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Patzauer, Rebecka, and Elin Wessel. "Mätosäkerhet vid kalibrering av referensutrustning för blodtrycksmätning : En modell för framtagning av mätosäkerhet för referensmanometer WA 767." Thesis, KTH, Skolan för teknik och hälsa (STH), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-191279.
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Avdelningen för Medicinsk teknik på Akademiska sjukhuset har uppdaterat befintliga kalibreringsprotokoll för Welch Allyn 767 som används som referensmanometer vid kalibrering av blodtrycksmätare. I protokollet ska det enligt ISO 9001 och ISO 13485 ingå att vid varje kalibreringspunkt ange mätosäkerheten. Rutiner kring detta var inte definierade. En modell för att ta fram mätosäkerhet utformades utifrån standardiserade metoder från “Guide to the expression of uncertainty in measurement” och anpassades för att kunna användas på den medicintekniska avdelningen. En mätmetod för kalibrering togs fram och med modellen beräknades mätosäkerhet för en referensmanometer. Mätosäkerheten med definierad mätmetod blev lägre än den av Welch Allyn specificerade mätosäkerheten på ± 3 mmHg. Felfortplantning från kalibrering till blodtrycksmätning undersöktes. Mätosäkerheten ökade i varje steg, varför avdelningen bör ta fram ett protokoll för hur kalibrering genomförs, och på så sätt förbättra spårbarheten.The department of Medical Technology at Akademiska sjukhuset has updated their current protocol for calibration for Welch Allyn 767, which serves as a reference manometer for blood pressure meters when being calibrated. According to ISO 9001 and ISO 13485, the protocol has to include a measurement uncertainty for every given point of calibration. The routines regarding this were undefined. A model for retrieving measurement uncertainty was designed using standardized methods from “Guide to the expression of uncertainty in measurement” and was customized to be used at the department of Medical Technology. A method for calibration was created and used to calculate the measurement uncertainty for the reference manometer. This measurement uncertainty was smaller than the one specified by Welch Allyn, which was ± 3 mmHg. Propagation of uncertainty from the calibration to the blood pressure measurement was investigated. The measurement uncertainty increased in every step. Therefore, the department should introduce a protocol for how a calibration is performed, and thereby improve the traceability.
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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.
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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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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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Takahashi, Osamu. "Evaluation of lower limb blood pressure measurement." Kyoto University, 2006. http://hdl.handle.net/2433/143812.
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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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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.
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Shennan, Andrew Hoseason. "Ambulatory blood pressure measurement in pregnancy and pre-eclampsia." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286663.
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McGowan, Neil. "The utility of out of office blood pressure measurement." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/24943.
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Ambulatory blood pressure measurement (ABPM) has improved prognostic power with respect to cardiovascular disease compared with office blood pressure (BP). It can be postulated that this is secondary to improved reproducibility of measurement, as a result of ABPMs ability to remove most of the factors leading to within-subject variability of BP measurement. In addition, the number of BP readings obtained from ABPM results in a statistically more accurate reflection of mean BP compared with a single office BP measurement. Repeated episodes of ABPM, with time intervals of six months to greater than three years, were examined in a cohort of treatment naïve subjects. BP was more reproducible when expressed as a continuous variable, as defined by the intra-class correlation coefficient (ICC), than when BP was referred to as a dichotomous variable (hypertensive/normotensive), as defined with a kappa statistic. This was true independent of time interval between episodes of monitoring. Linear regression analysis or multivariate binomial regression indicated that nocturnal blood pressure dip, expressed as either a continuous or dichotomous variable, was unable to be predicted from age, sex, mean awake systolic BP. Nocturnal blood pressure dipping was poorly reproducible when expressed as a dichotomous variable (dipper/non-dipper), irrespective of the time interval between measurements (k=0.29). Intra class correlation coefficient demonstrated improved reproducibility of nocturnal pressure fall when this is expressed as a percentage reduction of mean awake BP (ICC=0.6). This was constant independent of time interval. ABPM was used to demonstrate a significant BP reduction in patients with diabetes and high vascular risk, managed through a pharmacist-led cardiovascular risk clinic. Repeat ABPM six months post discharge was not significantly different from BP on discharge from the clinic. ABPM data currently needs clinician interpretation. Four studies, using national and international experts in hypertension, indicated poor agreement in interpretation and diagnosis of hypertension when all were faced with identical ABPM data. Computer software can be used to standardise diagnosis but management decisions will always rest with clinicians. Self blood pressure monitoring has been proposed as the future of hypertension management. Mean BP obtained with self monitoring of BP (SBPM), using the schedule defined by the European Society of Hypertension, was not significantly different to mean awake-time BP on ABPM. In addition, SBPM was preferred by over 80% of subjects. The author suggests that using only office BP for measuring blood pressure is outdated and inaccurate. The aim of this thesis was to demonstrate the utility of out of office blood pressure measurement and recommends this becomes part of everyday clinical practice. It is time hypertension management was brought into the 21st century!
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He, Shan. "Time-interval based Blood Pressure Measurement Technique and System." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/38600.
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Smart watches in future will have smart wristband. This work analyses properties of new developed capacitive wristband sensor that measures ballistocardiogram (BCG) from single point on the wrist. In addition, it considers applications of this sensor to monitoring heart rate variability. Another application is in estimating changes (trend) in systolic blood pressure continuously when combined with lead one electrocardiogram (ECG).
BP is one of the vital signs that indicates the health condition. It is commonly measured by cuff-based monitor using either auscultatory or oscillometric method. Cuff-based BP monitor is not portable and unable to measure BP continuously which means it is difficult to attach BP monitoring function on a wearable device. Significant research is conducted in estimating BP from pulse transit time (PTT) mathematically which would enable the cuffless BP measurement.
In this work, a new time reference, RJ interval, which is the time delay between ECG and BCG signal peaks was tested whether it can be used as a surrogate of PTT in cuffless BP estimation. Based on the study done on 10 healthy people, it was shown that RJ intervals can be useful in evaluating trends of systolic blood pressure.
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Kepe, Lulama Patrick. "Estimating measurement error in blood pressure, using structural equations modelling." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/53739.
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Thesis (MSc)--Stellenbosch University, 2004.ENGLISH ABSTRACT: Any branch in science experiences measurement error to some extent. This maybe due to conditions under which measurements are taken, which may include the subject, the observer, the measurement instrument, and data collection method. The inexactness (error) can be reduced to some extent through the study design, but at some level further reduction becomes difficult or impractical. It then becomes important to determine or evaluate the magnitude of measurement error and perhaps evaluate its effect on the investigated relationships. All this is particularly true for blood pressure measurement. The gold standard for measunng blood pressure (BP) is a 24-hour ambulatory measurement. However, this technology is not available in Primary Care Clinics in South Africa and a set of three mercury-based BP measurements is the norm for a clinic visit. The quality of the standard combination of the repeated measurements can be improved by modelling the measurement error of each of the diastolic and systolic measurements and determining optimal weights for the combination of measurements, which will give a better estimate of the patient's true BP. The optimal weights can be determined through the method of structural equations modelling (SEM) which allows a richer model than the standard repeated measures ANOVA. They are less restrictive and give more detail than the traditional approaches. Structural equations modelling which is a special case of covariance structure modelling has proven to be useful in social sciences over the years. Their appeal stem from the fact that they includes multiple regression and factor analysis as special cases. Multi-type multi-time (MTMT) models are a specific type of structural equations models that suit the modelling of BP measurements. These designs (MTMT models) constitute a variant of repeated measurement designs and are based on Campbell and Fiske's (1959) suggestion that the quality of methods (time in our case) can be determined by comparing them with other methods in order to reveal both the systematic and random errors. MTMT models also showed superiority over other data analysis methods because of their accommodation of the theory of BP. In particular they proved to be a strong alternative to be considered for the analysis of BP measurement whenever repeated measures are available even when such measures do not constitute equivalent replicates. This thesis focuses on SEM and its application to BP studies conducted in a community survey of Mamre and the Mitchells Plain hypertensive clinic population.
