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1
Sorvoja, H. (Hannu). "Noninvasive blood pressure pulse detection and blood pressure determination". Doctoral thesis, University of Oulu, 2006. http://urn.fi/urn:isbn:9514282728.
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Abstract
This thesis describes the development of pressure sensor arrays and a range of methods suitable for the long-term measurement of heart rate and blood pressure determination using a cuff and a pressure sensor array on the radial artery. This study also reviews the historical background of noninvasive blood pressure measurement methods, summarizes the accuracies achieved and explains the requirements for common national and international standards of accuracy.
Two prototype series of pressure transducer arrays based on electro-mechanical film (EMFi) were designed and tested. By offering high (∼TΩ) resistance, EMFi is an excellent material for low-current long-term measurement applications. About 50 transducer arrays were built using different configurations and electrode materials to sense low-frequency pressure pulsations on the radial artery in the wrist. In addition to uniform quality, essential requirements included an adequate linear response in the desired temperature range. Transducer sensitivity was tested as a function of temperature in the range of 25–45 °C at varying static and alternating pressures. The average sensitivity of the EMFi used in the transducers proved adequate (∼2.2 mV/mmHg and ∼7 mV/mmHg for normal and high sensitive films) for the intended purpose.
The thesis also evaluates blood pressure measurements by the electronic palpation method (EP) and compares the achieved accuracy to that of the oscillometric method (OSC) using average intra-arterial (IA) blood pressure as a reference. All of these three measurements were made simultaneously for each person. In one test group, measurements were conducted on healthy volunteers in sitting and supine position during increasing and decreasing cuff pressure. Another group, comprising elderly cardiac patients, was measured only in the supine position during cuff inflation. The results showed that the EP method was approximately as accurate as the OSC method with the healthy subjects and slightly more accurate with the cardiac patient group. The advantage of the EP method is that also the wave shape and velocity of arterial pressure pulses is available for further analysis, including the assessment of arterial stiffness.
2
Citty, Sandra Wolfe. "Ambulatory blood pressure biosituational feedback and systolic blood pressure estimation". [Gainesville, Fla.]: University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000663.
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Guilcher, Antoine. "Central blood pressure". Thesis, King's College London (University of London), 2012. https://kclpure.kcl.ac.uk/portal/en/theses/central-blood-pressure(cfe1a0fc-56e8-4338-a6aa-462c6d6de0bb).html.
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Central aortic systolic blood pressure (cSBP) differs from peripheral systolic blood pressure (pSBP) measured in the arm. cSBP may be estimated non-invasively by application of a generalised transfer function (GIF) to a high fidelity peripheral arterial waveform or from the late systolic shoulder (SBP2) of such a waveform. The relative accuracy of these estimates and the degree to which they depend on the accuracy of peripheral blood pressure is unknown. The interest in estimates of central blood pressure is driven in large part by the fact that aortic pulse pressure (cPP) is thought to be a better predictor of cardiovascular risk and response to antihypertensive treatment than peripheral BP. However, little is known concerning the mechanism by which drugs may reduce cPP independently of effects on peripheral BP. Objectives of this thesis were to: 1. Examine the relative accuracy of different methods (GTF and SBP2) for estimating cSBP and cPP from a high fidelity peripheral arterial waveform. 2. Determine errors introduced by non-invasive calibration of this waveform (as would be the case when such methods are used in practice), 3. Explore the use of a simplified method for estimating cSBP based upon pressure oscillations within an arm cuff. 4. Determine the mechanism by which nitroglycerin (NTG, a drug that has relatively selective actions to lower cSBP) lowers cPP. Pressure and in some cases combined pressure and flow velocity were acquired at the aortic root during cardiac catheterisation. Peripheral blood pressure was measured by oscillometry and peripheral blood pressure waveforms were obtained from blood pressure cuffs, radial tonometry and a servo-controlled finger cuff. To address objective 4 additional measurements of ventricular and arterial mechanics where made using ultrasound and magnetic resonance imaging.
4
Misner, Scottie. "High Blood Pressure". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2010. http://hdl.handle.net/10150/146443.
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Soueidan, Karen. "Augmented blood pressure measurement through the estimation of physiological blood pressure variability". Thesis, University of Ottawa (Canada), 2010. http://hdl.handle.net/10393/28828.
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Current noninvasive blood pressure (BP) measurement methods estimate the systolic and diastolic blood pressure (SBP and DBP) at two random instants in time. The BP variability and its serious consequences on the measurement are not recognized by most physicians. The standard for automated BP devices sets a maximum allowable system error of +/- 5 mmHg, even though natural BP variability often exceeds these limits. This thesis characterizes the variability of SBP and DBP and proposes a new approach to augment the conventional noninvasive measurement using simultaneous recordings of the oscillometric and continuous arterial pulse waveforms by providing: 1) The mean SBP (or DBP) over the measurement interval, 2) Their respective standard deviations, and 3) An indicator as to whether or not the oscillometric reading is an outlier. Recordings with healthy subjects showed that the approach has prominent potential and does not suffer from bias relative to the conventional method.
6
Abel, Evan Dale. "Insulin and blood pressure". Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257939.
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Wang, Fa-Liang. "Blood pressure monitoring system /". Online version of thesis, 1992. http://hdl.handle.net/1850/11172.
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Carstairs, Rachael Caroline. "Human cardiovascular responses to positive pressure breathing with counter pressure". Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322225.
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Swoboda, Marek Lec Ryszard Joseph Jeffrey. "Implantable arterial blood pressure sensor /". Philadelphia, Pa. : Drexel University, 2004. http://hdl.handle.net/1860/2968.
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Ahmed, Niaz. "Blood pressure in acute ischaemic stroke : blood pressure and stress in the acute phase of stroke and influence of initial blood pressure on stroke-outcome /". Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-700-2/.
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Mueller, Jonathon. "The effect of differentiation technique utilized in continuous noninvasive blood pressure measurement". Akron, OH : University of Akron, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=akron1145295553.
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Thesis (M.S.)--University of Akron, Dept. of Biomedical Engineering, 2006."May, 2006." Title from electronic thesis title page (viewed 01/16/2008) Advisor, Dale Mugler; Co-Advisor, Bruce Taylor; Committee member, Daniel Sheffer; Department Chair, Daniel Sheffer; Dean of the College, George K. Haritos; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.
12
Svensson, Per. "Blood pressure, blood pressure variability and myocardial ischemia : studies in patients with peripheral arterial disease and matched control subjects /". Stockholm, 2004. http://diss.kib.ki.se/2004/91-7349-826-2.
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Ng, Kim-Gau. "Oscillometric blood pressure measurement and simulation". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq20572.pdf.
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Luik, A. J. "Blood pressure control in hemodialysis patients". [Maastricht : Maastricht : Universiteit Maastricht] ; University Library, Maastricht University [Host], 1998. http://arno.unimaas.nl/show.cgi?fid=5947.
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Kattach, Hassan. "Blood pressure control in aortic stenosis". Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.526473.
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Clark, Phillipa Margaret. "Childhood blood pressure : aspects of programming". Thesis, University of Southampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242550.
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Zakrzewski, Aaron Michael. "Arterial blood pressure estimation using ultrasound". Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111743.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 155-163).
