 1.5 --- Organization of the Thesis --- p.16 / Chapter Chapter 2 --- Theory --- p.18 / Chapter 2.1 --- Introduction --- p.18 / Chapter 2.2 --- Blood Rheology --- p.18 / Chapter 2.2.1 --- Blood Composition --- p.18 / Chapter 2.2.2 --- Flow Properties of Blood --- p.19 / Chapter 2.2.3 --- Blood Vessels --- p.21 / Chapter 2.3 --- Principle of the PTT-Based Blood Pressure Measurement --- p.22 / Chapter 2.3.1 --- Wave Propagation in Blood Vessels --- p.22 / Chapter 2.3.2 --- Pulse Transit Time (PTT) --- p.27 / Chapter 2.3.3 --- Blood Pressure Measurement Based on PTT --- p.31 / Chapter 2.4 --- Effects of Temperature on Blood Pressure --- p.34 / Chapter 2.4.1 --- Human Body Temperature Regulation --- p.34 / Chapter 2.4.2 --- Physiological Responses to Decreased Temperature --- p.36 / Chapter 2.4.3 --- Effects of Temperature on Blood Pressure --- p.38 / Chapter 2.5 --- Possible Effects of Temperature on PTT-Based Blood Pressure Measurement --- p.47 / Chapter 2.5.1 --- Windkessel Model --- p.47 / Chapter 2.5.2 --- Phase Velocity --- p.49 / Chapter 2.5.3 --- Effects of temperature on PTT --- p.52 / Chapter 2.5.4 --- Possible Effects of temperature on PTT-based Blood Pressure Measurement --- p.53 / Chapter 2.6 --- Conclusion --- p.54 / Chapter Chapter 3 --- Algorithms in Calculating Pulse Transit Time: Wavelet-Based and Derivative-Based --- p.55 / Chapter 3.1 --- Introduction --- p.55 / Chapter 3.1.1 --- Wavelet Transform (WT) --- p.56 / Chapter 3.1.2 --- Wavelet Transform Modulus Maxima (WTMM) --- p.58 / Chapter 3.2 --- Experiment --- p.60 / Chapter 3.2.1 --- Subjects --- p.60 / Chapter 3.2.2 --- Equipment and Sensors --- p.61 / Chapter 3.2.3 --- Protocol --- p.61 / Chapter 3.3 --- Methods --- p.62 / Chapter 3.3.1 --- Wavelet-Based Algorithm of PTT Calculation --- p.62 / Chapter 3.3.2 --- Derivative-Based Algorithm of PTT Calculation --- p.65 / Chapter 3.3.3 --- PTT-Based Blood Pressure Estimation --- p.67 / Chapter 3.4 --- Results --- p.68 / Chapter 3.5 --- Discussion --- p.70 / Chapter 3.6 --- Conclusion --- p.72 / Chapter Chapter 4 --- Effects of Ambient Temperature on PTT-Based Blood Pressure Estimation --- p.74 / Chapter 4.1 --- Introduction --- p.74 / Chapter 4.2 --- Experiment --- p.74 / Chapter 4.2.1 --- Subjects --- p.74 / Chapter 4.2.2 --- Equipment --- p.75 / Chapter 4.2.3 --- Protocol --- p.76 / Chapter 4.3 --- Methods --- p.77 / Chapter 4.3.1 --- Features of Photoplethysmographic Signals --- p.78 / Chapter 4.3.2 --- Calculation of Pulse Transit Time (PTT) --- p.78 / Chapter 4.4 --- Results --- p.79 / Chapter 4.4.1 --- "Effects of Ambient Temperature on Blood Pressure, Heart Rate and Finger Skin Temperature" --- p.79 / Chapter 4.4.2 --- Effects of Ambient Temperature on the Features of Photoplethysmographic Signals --- p.82 / Chapter 4.4.3 --- Effects of Ambient Temperature on Pulse Transit Time --- p.84 / Chapter 4.4.4 --- PTT-Based Blood Pressure Estimation --- p.85 / Chapter 4.4.6 --- Evaluation of the Modified Equations of the PTT-Based Blood Pressure Measurement Approach --- p.89 / Chapter 4.5 --- Discussion --- p.94 / Chapter 4.6 --- Conclusion --- p.98 / Chapter Chapter 5 --- Effects of Local Temperature