AFRIKAANSE OPSOMMING: Elke vertakking van die wetenskap is tot 'n minder of meerdere mate onderhewig aan metingsfout. Dit is die gevolg van die omstandighede waaronder metings gemaak word soos die eenheid wat gemeet word, die waarnemer, die meetinstrument en die data versamelingsmetode. Die metingsfout kan verminder word deur die studie ontwerp maar op 'n sekere punt is verdere verbetering in presisie moeilik en onprakties. Dit is dan belangrik om die omvang ven die metingsfout te bepaal en om die effek hiervan op verwantskappe te ondersoek. Hierdie aspekte is veral waar vir die meting van bloeddruk by die mens. Die goue standaard vir die meet van bloeddruk is 'n 24-uur deurlopenee meting. Hierdie tegnologie is egter nie in primêre gesondheidsklinieke in Suid-Afrika beskikbaar nie en 'n stel van drie kwik gebasseerde bloedrukmetings is die norm by 'n kliniek besoek. Die kwaliteit van die standard kombinasie van die herhaalde metings kan verbeter word deur die modellering van die metingsfout van diastoliese en sistoliese bloeddruk metings. Die bepaling van optimale gewigte vir die lineêre kombinasie van die metings lei tot 'n beter skatting van die pasiënt se ware bloedruk. Die gewigte kan berekening word met die metode van strukturele vergelykings modellering (SVM) wat 'n ryker klas van modelle bied as die standaard herhaalde metings analise van variansie modelle. Dié model het minder beperkings en gee dus meer informasie as die tradisionele benaderings. Strukurele vergelykings modellering wat 'n spesial geval van kovariansie strukturele modellering is, is oor die jare nuttig aangewend in die sosiale wetenskap. Die aanhang is die gevolg van die feit dat meervoudige lineêre regressie en faktor analise ook spesiale gevalle van die metode is. Meervoudige-tipe meervoudige-tyd (MTMT) modelle is 'n spesifieke strukturele vergelykings model wat die modellering van bloedruk pas. Hierdie tipe model is 'n variant van die herhaalde metings ontwerp en is gebaseer op Campbell en Fiske (1959) se voorstel dat die kwaliteit van verskillende metodes bepaal kan word deur dit met ander metodes te vergelyk om sodoende sistematiese en stogastiese foute te onderskei. Die MTMT model pas ook goed in by die onderliggende fisiologies aspekte van bloedruk en die meting daarvan. Dit is dus 'n goeie alternatief vir studies waar die herhaalde metings nie ekwivalente replikate is nie. Hierdie tesis fokus op die strukturele vergelykings model en die toepassing daarvan in hipertensie studies uitgevoer in die Mamre gemeenskap en 'n hipertensie kliniek populasie in Mitchells Plain.
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Sabkha, Aimen. "Implantable Wireless Surface Acoustic Wave Sensors for Blood Pressure Measurement." Thesis, Oxford Brookes University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491086.
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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.
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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
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Oke, Adekunle, Esther Adeniran, Christian Nwabueze, and 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.
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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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Heimann, P. A. "Assessment of catheter-manometer systems used for invasive blood pressure measurement." Master's thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/27183.
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Direct measurement of blood pressure using a fluid-filled catheter and an electromechanical transducer is widely accepted in clinical practice. However, errors associated with the measurement are often not appreciated and these catheter-manometer systems are frequently unable to accurately reproduce applied pressures. To assess the accuracy of catheter-manometer systems used for invasive arterial blood pressure measurements, in vitro and in vivo evaluations were performed. The frequency response (described in terms of damped natural frequency and damping factor) for a variety of cannulae, pressure tubing and stopcocks (and combinations thereof) and their dependence on various parameters (catheter length, lumen diameter, fluid temperature and catheter material) were measured using an hydraulic pressure generator. The design and construction details of the pressure generator are presented. It was found that the damped natural frequency of the catheter-manometer system is directly proportional to lumen diameter of the pressure tubing/catheter. Furthermore, damping factor is inversely related to the damped natural frequency and stiffer catheter material (for identical radius ratios) results in higher damped natural frequency. Catheter length is inversely related to damped natural frequency and the resonant frequency decreases for an increase in fluid operating temperature. It was established that all catheter-manometer systems tested were under-damped (0.15 < β < 0.37) and that the damped natural frequency ranged from 10.5 Hz for 1500 mm to 27.0 Hz for pressure tubing of 300 mm in length. Furthermore, catheter-manometer systems which had pressure tubing in excess of 300 mm in length did not comply with the bandwidth requirements for accurate dynamic blood pressure measurement. For the in vivo assessment of the catheter-manometer system, the blood pressure waveform was analysed in the time and frequency domains. It was established that in 60 percent of the cases, the systolic pressure peak was higher when measured by a narrow bandwidth catheter-manometer system compared to that measured by a wide bandwidth system. Furthermore, values of dp/dt maximum were lower for wide bandwidth catheter-manometer systems than those measured by narrow bandwidth systems for heart rates above 90 beats per minute. In the frequency domain analysis, artifact was sometimes found to occur at frequencies higher than the bandwidth of the catheter-manometer system. This high frequency artifact was found to distort the blood pressure waveform and resulted in false high dp/dt and peak systolic pressures.
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Mårtensson, Sofie. "Improved Algorithm for Measurement of Blood Pressure based on a Laser Doppler Flowmetry Signal." Thesis, Linköpings universitet, Institutionen för medicinsk teknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-129192.
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People with diabetes suffer from a high risk of developing foot related diseases. It is therefore important to perform a blood pressure measurement on the toe to be able to diagnose and treat in time. Using laser Doppler flowmetry has been proven to be a useful technique for this purpose during a standard blood pressure measurement procedure using a cuff. The laser Doppler probe detects once the blood flow returns which can then be related to the pressure value. However, the algorithm currently used by the company for detection of return of blood flow is in need of improvements. This thesis aims to develop an improved algorithm, which is more robust against artifacts. Furthermore, a warning system for uncertainties in the detection will be developed and integrated with the new algorithm. To create the algorithm an investigation of the signals’ appearances was performed to obtain an understanding of what artifacts and characteristics the algorithm should be able to handle. First three different basic approaches were implemented and tested, namely model curve, threshold and pulsations. These algorithms were then combined into two different more complex algorithms. One of them consisted of the model curve and the pulsation algorithm, the second combined algorithm consisted of the threshold algorithm and the pulsation algorithm. From the result it was found that the second combined algorithm performed best. It had a high accuracy and a well-functioning warning system. However, the algorithm had problems to correctly detect the return of flow when it is characterised by a slow increase of the perfusion. The biggest contribution by this thesis is the newly developed warning system. A false detection can lead to a false diagnose to be given if the operator is not attentive. The warning system is therefore an important feature since it can prevent this from occurring.
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Mueller, Jonathon W. "The effect of differentiation technique utilized in continuous noninvasive blood pressure measurement." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1145295553.
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Manning, Lisa Suzanne. "Blood pressure variability : its definition, measurement, and prognostic significance in acute stroke." Thesis, University of Leicester, 2016. http://hdl.handle.net/2381/37832.
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Background: How best to manage elevated blood pressure (BP) in the acute stroke period remains unclear. Blood pressure variability (BPV), that is variability in BP over a period of time, may predict outcome in acute stroke, and could explain the ongoing uncertainty surrounding acute stroke BP management. Moreover, it presents a potentially modifiable therapeutic target. Evidence of the effect of BPV on outcome following stroke is scarce, and how best to measure or define BPV in acute stroke is unknown. Objectives: This thesis aimed to determine the prognostic significance of BPV in acute stroke, and to investigate how best to measure and define BPV in the immediate post-stroke period. Methods: The following studies were undertaken: a systematic review and meta‐analysis of observational studies to assess the effect of BPV on outcome in acute stroke; a feasibility study to assess the ability of a novel BP measurement device to capture very‐short‐term BPV; post‐hoc analyses of three acute stroke randomised controlled trials to assess the effect of BPV on outcome using individual patient data; a prospective observational study to measure acute stroke BPV using a variety of measurement techniques. Results: This thesis has demonstrated that greater BPV is associated with poor outcome in acute stroke. However, the presence and strength of this relationship is influenced by a number of factors including: frequency, timing, and nature of BP measurements; time from stroke onset; BPV parameters; use of thrombolytic therapy; and the timing of outcome measures. For the first time in acute stroke, the observational study describes and compares beat‐to‐beat, casual cuff, and ambulatory BP monitoring (ABPM) derived BPV, showing that it is feasible and acceptable to patients to measure BPV using casual cuff and beat‐to‐beat measurements, and reports significant associations between beat‐to‐beat and casual cuff BPV parameters and outcome.
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Chin, Kong Yien. "A new approach for non-invasive continuous arterial blood pressure measurement in human." Thesis, University of Leicester, 2011. http://hdl.handle.net/2381/10253.