While blood pressure is commonly used by doctors as an indicator of patient health, the available techniques to measure the quantity suffer from many inconveniences such as cutting off blood flow, being cumbersome to use, being invasive, or being inaccurate. The research addresses many of these inconveniences by developing and evaluating a novel ultrasound-based blood pressure measurement technique that is non-invasive and non-occlusive. The technique proceeds in three steps: data acquisition, data reduction, and optimization. In the data acquisition step, an ultrasound probe is placed on a patient's artery and a force sweep is conducted such that the contact force gradually increases; both the applied force and B-Mode images are recorded. In the data-reduction step, the Star-Kalman filter is applied in order to find the size of the artery in each image frame captured. The segmentation data and contact force data are inputs into the optimization step which consists of two sequential optimizations; the first makes many modeling assumptions and gives an estimate of pulse pressure while the second makes less assumptions and uses the approximation of pulse pressure to obtain absolute values of systolic and diastolic blood pressure. Central to the optimization algorithm is a computational biomechanical model of the artery and surrounding tissue, which is numerically modeled using finite elements. The impact of major modeling assumptions is corrected with a one time calibration. The technique is validated on a number of different data sets. Major data sets discussed include data taken on the carotid artery of (1) 24 single-visit nominally healthy volunteers, (2) two multi-visit nominally healthy volunteers, (3) one multi-visit hypertensive volunteer, and (4) one multi-visit hypotensive volunteer; additional miscellaneous data sets are taken and analyzed as part of this dissertation. The algorithm performance is quantified against readings from an automatic oscillometric cuff. Results show that systolic and diastolic blood pressures can be predicted by the algorithm. The technology discussed in this dissertation represents a proof-of-concept of a blood pressure measurement technique that could occupy a clinical middle ground between the invasive catheter and cuff-based techniques.
by Aaron Michael Zakrzewski.
Ph. D.
18
Huang, Zijian. "Statistical methods for blood pressure prediction". HKBU Institutional Repository, 2020. https://repository.hkbu.edu.hk/etd_oa/801.
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Blood pressure is one of the most important indicators of human health. The symptoms of many cardiovascular diseases like stroke, atrial fibrillation, and acute myocardial infarction are usually indicated by the abnormal variation of blood pressure. Severe symptoms of diseases like coronary syndrome, rheumatic heart disease, arterial aneurysm, and endocarditis also usually appear along with the variation of blood pressure. Most of the current blood pressure measurements rely on the Korotkoff sounds method that focuses on one-time blood pressure measuring but cannot supervise blood pressure continuously, which cannot effectively detect diseases or alert patients. Previous researches indicating the relationship between photoplethysmogram (PPG) signal and blood pressure brought up the new research direction of blood pressure measurement method. Ideally, with the continuous supervision of the PPG signal, the blood pressure of the subject could be measured longitudinally, which matches the current requirements of blood pressure measurement better as an indicator of human health. However, the relationship between blood pressure and PPG signal is very comprehensive that is related to personal and environmental status, which leads to the research challenge for many previous works that tried to find the mapping from PPG signal to blood pressure without considering other factors. In this thesis, we propose two statistical methods modeling the comprehensive relationships among blood pressure, PPG signals, and other factors for blood pressure prediction. We also express the modeling and predicting process for the real data set and provide accurate prediction results that achieve the international blood pressure measurement standard. In the first part, we propose the Independent Variance Components Mixed- model (IVCM) that introduces the variance components to describe the relationship among observations. The relationship indicators are collected as information to divide observations into different groups. The latent impacts from the properties of groups are estimated and used for predicting the multiple responses. The Stochastic Approximation Minorization-maximization (SAM) algorithm is used for IVCM model parameter estimation. As the expansion of Minorization-maximization (MM) algorithm, the SAM algorithm could provide comparable-level estimations as MM algorithm but with faster computing speed and less computational cost. We also provide the subsampling prediction method for IVCM model prediction that could predict multiple responses variables with the conditional expectation of the model random effects. The prediction speed of the subsampling method is as fast as the SAM algorithm for parameter estimation with very small accuracy loss. Because the SAM algorithm and subsampling prediction method requires assigning tuning parameters, a great amount of simulation results are provided for the tuning parameter selection. In the second part, we propose the Groupwise Reweighted Mixed-model (GRM) to describe the variation of random effects as well as the potential components of mixture distributions. In the model, we combine the properties of mixed-model and mixture model for modeling the comprehensive relationship among observations as well as between the predictive variables and the response variables. We bring up the Groupwise Expectation Minorization-maximization (GEM) algorithm for the model parameter estimation. Developed from MM algorithm and Expectation Maximization (EM) algorithm, the algorithm estimates parameters fast and accurate with adopting the properties of the diagonal blocked matrix. The corresponding prediction method for GRM model is provided as well as the simulations for the number of components selection. In the third part, we apply the IVCM model and the GRM model in modeling real data and predicting blood pressure. We establish the database for modeling blood pressure with PPG signals and personal characteristics, extract PPG features from PPG signal waves, and analyze the comprehensive relationship between PPG signal and blood pressure with the IVCM model and the GRM model. The blood pressure prediction results from different models are provided and compared. The best prediction results not only achieve the international blood pressure measurement standard but also show great performance in high blood pressure prediction
19
Morrell, Stephen L. "Aircraft noise and child blood pressure". Connect to full text, 2003. http://hdl.handle.net/2123/594.
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Thesis (Ph. D.)--University of Sydney, 2003.Title from title screen (viewed Apr. 29, 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Public Health, Faculty of Medicine. Includes bibliography. Also available in print form.
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Morrell, Stephen Louis. "Aircraft noise and child blood pressure". Thesis, The University of Sydney, 2003. http://hdl.handle.net/2123/594.
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The purpose of the study was to examine the existence of an association between child blood pressure (BP) and exposure to domestic jet aircraft noise in the context of the construction of a new parallel north-south runway at Sydney (Kingsford-Smith) Airport. The baseline study was commissioned and funded by the Federal Airports Corporation (FAC), with measurements conducted in 1994 and 1995. A follow-up longitudinal component to the study was subsequently commissioned and funded by the FAC in 1997, and measurements conducted in the same year. As the same individuals were measured and re-measured over changing conditions of exposure to aircraft noise, the quasiexperimental nature of the study allowed inferences to be made regarding exposure to aircraft noise and child BP. The main hypotheses for testing were that BP, and within-subject longitudinal changes in BP, are positively related to domestic jet aircraft noise exposure and longitudinal changes in domestic jet aircraft noise exposure respectively. Subsidiary hypotheses tested for evidence of short- and long-term BP adaptation effects where BPs were related to prior changes to aircraft noise exposures. A sample of 75 primary schools within a 20 km radius of Sydney Airport under various noise exposure conditions, both existing and those projected with the advent of the new runway, participated in the study. The baseline cohort comprised 1,230 Year 3/4 children attending the schools in 1994 and 1995, and the follow-up participants comprised 628 of the original baseline sample re-measured in 1997. Study participants were enrolled by active parental consent. The baseline response rate was approximately 40% of children in the participating schools. Systolic (SBP) and diastolic (DBP) blood pressure readings of the children were taken using automated BP measuring equipment along with anthropometric measurements (heights, weights, skinfold thicknesses and waist measurements). Parental surveys captured items pertaining to the child�s ethnic background as measured by the country of birth of the child and parent(s), residential address and housing structure, child eating habits and activity levels, along with family and child history of high blood pressure. Aircraft noise exposure data were collected by the National Acoustic Laboratories and processed into the energy-averaged noise metric used in Australia for aircraft noise exposure assessment called the Australian Noise Exposure Index (ANEI). Mean exposures for a given calendar month were used in the analysis. ANEI values were geocoded to exact geographic locations using digitised street maps from which values for each house and school address, also geocoded, were interpolated. A child BP measured in a given month was matched to a aircraft noise exposure value both at their school and residential address for that month for analysis. After adjusting for confounding and other factors, the cross-sectional relationship between BP and aircraft noise exposure was found to be inconsistent. SBP was nonsignificantly negatively associated with school aircraft noise exposure at baseline (0.05 mmHg/ANEI, cluster-sampling-adjusted p>0.05), but positively and non-significantly associated with school aircraft noise exposure at follow-up (0.05 mmHg/ANEI, p>0.05). As for SBP, baseline DBP was significantly negatively related to school aircraft noise exposure at (0.09 mmHg/ANEI, p<0.001) and non-significantly positively associated with school aircraft noise exposure at follow-up (0.05 mmHg/ANEI, p>0.05). Within-subject BP changes, occurring from baseline to follow-up, regressed on corresponding longitudinal changes in aircraft noise exposures produced inconsistent results. SBP change was positively and non-significantly (0.027 mmHg/ANEI, p>0.05) associated with corresponding school aircraft noise exposure change, while SBP change was negatively associated total aircraft noise exposure change (statistically nonsignificant, 0.06 mmHg/ANEI, p>0.05). DBP changes were similarly and nonsignificantly related to corresponding aircraft noise exposure changes. Some evidence for short-term BP adaptation to recent changes in aircraft noise exposure was found. Consistent negative associations between systolic and diastolic BP and recent changes in school aircraft noise exposure were found. This association was statistically significant at study baseline (SBP: 0.19 mmHg/ANEI, p<0.001; DBP: 0.12 mmHg/ANEI, p<0.001), and of similar magnitude although not statistically significant at follow-up (SBP: 0.14 mmHg/ANEI; DBP: 0.10 mmHg/ANEI, p>0.05). In the presence of inconsistent cross-sectional BP-aircraft noise exposure associations, this finding is consistent with evidence of a homoeostatic BP response to recent changes in aircraft noise exposure, where resting BP returns to pre-existing levels unrelated to aircraft noise exposure. The public health implication of this finding appears to be benign.