on PTT-Based Blood Pressure Estimation --- p.99 / Chapter 5.1 --- Introduction --- p.99 / Chapter 5.2 --- Methods --- p.99 / Chapter 5.3 --- Results --- p.100 / Chapter 5.3.1 --- "Effects of Local Temperature on Blood Pressure, Heart Rate and Finger Skin Temperature" --- p.100 / Chapter 5.3.2 --- Effects of Local Temperature on Pulse Transit Time --- p.102 / Chapter 5.3.3 --- Effects of Local Temperature on the Features of Photoplethysmographic Signal --- p.103 / Chapter 5.3.4 --- Effects of Local Temperature on PTT-Based Blood Pressure Estimation --- p.104 / Chapter 5.4 --- Discussion --- p.105 / Chapter 5.5 --- Conclusion --- p.107 / Chapter Chapter 6 --- Conclusion and Future Study --- p.108 / Chapter 6.1 --- Major Contributions --- p.108 / Chapter 6.2 --- Future Study --- p.110 / References --- p.112 / Chapter Appendix A --- Motion Artifact Reduction from PPG signal Based on a Wavelet Approach --- p.122 / Chapter A.l --- Introduction --- p.122 / Chapter A.1.1 --- Motion Artifact --- p.122 / Chapter A.1.2 --- Stationary Wavelet Transform (SWT) --- p.123 / Chapter A.2 --- Experiment --- p.124 / Chapter A.2.1 --- Subjects --- p.124 / Chapter A.2.2 --- Equipment --- p.124 / Chapter A.2.3 --- Protocol --- p.125 / Chapter A.3 --- Methods --- p.126 / Chapter A.3.1 --- Algorithm --- p.126 / Chapter A.3.2 --- Data Analysis --- p.128 / Chapter A.4 --- Results --- p.129 / Chapter A.5 --- Discussion --- p.131 / Chapter A.6 --- Conclusion --- p.133 / Reference --- p.133 / Appendix B Derivation of the Moens-Korteweg Equation --- p.134 / Reference --- p.136
6

A new model for the generation of photoplethysmographic signal with its application to the analysis of beat-to-beat blood pressure variability.

January 2004 (has links)
Gu Yingying. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 155-164). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- IPFM Model --- p.1 / Chapter 1.1.1 --- Description of IPFM Model --- p.1 / Chapter 1.1.2 --- Background of IPFM Related Modeling --- p.3 / Chapter 1.2 --- Windkessel Model --- p.8 / Chapter 1.2.1 --- Background of the Windkessel Model --- p.8 / Chapter 1.2.2 --- Windkessel Related Modeling --- p.13 / Chapter 1.3 --- Photoplethysmogram (PPG) --- p.14 / Chapter 1.3.1 --- Principle of PPG --- p.14 / Chapter 1.3.2 --- Characteristics of PPG Signal --- p.16 / Chapter 1.4 --- A Study on the Beat-to-Beat BPV --- p.18 / Chapter 1.5 --- Main Purposes of the Study --- p.19 / Chapter 1.6 --- Organization of the Thesis --- p.20 / Chapter 2 --- Spectral Analysis on the IPFM Process --- p.22 / Chapter 2.1 --- Introduction --- p.22 / Chapter 2.2 --- A Theoretical Study on the Neural Firing Rate Function --- p.23 / Chapter 2.2.1 --- Mathematical Derivation of the Neural Firing Rate --- p.23 / Chapter 2.2.2 --- Spectral Analysis of the IPFM Process --- p.27 / Chapter 2.2.3 --- Reconstruction of Neural Firing Rate through LPF --- p.30 / Chapter 2.3 --- Effects of Neural Dynamics --- p.33 / Chapter 2.4 --- Discussion & Conclusion --- p.35 / Chapter 3 --- A New Model for the Generation of PPG --- p.37 / Chapter 3.1 --- Introduction --- p.37 / Chapter 3.2 --- Principles of PPG --- p.38 / Chapter 