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The need for continuous noninvasive arterial blood pressure (ABP) monitoring from an artery closer to the heart (i.e. the ascending aorta) has led to the research and development work presented in this thesis. Clinical applications of continuous ABP waveform include assessments of cardiac function, cerebral autoregulation, autonomic function, arterial elasticity, physiological measurements in aerospace research, and also monitoring in anaesthesia and critical care. The superficial temporal artery (STA) was chosen as the measurement site and the measurement technique was the arterial volume clamping with photoplethysmography (PPG). The optoelectronic circuitry to measure PPG is contained in a specially designed probe placed over the STA and kept in place with a lightweight aluminium head frame. The complete prototype device (STAbp) also includes original designs for the pneumatic, electronic, signal processing, control and display sub-systems. A self-calibration feature that regularly updates the PPG reference level (Setpt) was also included to ensure accurate continuous ABP recording. The performance of the STAbp was compared against the Finapres®. Five parameters were evaluated: resting ABP (agreement, signal bandwidth, frequency response and magnitude squared coherence, and assessment of drift) and ABP dynamic change during isometric handgrip exercise. The agreement of resting ABP gave bias (SD) of -23.1 (15.05), -10.8 (13.83) and -12.4 (12.93) mmHg for systolic, mean (MAP) and diastolic pressures respectively. Further investigations were carried out to understand factors that can affect the accuracy of ABP measurements, notably the sensitivity of ABP to perturbation of the Setpt. Also, differences between the external compressing pressure at the PPG peak pulsation amplitude and the MAP were found to be normally distributed with mean (SD) of -4.7 (5.63) mmHg. In conclusion, it is demonstrated that the new STAbp device has great potential as a new tool for a wide range of clinical and research applications which require continuous ABP waveforms.
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Smithers, Breana Gray. "Evaluating the Pulse Sensor as a Low-Cost and Portable Measurement of Blood Pulse Waveform." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc849682/.
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This study was aimed at determining whether the digital volume pulse waveform using the Pulse Sensor can be used to extract features related to arterial compliance. The Pulse Sensor, a low-cost photoplethysmograph, measures green light reflection in the finger and generates output, which is indicative of blood flow and can be read by the low-cost Arduino UNO™. The Pulse Sensor code was modified to increase the sampling frequency and to capture the data in a file, which is subsequently used for waveform analysis using programs written in the R system. Waveforms were obtained using the Pulse Sensor during two 30-s periods of seated rest, in each of 44 participants, who were between the ages of 20 and 80 years. For each cardiac cycle, the first four derivatives of the waveform were calculated and low-pass filtered by convolution before every differentiation step. The program was written to extract 19 features from the pulse waveform and its derivatives. These features were selected from those that have been reported to relate to the physiopathology of hemodynamics. Results indicate that subtle features of the pulse waveform can be calculated from the fourth derivative. Feature misidentification occurred in cases of saturation or low voltage and resulted in outliers; therefore, trimmed means of the features were calculated by automatically discarding the outliers. There was a high efficiency of extraction for most features. Significant relationships were found between several of the features and age, and systolic, diastolic, and mean arterial blood pressure, suggesting that these features might be employed to predict arterial compliance. Further improvements in experimental design could lead to a more detailed evaluation of the Pulse Sensor with respect to its capability to predict factors related to arterial compliance.
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Bodey, Angela Rosamund. "A clinical and comparative study of canine hypertension." Thesis, Royal Veterinary College (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244138.
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Karachaliou, Fotini-Heleni. "The Avon Childhood Diabetes Project : evolution of microvascular disease and autonomic neuropathy." Thesis, University of Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389377.
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Stevens, Sarah Louise. "Improving cardiovascular risk prediction through more accurate and alternative methods of blood pressure measurement." Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:1da71d0e-5bb3-43c4-b442-194bb251359e.
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Background Cardiovascular risk scores are used to estimate absolute risk of disease and identify patients who will benefit most from treatments to lower risk. As a key risk factor for cardiovascular disease, blood pressure is accounted for in many risk scores, but is inherently variable and may be influenced by both biological and measurement factors. This thesis aims to determine how routinely collected blood pressure measurements should best be used for accurate estimation of cardiovascular risk. Methods This thesis describes four main studies. A patient survey and prospective study establish the current practice of blood pressure measurement. Secondary analyses of data from blood pressure monitoring trials determine how risk estimates may be affected by the use of different summary measures of blood pressure. A systematic review evaluates the evidence of an association between blood pressure variability and cardiovascular risk. Finally, a cohort study in the Clinical Practice Research Datalink determines if inclusion of blood pressure variability in cardiovascular risk scores may improve risk estimation. Results Current practice of blood pressure measurement may differ from that in risk score derivation studies. However, these differences have limited effects on cardiovascular risk estimates with few patients reclassified across risk thresholds. Increased long-term variability in blood pressure is in itself a risk factor for cardiovascular disease over and above mean blood pressure but its inclusion in a cardiovascular risk score does not materially improve the accuracy of risk estimates. Conclusions Healthcare professionals should continue to estimate risk for primary prevention of cardiovascular disease using the blood pressure measurements available to them, whether measured at home or in the clinic. There is also no additional benefit of considering measures of long-term blood pressure variability in risk estimation.
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Cloutier, Lyne. "L'évaluation des connaissances théoriques et pratiques des infirmières à l'égard de la mesure de la pression artérielle." Thèse, Université de Sherbrooke, 2007. http://savoirs.usherbrooke.ca/handle/11143/4248.
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L'hypertension artérielle (HTA) est un problème de santé sérieux qui affecte 22% des canadiens et dont les complications sont nombreuses. Ces complications peuvent être diminuées par un diagnostic précoce et un traitement efficace et plusieurs auteurs affirment que l'exactitude de la mesure de la pression artérielle (PA) est la pierre angulaire pour établir le diagnostic et assurer un suivi adéquat. Quoique cette mesure soit réalisée très fréquemment, des études réalisées ailleurs qu'au Québec indiquent que les connaissances des infirmières à l'égard de la mesure de la PA sont insuffisantes pour des éléments reconnus comme ayant une influence significative sur les résultats de la mesure de la PA. À notre connaissance, aucune étude concernant les connaissances des infirmières n'a été publiée au Canada. Cette étude a donc pour but de décrire les connaissances théoriques et pratiques des infirmières pour la mesure de la PA en regard des recommandations du Programme éducatif canadien pour le contrôle de l'hypertension artérielle (2004) et comparer les relations entre ces variables. Une enquête par questionnaire auto administré pour décrire les connaissances théoriques ainsi qu'une observation directe par échantillonnage exhaustif pour décrire les connaissances pratiques ont été utilisées pour un premier échantillon de 50 infirmières. Une enquête postale transversale par échantillonnage aléatoire a été utilisée pour décrire les connaissances théoriques auprès d'un deuxième échantillon de 307 infirmières. Les outils ont été testés pour leur validité et leur fidélité dans le cadre de cette étude. L'étude a été approuvée par le comité d'éthique du centre de recherche clinique du CHUS. Les résultats quant aux données sociodémographiques démontrent que les infirmières ayant participé à l'une ou l'autre partie de l'étude sont semblables aux autres infirmières du Québec à l'égard du genre, de l'âge, du type d'emploi et de l'expérience. Elles sont toutefois statistiquement différentes pour le niveau de formation. Le score obtenu par les infirmières des deux échantillons pour le questionnaire sur les connaissances théoriques est de moins de 60%. On peut donc conclure qu'il existe des lacunes importantes en regard des connaissances théoriques acquises. Par ailleurs, ces infirmières croient dans de très fortes proportions posséder les connaissances théoriques et pratiques nécessaires à une mesure exacte de la PA. Pour les connaissances pratiques, le score global des infirmières est de 38%. Force est de croire que malgré le processus de mise à jour annuel et d'implantation des recommandations canadiennes, les connaissances pratiques des infirmières ne sont pas équivalentes au contenu de ces recommandations. Les infirmières qui détiennent un niveau de formation supérieur, celles qui ont lu les recommandations et celles qui ont suivi une formation continue sur la mesure de la PA obtiennent de résultats légèrement supérieurs aux autres infirmières. Considérant la fréquence avec laquelle les infirmières mesurent la PA et l'impact que peut avoir une mesure inexacte, il est important d'entreprendre dès maintenant des actions concrètes pour améliorer cette situation en mettant en place des formations continues régulières sur le sujet et en s'assurant que les programmes de formation initiale incluent une formation théorique et pratique fondée sur les recommandations en vigueur. Il semble également crucial de stimuler l'implantation des recommandations du PECH auprès des infirmières et d'évaluer l'impact de ces mesures par la suite.
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Wåhlin, Anders. "Cerebral blood flow and intracranial pulsatility studied with MRI : measurement, physiological and pathophysiological aspects." Doctoral thesis, Umeå universitet, Radiofysik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-55424.