21
Morrell, Stephen Louis. "Aircraft noise and child blood pressure". University of Sydney. Public Health, 2003. http://hdl.handle.net/2123/594.
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The purpose of the study was to examine the existence of an association between child blood pressure (BP) and exposure to domestic jet aircraft noise in the context of the construction of a new parallel north-south runway at Sydney (Kingsford-Smith) Airport. The baseline study was commissioned and funded by the Federal Airports Corporation (FAC), with measurements conducted in 1994 and 1995. A follow-up longitudinal component to the study was subsequently commissioned and funded by the FAC in 1997, and measurements conducted in the same year. As the same individuals were measured and re-measured over changing conditions of exposure to aircraft noise, the quasiexperimental nature of the study allowed inferences to be made regarding exposure to aircraft noise and child BP. The main hypotheses for testing were that BP, and within-subject longitudinal changes in BP, are positively related to domestic jet aircraft noise exposure and longitudinal changes in domestic jet aircraft noise exposure respectively. Subsidiary hypotheses tested for evidence of short- and long-term BP adaptation effects where BPs were related to prior changes to aircraft noise exposures. A sample of 75 primary schools within a 20 km radius of Sydney Airport under various noise exposure conditions, both existing and those projected with the advent of the new runway, participated in the study. The baseline cohort comprised 1,230 Year 3/4 children attending the schools in 1994 and 1995, and the follow-up participants comprised 628 of the original baseline sample re-measured in 1997. Study participants were enrolled by active parental consent. The baseline response rate was approximately 40% of children in the participating schools. Systolic (SBP) and diastolic (DBP) blood pressure readings of the children were taken using automated BP measuring equipment along with anthropometric measurements (heights, weights, skinfold thicknesses and waist measurements). Parental surveys captured items pertaining to the child�s ethnic background as measured by the country of birth of the child and parent(s), residential address and housing structure, child eating habits and activity levels, along with family and child history of high blood pressure. Aircraft noise exposure data were collected by the National Acoustic Laboratories and processed into the energy-averaged noise metric used in Australia for aircraft noise exposure assessment called the Australian Noise Exposure Index (ANEI). Mean exposures for a given calendar month were used in the analysis. ANEI values were geocoded to exact geographic locations using digitised street maps from which values for each house and school address, also geocoded, were interpolated. A child BP measured in a given month was matched to a aircraft noise exposure value both at their school and residential address for that month for analysis. After adjusting for confounding and other factors, the cross-sectional relationship between BP and aircraft noise exposure was found to be inconsistent. SBP was nonsignificantly negatively associated with school aircraft noise exposure at baseline (0.05 mmHg/ANEI, cluster-sampling-adjusted p>0.05), but positively and non-significantly associated with school aircraft noise exposure at follow-up (0.05 mmHg/ANEI, p>0.05). As for SBP, baseline DBP was significantly negatively related to school aircraft noise exposure at (0.09 mmHg/ANEI, p<0.001) and non-significantly positively associated with school aircraft noise exposure at follow-up (0.05 mmHg/ANEI, p>0.05). Within-subject BP changes, occurring from baseline to follow-up, regressed on corresponding longitudinal changes in aircraft noise exposures produced inconsistent results. SBP change was positively and non-significantly (0.027 mmHg/ANEI, p>0.05) associated with corresponding school aircraft noise exposure change, while SBP change was negatively associated total aircraft noise exposure change (statistically nonsignificant, 0.06 mmHg/ANEI, p>0.05). DBP changes were similarly and nonsignificantly related to corresponding aircraft noise exposure changes. Some evidence for short-term BP adaptation to recent changes in aircraft noise exposure was found. Consistent negative associations between systolic and diastolic BP and recent changes in school aircraft noise exposure were found. This association was statistically significant at study baseline (SBP: 0.19 mmHg/ANEI, p<0.001; DBP: 0.12 mmHg/ANEI, p<0.001), and of similar magnitude although not statistically significant at follow-up (SBP: 0.14 mmHg/ANEI; DBP: 0.10 mmHg/ANEI, p>0.05). In the presence of inconsistent cross-sectional BP-aircraft noise exposure associations, this finding is consistent with evidence of a homoeostatic BP response to recent changes in aircraft noise exposure, where resting BP returns to pre-existing levels unrelated to aircraft noise exposure. The public health implication of this finding appears to be benign.
22
Corradetti, Alessandra. "Ambulatory blood pressure monitoring in pregnancy". Doctoral thesis, Università Politecnica delle Marche, 2011. http://hdl.handle.net/11566/243017.
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Hypertensive disorders are among the most common medical complications of pregnancy and a leading cause of maternal and perinatal morbidity and mortality world-wide. Blood pressure measurement plays a central role in the screening and management of hypertension during pregnancy. In recent years the validity of conventional (clinic) blood pressure measurement has been questioned and efforts have been made to improve the technique with ambulatory automated devices that provide a large number of measurements over a period of time, usually a 24-hour period.
This review focuses the application and the role of ambulatory blood pressure monitoring (ABPM) in non pregnant and pregnant individuals.
The development of non invasive ambulatory blood pressure monitoring (ABPM) devices has been a great impetus to clinical hypertension research, and ABPM is now widely used in clinical practice.
This position statement examines the evidence to support the use of ABPM, and provides guidance on how and when it should be applied in practice and how to interpret an ambulatory blood pressure (ABP) profile. A literature review of research in ABPM in pregnancy is presented, revealing good prediction of certain outcomes. The main topics addressed include the methodology of ambulatory blood pressure monitoring, its diagnostic and therapeutic thresholds, its clinical applications in hypertension, with specific reference to pregnant population, and its applications in research.
