DEVELOPMENT OF CONTINUOUS REMOTE BLOOD PRESSURE MONITORING SYSTEM

The conventional method to measure blood pressure of human is either by using a manual measurement by qualified personal (doctors or nurses) using sphygmomanometers or an automatic measurement completed via blood pressure devices. Both of these methods however have a drawback that may lead to misidentification or fatalities. For manual measurement; there are many parameters that may lead to misreading patient's blood pressure such as the level of patient's nerve due to the environmental factor (doctors office), while the automated measurement that widely used in hospital has to be monitored manually at certain time intervals by a nurses

Automatic noninvasive measurement of systolic blood pressure using photoplethysmography

<p>Abstract</p> <p>Background</p> <p>Automatic measurement of arterial blood pressure is important, but the available commercial automatic blood pressure meters, mostly based on oscillometry, are of low accuracy.</p> <p>Methods</p> <p>In this study, we present a cuff-based technique for automatic measurement of systolic blood pressure, based on photoplethysmographic signals measured simultaneously in fingers of both hands. After inflating the pressure cuff to a level above systolic blood pressure in a relatively slow rate, it is slowly deflated. The cuff pressure for which the photoplethysmographic signal reappeared during the deflation of the pressure-cuff was taken as the systolic blood pressure. The algorithm for the detection of the photoplethysmographic signal involves: (1) determination of the time-segments in which the photoplethysmographic signal distal to the cuff is expected to appear, utilizing the photoplethysmographic signal in the free hand, and (2) discrimination between random fluctuations and photoplethysmographic pattern. The detected pulses in the time-segments were identified as photoplethysmographic pulses if they met two criteria, based on the pulse waveform and on the correlation between the signal in each segment and the signal in the two neighboring segments.</p> <p>Results</p> <p>Comparison of the photoplethysmographic-based automatic technique to sphygmomanometry, the reference standard, shows that the standard deviation of their differences was 3.7 mmHg. For subjects with systolic blood pressure above 130 mmHg the standard deviation was even lower, 2.9 mmHg. These values are much lower than the 8 mmHg value imposed by AAMI standard for automatic blood pressure meters.</p> <p>Conclusion</p> <p>The photoplethysmographic-based technique for automatic measurement of systolic blood pressure, and the algorithm which was presented in this study, seems to be accurate.</p

Significantly Reduced Blood Pressure Measurement Variability for Both Normotensive and Hypertensive Subjects: Effect of Polynomial Curve Fitting of Oscillometric Pulses

This study aimed to compare within-subject blood pressure (BP) variabilities from different measurement techniques. Cuff pressures from three repeated BP measurements were obtained from 30 normotensive and 30 hypertensive subjects. Automatic BPs were determined from the pulses with normalised peak amplitude larger than a threshold (0.5 for SBP, 0.7 for DBP, and 1.0 for MAP). They were also determined from cuff pressures associated with the above thresholds on a fitted curve polynomial curve of the oscillometric pulse peaks. Finally, the standard deviation (SD) of three repeats and its coefficient of variability (CV) were compared between the two automatic techniques. For the normotensive group, polynomial curve fitting significantly reduced SD of repeats from 3.6 to 2.5 mmHg for SBP and from 3.7 to 2.1 mmHg for MAP and reduced CV from 3.0% to 2.2% for SBP and from 4.3% to 2.4% for MAP (all P<0.01). For the hypertensive group, SD of repeats decreased from 6.5 to 5.5 mmHg for SBP and from 6.7 to 4.2 mmHg for MAP, and CV decreased from 4.2% to 3.6% for SBP and from 5.8% to 3.8% for MAP (all P<0.05). In conclusion, polynomial curve fitting of oscillometric pulses had the ability to reduce automatic BP measurement variability

DEVELOPMENT OF CONTINUOUS REMOTE BLOOD PRESSURE MONITORING SYSTEM

The conventional method to measure blood pressure of human is either by using a manual measurement by qualified personal (doctors or nurses) using sphygmomanometers or an automatic measurement completed via blood pressure devices. Both of these methods however have a drawback that may lead to misidentification or fatalities. For manual measurement; there are many parameters that may lead to misreading patient's blood pressure such as the level of patient's nerve due to the environmental factor (doctors office), while the automated measurement that widely used in hospital has to be monitored manually at certain time intervals by a nurses