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During each cardiac cycle pulsatile arterial blood inflates the vascular bed of the brain, forcing cerebrospinal fluid (CSF) and venous blood out of the cranium. Excessive arterial pulsatility may be part of a harmful mechanism causing cognitive decline among elderly. Additionally, restricted venous flow from the brain is suggested as the cause of multiple sclerosis. Addressing hypotheses derived from these observations requires accurate and reliable investigational methods. This work focused on assessing the pulsatile waveform of cerebral arterial, venous and CSF flows. The overall aim of this dissertation was to explore cerebral blood flow and intracranial pulsatility using MRI, with respect to measurement, physiological and pathophysiological aspects. Two-dimensional phase contrast magnetic resonance imaging (2D PCMRI) was used to assess the pulsatile waveforms of cerebral arterial, venous and CSF flow. The repeatability was assessed in healthy young subjects. The 2D PCMRI measurements of cerebral arterial, venous and CSF pulsatility were generally repeatable but the pulsatility decreased systematically during the investigation. A method combining 2D PCMRI measurements with invasive CSF infusion tests to determine the magnitude and distribution of compliance within the craniospinal system was developed and applied in a group of healthy elderly. The intracranial space contained approximately two thirds of the total craniospinal compliance. The magnitude of craniospinal compliance was less than suggested in previous studies. The vascular hypothesis for multiple sclerosis was tested. Venous drainage in the internal jugular veins was compared between healthy controls and multiple sclerosis patients using 2D PCMRI. For both groups, a great variability in the internal jugular flow was observed but no pattern specific to multiple sclerosis could be found. Relationships between regional brain volumes and potential biomarkers of intracranial cardiac-related pulsatile stress were assessed in healthy elderly. The biomarkers were extracted from invasive CSF pressure measurements as well as 2D PCMRI acquisitions. The volumes of temporal cortex, frontal cortex and hippocampus were negatively related to the magnitude of cardiac-related intracranial pulsatility. Finally, a potentially improved workflow to assess the volume of arterial pulsatility using time resolved, four-dimensional phase contrast MRI measurements (4D PCMRI) was evaluated. The measurements showed good agreement with 2D PCMRI acquisitions. In conclusion, this work showed that 2D PCMRI is a feasible tool to study the pulsatile waveforms of cerebral blood and CSF flow. Conventional views regarding the magnitude and distribution of craniospinal compliance was challenged, with important implications regarding the understanding of how intracranial vascular pulsatility is absorbed. A first counterpoint to previous near-uniform observations of obstructions in the internal jugular veins in multiple sclerosis was provided. It was demonstrated that large cardiac- related intracranial pulsatility were related to smaller volumes of brain regions that are important in neurodegenerative diseases among elderly. This represents a strong rationale to further investigate the role of excessive intracranial pulsatility in cognitive impairment and dementia. For that work, 4D PCMRI will facilitate an effective analysis of cerebral blood flow and pulsatility.
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Vonesh, Michael John 1964. "A non-invasive method of estimating pulmonary artery pressure in the total artificial heart." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276785.
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A non-invasive, in vitro method of estimating mean pulmonary artery pressure (PAP) was developed. This information was obtained by establishing a relationship between the pneumatic right drive pressure (RDP) and PAP waveforms. The RDP-PAP relationship was formalized into a series of multiple-linear regression equations for TAH cardiac cycles of known fill volume (FV). Correlation of computed estimates of PAP to actual measurements showed that these equations were greater than 92% accurate within 1.84 mmHg. In addition, while the RDP-PAP relationships were wholly dependent on FV, it was shown that they are independent of the manner in which FV was obtained. This method proved useful over the clinical operating range of the pneumatic heart driver, as well as over the normal physiological range of PAP in the human. Effectiveness of this method in vivo needs to be demonstrated.
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Dalla, Sangita. "The accuracy of non-invasive blood pressure monitoring when compared to intra-arterial blood pressure monitoring in patients with severe pre-eclampsia during an acute hypertensive crisis." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5325.
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Thesis (MMed (Obstetrics and Gynaecology))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: OBJECTIVE: The aim of this study was to compare the accuracy of non-invasive blood pressure measurements, using automated and manual devices, against invasive intra-arterial blood pressure measurements in patients with pre-eclampsia, during a hypertensive blood pressure peak. STUDY DESIGN: In this prospective study, women admitted to the Obstetrics Critical Care Unit, with confirmed pre-eclampsia and acute severe hypertension, who had an intra-arterial line in situ, were asked to participate. During an intra-arterial blood pressure peak, both an automated oscillometric and a blinded manual aneroid sphygmomanometric blood pressure was recorded. These two methods of blood pressure measurements were compared to intra-arterial blood pressure measurements. The accuracy of a mean arterial pressure (MAP) ≥ 125mmHg in detecting a systolic blood pressure (SBP) ≥ 160mmHg, using all three methods, was also determined. RESULTS: There was poor correlation between intra-arterial SBP and automated and manual SBP (r = 0.34, p < 0.01; r = 0.41, p < 0.01 respectively). The mean differences between automated and manual SBP compared to the intra-arterial SBP was 24 ± 17mmHg (p < 0.01) and 20 ± 15 mmHg (p < 0.01) respectively. There was better correlation between intra-arterial diastolic blood pressure (DBP) and automated and manual DBP (r = 0.61, p < 0.01; r = 0.59, p < 0.01 respectively). The mean differences of the automated and manual DBP was not statistically significant when compared to the intra-arterial DBP. There was poor correlation between the intra-arterial MAP and the automated MAP (r = 0.44, p < 0.01) and good correlation with the manual MAP (r = 0.56, p < 0.01). The mean differences of the automated and manual MAP were statistically significant (5 ± 13mmHg, p < 0.01; 8 ± 11mmHg, p < 0.01 respectively). The sensitivity of automated and manual methods in detecting a SBP ≥ 160mmHg was 23.4% and 37.5% respectively. A MAP ≥ 125mmHg in detecting a SBP ≥ 160mmHg, when using intra-arterial, automated and manual methods of blood pressure measurements showed low sensitivity (35.9%, 21.9% and 17.2% respectively). CONCLUSION: This study demonstrated that both the automated and manual methods of blood pressure measurements were not an accurate measure of the true systolic intra-arterial blood pressure, when managing pre-eclamptic patients with acute severe hypertension. In such situations, intra-arterial blood pressure monitoring should be used when possible. When this is not possible, manual aneroid sphygmomanometry is recommended. Underestimating blood pressure, particularly SBP, may lead to severe maternal morbidity and mortality.
AFRIKAANSE OPSOMMING: DOELWIT: Die doel van hierdie studie is om die akuraatheid van nie invasiewe bloeddruk metings, wanneer geneem met outomatiese en manuele aparate, te vergelyk met intra-arteriele bloed druk metings in pasiente met pre-eklampsie, gedurende ‘n hipertensiewe bloeddruk piek. STUDIE ONTWERP: In hierdie prospektiewe beskrywende dwarssnit studie, was pasiente wat toegelaat was tot die Obstetriese Kritieke Sorg Eenheid met pre-eklampsie, akute erge hipertensie en ‘n intra-arteriele lyn in situ gevra om deel te neem. Gedurende ‘n intra-arteriele erge hipertensiewe piek is beide die outomatiese ossilometriese en die geblinde aneroide sfigmometer lesing neergeskryf. Hierdie twee metodes van non invasiewe bloed druk lesings is vergelyk met intra-arteriele bloed druk lesings. Die akuraatheid van ‘n gemiddelde arteriele bloeddruk ≥ 125mmHg om ‘n sistoliese bloeddruk ≥ 160mmHg op te tel met gebruik van al die drie metodes is ook uitgewerk. RESULTATE: Daar was swak korrelasie tussen intra-arteriele sistoliese bloed druk (SBD) metings en outomatiese en manuele SBD (r = 0.34, p < 0.01; r = 0.41, p < 0.01 onderskeidelik). Die gemiddelde verskille tussen outomatiese en manuele SBD wanneer vergelyk met intra-arteriele SBD was 24 ± 17mmHg (p < 0.01) en 20 ± 15 mmHg (p < 0.01) onderskeidelik. Beter korrelasie was gevind tussen intra-arteriele diastoliese bloed druk (DBD) en outomatiese en manuele DBD (r = 0.61, p < 0.01; r = 0.59, p < 0.01 onderskeidelik). Die gemiddelde verskille tussen outomatiese en manuele DBD wanneer dit vergelyk was met intra-arteriele DBD was nie statisties betekenisvol nie. Daar was swak korrelasie tussen intra arteriele gemiddelde arteriele bloeddruk en outomatiese gemiddelde arteriele bloeddruk (r = 0.44, p < 0.01) en beter korrelasie met manuele gemiddelde arteriele bloeddruk (r = 0.56, p < 0.01). Die gemiddelde verskille van outomatiese en manuele gemiddelde arteriele bloeddruk was betekenisvol (5 ± 13mmHg, p < 0.01; 8 ± 11mmHg, p < 0.01 onderskeidelik). Die sensitiwiteit van outomatiese en manuele metodes om ‘n intra-arteriele SBD ≥ 160mmHg op te tel was 23.4% en 37.5% onderskeidelik. Die vermoë van ‘n gemiddelde arteriele bloeddruk ≥ 125mmHg om ‘n SBD ≥ 160mmHg op te tel, gemeet deur intra-arterieel, outomatiese en manuele metodes het lae sensitiwiteit getoon (35.9%, 21.9% en 17.2% onderskeidelik). GEVOLGTREKKING: Hierdie studie het gedemonstreer dat outomatiese en manuele metodes van bloeddruk meting nie akurate metodes is om ware intra-arteriele sistoliese bloeddruk te meet in pasiente met erge pre-eklampsie tydens ‘n erge hipertensiewe episode nie. In hierdie omstandighede moet intra-arteriele bloeddruk gemeet word indien beskikbaar. Indien dit nie beskikbaar is nie moet die manuele aneroiede sfigmomanometer gebruik word. Onderskatting van bloeddruk, veral sistoliese bloeddruk, kan lei tot erge moederlike morbiditeit en mortaliteit.