I analyzed recently studies, whit an extensive database on complicated pregnancies, to assess the real applications of this technique in different obstetrics conditions. ABPM is then compared with different methods such as sphygmomanometer measurements or home blood pressure monitoring. The data show that blood pressure values obtained by 24-hour ABPM is superior in predicting low birth weight, prematurity and proteinuria, and the studies confirm that ambulatory blood pressure monitoring devices more accurately reflect a patient’s blood pressure and correlate more closely with end-organ complications than blood pressure levels measured in the physician’s office. These findings mirror the relevant areas in obstetric practice of improved diagnosis and identifying high risk pregnancy.
Ambulatory blood pressure monitoring may be particularly helpful in clinical situations such as "white coat" hypertension and has a role in assessing apparent drug-resistant hypertension, symptomatic hypotension or hypertension, in the elderly, in hypertension in pregnancy and to assess adequacy of control in patients at high risk of cardiovascular disease. AMBP is also being increasingly used in clinical trials that assess the antihypertensive effects of medications.
However, there are significant gaps in knowledge of the pathophysiology of the hypertensive disorders of pregnancy which hamper efforts to improve clinical care. In fact there is no randomized controlled trial evidence to support the use of ambulatory blood pressure monitoring during pregnancy. Randomized trials with adequate design and sample sizes are needed to evaluate the possible advantages and risks of ambulatory blood pressure monitoring during pregnancy, in particular in hypertensive pregnant women.
Future research should also concentrate on randomized controlled trials that should evaluate not only clinical outcomes, but also use of health care resources and women's views.
23
Kumagai, Kyoko. "Central blood pressure relates more strongly to retinal arteriolar narrowing than brachial blood pressure: The Nagahama Study". Kyoto University, 2015. http://hdl.handle.net/2433/199173.
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Jonnada, Srikanth. "Cuff-less Blood Pressure Measurement Using a Smart Phone". Thesis, University of North Texas, 2012. https://digital.library.unt.edu/ark:/67531/metadc115102/.
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Blood pressure is vital sign information that physicians often need as preliminary data for immediate intervention during emergency situations or for regular monitoring of people with cardiovascular diseases. Despite the availability of portable blood pressure meters in the market, they are not regularly carried by people, creating a need for an ultra-portable measurement platform or device that can be easily carried and used at all times. One such device is the smartphone which, according to comScore survey is used by 26.2% of the US adult population. the mass production of these phones with built-in sensors and high computation power has created numerous possibilities for application development in different domains including biomedical. Motivated by this capability and their extensive usage, this thesis focuses on developing a blood pressure measurement platform on smartphones. Specifically, I developed a blood pressure measurement system on a smart phone using the built-in camera and a customized external microphone. the system consists of first obtaining heart beats using the microphone and finger pulse with the camera, and finally calculating the blood pressure using the recorded data. I developed techniques for finding the best location for obtaining the data, making the system usable by all categories of people. the proposed system resulted in accuracies between 90-100%, when compared to traditional blood pressure meters. the second part of this thesis presents a new system for remote heart beat monitoring using the smart phone. with the proposed system, heart beats can be transferred live by patients and monitored by physicians remotely for diagnosis. the proposed blood pressure measurement and remote monitoring systems will be able to facilitate information acquisition and decision making by the 9-1-1 operators.
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Tronvik, Erling. "Migraine, blood pressure andthe renin- angiotensin system". Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for nevromedisin, 2009. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-5398.
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Mafi, Majid. "Blood Pressure Estimation Using Oscillometric Pulse Morphology". Thesis, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20630.
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This thesis work presents the analysis of Oscillometric blood pressure pulse waveform under different pressure points (Systolic, Mean Arterial, and Diastolic Pressures). Pulse waveforms' characteristics were determined from the waveforms at three different pressures and are compared for subjects at three different age groups. Estimation of blood pressure using a morphology based approach was done by using the change of pulse waveform characteristics at different pressure points. Pulse waveforms' characteristics that were obtained from pulse waveforms are utilized to estimate SBP, MAP, and DBP. The estimates obtained with pulse morphology based technique are compared with a BP measurement device and Maximum Amplitude Algorithm. Maximum slope of the pulse was also used for blood pressure estimation. The effect of movement and breathing on proposed method and MAA were compared and it was observed that breathing artifacts affect less the proposed method.
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Lin, Han-Chun (Vivien). "Specialised non-invasive blood pressure measurement algorithm". AUT University, 2007. http://hdl.handle.net/10292/976.
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Blood pressure is one of the fundamental clinical measures. For more than 100 years, clinicians and researchers have used the mercury sphygmomanometer for blood pressure measurement. Environmental concern about mercury contamination has highlighted the need to find a replacement for traditional mercury sphygmomanometers. A number of currently used non-invasive blood pressure measurement methods have been studied in this research. The most commonly used automatic pressure monitoring method nowadays is the Oscillometric method. Height-based and Slope-based criteria are the two general means used to determine the systolic and diastolic pressures. However, these two criteria have many disputed points, making them debatable as a good standard for blood pressure measurement. For this reason, the auscultatory method continues to be the gold-standard for non-invasive blood pressure measurement. Current research uses a newly developed cuff with three different lengths of piezo film sensors and a pressure sensor to collect signals from the brachial artery. The objectives of the research are to process the measured signal from the sensors and develop a blood pressure measurement algorithm that will accurately determine the blood pressure noninvasively. Signal processing and heart beat / heart rate detection software have been developed. The best algorithm has been selected from three developed algorithms for further modification and validation. The final algorithm used two feed-forward Neural Networks to classify the acquired pressure signals into various regions of the pressure signals. The final algorithm has been tested on 258 measurements from 86 subjects. The testing result showed that the algorithm achieved grade A for both systolic and diastolic pressures according to the British Hypertension Society protocol. The mean differences (SD) between the observers and the developed algorithm were 1.44 (5.27) mmHg and 1.77 (6.17) mmHg for systolic and diastolic pressures, respectively, which also fulfilled the Association for the Advancement of Medical Instrumentation protocol. In conclusion, this algorithm was successfully developed and it is recommended for further clinical trial in a wider adult population. Further development of this algorithm also includes extending to other subgroups such as pregnant women, arrhythmia, diabetics and other subjects with diseases.
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Brown, Ian James. "Carbohydrate intake and blood pressure : INTERMAP study". Thesis, Imperial College London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443830.
Pełny tekst źródłaStreszczenie:
The International Collaborative Study of Macronutrients, Micronutrients and Blood Pressure (INTERMAP) is a cross-sectional study investigating the role of macronutrients in blood pressure (BP). Data included four 24-hour dietary recalls; two 24-hour urine collections; eight BP readings; and questionnaire data for 4,680 men and women aged 40-59 years from 17 population samples in four countries (Japan, People's Republic of China, United Kingdo'm [UK], and United States of America [USA]). Aims were to (1) test the hypothesis that there ,. a direct relation of dietary starch intake to the systolic and diastolic BP of individuals; (2) explore associations of total carbohydrate (CHO) and subfractions with BP; (3) calculate dietary glycaemic index (GI) and glycaemic load (GL) for participants; and (4) explore associations of dietary GI and GL with BP. In multiple regression analyses, starch, total CHO, galactose and lactose intakes (% total energy, intake [TEl]) were inversely related to BP. Adjusting for non-dietary factors, sodium/potassium excretion and alcohol intake, the difference in systolic BP associated with 14.1% TEl (2 standard deviations) higher intake of starch was -1.2 (95% confidence intervals -2.2, -0.3) mmHg, while 16.3% higher total CHO intake was associated with a -1.3 (-2.2, :-0.3) mmHg difference. Among, UK and USA participants, 0.2% TEl higher galactose intake was associated with a -1.6 (-2.6, -0.6) mmHgdifference in systolic BP, while 3.6% TEl higher lactose intake was associated with a -1.9 (-3.0, -0.8) mmHg difference. Dietary GI and GL values were estimated for UK and Japanese participants, but were not associated with BP in regression analyses adjusted for multiple confounders. Low-order inverse associations between starch, total CHO, galactose, lactose and BP were observed. More research is needed from animal models, population studies, and randomised trials to determine if CHO intake has a role in the prevention and control of high BP.