3.2.1 --- Relationship between Pressure and Flow --- p.38 / Chapter 3.2.2 --- Peripheral Pressure and Flow Curves --- p.41 / Chapter 3.2.3 --- Generation of PPG signal --- p.43 / Chapter 3.3 --- Model Description --- p.44 / Chapter 3.3.1 --- IPFM model --- p.45 / Chapter 3.3.2 --- Windkessel model --- p.46 / Chapter 3.3.3 --- New Model for the Generation of PPG --- p.49 / Chapter 3.4 --- Simulation --- p.51 / Chapter 3.4.1 --- Generation of ECG --- p.51 / Chapter 3.4.2 --- Generation of PPG --- p.57 / Chapter 3.4.3 --- Effects of the Modulation Depth on the Output --- p.65 / Chapter 3.4.4 --- Effects of Mean Autonomic Tone on HRV --- p.72 / Chapter 3.5 --- Discussion & Conclusion --- p.75 / Chapter 4 --- A Correlation Study on the Beat-to-Beat Features of Photoplethysmographic Signals --- p.80 / Chapter 4.1 --- Introduction --- p.80 / Chapter 4.2 --- Methodology --- p.81 / Chapter 4.2.1 --- Experimental Conditions --- p.81 / Chapter 4.2.2 --- Definition of the Parameters --- p.82 / Chapter 4.3 --- Data Analysis --- p.85 / Chapter 4.3.1 --- At Normal Relaxed State --- p.85 / Chapter 4.3.2 --- At Different Levels of Contacting Force --- p.87 / Chapter 4.3.3 --- At Different Levels of Local Skin Finger Temperature --- p.90 / Chapter 4.3.4 --- At Dynamic State --- p.93 / Chapter 4.3.5 --- Repeatability Study --- p.95 / Chapter 4.3.6 --- Spectral Analysis --- p.96 / Chapter 4.4 --- Discussion --- p.98 / Chapter 5 --- The Estimation of the Beat-to-Beat Blood Pressure Variability --- p.103 / Chapter 5.1 --- Introduction --- p.103 / Chapter 5.2 --- BP Estimation using FY Interval --- p.104 / Chapter 5.2.1 --- Multi-Beat BP Estimation under Different Levels of Contacting Force --- p.104 / Chapter 5.2.2 --- Beat-to-Beat BP Estimation --- p.108 / Chapter 5.2.3 --- Repeatability Study --- p.112 / Chapter 5.3 --- A Study on the Beat-to-Beat BPV --- p.113 / Chapter 5.3.1 --- Background of the Beat-to-Beat BPV --- p.113 / Chapter 5.3.2 --- Analysis of the Beat-to-Beat BPV --- p.115 / Chapter 5.4 --- Improving the PPG Model with the Time-Varying BP --- p.120 / Chapter 5.4.1 --- Modification of the Model --- p.121 / Chapter 5.4.2 --- Simulation --- p.127 / Chapter 5.4.3 --- Application of the PPG Model --- p.132 / Chapter 5.5 --- Discussion & Conclusion --- p.134 / Chapter 6 --- A Novel Biometric Approach --- p.139 / Chapter 6.1 --- Introduction --- p.139 / Chapter 6.2 --- Human Verification by PPG Signal --- p.140 / Chapter 6.2.1 --- Experiment --- p.141 / Chapter 6.2.2 --- Feature Extraction --- p.142 / Chapter 6.2.3 --- Decision-making --- p.143 / Chapter 6.2.4 --- Results --- p.146 / Chapter 6.3 --- Discussion --- p.149 / Chapter 7 --- Conclusions --- p.151 / Chapter 7.1 --- Conclusions of Major Contributions --- p.151 / Chapter 7.2 --- Work to Be Done --- p.154
7

Noninvasive and cuffless blood pressure measurement: the effects of contacting force and dynamic exercise. / CUHK electronic theses & dissertations collection

January 2004 (has links)
Teng Xiaofei. / "June 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references. / 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. / Abstracts in English and Chinese.