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Talts, Jaak. "Continuous non-invasive blood pressure measurement: comparative and methodological studies of the differential servo-oscillometric method /." Online version, 2004. http://dspace.utlib.ee/dspace/bitstream/10062/932/5/Talts.pdf.
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BOEGEHOLD, MATTHEW ALAN. "THE ROLE OF OXYGEN IN ESCAPE OF SKELETAL MUSCLE ARTERIOLES FROM SYMPATHETIC NERVE STIMULATION (MICROCIRCULATION, BLOOD FLOW)." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/183816.
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In these experiments, we tested the hypothesis that sympathetic escape in skeletal muscle is mediated through a fall in parenchymal cell oxygen levels following blood flow reduction. This hypothesis predicts that if the fall in parenchymal cell PO₂ during stimulation can be minimized, escape should be reduced. To test this prediction, we studied the behavior of superficial arterioles of the cat sartorius muscle during 3 minutes of sympathetic nerve stimulation. The muscle was covered with silicone oil equilibrated with 0%, 5% and 10% oxygen. During stimulation under 0% oxygen, 90% of visible arterioles showed a significant secondary relaxation (escape). The relaxation averaged 55% of the initial constriction. Under 5% oxygen, resting arteriolar diameter was reduced by an average of 12% and escape was significantly reduced throughout the arteriolar network. Under 10% ambient oxygen, there was an additional 5% reduction in resting diameter and a further reduction of escape. Escape was not attenuated when control diameter was reduced to the same degree with arginine vasopressin, suggesting that the effect of oxygen was specific rather than secondary to an increase in vascular tone. The above observations are also consistent with the hypothesis that escape is mediated through a fall in vascular wall PO₂. To evaluate this possibility, periarteriolar and parenchymal tissue PO₂ were measured with oxygen microelectrodes during sympathetic stimulation under 0% and 10% oxygen suffusion of the muscle. In the proximal arterioles, the periarteriolar PO₂ during control and during stimulation was identical under 0% and 10% oxygen yet escape was reduced by 75% under 10% oxygen. Similarly, escape was reduced 90% in the distal arterioles under 10% oxygen but periarteriolar PO₂ was very nearly the same as that measured under 0% oxygen. In contrast, mean parenchymal tissue PO₂ fell to low levels during stimulation under 0% oxygen but did not fall below normal levels during stimulation under 10% oxygen. These findings argue against the hypothesis that a fall in vascular wall PO₂ is responsible for escape. The findings are consistent with the hypothesis that sympathetic escape in skeletal muscle is mediated through a fall in parenchymal cell PO₂. (Abstract shortened with permission of author.)
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Fang, Wei Xuan. "An exploration on real-time cuffless blood pressure estimation for e-home healthcare." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2550475.
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Abolarin, David. "Non-invasive Estimation of Blood Pressure using Harmonic Components of Oscillometric Pulses." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34114.
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This research presents a pulse-by-pulse analysis of Oscillometric blood pressure waveform at systolic, diastolic and mean arterial pressure points.
Using a mathematical optimization technique, pulses are characterized into component harmonic by minimizing the least square error. The results at the important pressure points are analyzed and compared for different subject using different waveform extraction techniques.
Blood pressure is estimated using the harmonic parameters. The approach studies changes in the parameters as oscillometric blood pressure recording is done. 8 harmonic parameters are obtained from the pulse characterization and are used to estimate Systolic arterial Blood Pressure, Mean arterial Blood Pressure, and Diastolic arterial Blood Pressure. The estimates are compared with our reference value to determine which has the best agreement. The proposed method is further compared with Maximum Amplitude Algorithm and Pulse Morphology Algorithm.
The effect of oscillometric waveform extraction methods on the proposed method is observed. The experiment established the fact that the extraction technique can alter the shape of oscillometric pulses. The methods were compared and it was observed that the used extraction methods did not make any significant difference on the accuracy, using this technique.
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Cole, Sarajane. "The effects of supervisor intervention on hypertensive employees' blood pressure in an industrial hypertension program." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43391.
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Williams, Angela B. "Incidence and implications of atypical exercise blood pressure responses in adults without diagnosed coronary heart disease." Thesis, Virginia Tech, 1985. http://hdl.handle.net/10919/45657.
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Data were collected from the initial symptomâ limited
maximal exercise tests of 161 patients without. diagnosed
coronary heart disease (CHD). Subjects were grouped
according to their systolic (SBP) and diastolic (DBP) blood
pressure changes between the final two stages of exercise.Master of Science
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Campbell, Diane L. "The influence of aerobic exercise on double product break point in low to moderate risk adults." Muncie, Ind. : Ball State University, 2009. http://cardinalscholar.bsu.edu/641.
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Al-Kadi, Hanan. "A study of blood pressure throughout normal primigravid pregnancy in a Saudi population with some physiological studies in early pregnancy." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367113.
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Antunes, Raquel Coelho Loyo Pequito. "Comparison of invasive and non-invasive blood pressure measurements in anaesthetised adult horses using an automated monitor." Master's thesis, Universidade de Lisboa, Faculdade de Medicina Veterinária, 2020. http://hdl.handle.net/10400.5/20192.
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Dissertação de Mestrado Integrado em Medicina VeterináriaBlood pressure is defined as the product of cardiac output (CO) and peripheral vascular resistance (PVR) and is an extremely useful haemodynamic parameter that allows an indirect way of assessing the cardiovascular performance which reflects the organ perfusion. Clinically, arterial blood pressure measurement can be useful for diagnosis, therapeutic monitoring and prognosis of different diseases. It can be obtained either invasively or non-invasively, with pro and cons for each of these. Nowadays, the invasive blood pressure measurement is considered to be the gold-standard in horses undergoing general anaesthesia providing its continuous monitoring. However, to extend its usefulness as a clinical parameter, a trustworthy non-invasive technique which is practical and easily applied to conscious and anaesthetized horses is required. This study aimed at determining the accuracy and precision of a non-invasive blood pressure measurement method when compared to the gold-standard method (invasive blood pressure). To do so, invasive and non-invasive blood pressure measurements were collected simultaneously using the EDAN iM8 VET multiparameter monitor, in eleven horses presented for elective surgical procedures at an equine referral hospital, between September of 2019 and April of 2020. We started by investigating the correlation between simultaneous invasive and non-invasive methods of blood pressure measurement. Furthermore, we intended to identify whether this correlation differed when conditions like the horse’s recumbency and blood pressure range (hypo-, normo-, and hypertension) varied. We showed that, despite being less accurate than the invasive (gold-standard) method, the non-invasive blood pressure measurement method, using the EDAN iM8 VET multiparameter monitor, is reliable for the use in healthy anaesthetized horses. Moreover, we showed that for the horses in left lateral recumbency a stronger correlation between methods was seen.