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Geeganage, Chamila Manohari. "Management of Blood Pressure in Acute stroke". Thesis, University of Nottingham, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.523082.
Pełny tekst źródła
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Sare, Gillian Mary. "high blood pressure in acute ischaemic stroke". Thesis, University of Nottingham, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.537647.
Pełny tekst źródła
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Ma, Po-wing, i 馬寶詠. "Effects of blood pressure on neurocognitive functions". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/209531.
Pełny tekst źródłaStreszczenie:
Prior clinical studies have documented that high blood pressure is one of the prominent risk factors leading to cerebrovascular disease and subsequent cognitive impairment. The present study aims to examine the relationship between blood pressure and brain and cognitive function in a community sample. This study recruited 41 elderly persons aged 60–70. Multiple imaging modalities were adopted to assess white matter microstructure, regional brain volume, and resting-state neural activity while a set of neuropsychological tests was used to assess cognitive function. With blood pressure measured at clinical interview, correlation and regression analyses were performed. Results showed reduced white matter integrity with increased systolic blood pressure in the splenium of the corpus callosum and inferior longitudinal fasciculus in the absence of change in brain volume or neural activity. Also, increased systolic blood pressure was found to be correlated with poorer cognitive performance in information processing speed. The results held significant after controlling age, sex, and education. These observations of the subclinical sample suggest that high blood pressure relates to subtle changes in the brain and cognitive deficits. Blood pressure control, as a relatively modifiable factor, should be taken seriously in community-dwelling elderly.published_or_final_version
Clinical Psychology
Doctoral
Doctor of Psychology
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Muñoz, Aguilera Eva Mª. "Periodontitis and Blood Pressure: Exploring the Association". Doctoral thesis, Universitat Internacional de Catalunya, 2021. http://hdl.handle.net/10803/673279.
Pełny tekst źródłaStreszczenie:
Background: Recent evidence suggests a link between periodontitis and hypertension;
however, the nature and magnitude of the association are yet to be determined. The aim
of this PhD was to further our understanding of this relationship.
Material & Methods: To investigate the research hypothesis, three studies were
conducted. A robust systematic review (part 1) intended to ascertain whether patients
with periodontitis were more likely to have hypertension when compared to those without
periodontitis. Secondary objectives evaluated i: linear relationship between periodontitis
(extent/severity) and hypertension [measures of blood pressure (BP)], ii: the mean BP
values in periodontitis versus non-periodontitis and iii: the effect of periodontal therapy
on systolic (SBP) and diastolic blood pressure (DBP). A cross-sectional analysis (part 2)
of two well-established surveys of representative samples of USA and Korean
populations was designed with to further assess, i: the degree of association between
periodontitis and hypertension, ii: the potential role of systemic inflammation in
mediating this association. A post-hoc nested case-control study (part 3) in a sample of
systemically healthy participants with the objective to investigate i: the association
between periodontitis and mean BP levels, ii: the relationship with systemic inflammatory
makers and its mediation effect, iii: the level of possible undetected hypertension in the
sample population.
Results: The systematic review included 81 studies (comprising observational and
interventional designs). Moderate-severe periodontitis (OR = 1.22; 95% CI: 1.10–1.35,
P=0.0001) and severe periodontitis (OR = 1.49; 95% CI: 1.09–2.05, P=0.01) were
associated with hypertension. Diagnosis of periodontitis increased the likelihood of
hypertension in prospective studies (OR = 1.68; 95% CI: 0.85–3.35, P=0.14). Further,
participants with periodontitis exhibited higher mean SBP (WMD = 4.49 mm Hg; 95%
CI: 2.88–6.11, P=0.00001) and DBP (WMD = 2.03 mmHg; 95% CI: 1.25–2.81,
P=0.00001) when compared to controls. Less than half (5 out of 12) of interventional
studies confirmed a reduction in BP following the treatment of periodontitis, ranging from
an average of 3-12.5 mm Hg of SBP and from 0-10 mm Hg of DBP.
The cross-sectional study results confirmed that participants with periodontitis had
increased odds of hypertension (NHANES: OR = 1.3, 95% CI: 1.0–1.6, P= 0.025.
KNHANES: OR = 1.2, 95% CI: 1.0–1.4, P=0.041) and actual SBP≥140 mmHg
(NHANES: OR = 1.6, 95% CI: 1.1–2.3, P<0.001; KNHANES: OR = 1.3, 95% CI: 1.0–
1.6, P<0.031) following adjustment of traditional confounders and confirmed in
participants not taking antihypertensive medications. Diagnosis of periodontitis was
directly associated with WBC in both surveys and with CRP levels in the NHANES.
Mediation analyses confirmed that CRP acted as a mediator in the association between
periodontitis and hypertension in both populations. WBC acted as a mediator in the
KNHANES whilst in the NHANES, its effect was dependent of CRP inclusion in the
model.
Lastly, from the nested case-control study cases (participants with severe periodontitis)
presented with 3.36 mm Hg (95% CI, 0.91–5.82, P=0.007) higher mean SBP and 2.16
mm Hg (95% CI, 0.24–4.08, P=0.027) higher DBP than controls (without periodontitis).
Diagnosis of periodontitis was associated with mean SBP (β=3.46±1.25, P=0.005) and
greater odds of SBP≥140 mmHg (OR = 2.3, 95% CI, 1.15–4.60, P=0.018) independent
of common cardiovascular risk factors. Similar findings were observed when continuous
measures of periodontal status were modelled against SBP. Measures of systemic
inflammation although elevated in periodontitis were not found to be mediators of the
association between periodontitis and arterial BP values in this sample of participants
without hypertension.