8

A bio-model-based cuffless technique for non-invasive and continuous measurement of arterial blood pressure. / CUHK electronic theses & dissertations collection

January 2007 (has links)
Consequently, this study aims to develop novel technologies that can measure BP non invasively and continuously without a cuff. The proposed method estimates BP using features including pulse transit time (PTT), which is defined as the time interval from R wave of electrocardiogram to onset of photoplethysmogram within the same heart cycle. / Despite the importance of controlling blood pressure (BP) to our health, BP remains inadequately managed worldwide. Due to global ageing and change of human lifestyles, the number of hypertensives is anticipated to continue rising from approximately 1 billion in 2000 to 1.56 billion by 2025. A stumbling block to BP management is high BP usually develops without obvious symptoms. As a result, many people are unaware of their condition until severe problems such as a stroke, a heart attack or kidney failure have occurred. In China, over 100 million people do not know they have developed hypertension and are living under a potential risk to their health. In addition to high BP, variations of BP are also independent indicators of morbidity and mortality of severe diseases. Yet, sudden changes in BP are difficult to be detected by state-of-the-art BP meters, which operate on principles that require an inflatable cuff to give only a snapshot of BP. / Lastly, since the technology required information from several sensors that are placed on different body parts of a person, development of body area network (BAN) has been an important research focus. The concluding chapter of this thesis presents a new concept in this area, namely the hybrid body area network (h-BAN). In particular, the use of biological channels (bio-channels) for intra-BAN communication and securing wireless intra-BAN communication is discussed. / Nevertheless, a major challenge of this approach is its requirement of a calibration procedure. One possible solution is to calibrate against a cuff-based device, but this is inconvenient particularly when calibration has to be refreshed from time to time. Therefore, a bio-model is proposed and developed for PTT along an artery where the hydrostatic component of BP varies. The model can be applied to calibrate the cuffless PTT-based approach and estimate BP by simple movements such as hand elevation. Several experiments were conducted to validate the assumptions of this model and the results were found to be promising. / The proposed PTT-based technology was evaluated on 85 subjects (aged 57+/-29 yrs., including 39 hypertensives) whilst they were at rest in a sitting posture. A total of 999 pairs of systolic BP (SBP) and diastolic BP (DBP) estimations were made with reference to conventional cuff-based devices (i.e. a mercury sphygmomanometer and an oscillometric device) over a period of 6.4 weeks. The results of the study show that reference and estimated BP differed by 0.4+/-9.3 mmHg and 0.8+/-5.8 mmHg for SBP and DBP respectively (AAMI required mean and SD to be less than 5 and 8 mmHg correspondingly). / The results of both studies show that the accuracy of the PTT-based technique is comparable to the cuff-based approaches. This technique is potentially useful to measure BP continuously. / To conclude, this work developed a non-invasive and cuffless approach for BP measurement and addressed several key issues of this approach, i.e. the analysis, calibration, and implementation of it. The work can help to realise new BP management schemes in mobile health (m-Health) and personalised healthcare systems, which are developed to cater for the needs of the increasing aging population world-wide and to prevent and control chronic diseases like hypertension. / To further the investigation, a second study which was to investigate in a clinical setting for post-operation condition, was carried out on 8 patients (aged 55+/-18 yrs.) using the averaged invasive arterial-line and cuff readings taken at intervals of 40.0+/-24.7 min. as reference. After calibrating the new approach on each individual, it can estimate SBP and DBP within 3.3+/-6.5 mmHg and 4.3+/-6.4 mmHg of the reference for the complete set of 89 estimations. / Poon, Chung Yan Carmen. / "December 2007." / Adviser: Yuon-Ting Zhang. / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4888. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 91-103). / 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, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
9

Cuffless calibration and estimation of continuous arterial blood pressure.