RESUMO - COMPARAÇÃO DA MEDIÇÃO DA PRESSÃO ARTERIAL INVASIVA E NÃO INVASIVA EM CAVALOS ADULTOS ANESTESIADOS USANDO UM MONITOR AUTOMÁTICO - A pressão arterial é definida como o produto do débito cardíaco (DC) pela resistência vascular periférica (RVP) e é um parâmetro hemodinâmico extremamente útil, que permite avaliar, indiretamente, o desempenho cardiovascular, refletindo a perfusão dos órgãos. Clinicamente, a medição da pressão arterial pode ser útil para diagnóstico, monitorização terapêutica e prognóstico de diferentes doenças, e pode ser obtida de forma invasiva ou não invasiva, com vantagens e desvantagens para cada um. Atualmente, a medição da pressão arterial invasiva é considerada a técnica padrão em cavalos submetidos a anestesia geral, proporcionando uma monitorização contínua da pressão arterial. No entanto, para alargar a utilidade deste parâmetro hemodinâmico, é necessário ter uma técnica não invasiva confiável, prática e de fácil aplicação, tanto em cavalos conscientes como em anestesiados. Este estudo teve como objetivo determinar a precisão do método não invasivo de medição da pressão arterial, quando comparado ao método padrão (medição invasiva da pressão arterial). Para tal, as medições da pressão arterial, tanto invasivas como não invasivas, foram recolhidas simultaneamente, usando o monitor multiparamétrico EDAN iM8 VET, em onze cavalos sujeitos a procedimentos cirúrgicos eletivos num hospital de referência, entre setembro de 2019 e abril de 2020. Começamos por investigar a correlação entre medições da pressão arterial efectuadas simultaneamente com os métodos invasivo e não invasivo. Além disso, pretendemos identificar se a correlação diferia quando condições como o decúbito do cavalo durante o procedimento cirúrgico e o intervalo de pressão arterial (hipo, normo e hipertensão) variavam. Os resultados obtidos sugerem que, apesar de ser menos preciso do que o método invasivo (padrão), o método não invasivo de medição da pressão arterial, usando o monitor multiparamétrico EDAN iM8 VET, é confiável para o uso em cavalos saudáveis anestesiados. Além disso, mostramos que para os cavalos em decúbito lateral esquerdo há uma correlação mais forte entre os métodos estudados.
N/A
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Hope, Sarah A. "Arterial pressure waves : waveform characteristics, their associations and factors influencing their propagation." Monash University, Faculty of Medicine, Nursing and Health Sciences, 2003. http://arrow.monash.edu.au/hdl/1959.1/5566.
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Huang, Yen-Ming, and 黃彥銘. "Signal Processing for Blood Pressure Measurement." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/39782989563216291606.
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碩士國立臺灣大學
電子工程學研究所
103
Blood pressure (BP) is one of the most important signs of human cardiovascular health. The precision measurement of the blood pressure is necessary in diagnosis and treatment of hypertension and the risks related blood pressure. While the traditional auscultatory method using mercury sphygmomanometer is still viewed as the most accurate non-invasive blood pressure measurement method, it is complicated and only suitable for medical personnel. Currently, self-blood pressure monitoring devices are popular in the market and widely used in homecare. Most of those devices are based on the oscillometric method, as it requires less professional training and is less sensitive to external noise. However, most of these work well on young healthy subjects, but show less precision in some cases such as older people. Most of the devices in the market can only provide single time BP value, it’s unable to see the continuous change in BP. However, by continuous way, we can get more physiological information than traditional non-continuous measurement. As a result, a novel blood pressure sensor and signal processing algorithm for removing noise have been developed in this study. It can accurately determine blood pressure non-invasively for all age group. The effective signal processing is based on Ensemble Empirical Mode Decomposition (EEMD) method to remove the noise from the sensor. Due to the non-stationary characteristics of BP, EEMD is practical to achieve accurate decomposition. The signal can be decomposed into several Intrinsic Mode Functions (IMFs) by EEMD. The results suggest that that the proposed EEMD can indeed effective separate the pure BP from the sensor output.
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Chien, Bo-Ru, and 簡伯儒. "Blood Pressure Measurement Based On Piezoelectric Sensor." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/8264w6.
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"Cuffless blood pressure measurement with temperature compensation." 2004. http://library.cuhk.edu.hk/record=b5891968.
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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
41
Hsiang, Tsau-Yuan, and 向才園. "Comparison the Methods of Blood Pressure Measurement and the Relationship between Blood Pressure and Microalbuminuria." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/81894949549093112486.
Full textAbstract:
碩士臺灣大學
獸醫學研究所
96
Systemic blood pressure (SBP) level is a reference for diagnosis, treatment and clinical research in veterinary medicine and is used extensively in veterinary patients as a part of clinical assessment. Microalbuminuria is associated with increased risk of deterioration of hypertension. The aim of first part of the study was to evaluate the precision and efficiency of 2 indirect methods of systemic blood pressure measurement in conscious dogs in a clinical setting. Secondly, to evaluate use of semiquantitative test strips that was designed for human urine albumin in detection of canine microalbuminuria, and to evaluate association between microalbuminuria and systemic blood pressure (SBP) in dogs. The mean SBP values, measured by Doppler sphygmomanometry on 2 separate occasions, were 156 38.2 mmHg and 150 34.1 mmHg, respectively. Using oscillometry, the mean SBP values were 138 36.9 mm Hg and 133 33.5 mm Hg on 2 separate occasions. There were significant differences between the SBP readings for both methods on the same occasion (P<0.001). The coefficients of variance from 5 consecutive measurements in the same dog obtained by Doppler sphygmomanometry on the 2 separate occasions were 4.1 3.2% and 3.1 1.7%; that of the oscillometric method on the 2 separate occasions were 18.7 ± 11.3% and 17.2 ± 12.5%. The coefficients of variance of these 2 methods were statistically different on each occasion (P<0.001). Five consecutive SBP readings were obtained for each dog within 6 minutes on both occasions using Doppler sphygmomanometry. More than 15 minutes was required to complete 5 consecutive SBP readings by oscillometric sphygmomanometry for all dogs on each occasion. The results of this part of the study indicate that Doppler sphygmomanometry provides more efficient and precise measurements of the SBP level than oscillometric testing in conscious dogs in a clinical setting. The albumin-binding dye dipsticks for detecting canine albumin controls at the concentrations within assigned ranges (10 to 150 mg/L) were 100% concordance. However, canine globulin concentrations over 80 mg/L were detected false positively as presence of albumin. Off 100 clinically healthy dogs, 61 had negative result of microalbuminuria test, 39 were positive. Microalbuminuria was not associated with the blood pressure status (P = 0.71). Whereas microalbuminuria presented using urine albumin: creatinine ratio (UACR), 53 of 100 dogs did not have microalbuminuria, 45 were albuminuric, and 2 had proteinuria. The UACR was not associated with the blood pressure status (P = 0.65).
42
Hsiang, Tsau-Yuan. "Comparison the Methods of Blood Pressure Measurement and the Relationship between Blood Pressure and Microalbuminuria." 2008. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2101200816104900.
Full text
43
Ding, Cang-Yi, and 丁蒼毅. "Continuous Blood Pressure Measurement System Based on Low Cuff Pressure Approach." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/60252329703720630525.
Full textAbstract:
碩士國立中央大學
電機工程研究所
95
The main propose of the thesis is to acquire the continuous pulse vibration at the patient’s radial artery based on low cuff pressure approach. By introducing the pulse vibration to the low pressure translating formula of dynamic blood pressure tracking capability, continuous blood pressure measurement system based on low cuff pressure approach is achieved. The interface of the system is completed by LabVIEW 7.0. The digital output and the analog input signals are operated by utilizing National Instruments Data Acquisition (USB-6009) Multifunction I/O Card. There are two kinds of signals at the output of the pressure sensor. They are the signal of cuff pressure and the signal of pulse vibration. A filtering and amplifying circuit is introduced to separate the two signals into two analog input channels of USB-6009. Hence, blood pressure can be calculated after acquiring the data. According to the experimental results, it proves the feasibility of measuring continuous blood pressure by low pressure approach. Moreover, a continuous blood pressure measurement system based on low cuff pressure approach of dynamic blood pressure tacking capability is achieved. 24-hours portable continuous blood pressure measurement instrument could be developed to provide more information for research and medical uses in the future.
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Su, Wan-Leng, and 蘇琬稜. "Realization of a portable low-pressure continuous blood pressure measurement device." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/33114225955962454465.
Full textAbstract:
碩士中原大學
生物醫學工程研究所
97
In clinical application, invasive blood measurement can provide accurate blood pressure signal. However, it is not safe. And it is not suitable for routine inspection. Therefore, many non-invasive blood pressure measurement devices in the market provide users with simple method for home care. But, most of them can only provide diastolic, systolic and mean blood pressure reading, without other detail blood pressure information. For this reason, in this study, improvements were made on the existing continuous blood pressure measurement system to make it smaller and portable. The system hardware includes blood pressure calibration, constant pressure control, and peripheral display devices. The proposed system uses micro-controller, C8051F320, to process signal and to calculate parameters in real time. It controls pump voltage in order to maintain the cuff pressure around 39 to 41 mmHg. Thus, it is possible to record continuous blood pressure signals in a long-term situation. In this study, six normal, healthy volunteers who have no heart diseases were recruited to perform Valsalva maneuver in order to change their blood pressure. At the same time, the continuous blood pressure signal were recorded from the left hand while the conventional blood pressure reading were obtained from subjects’ right hand using a bedside monitor (model 9036, Spacelab, USA). In the result analysis, comparisons were made between the real-time results from the proposed system and results computed by Matlab at three time periods including: before, during and after breath holding. Four control measurements were obtained from volunteers’ right hand using the Spacelab monitor. The results demonstrate that the real-time variation of the continuous blood pressure waveform obtained using the proposed system match the same physiology phenomena that PP decrease after breath holding. However, when compared with control blood pressure, there is no significant decrease in PP value. This may due to the fact that the time of measurement is after the end of breath holding. Comparing the tau values between the proposed system and Matlab, there is significant different (P<0.05). The reason of this different may be caused by the fact that the Matlab program uses floating point computation. The outcome proves that the device can trace the dynamic changes of user’s blood pressure. The device will achieve the expected purpose in a environment that requires real-time information of blood pressure.