Conclusions: Diagnosis of periodontitis is consistently associated with increased odds of
hypertension, higher SBP/DBP levels and systemic inflammatory biomarkers. Patient-centred
approaches integrating both the medical and dental communities will be crucial
in the prevention and management not only of periodontitis but also hypertension and its
complications.Antecedentes: La evidencia actual sugiere una relación entre la periodontitis e hipertensión, sin embargo, la naturaleza y la magnitud de esta asociación están por determinar. Por lo tanto, esta tesis doctoral tiene el objetivo de discernir su relación. Material y métodos: Para estudiar la hipótesis de la investigación, tres metodologías fueron llevadas a cabo. La revisión sistemática de la literatura (1ª parte), cuyo objetivo primario fue investigar si pacientes con periodontitis presentaban un mayor riesgo de hipertensión en comparación con aquellos sin periodontitis. Los objetivos secundarios evaluaron i: la relación lineal de la periodontitis (extensión/severidad) con la hipertensión [medidas de presión arterial (PA)], ii: los valores medios de la PA en periodontitis versus no periodontitis, iii: el efecto del tratamiento periodontal en la PA sistólica (PAS) y diastólica (PAD). El estudio transversal (2ª parte) de dos bases de datos representativas de las poblaciones norteamericana y coreana tuvo como objetivos i: corroborar los resultados de la revisión sistemática en cuanto al riesgo de hipertensión en pacientes con periodontitis y ii: analizar la asociación con la inflamación sistémica y su posible efecto mediador. El estudio de casos y controles (3ª parte) se diseñó con el objetivo de investigar i: la asociación entre periodontitis y los valores medios de PAS/PAD, ii: la relación con los marcadores de inflamación sistémica y su posible efecto mediador, iii: ll porcentaje de hipertensión no diagnosticada en la población de estudio. Resultados: La revisión sistemática incluyó 81 estudios (observacionales y de intervención). La periodontitis moderada a severa (OR = 1.22; 95% CI: 1.10–1.35, P=0.0001) y la periodontitis severa (OR = 1.49; 95% CI: 1.09–2.05, P=0.01) se asociaron a hipertensión. Además, los estudios longitudinales de cohortes confirmaron los resultados; la periodontitis incrementó el riesgo de hipertensión (OR = 1.68; 95% CI: 0.85–3.35, P=0.14). Los valores de PAS (WMD = 4.49 mmHg; 95% CI: 2.88–6.11, P=0.00001) y PAD (WMD = 2.03 mmHg; 95% CI: 1.25–2.81, P=0.00001) se encontraron más elevados en pacientes periodontales en comparación con aquellos sin la enfermedad. Por último, solamente 5 de 12 estudios de intervención confirmaron una reducción en PAS=3-12.5 mmHg y de PAD=0-10 mmHg tras el tratamiento periodontal. Los resultados del estudio transversal mostraron que participantes con periodontitis tenían un riesgo de hipertensión aumentado (NHANES: OR = 1.3, 95% CI: 1.0–1.6, P=0.025; KNHANES: OR = 1.2, 95% CI: 1.0–1.4, P=0.041) y además, de PAS≥140 mmHg (NHANES: OR = 1.6, 95% CI: 1.1–2.3, P<0.001; KNHANES: OR = 1.3, 95% CI: 1.0–1.6, P<0.031) después de ajustar las variables de confusión. Los resultados se confirmaron en aquellas personas que no tomaban medicación antihipertensiva. La periodontitis estaba directamente asociada con el recuento de glóbulos blancos (RGB) en las dos bases de datos y con la proteína C-reactiva (PCR) en NHANES. Los análisis de mediación confirmaron que la PCR medió la relación entre periodontitis e hipertensión en las dos poblaciones. El RGB actuó como mediador en KNHANES mientras que en NHANES, el efecto de mediación dependió de la inclusión de la PCR en el modelo. Los resultados del estudio de casos y controles mostraron que los individuos con periodontitis severa (casos) presentaron una PAS [3.36 mm Hg (95% CI, 0.91–5.82, P=0.007)] y PAD [2.16 mmHg (95% CI, 0.24–4.08, P=0.027)] más elevada que los controles (individuos sin periodontitis). La periodontitis estaba asociada con la PAS [variable continua (β=3.46±1.25, P=0.005)] y un riesgo más elevado de tener PAS≥140 mmHg (OR = 2.3, 95% CI, 1.15–4.60, P=0.018), independientemente de variables cardiovasculares comunes. Se obtuvieron resultados similares cuando el modelo se realizó con variables periodontales continuas y PAS. Las medidas de inflamación sistémica (PCR y RGB) se encontraron elevadas en pacientes con periodontitis, pero no actuaron como mediadoras de la asociación entre periodontitis y los valores de PA. Conclusiones: La periodontitis está asociada con un mayor riesgo de padecer valores de PA elevada e hipertensión, así como también de marcadores de inflamación sistémica, los cuales podrían actuar como mediadores de la asociación. La integración de estrategias de salud por parte de las comunidades médica y dental con la atención centrada en el paciente son clave tanto en la prevención como en el control de la periodontitis e hipertensión con el objetivo de disminuir el riesgo cardiovascular.
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Zhou, Bin. "Worldwide trends in blood pressure and diabetes". Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/56634.
Pełny tekst źródłaStreszczenie:
High blood pressure and diabetes are leading causes of loss of health and included in the targets set by the World Health Organization to control non-communicable diseases (NCDs) globally. My thesis aims to provide comparable estimates of levels and trends in blood pressure and diabetes worldwide. Data were collated via the NCD Risk Factor Collaboration (NCD-RisC) network, from population-based studies that had measured blood pressure from 1975 to 2015, or had measured one or more biomarkers of diabetes from 1980 to 2014. A total of 1,479 studies with 19.1 million participants aged 18 years or older were used in the blood pressure analysis, and 751 studies with 4.4 million participants in the diabetes analysis. I used a Bayesian hierarchical model to estimate trends for 200 countries in the world. Overall, there have been divergent trends in blood pressure, seeing a shift of high blood pressure levels from high-income countries to low- and middle-income countries. The global number of adults affected with raised blood pressure has almost doubled since 1975, driven by population growth and ageing, reaching 1.13 billion in 2015. Similarly, age-standardised diabetes prevalence has increased in almost every country, except those in north-western Europe where the trends have been largely flat. The number of adults affected with diabetes has nearly quadrupled, totalling 422 million in 2014. If post-2000 trends continue, for the world as a whole, the probabilities of meeting the global targets of 25% reduction in raised blood pressure and no rise in diabetes compared to their 2010 levels are 0% for blood pressure and ≤1% for diabetes. A preliminary analysis showed diminishing associations of blood pressure and diabetes with national macroeconomic indicators over time, and weak associations with some measures of food and nutrition.
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Schroeder, Knut. "Improving adherence to blood pressure lowering medication". Thesis, University of Bristol, 2003. http://hdl.handle.net/1983/799b44ff-e10d-49c6-80a3-363521922f9c.
Pełny tekst źródłaStreszczenie:
Lack of adherence to long-tenn therapies has been recognised for many years as a major problem, commonly undennining the effectiveness of medical care. The main objectives of this thesis were to evaluate the effect of nurse-led adherence support compared with usual care on adherence, blood pressure and costs, and to compare a newly developed adherence self-report tool with electronic monitoring. A total of 245 uncontrolled hypertensive patients with a diagnosis of essential hypertension were recruited in 22 general practices in Avon. A validation study of an adherence self-report tool compared with electronic monitoring showed that self-report can predict timing compliance at higher levels of adherence. More research is needed on the usefulness of this tool in day-to-day practice and in a more representative study sample. The main study of this thesis, the RCT, compared a nurse-led adherence support consultation followed by a re-inforcement appointment two months later with usual care alone. The main outcomes in this RCT were adherence to blood pressure lowering medication ('timing compliance'), systolic and diastolic blood pressure, and costs. There was no evidence of an effect of nurse-led adherence support on timing compliance (difference between means: -1.0,95% CI: -5.1 to 3.1, p=0.63), systolic blood pressure (difference between means: -2.7 mmHg, 95% CI: -7.2 to 1.8, p=0.24) or diastolic blood pressure (0.2, 95% CI: -1.9 to 2.3, p=0.85). With respect to the evaluation of the adherence self-report tool, there is strong evidence that a reduction of one level of self-reported adherence is associated with a decrease in timing compliance of around 5% (p=0.0004). In conclusion, nurse-led adherence support was no more effective than usual care in terms of increasing adherence or reducing blood pressure. Baseline adherence levels were high in both comparison groups, leaving little room for further improvement. In the few participants who did have medication problems, the intervention appeared to be successful, but further research is needed to consolidate this finding.
35
Takahashi, Osamu. "Evaluation of lower limb blood pressure measurement". Kyoto University, 2006. http://hdl.handle.net/2433/143812.
Pełny tekst źródła
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Larkins, Nicholas George. "Blood pressure and albuminuria among Australian children". Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/20227.