January 2009 (has links)
Gu, Wenbo. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references. / Abstract also in Chinese. / Acknowledgment --- p.i / Abstract --- p.ii / 摘要 --- p.iii / List of Figures --- p.vi / List of Tables --- p.vii / List of Abbreviations --- p.viii / Contents --- p.ix / Chapter 1. --- Introduction --- p.1 / Chapter 1.1. --- Arterial blood pressure and its importance --- p.1 / Chapter 1.2. --- Current methods for non-invasive blood pressure measurement --- p.4 / Chapter 1.2.1. --- The auscultatory method (mercury sphygmomanometer) --- p.4 / Chapter 1.2.2. --- The oscillometric method --- p.5 / Chapter 1.2.3. --- The tonometric method --- p.7 / Chapter 1.2.4. --- The volume-clamp method --- p.7 / Chapter 1.3. --- Blood pressure estimation based on pulse arrival time --- p.8 / Chapter 1.4. --- Objectives and structures of this thesis --- p.10 / Chapter 2. --- Hemodynamic models: relationship between PAT and BP --- p.14 / Chapter 2.1. --- The generation of arterial pulsation --- p.14 / Chapter 2.2. --- Pulse wave velocity along the arterial wall --- p.15 / Chapter 2.2.1. --- Moens-Korteweg equation --- p.15 / Chapter 2.2.2. --- Bergel wave velocity --- p.18 / Chapter 2.3. --- Relationship between PWV and BP --- p.19 / Chapter 2.3.1. --- Bramwell-Hill´ةs model --- p.20 / Chapter 2.3.2. --- Volume-pressure relationship --- p.20 / Chapter 2.3.3. --- Hughes' model --- p.22 / Chapter 2.4. --- The theoretical expression of PAT-BP relationship --- p.23 / Chapter 3. --- Estimation and calibration of arterial BP based on PAT --- p.25 / Chapter 3.1. --- PAT measurement --- p.25 / Chapter 3.1.1. --- Principle of ECG measurement --- p.25 / Chapter 3.1.2. --- Principle of PPG measurement --- p.26 / Chapter 3.1.3. --- Calculation of PAT --- p.28 / Chapter 3.2. --- Calibration methods for PAT-BP estimation --- p.29 / Chapter 3.2.1. --- Calibration based on cuff BP readings --- p.30 / Chapter 3.2.2. --- Calibration by hydrostatic pressure changes --- p.31 / Chapter 3.2.3. --- Calibration by multiple regression --- p.33 / Chapter 3.3. --- Model-based calibration with PPG waveform parameters --- p.34 / Chapter 3.3.1. --- Model-based equation with parameters from PPG waveform --- p.34 / Chapter 3.3.2. --- Selection of parameters from PPG waveform --- p.36 / Chapter 4. --- Cuffless calibration approach using PPG waveform parameter for PAT-BP estimation --- p.43 / Chapter 4.1. --- Introduction --- p.43 / Chapter 4.2. --- Experiment I: young group in sitting position including rest and after exercise states --- p.43 / Chapter 4.2.1. --- Experiment protocol --- p.43 / Chapter 4.2.2. --- Data Analysis --- p.44 / Chapter 4.2.3. --- Experiment results --- p.46 / Chapter 4.3. --- Experiment II: over-month observation using wearable device in sitting position --- p.48 / Chapter 4.3.1. --- Body sensor network for blood pressure estimation --- p.49 / Chapter 4.3.2. --- Experiment protocol and data collection --- p.50 / Chapter 4.3.3. --- Experiment results --- p.50 / Chapter 4.4. --- Experiment III: contactless monitoring in supine position --- p.51 / Chapter 4.4.1. --- The design of the contactless system --- p.52 / Chapter 4.4.2. --- Experiment protocol and data collection --- p.53 / Chapter 4.4.3. --- Experiment results --- p.53 / Chapter 4.5. --- Discussion --- p.55 / Chapter 4.5.1. --- Discussion of Experiments I and II --- p.55 / Chapter 4.5.2. --- Discussion of Experiments II and III --- p.57 / Chapter 4.5.3. --- Conclusion --- p.58 / Chapter 5. --- Cuff-based calibration approach for BP estimation in supine position --- p.61 / Chapter 5.1. --- Introduction --- p.61 / Chapter 5.2. --- Experiment protocol --- p.61 / Chapter 5.2.1. --- Experiment IV: exercise experiment in supine position in lab --- p.61 / Chapter 5.2.2. --- Experiment V: exercise experiment in supine position in PWH --- p.63 / Chapter 5.3. --- Data analysis --- p.65 / Chapter 5.3.1. --- Partition of signal trials and selection of datasets --- p.65 / Chapter 5.3.2. --- PPG waveform processing --- p.66 / Chapter 5.4. --- Experiment results --- p.68 / Chapter 5.4.1. --- Range and variation of reference SBP --- p.68 / Chapter 5.4.2. --- PAT-BP individual best regression --- p.69 / Chapter 5.4.3. --- Multiple regression using ZX and arm length --- p.72 / Chapter 5.4.4. --- One-cuff calibration improved by PPG waveform parameter --- p.72 / Chapter 5.5. --- Discussion --- p.74 / Chapter 6. --- Conclusion --- p.76
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Evaluation of the wearable cuff-less blood pressure measuring devices.

January 2009 (has links)
Yan, Renfei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 69-77). / Abstract also in Chinese. / ABSTRACT --- p.I / ACKNOWLEDGEMENT --- p.V / LIST OF FIGURES --- p.VI / LIST OF TABLES --- p.VIII / LIST OF ABBREVIATIONS --- p.IX / Chapter CHAPTER 1. --- INTRODUCTION TO BLOOD PRESSURE MEASURING DEVICES AND EVALUATION STANDARDS --- p.1 / Chapter 1.1. --- Current situation on hypertension --- p.1 / Chapter A. --- Prevalence of hypertension --- p.1 / Chapter B. --- Low awareness of hypertension --- p.1 / Chapter 1.2. --- Calls for better management of hypertension --- p.2 / Chapter 1.3. --- Blood pressure measuring devices --- p.3 / Chapter A. --- Conventional devices and their limitations --- p.3 / Chapter B. --- Wearable cuff-less devices --- p.4 / Chapter 1.4. --- Evaluation of the wearable cuff-less devices --- p.6 / Chapter 1.5. --- Objectives of the thesis --- p.7 / Chapter 1.6. --- Structure of the thesis --- p.7 / Chapter CHAPTER 2. --- REVIEW ON CURRENT STANDARDS --- p.8 / Chapter 2.1. --- Introduction to current standards --- p.8 / Chapter A. --- AAMI standard --- p.8 / Chapter B. --- BHS protocol --- p.8 / Chapter C. --- ESH protocol --- p.9 / Chapter 2.2. --- Comparison of current standards --- p.9 / Chapter A. --- Evaluation scope --- p.9 / Chapter B. --- Validation protocol --- p.10 / Chapter C. --- Accuracy criteria --- p.10 / Chapter D. --- Testing reference --- p.13 / Chapter E. --- Recruitment of subjects --- p.13 / Chapter F. --- Ambulatory monitors --- p.14 / Chapter G. --- Special groups of population --- p.15 / Chapter H. --- Statistical considerations --- p.16 / Chapter 2.3. --- Major challenges for the evaluation of cuff-less devices --- p.17 / Chapter A. --- Lack of experimental data --- p.19 / Chapter B. --- Re-examination of the statistical considerations --- p.19 / Chapter C. --- Feature oriented design of