45
Wu, Shang-Min, and 吳尚旻. "Cellular/Iridium Mobile Telemedicine Blood Pressure Measurement Scheme." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/07752909341969945267.
Full textAbstract:
碩士國立臺灣海洋大學
電機工程學系
101
This thesis developed a cellular/iridium blood pressure and body temperature remote measurement platform. The advantages of adopting a cellular digital data system include rapid wireless transmission speeds and reduced costs. Employing an iridium digital data system eliminates the environmental limitations of the cellular base station signal. For example, the iridium digital data system can be used at sea or in marine environments. However, the transmission rate of the iridium digital data system is 1 kbps, substantially less than that of the cellular digital data system. Therefore, this study developed a cellular and an iridium blood pressure and body temperature remote measurement system. The cellular measurement system comprised the following three function modules: 1) blood pressure and body temperature measurement, 2) webpage upload and download, and 3) webpage comment and communication. The iridium measurement system contained the following three function modules: 1) blood pressure and body temperature measurement, 2) file transfer protocol upload and download, and 3) message comment and communication. Field tests were conducted on National Highway No. 1, between Keelung City and Taipei, and at Taipei Train Station, the Port of Keelung, and between the Port of Keelung and Keelung Islet. The results indicated that the cellular/iridium blood pressure and body temperature remote measurement system developed in this study exhibited excellent performance regarding remote measurements.
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Lin, Chun-yu, and 林俊佑. "A Novel Cuffless Technique for Blood Pressure Measurement." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/84myca.
Full textAbstract:
碩士國立中央大學
電機工程學系
103
Hypertension was usually among the leading causes of death in Taiwan. Its complication combines with stroke, myocardial infarction, hypertension with hypertensive nephropathy, cardiovascular disease, etc. Everyone becomes High-risk groups. Blood pressure is not just a physiological parameters. It is an issue that we need to concern. This study measures Electrocardiograph R wave and Photoplethysmogram characteristic points in fingertip to obtain pulse transit time. The distance between jugular notch and fingertip is divided by pulse transit time to obtain pulse wave velocity. In order to build a continuous noninvasively estimation systolic blood pressure method. Six subjects(23.5±1.76 age) go jogging to induce pulse wave velocity change and do linear regression on systolic blood pressure measured by HEM-7320.The error is 4.29±5.26mmHg. And sixteen hypertension patient (60.93±12.06 age)have the error 39.88±23.62mmHg. Study results that we can exactly assess systolic blood pressure in normal subjects. The error range compared with electric sphygmomanometer can be accept. But we underestimate systolic blood pressure in hypertension subjects. It may be affected by arterial occlusion. In the future, we will focus on cardiovascular disease patient. And we expect this method can be applied in different groups.
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"Evaluation of the wearable blood pressure measurement devices." 2006. http://library.cuhk.edu.hk/record=b5896536.
Full textAbstract:
Xiang Xiaoyan.Thesis (M.Phil.)--Chinese University of Hong Kong, 2006.
Includes bibliographical references.
Abstracts in English and Chinese.
Chapter Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Background of Hypertension --- p.1
Chapter 1.1.1 --- Definition of Blood Pressure --- p.1
Chapter 1.1.2 --- Hypertension and Its Prevalence --- p.2
Chapter 1.2 --- Blood Pressure Measurement Techniques --- p.5
Chapter 1.2.1 --- Invasive Blood Pressure Measurement Techniques --- p.5
Chapter 1.2.2 --- Non-invasive Blood Pressure Measurement Techniques --- p.6
Chapter 1.3 --- Accurate BP Measurements --- p.12
Chapter 1.3.1 --- Error Source for BP Measurement by Conventional Techniques --- p.12
Chapter 1.3.2 --- Accurate BP Measurement --- p.13
Chapter 1.4 --- Objectives of the Thesis --- p.15
Chapter 1.5 --- Organization of the Thesis --- p.16
References --- p.17
Chapter Chapter 2 --- Current Standards for the Conventional Blood Pressure Measurement Devices --- p.20
Chapter 2.1 --- Introduction --- p.20
Chapter 2.2 --- Current Standards for the Cuff-based BP Measurement Devices --- p.21
Chapter 2.2.1 --- AAMI Standard --- p.21
Chapter 2.2.2 --- BHS Protocol --- p.22
Chapter 2.2.3 --- Other Protocols --- p.23
Chapter 2.3 --- Comparison of the 2002 AAMI and 1993 BHS Protocols - Protocol Setup --- p.25
Chapter 2.4 --- Comparison of the 2002 AAMI and 1993 BHS Protocols 一 Accuracy Criteria --- p.29
Chapter 2.5 --- Relationship between the AAMI Accuracy Criteria and the BHS Grading System --- p.31
Chapter 2.5.1 --- Theoretical Mapping Relationship --- p.31
Chapter 2.5.2 --- Application of the Mapping Model: Estimate the BHS Grades from the Reported Sample ME and SD --- p.34
Chapter 2.5.3 --- Application of the Mapping Model: Explain the Evaluation of the Results from the Clinical Survey by the ESH --- p.36
Chapter 2.6 --- Discussion --- p.36
References --- p.40
Chapter Chapter 3 --- Distribution Analysis of the Blood Pressure Measurement Errors --- p.42
Chapter 3.1 --- Introduction --- p.42
Chapter 3.2 --- Error Distribution Estimated from the Published Data --- p.43
Chapter 3.2.1 --- Methodology --- p.43
Chapter 3.2.2 --- Data Analysis --- p.44
Chapter 3.2.3 --- Session Summary --- p.46
Chapter 3.3 --- Error Distribution Estimated from the Experimental Data --- p.46
Chapter 3.3.1 --- BP Measurement Error Obtained from Automatic BP Meter --- p.46
Chapter 3.3.2 --- Distribution Analysis by the Normal Quantile-Quantile Plot --- p.47
Chapter 3.3.3 --- Background of Student's t Distribution --- p.48
Chapter 3.3.4 --- Parameter Estimation - Maximum Likelihood Method --- p.50
Chapter 3.3.5 --- Goodness-of-fit Test - Kolmogorov-Smirnov Test --- p.53
Chapter 3.3.6 --- Goodness-of-fit Test ´ؤ Chi-Square Test --- p.56
Chapter 3.4 --- Discussion --- p.63
References --- p.65
Chapter Chapter 4 --- A Model Based Study of the Parameters Used by Existing Standards --- p.67
Chapter 4.1 --- Introduction --- p.67
Chapter 4.2 --- Background of Method Comparison Study --- p.68
Chapter 4.2.1 --- Four Areas in Method Comparison Study --- p.68
Chapter 4.2.2 --- Analysis of Previous Methodology and Statistical Parameters --- p.70
Chapter 4.3 --- Theoretical Mapping Relationship: Based on the General t Distribution --- p.72
Chapter 4.3.1 --- "Relationship among CP5, CP10 and CP15 in Each Grade for the 1993 BHS Protocol" --- p.76
Chapter 4.3.2 --- Relationships between the Criteria in Each Grade for the 1993 BHS Protocol and the AAMI Standard --- p.77
Chapter 4.3.3 --- Comparison of Parameters --- p.80
Chapter 4.4 --- Mean of the Absolute Errors (MAE) and Its Estimation --- p.81
Chapter 4.4.1 --- The Relationship between MAE and Other Parameters --- p.81
Chapter 4.4.2 --- Analysis of the Example Data --- p.84
Chapter 4.4.3 --- Estimation of MAEt --- p.84
Chapter 4.5 --- Discussion --- p.88
References --- p.90
Chapter Chapter 5 --- Experimental Study and an Evaluation Protocol Proposed for the Wearable BP Measurement Devices --- p.92
Chapter 5.1 --- Introduction --- p.92
Chapter 5.2 --- Description of the Experiment --- p.93
Chapter 5.3 --- Data Analysis --- p.95
Chapter 5.3.1 --- Data Used for the Study --- p.95
Chapter 5.3.2 --- Error Distribution Analysis --- p.96
Chapter 5.3.3 --- Evaluation of the Automatic BP Meter and the PTT-Based BP Measurement Device by AAMI and 1993 BHS Standards --- p.99
Chapter 5.3.4 --- Evaluation the Automatic BP Meter and the PTT-Based BP Measurement Device by the Proposed Parameter --- p.101
Chapter 5.4 --- Proposed Evaluation Procedure --- p.101
Chapter 5.4.1 --- Introduction --- p.101
Chapter 5.4.2 --- Determination of Parameters and Criteria --- p.102
Chapter 5.4.3 --- Proposed Evaluation Procedure --- p.103
Chapter 5.5 --- Discussion --- p.105
References --- p.108
Chapter Chapter 6 --- Conclusion and Future Work --- p.110
Chapter 6.1 --- Conclusion and Major Contributions --- p.110
Chapter 6.2 --- Future Works --- p.113
References --- p.115
Appendix A Deviation of Some Equations --- p.116
Chapter A.1 --- CP for Certain Limit of L as a Function of ME and SD --- p.116
Chapter A.2 --- MAE as a Function of Location and Scale Parameters --- p.119
Chapter A.3 --- "Relationship between ME, MAE and Root Mean Squared Error (RMSE) if the error distribution is unknown" --- p.121
Appendix B List of Publications and Awards Related to This Study --- p.123
48
Wu, Yu-Chen, and 吳毓晨. "Hardware Implementation of Cuffless Continuous Blood Pressure Measurement." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/60341298958403165009.