Pełny tekst źródłaStreszczenie:
There is a progressive and substantial shift in the global burden of disease towards non-communicable diseases, of which high blood pressure is one of the most important. While the relationship between blood pressure and risk is a continuous one, modified by individual- and population-level risk factors, the term hypertension is often applied to denote a blood pressure threshold associated with increased mortality that might justify intervention. Hypertension is a lifecourse disease with risk-factors that begin in early life playing an important role in establishing adverse risk trajectories. Kidney disease is another important non-communicable disease with an increasing global and Australian prevalence. Hypertension and kidney disease are linked, each may lead or exacerbate the other, and both are associated with albuminuria. This thesis, by publication, examines the prevalence and correlates of hypertension and albuminuria among Australian children. Chapter 1 is an introduction, including aims and a thesis overview. Chapters 2 and 3 are narrative reviews of hypertension and proteinuria respectively. Chapters 4 to 6 examine the prevalence and correlates of hypertension among Australian children. Chapter 4 uses data from children participating in the Australian Health Survey, and was the first nationwide, population-based estimate of the prevalence of hypertension among Australian children. Chapter 5 is a sub-study of 657 children from the Study of Environment on Aboriginal Resilience and Child Health, which is investigating the health of urban Aboriginal Australian children. Chapter 6 re-visits the national prevalence of hypertension among Australian children using data from the Longitudinal Study of Australian Children at 10 to 12 years of age. This study included 7139 children and captured a wide range of known and possible factors associated with hypertension in children, allowing for a more detailed examination of the predictors of hypertension in this population. Chapters 7 and 8 examine the prevalence of albuminuria among Australian children, also using data from the Australian Health Survey and Longitudinal Study of Australian Children. Given the lack of previous population-based research, we focus on the prevalence of albuminuria using the most widely used threshold of an albumin-to-creatinine (ACR) > 3.4 mg/mmol. We also examine the distribution of the urine ACR and its components among children to examine the validity of this threshold. Chapter 9 is a methods paper reviewing the handling of missing data and modern statistical methods that minimise bias where data are missing, as is common among survey and longitudinal data, and applied to the studies presented. Chapter 10 is a summation of this body of work and explores potential directions for future research.
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Lynch, Dorine A. "Basic Quality Care Blood Pressure Teaching Plan". ScholarWorks, 2019. https://scholarworks.waldenu.edu/dissertations/7821.
Pełny tekst źródłaStreszczenie:
Hypertension (HTN) is a leading risk factor for cardiovascular disease complications, disability, and mortality. Delayed detection of HTN increases the risk of the patient developing heart disease, renal failure, and stroke, which are among the leading causes of death in the US. Educating healthcare providers is, therefore, necessary to ensure accuracy when measuring blood pressure (BP) to improve the likelihood of early detection and commencement of treatment. The BP teaching project involved the development of an evidence-based teaching program to educate nurses at an East Coast Veterans' Administration Center on the guidelines of measuring BP. The practice-focused question addressed whether the literature would support a continuing education program in BP measurement to improve the nurses' knowledge and skills necessary to promote patients' quality of life related to HTN. The evidence-based literature supported education and provided the information used to develop the teaching modules. The frameworks guiding the project included practice modules grounded in quality improvement and, more specifically, the plan, do, study, and act cycles. The findings indicated a highly significant increase in nurses' knowledge of BP measurement after the educational session (p< 0.001). The implications for positive social change included improving the health outcomes of veterans and promoting HTN management in the East Coast VA primary care centers.
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Jones, Martin A. "Ambulatory blood pressure monitoring in the assessment of blood pressure variations and control in patients with chronic renal failure". Thesis, University of Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336936.
Pełny tekst źródła
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Oke, Adekunle, Esther Adeniran, Christian Nwabueze i Nathan Hale. "Association between Home Blood Pressure Monitoring and Total Office Visits among Medicare Beneficiaries with self-reported High Blood Pressure". Digital Commons @ East Tennessee State University, 2021. https://dc.etsu.edu/asrf/2021/presentations/30.
Pełny tekst źródłaStreszczenie:
High blood pressure (BP) is the most significant risk factor for cardiovascular disease and a major contributor to chronic disease burden in the United States. Chronic conditions are the most common reason for office-based physician visits among adults, accounting for 37% of all visits. Home BP monitoring when combined with clinical support may help engagement with care and improve condition control. This study examines the extent to which home BP measurement is associated with total office visits among Medicare beneficiaries with self-reported high BP and the influence by other related factors.
The 2018 Medicare Current Beneficiary Survey (MCBS) was used in the study. The study population consists of Medicare beneficiaries (n=4,456) with self-reported high BP who had at least one total office visit in the year. Total office visits served as the outcome and were dichotomized to low (1-5 visits) and high (greater than 5 visits), while self-reported home BP measurement was the primary independent variable. Andersen’s conceptual framework was used to establish the co-variates [Predisposing factors: age, gender, race, education; Enabling factors: insurance plan (Medicare Advantage, MA), income, patients’ satisfaction (a. quality, b. information); Individual needs: smoking, BMI; Environment: region]. Bivariate analysis using a chi-square test for independence, unadjusted and adjusted logistic regression was conducted using SAS v 9.4.
Of the study population, 57.9% reported measuring blood pressure at home. Approximately 95.6% and 94.2% of beneficiaries were satisfied with the quality of care received and information about their symptoms respectively. Bivariate analysis showed a significant relationship between total office visits and home BP measurement (p<0.05). Unadjusted logistic regression results noted that those who reported home BP measurement had increased odds of high total office visits [uOR: 1.17 (1.02-1.33)]. This relationship was slightly increased in the adjusted analysis when accounting for other factors of interest [aOR:1.22 (1.06- 1.40)]. Those aged 65-74 years had reduced odds [aOR: 0.77 (0.61 -0.98)], females had increased odds [aOR: 1.38 (1.19 – 1.61)], and those with higher education had increased odds [aOR: 1.41 (1.14 -1.75)] of high total office visits. Those not enrolled in MA [aOR: 3.37 (2.31- 4.90)] and those who earn $25,000 or more [aOR: 1.23 (1.04 -1.45)] had increased odds of high total office visits. Those who have never smoked [aOR: 0.81 (0.69-0.94)] and those from the non-metro region [aOR: 0.65 (0.56-0.76)] had reduced odds of high total office visits.
We conclude that those who engage in home BP monitoring are more likely to have a high number of total office visits. The use of home BP monitoring could reflect the severity of high BP suggesting the need for regular follow-up and frequent use of services. Further studies that explore this association are recommended.
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O'Flynn, Ellen Ivy. "Comparison of methods of measuring the brachial systolic pressure in determining the ankle/brachial index". Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/29735.
Pełny tekst źródłaStreszczenie:
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
41
Jayasinghe, Dulip. "The effect of blood pressure on the cerebral blood flow of preterm infants". Thesis, University of Leeds, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490972.
