Signal quality measures for unsupervised blood pressure measurement

Sukor, J Abdul; Redmond, Stephen J.; Grace, Clare; Lovell, Nigel H.

doi:10.1088/0967-3334/33/3/465

Cited by 15 publications

(4 citation statements)

References 29 publications

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“…Additional advantages of our modified auscultatory method are that algorithms can be readily implemented for the identification of measurement noise or signal artefact [ 30 ] and cardiac arrhythmia [ 31 ]. Once these are identified, the measurement can be either aborted or the impact of the artefact minimized using signal processing methods.…”

Section: Discussionmentioning

confidence: 99%

Novel methods of testing and calibration of oscillometric blood pressure monitors

Celler¹,

Argha²,

Le³

et al. 2018

PLoS ONE

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We present a robust method for testing and calibrating the performance of oscillometric non-invasive blood pressure (NIBP) monitors, using an industry standard NIBP simulator to determine the characteristic ratios used, and to explore differences between different devices. Assuming that classical auscultatory sphygmomanometry provides the best approximation to intra-arterial pressure, the results obtained from oscillometric measurements for a range of characteristic ratios are compared against a modified auscultatory method to determine an optimum characteristic ratio, Rs for systolic blood pressure (SBP), which was found to be 0.565. We demonstrate that whilst three Chinese manufactured NIBP monitors we tested used the conventional maximum amplitude algorithm (MAA) with characteristic ratios Rs = 0.4624±0.0303 (Mean±SD) and Rd = 0.6275±0.0222, another three devices manufactured in Germany and Japan either do not implement this standard protocol or used different characteristic ratios. Using a reference database of 304 records from 102 patients, containing both the Korotkoff sounds and the oscillometric waveforms, we showed that none of the devices tested used the optimal value of 0.565 for the characteristic ratio Rs, and as a result, three of the devices tested would underestimate systolic pressure by an average of 4.8mmHg, and three would overestimate the systolic pressure by an average of 6.2 mmHg.

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Section: Discussionmentioning

confidence: 99%

Novel methods of testing and calibration of oscillometric blood pressure monitors

Celler¹,

Argha²,

Le³

et al. 2018

PLoS ONE

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show abstract

“…All HbA 1c values were transformed to the National Glycohemoglobin Standardization Program (NGSP) standard levels using the formula HbA 1c (NGSP) = (0.923× HbA 1c [Mono-S]) +1.345 [24]. BP, as standard for the NDR, was given as the mean value of two readings (Korotkoff 1–5 [25]) in the supine position according to national guidelines. A smoker was defined as an individual who smoked at least one cigarette per day, or used a pipe daily, or had stopped smoking within the previous 3 months.…”

Section: Methodsmentioning

confidence: 99%

Towards Renewed Health Economic Simulation of Type 2 Diabetes: Risk Equations for First and Second Cardiovascular Events from Swedish Register Data

et al. 2013

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ObjectivePredicting the risk of future events is an essential part of health economic simulation models. In pursuit of this goal, the current study aims to predict the risk of developing first and second acute myocardial infarction, heart failure, non-acute ischaemic heart disease, and stroke after diagnosis in patients with type 2 diabetes, using data from the Swedish National Diabetes Register.Material and MethodsRegister data on 29,034 patients with type 2 diabetes were analysed over five years of follow up (baseline 2003). To develop and validate the risk equations, the sample was randomly divided into training (75%) and test (25%) subsamples. The Weibull proportional hazard model was used to estimate the coefficients of the risk equations, and these were validated in both the training and the test samples.ResultsIn total, 4,547 first and 2,418 second events were observed during the five years of follow up. Experiencing a first event substantially elevated the risk of subsequent events. There were heterogeneities in the effects of covariates within as well as between events; for example, while for females the hazard ratio of having a first acute myocardial infarction was 0.79 (0.70–0.90), the hazard ratio of a second was 1.21 (0.98–1.48). The hazards of second events decreased as the time since first events elapsed. The equations showed adequate calibration and discrimination (C statistics range: 0.70–0.84 in test samples).ConclusionThe accuracy of health economic simulation models of type 2 diabetes can be improved by ensuring that they account for the heterogeneous effects of covariates on the risk of first and second cardiovascular events. Thus it is important to extend such models by including risk equations for second cardiovascular events.

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“…Figure 2 shows the distribution of SBP, DBP and pulse pressure (PP) in the collected data. A more detailed description of the experimental protocol as well as equipment configuration are provided in [ 18 ].…”

Section: Methodsmentioning

confidence: 99%

“…The cuff pressure signal was detrended using a first-order band-pass Butterworth filter of 0.5–5 Hz, chosen based on the assumption of a maximum heart rate of 300 beats per minute [ 18 ] to transform the signal morphology into a pulsatile oscillometric waveform. A forward-backward filter was used to achieve a zero-phase response.…”

Section: Methodsmentioning

confidence: 99%

Improved Measurement of Blood Pressure by Extraction of Characteristic Features from the Cuff Oscillometric Waveform

Lim

Jassim

et al. 2015

Sensors

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We present a novel approach to improve the estimation of systolic (SBP) and diastolic blood pressure (DBP) from oscillometric waveform data using variable characteristic ratios between SBP and DBP with mean arterial pressure (MAP). This was verified in 25 healthy subjects, aged 28 ± 5 years. The multiple linear regression (MLR) and support vector regression (SVR) models were used to examine the relationship between the SBP and the DBP ratio with ten features extracted from the oscillometric waveform envelope (OWE). An automatic algorithm based on relative changes in the cuff pressure and neighbouring oscillometric pulses was proposed to remove outlier points caused by movement artifacts. Substantial reduction in the mean and standard deviation of the blood pressure estimation errors were obtained upon artifact removal. Using the sequential forward floating selection (SFFS) approach, we were able to achieve a significant reduction in the mean and standard deviation of differences between the estimated SBP values and the reference scoring (MLR: mean ± SD = −0.3 ± 5.8 mmHg; SVR and −0.6 ± 5.4 mmHg) with only two features, i.e., Ratio2 and Area3, as compared to the conventional maximum amplitude algorithm (MAA) method (mean ± SD = −1.6 ± 8.6 mmHg). Comparing the performance of both MLR and SVR models, our results showed that the MLR model was able to achieve comparable performance to that of the SVR model despite its simplicity.

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Signal quality measures for unsupervised blood pressure measurement

Cited by 15 publications

References 29 publications

Novel methods of testing and calibration of oscillometric blood pressure monitors

Novel methods of testing and calibration of oscillometric blood pressure monitors

Towards Renewed Health Economic Simulation of Type 2 Diabetes: Risk Equations for First and Second Cardiovascular Events from Swedish Register Data

Improved Measurement of Blood Pressure by Extraction of Characteristic Features from the Cuff Oscillometric Waveform

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