Full textAbstract:
碩士中原大學
電機工程研究所
104
The thesis intended to design a dynamic non-invasive, comfortable, and convenient blood pressure monitoring system for long-term continuous measurement. The non-invasive continuous blood pressure monitoring method was performed by the relative time variation between the chest electrocardiogram (ECG) and photoplethysmography (PPG) signals, to estimate the pulse arrival time (PAT) and to integrate the heart rate (HR) signal to approximate the blood pressure in design. The primary content focused on the design and realization of hardware circuit for the ECG and PPG devices. In the required physiological parameters for blood pressure estimation, for acquiring ECG signals at the sensor of system, the R-wave position in ECG was the essential point of feature to identify. The analog signal processing circuit design for the part relied on the bi-electrode collector to measure the signals from the lead II of ECG. By the circuit design of bi-electrode ECG, via the amplification, low-pass filter, reverse amplification, and role-to-role circuitry, it was possible to obtain a complete, low-noise ECG waveform. In addition, for the PPG signals, the near-infrared red LED was used as the emission source along with two light sensors at both ends to receive the wave peak position of PPG signals during systole as the primary feature. The reason for using two PPG light sensors was to enhance the acquisition and the use of optical silicone as filling at the light source and the sensors would enhance the specific wave peak of PPG. The circuitry design of PPG device, via low-pass filter, high-pass filter, and inverse amplification, would allow acquisition of complete low-noise PPG waveform. In the overall completed system design, at the end of analogy amplifier signal circuitry, the signals of ECG and PPG would pass through the micro-controller with setting of sampling frequency of 2kHz and convert the analog signal into digital form. The design of sampling frequency at 2kHz was to reduce the detection error of pulse arrival time parameter in the blood pressure estimation. The system would save the digital sensor data on the Micro SD card and via the user interface, the characteristic signal point would be annotated for blood pressure estimation. For the hardware design of sensor of ECG and PPG, experiment would be conducted to verify the signals for required physiological parameters for blood pressure calculation, and discussion would focus on the optimization effect of signal enhancement by optical silicone in the PPG. Lastly, the result of blood pressure estimation would be simulated to test the accuracy of overall sensor system.
49
Chung, Wen-Yao, and 鍾文耀. "Development of the phantom blood pressure calibration system for validation of real-time continuous low-pressure blood pressure measurement device." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/46907833508681702152.
Full textAbstract:
碩士中原大學
醫學工程研究所
97
Blood pressure and blood pressure waveform are indicators for clinical evaluation of heart functions. The physiological reaction mechanism will influence the changes of blood pressure and blood pressure waveform. There is no calibration tool for commercial device using common non-invasive blood pressure measurement method, such as auscultation and oscillation. Thus, this study develops the phantom blood pressure calibration system (PBPCS) to calibrate the non-invasive measurement oscillomatric devices. Additionally, this system can adjust and output different basic blood pressure (diastolic pressure) and flow (systolic pressure) in order to provide proper setting for the calibration of blood pressure measurement devices. At the same time, this research integrates the custom made non-invasive continuous blood pressure system from this laboratory [1] with the real-time digital signal processing chips and the PID controller for pump control into one complete system. The constructed system has two blood pressure measurement capabilities: oscillometric blood pressure measurement and continuous blood pressure measurement. and use the phantom blood pressure calibration system to adjust the two kind of blood pressure meters. This research have three aspects, the first part compares the blood pressure measurements of integrated device using oscillometric blood pressure measurement method and bedside monitor (Spacelabs). This experiment measures ten subjects and repeat twice measurements for each subject. Results demonstrate that the most of the difference of mean pressure and diastolic pressure between the integrated device and the bedside monitor are less than 10 mmHg. However, lots of the systolic pressures differs more than 10 mmHg. Over all, there are significant differences on systolic pressure, diastolic pressure and mean pressure obtained by the integrated device and the bedside monitor. And, the correlation coefficient is 0.867. The second aspect is to assess the performance of the PBPCS in oscillometric blood pressure measurement by adjusting and outputting different basic blood pressure (diastolic pressure) and flow (systolic pressure). Results demonstrate that when the settings of PBPCS for systolic, diastolic and mean pressure are 139 mmHg, 60 mmHg and 86 mmHg, respectively, the measured results of the integrated device are 32.4±5.32 mmHg, 48.4±2.80 mmHg and 94.5±5.48 mmHg, respectively. On the other hand, the measured results of the bedside monitor are 143.6±1.51 mmHg, 88±1.05 mmHg and 105.4±1.17 mmHg, respectively. These results indicate that the systolic pressures and mean pressures from the integrated device are adjacent to the PBPCS setting. However, the integrated device underestimates the diastolic pressures. On the other hand, the bedside monitor overestimates the diastolic and mean pressures. Nevertheless, there are significant differences between PBPCS settings and measurements from both devices. The third part of this research is to use the PBPCS to evaluate the continuous blood pressure measurement system under different settings. The results demonstrate that when the PBPCS keeps systolic pressure constant and elevates the diastolic pressure, the blood pressure pulse wave has the tendency to decrease in amplitude. On the other hand, when the PBPCS keeps diastolic pressure constant and elevates the systolic pressure, the pulse wave amplitude increases. When the PBPCS adjusts systolic and diastolic pressures at the same time, due to the combined effect of changes in diastolic and systolic pressures, the change of pulse wave amplitude is uncertain. By way of the preceding results of three experiments, this research develops the PBPCS to calibrate the non-invasive blood pressure measurement devices successfully. At the same time, it can be used for related tests of continuous blood pressure measurements system. In the future, there are several improvement can be made including: the material of the phantom, pipeline and control mechanism of the PBPCS in order to provide more realistic and more accurate blood pressure simulation. At the same time, the PBPCS can be used to validate and test the parameters setting for oscillometric blood pressure and continuous blood pressure measurements.
50
Chen, Tzung-Yu, and 陳棕瑀. "Non-invasive Blood Pressure Measurement using Piezoelectric Strain Gauges." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/444we2.
Full textAbstract:
碩士國立中山大學
機械與機電工程學系研究所
104
As the global population is increasingly aging, long-term physiological monitoring system for senior citizen need to be developed and established. Among all the physiological monitoring system, blood pressure monitoring is one of the most important physiological signals. Conventional blood pressure monitor, such as mercurial sphygmomanometer and electric sphygmomanometer are all applying compression to artery by using inflatable cuff. For long-term blood pressure monitoring user, compressing artery may cause the measurement section uncomfortable, and it can’t monitor continuous blood pressure. Nowadays, estimating blood pressure by cuffless method has become increasingly important and is widely research. This thesis proposes a method to estimate blood pressure using pulse transit time and strain of epidermis. First, using the thick-cylinder theory and pulse wave velocity to establish blood pressure estimation equation. Continuously, setting piezoelectric strain sensor and photoplethysmography sensor at wrist above radial artery and finger tip, respectively. Because two devices are set at a fixed distance, so that can cause a time delay between blood pressure pulse signals and photoplethysmography signals. Using pulse transit time and blood pressure pulse signals to calculate blood pressure by blood pressure estimation equation.