Pełny tekst źródłaStreszczenie:
During the early postnatal period, some preterm infants experience periods of hypoxia, hypotension or both. Hypotension is associated with significant cerebral lesions and contributes to morbidity and mortality. The aetiology of the lesions is thought to be secondary to a loss of Cerebral Blood Flow (CBF) autoregulation, resulting in a pressure-passive CBF. Treatment of hypotension may require the use of inotropic agents that may also affect CBF. CBF can be measured by a number of techniques; one quantitative method is the intravenous 133Xe technique. To investigate the effects of blood pressure on the CBF of preterm infants, CBF was measured before and after treatment of hypotension. Infants received, in a stepwise manor, volume replacement, a dopamine. infusion of 5 JJ9/kg/min then randomisation between 10 JJ9/kg/min of dopamine (Group 1), or the addition of dobutamine infusion at 10 JJg/kg/min (Group 2). Analysis was performed in two stages; the infants were grouped according to blood pressure during acquisition of serial CBF estimates and analysed for the presence of autoregulation; secondly, the effect of inotropes on CBF was modelled. Sixty-one CBF recordings were obtained from 16 infants. Five infants were normotensive during CBF estimation, 11 were hypotensive at least once. CBF-MABP reactivity (95% CI) of the normotensive group was 1.9% (-0.8% to 4.7%) I mmHg llMABP; hypotensive group 1.9% (0.8% to 3.0). The PaCOz-CBF reactivity of the normotensive infants was 11.1% (6.8% to 15.5%) I KPa llPaCOz, that of the hypotensive infants was 4.1% (-5.0% to 14.1%). Twelve infants received at least 5 JJ9/kg/min of dopamine, 5 were SUbsequently randomised to Group1, 5 randomised to Group2. When the effects of MABP, PaC02 , postnatal age, dose of dopamine and dobutamine were modelled on CBF, MABP (2.1% (95% CI1.13.3%)/ mmHg L\MABP; p=0.0003) and postnatal age (1.1% (95% CI 0.12.1 %)/hour L\postnatal age; p=0.03) were found to be significant predictors of change in CBF. The 95% CI of MABP-CBF reactivity of the normotensive infants encompassed 0, interpreted as intact autoregulation, the lower CI of the hypotensive group did not, which was interpreted as absent autoregulation. Inotropes were not observed to affect CBF directly but could through increase in MABP via pressure-passive CBF.
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Radhakrishna, Smitha. "Commercialization of contact-free blood pressure monitoring technology". Cleveland, Ohio : Case Western Reserve University, 2010. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1270228233.
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Wikström, Martin. "Compensating for Respiratory Artifacts in Blood Pressure Waveforms". Thesis, Linköping University, Department of Electrical Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2942.
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Cardiac catheterization has for a long time been a valuable way to evaluate the hemodynamics of a patient. One of the benefits is that the entire blood pressure waveform can be recorded and visualized to the cardiologist. These measurements are however disturbed by different phenomenon, such as respiration and the dynamics of the fluid filled catheter, which introduces artifacts in the blood pressure waveform. If these disturbances could be removed, the measurement would be more accurate. This report focuses on the effects of respiratory artifacts in blood pressure signals during cardiac catheterization.
Four methods, a standard bandpass filter, two adaptive filters and one wavelet based method are considered. The difference between respiratory artifacts in systolic and diastolic pressure is studied and dealt with during compensation. All investigated methods are implemented in Matlab and validated against blood pressure signals from catheterized patients.
The results are algorithms that try to correct for respiratory artifacts. The rate of success is hard to determine since only a few measured blood pressure signals have been available and since the size and appearance of the actual artifacts are unknown.
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Baktash, Seddigheh. "Ratio-Independent Arterial Stiffness-Based Blood Pressure Estimation". Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/30971.
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Blood pressure is one of the crucial vital signs that still lacks measurement accuracy in clinical environments. It is reported by physicians that automated non-invasive blood pressure measurement devices, which are usually based on the oscillometric method, do not provide accurate estimation of blood pressure. This problem has been addressed in this work by incorporating arterial stiffness in blood pressure measurement. Pulse transit time is first used to estimate arterial stiffness parameters. Afterwards, these parameters are fixed into a model of the oscillometric envelope which can then be used to curve fit measured data using only four free parameters: systolic, diastolic, mean blood pressure and minimum lumen area. The proposed individualized technique is independent of any experimentally determined ratio, commonly used in existing oscillometric methods. The accuracy of the proposed technique is evaluated by comparing with (1) the same model without incorporation of arterial stiffness (i.e. a purely oscillometric technique), and (2) Omron device measurements. The results are promising and meet the criteria recommended by the ANSI/AAMI SP - 10 standard for non-invasive blood pressure measurement techniques.
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Correia, Anabela G. 1975. "The renal medullary circulation and blood pressure control". Monash University, Dept. of Physiology, 2001. http://arrow.monash.edu.au/hdl/1959.1/8480.
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Johnson, J. V. "Vasopressin and blood pressure regulation in the rat". Thesis, University of Nottingham, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376525.
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Hylton, P. Antoinette. "Blood pressure and lifestyle in UK African-Caribbeans". Thesis, City University London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363352.
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Bull, Adrian Richard. "Early determinants of blood pressure and related disease". Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238962.
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Sun, James Xin. "Cardiac output estimation using arterial blood pressure waveforms". Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/41625.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references (p. 73-74).
Cardiac output (CO) is a cardinal parameter of cardiovascular state, and a fundamental determinant of global oxygen delivery. Historically, measurement of CO has been limited to critically-ill patients, using invasive indicator-dilution methods such as thermodilution via Swan-Ganz lines, which carry risks. Over the past century, the premise that CO could be estimated by analysis of the arterial blood pressure (ABP) waveform has captured the attention of many investigators. This approach of estimating CO is minimally invasive, cheap, and can be done continuously as long as ABP waveforms are available. Over a dozen different methods of estimating CO from ABP waveforms have been proposed and some are commercialized. However, the effectiveness of this approach is nebular. Performance validation studies in the past have mostly been conducted on a small set of subjects under well-controlled laboratory conditions. It is entirely possible that there will be circumstances in real world clinical practice in which CO estimation produces inaccurate results. In this thesis, our goals are to (1) build a computational system that estimates CO using 11 of the established methods; (2) evaluate and compare the performance of the CO estimation methods on a large set clinical data, using the simultaneously available thermodilution CO measurements as gold-standard; and (3) design and evaluate an algorithm that identifies and eliminates ABP waveform segments of poor quality. Out of the 11 CO estimation methods studied, there is one method (Liljestrand method) that is clearly more accurate than the rest. Across our study population of 120 subjects, the Liljestrand method has an error distribution with a 1 standard deviation error of 0.8 L/min, which is roughly twice that of thermodilution CO. These results suggest that although CO estimation methods may not generate the most precise values, they are still useful for detecting significant (>1 L/min) changes in CO.
by James Xin Sun.
M.Eng.
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Barrera, Vergara Lena. "Factors affecting blood pressure control in primary care". Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/18090.
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Background: Hypertension is the main cardiovascular risk factor. Worldwide, 40% of adults aged 25 years and over have hypertension. Only around 25% of hypertensive patients had controlled hypertension (CH). I assessed the association between individual factors, physician factors and health system factors with having CH. Methods: Population included 17252 hypertensive adults (HA) registered with 28 general practices in Wandsworth, London between 1998 and 2007. Comparison of two blood pressure targets was performed by cross-sectional analysis. Changes in antihypertensive prescribing were evaluated using logistic models. A Bayesian frailty survival model was developed to assess the relationship between potential risk factors and CH with blood pressure <=140/90 mm Hg. Results: In 2007, 26 (93%) practices had more than 70% HA with CH using the QOF target. Using the NICE target of 140/90 mm Hg 4 (14.2%) of practices had more than 70% HAs with CH. In 1998 49.0% HA were not prescribed antihypertensive medication but only 14.8% in 2007. The introduction of the 2006 NICE guidelines was associated with an increase in recommended monotherapy prescribing. 37% of 11373 HA used for survival analysis had CH in 1998 and 62.4% had CH in 2007. Being older, increases in body mass index and higher levels of cholesterol were negatively associated with having CH, hazard ratio (HR) 0.99 (95% credible interval 0.99 – 0.99), HR 0.93 (95% credible interval 0.88 – 099) and HR 0.89 (95% credible interval 0.79 – 0.99) respectively. HA registered after the introduction of Quality and Outcomes Framework (QOF) were more likely to have CH, HR 2.05 (95% credible interval 1.94 – 2.16). Conclusion: In this cohort of HA being treated in primary care, individual factors were mainly associated with not having CH. Blood pressure control rates increased over the period. The use of national hypertension guidelines and the QOF could contribute to this improvement.