Developing Continuous Remote Blood Pressure Monitoring System

Normal method of monitoring the blood pressure is through manually measured by medical practitioners through the use of sphygmomanometers or automatically by blood pressure devices. These methods having drawbacks which might concur fatalities. Manual measurement is susceptible to human errors and environmental fluctuations. High or low pressure during the time interval in which the medical practitioners did not measure the pressure might not be administered in the treatment of the patient meaning there is a gap in data which might lead to misdiagnosis. Wireless System module is been used to obtain the objective of this project in which desirably a wireless monitoring system is designed

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

Liu, Yinbo.Thesis (M.Phil.)--Chinese University of Hong Kong, 2008.Includes bibliographical references (leaves 74-79).Abstracts in English and Chinese.Abstract --- p.iList of Figures --- p.ivList of Tables --- p.viiiIntroduction --- p.1Chapter 1.1 --- Current status of Blood Pressure Management --- p.1Chapter 1.2 --- Current Status of Noninvasive Blood Pressure Measurement Techniques --- p.4Chapter 1.3 --- Motivations and Objectives of This Thesis --- p.9Chapter 1.4 --- Organization of This Thesis --- p.9Backgrounds --- p.11Chapter 2.1 --- Principle of the Pulse Transit Time-based Approach for BP Measurement --- p.11Chapter 2.1.1 --- General Descriptions --- p.11Chapter 2.1.2 --- Pressure Wave Propagation in Cylindrical Arteries --- p.13Chapter 2.1.3 --- Determining the PTT for BP Measurement --- p.14Chapter 2.2 --- Backgrounds for Pressure Related Elastic Properties of Artery --- p.17Chapter 2.2.1 --- Transmural Pressure and Its Components --- p.17Chapter 2.2.2 --- Volume-pressure Models --- p.19Chapter 2.2.3 --- Types and Structure of the Artery and Its Properties --- p.20Chapter 2.3 --- Literature Review on the Calibration Methods for Cuffless Blood Pressure Measurements --- p.22Chapter 2.4 --- Section Summary --- p.25Investigations on Factors Affecting PTT or BP --- p.26Chapter 3.1 --- The Effects of External Pressure --- p.26Chapter 3.1.1 --- Background --- p.26Chapter 3.1.2 --- Experimental protocol --- p.28Chapter 3.1.3 --- Analysis for the Effects of External Pressure on PTT --- p.30Chapter 3.1.4 --- Section Discussions --- p.31Chapter 3.2 --- The Effects of Hydrostatic Pressure --- p.32Chapter 3.2.1 --- Experimental protocol --- p.33Chapter 3.2.2 --- Analysis for the Effects of Hydrostatic Pressure on PTT --- p.34Chapter 3.2.3 --- Section Discussions --- p.37Chapter 3.2.4 --- Section Summary --- p.38Modeling the Effect of Hydrostatic Pressure on PTT for A Calibration Method --- p.39Chapter 4.1 --- Current Status of Hydrostatic Calibration Approaches --- p.39Chapter 4.2. --- Modeling Pulse Transit Time under the Effects of Hydrostatic Pressure for A Hydrostatic Calibration Method: --- p.40Chapter 4.2.1 --- Basic BP-PTT model --- p.40Chapter 4.2.2 --- V-P relationship Represented by a Sigmoid Curve --- p.40Chapter 4.2.3 --- Relating PTT with Hydrostatic Pressure --- p.41Chapter 4.2.4 --- Implementing the Hydrostatic Calibration Method for BP Estimation --- p.43Chapter 4.3. --- Preliminary Experiment --- p.44Chapter 4.3.1. --- Experimental Protocol and Methodology --- p.44Chapter 4.3.2. --- Experimental Analysis --- p.46Chapter 4.4. --- Section Discussions --- p.48Chapter 4.5. --- A Novel Implementation Algorithm of Hydrostatic Calibration Method for Cuffless BP Estimation --- p.49Chapter 4.6. --- Section Summary --- p.50Experimental Studies for the Hydrostatic Calibration Approach --- p.51Chapter 5.1 --- Experimental Analysis --- p.51Chapter 5.1.1 --- Experimental Protocol --- p.51Chapter 5.1.2 --- Methodology --- p.53Chapter 5.1.3 --- Preparations --- p.54Chapter 5.1.4 --- Experimental Results --- p.56Chapter 5.2 --- Section Discussions --- p.63Chapter 5.3 --- Section Summary --- p.70Conclusions and Suggestions for Future Works --- p.71Chapter 6.1 --- Conclusions --- p.71Chapter 6.2 --- Suggestions for Future Works --- p.72Reference --- p.7