scholarly journals Blood Pressure Models for Wearable Sensors

2021 ◽  
Author(s):  
Ana Carolina Gonçalves Seabra ◽  
Alexandre Ferreira da Silva ◽  
Thomas Stieglitz ◽  
Ana Belen Amado Rey
Keyword(s):  
Blood Pressure ◽  
Linear Model ◽  
In Silico ◽  
Ex Vivo ◽  
Wearable Sensors ◽  
Mean Difference ◽  
Medical Instrumentation ◽  
Non Invasive ◽  
Luminal Area ◽  
The Us

<div>As cardiovascular diseases are one of the most prominent illnesses, a continuous, non-invasive, and comfortable monitoring of blood pressure (BP) is indispensable. This paper investigates the best method for obtaining highly accurate BP values in non-invasive measurements when using an ultrasound (US) sensor projected for a wrist-worn device. State-of-the-art BP models were analyzed and qualitatively compared. Relevant arterial parameters such as luminal area, flow velocity and pulse wave velocity, of 729 subjects were extracted from a computer simulated database and served as input parameters for the wearable US. A linear in-silico model calibrated to each arterial-site revealed to be most accurate model. The linear model was used for the extraction of BP by using the US sensor and validated with a commercial pressure sensor in an ex-vivo experimental setup. The results showed an in-silico pulse pressure correlation of 0.978 and mean difference of (-2.134±2.477) mmHg at the radial artery and ex-vivo pressure correlation of 0.994 and mean difference of (0.554 ± 2.315) mmHg. Thus, with the linear model, the US measurement complies with the Association for the Advancement of Medical Instrumentation standard with deviations lower than 5 mmHg.</div>

scholarly journals Arterial Flow and Diameter-based Blood Pressure Models-an In-silico Comparison

2021 ◽  
Author(s):  
Ana Carolina Gonçalves Seabra ◽  
Alexandre Ferreira da Silva ◽  
Thomas Stieglitz ◽  
Ana Belen Amado Rey
Keyword(s):  
Blood Pressure ◽  
In Silico ◽  
Model Comparison ◽  
Pulse Wave ◽  
Ex Vivo ◽  
Mean Difference ◽  
Arterial Tree ◽  
Non Invasive ◽  
Luminal Area ◽  
Ultrasound Sensor

<div>This paper investigates the best method for obtaining highly accurate blood pressure values in non-invasive measurements when using an ultrasound sensor. Deviations of the model should be less than 5 mmHg from the actual values. Different blood pressure models were analyzed and qualitatively compared. Relevant arterial parameters such as luminal area, flow velocity and pulse wave velocity, of 729 subjects were extracted from a computer simulated database and served as input parameters. Due to pulse wave variations through the arterial tree, such as viscoelasticity and arterial stiffness, the applied algorithms need to be specifically adapted to each arterial site. In-silico model comparison at different arterial sites were used to identify the parameters for individual equations that deduce the blood pressure at different arteries (carotid, brachial and radial). A linear model calibrated luminal area pulse wave to blood pressure and revealed to be most accurate model. The model was validated with a commercial pressure sensor in an ex-vivo experimental setup. The results showed an in-silico pulse pressure correlation of 0:978 and mean difference of (-2.134 ±2.477) mmHg at the radial artery and ex-vivo pressure correlation of 0:994 and mean difference of (0.554 ±2.315) mmHg.</div>

scholarly journals Arterial Flow and Diameter-based Blood Pressure Models-an In-silico Comparison

2021 ◽  
Author(s):  
Ana Carolina Gonçalves Seabra ◽  
Alexandre Ferreira da Silva ◽  
Thomas Stieglitz ◽  
Ana Belen Amado Rey
Keyword(s):  
Blood Pressure ◽  
In Silico ◽  
Model Comparison ◽  
Pulse Wave ◽  
Ex Vivo ◽  
Mean Difference ◽  
Arterial Tree ◽  
Non Invasive ◽  
Luminal Area ◽  
Ultrasound Sensor