the validation protocol --- p.19 / Chapter D. --- Selection of testing reference --- p.79 / Chapter CHAPTER 3. --- ERROR DISTRIBUTION MODEL --- p.21 / Chapter 3.1. --- Distribution assumption in current standards --- p.21 / Chapter 3.2. --- Distribution analysis from published reports --- p.22 / Chapter A. --- Methodology --- p.22 / Chapter B. --- Data analysis --- p.23 / Chapter C. --- Results --- p.23 / Chapter 3.3. --- Distribution analysis on a cuff-less device --- p.29 / Chapter A. --- Experiment --- p.29 / Chapter B. --- Data analysis --- p.31 / Chapter C. --- Results --- p.31 / Chapter 3.4. --- Discussion --- p.33 / Chapter A. --- Supporting evidence for t4 distribution --- p.33 / Chapter B. --- Implications for the application of t4 distribution --- p.34 / Chapter 3.5. --- Section Summary --- p.35 / Chapter CHAPTER 4. --- EVALUATION SCALE TO ASSESS THE ACCURACY --- p.36 / Chapter 4.1. --- Considerations for parameter selection --- p.37 / Chapter A. --- Outlying errors and system bias --- p.37 / Chapter B. --- Accuracy at different levels of blood pressure --- p.37 / Chapter 4.2. --- Description of selected parameters --- p.38 / Chapter 4.3. --- Theoretical relationship between “new´ح and “old´ح parameters --- p.38 / Chapter A. --- Mathematical relationship --- p.39 / Chapter B. --- Mapping relationship --- p.40 / Chapter 4.4. --- Assessment of accuracy at increasing blood pressure levels --- p.41 / Chapter A. --- Data transformation --- p.41 / Chapter B. --- Experimental study --- p.41 / Chapter 4.5. --- Discussion and application --- p.43 / Chapter A. --- Parameter selection --- p.43 / Chapter B. --- Sample size --- p.45 / Chapter C. --- Accuracy criteria --- p.46 / Chapter 4.6. --- Section summary --- p.47 / Chapter CHAPTER 5. --- FEATURE ORIENTED PROTOCOL DESIGN --- p.48 / Chapter 5.1. --- Rationale of accuracy assessment with BP change --- p.48 / Chapter 5.2. --- Experiment one --- p.49 / Chapter 5.3. --- Experiment two --- p.49 / Chapter 5.4. --- Data analysis --- p.49 / Chapter 5.5. --- Results --- p.50 / Chapter A. --- Experiment one --- p.50 / Chapter B. --- Experiment two --- p.52 / Chapter 5.6. --- Discussion --- p.58 / Chapter A. --- Difference between cuff-less and cuff-based devices --- p.58 / Chapter B. --- Correlation between accuracy and blood pressure changes --- p.58 / Chapter C. --- Inducement of blood pressure change --- p.59 / Chapter D. --- Other factors affect the accuracy --- p.60 / Chapter 5.7. --- Section summary --- p.61 / Chapter CHAPTER 6. --- PROPOSAL FOR THE EVALUATION OF WEARABLE CUFF-LESS DEVICES --- p.62 / Chapter 6.1. --- Scope --- p.62 / Chapter 6.2. --- Purpose --- p.62 / Chapter 6.3. --- Subject selection --- p.63 / Chapter 6.4. --- Main validation --- p.64 / Chapter A. --- Static test --- p.64 / Chapter B. --- Test with blood pressure change --- p.65 / Chapter C. --- Test after a certain period of time --- p.65 / Chapter 6.5. --- Data analysis and reporting --- p.66 / Chapter A. --- Statistical report --- p.66 / Chapter B. --- Graphical representation --- p.67 / Chapter 6.6. --- Conclusion and future work --- p.67 / REFERENCES --- p.69 / LIST OF PUBLICATIONS AND AWARDS --- p.78

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