<div>This paper investigates the best method for obtaining highly accurate blood pressure values in non-invasive measurements when using an ultrasound sensor. Deviations of the model should be less than 5 mmHg from the actual values. Different blood pressure models were analyzed and qualitatively compared. Relevant arterial parameters such as luminal area, flow velocity and pulse wave velocity, of 729 subjects were extracted from a computer simulated database and served as input parameters. Due to pulse wave variations through the arterial tree, such as viscoelasticity and arterial stiffness, the applied algorithms need to be specifically adapted to each arterial site. In-silico model comparison at different arterial sites were used to identify the parameters for individual equations that deduce the blood pressure at different arteries (carotid, brachial and radial). A linear model calibrated luminal area pulse wave to blood pressure and revealed to be most accurate model. The model was validated with a commercial pressure sensor in an ex-vivo experimental setup. The results showed an in-silico pulse pressure correlation of 0:978 and mean difference of (-2.134 ±2.477) mmHg at the radial artery and ex-vivo pressure correlation of 0:994 and mean difference of (0.554 ±2.315) mmHg.</div>

scholarly journals Aortic Calcification Affects Noninvasive Estimates of Central Blood Pressure in Patients with Severe Chronic Kidney Disease

2019 ◽  
Vol 44 (4) ◽  
pp. 704-714 ◽  
Author(s):  
Rasmus Kirkeskov Carlsen ◽  
Simon Winther ◽  
Christian D. Peters ◽  
Esben Laugesen ◽  
Dinah S. Khatir ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Calcium Score ◽  
Mean Difference ◽  
Aortic Calcification ◽  
Ct Scans ◽  
Central Blood Pressure ◽  
Non Invasive ◽  
Ckd Stage

Background: Central blood pressure (BP) assessed noninvasively considerably underestimates true invasively measured aortic BP in chronic kidney disease (CKD) patients. The difference between the estimated and the true aortic BP increases with decreasing estimated glomerular filtration rates (eGFR). The present study investigated whether aortic calcification affects noninvasive estimates of central BP. Methods: Twenty-four patients with CKD stage 4–5 undergoing coronary angiography and an aortic computed tomography scan were included (63% males, age [mean ± SD ] 53 ± 11 years, and eGFR 9 ± 5 mL/min/1.73 m2). Invasive aortic BP was measured through the angiography catheter, while non-invasive central BP was obtained using radial artery tonometry with a SphygmoCor® device. The Agatston calcium score (CS) in the aorta was quantified on CT scans using the CS on CT scans. Results: The invasive aortic systolic BP (SBP) was 152 ± 23 mm Hg, while the estimated central SBP was 133 ± 20 mm Hg. Ten patients had a CS of 0 in the aorta, while 14 patients had a CS >0 in the aorta. The estimated central SBP was lower than the invasive aortic SBP in patients with aortic calcification compared to patients without (mean difference 8 mm Hg, 95% CI 0.3–16; p = 0.04). The brachial SBP was lower than the aortic SBP in patients with aortic calcification compared to patients without (mean difference 10 mm Hg, 95% CI 2–19; p = 0.02). Conclusion: In patients with advanced CKD the presence of aortic calcification is associated with a higher difference between invasively measured central aortic BP and non-invasive estimates of central BP as compared to patients without calcifications.

Abstract MP023: Changes in Systolic Blood Pressure Differs by Immigration History in a Cohort of Older Mexican Americans

Circulation ◽  
2017 ◽  
Vol 135 (suppl_1) ◽  
Author(s):  
Tu My To ◽  
John M Neuhaus ◽  
May Sudhinaraset ◽  
Michelle A Albert ◽  
Mary N Haan
Keyword(s):  
Risk Factors ◽  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Linear Model ◽  
Mexican Americans ◽  
Linear Time ◽  
Community Dwelling ◽  
Foreign Born ◽  
Immigration History ◽  
The Us

Background: Studies on immigrant health suggest that foreign-born individuals have better health outcomes than their native-born counterparts due to health selection. However, effects of immigration history on changes in cardiovascular conditions and risk factors are less well understood. Objective and Hypothesis: We examined the association between immigration history and change in systolic blood pressure (SBP). We hypothesized that Mexican Americans born outside the US and immigrated after age 30 (FB30+), would have lower SBP at baseline and have slower increase in SBP compared to people who were born in the US (US-B) or immigrated from Mexico before age 30 (FB<30). Methods: Participants come from the Sacramento Area Latino Study on Aging (n=1789), a longitudinal cohort of community-dwelling older Mexican Americans (mean age=70.6 years); 51% were born in Mexico. Immigration history was categorized as US-B, FB<30, and FB30+. SBP measures were available at baseline and at five follow-ups over ten years. A mixed effects linear model was used to examine the association between immigration history and SBP. Other covariates included gender, education, current hypertension medication use, and baseline measures of age, BMI, and diabetes. Follow up time was defined as time since enrollment. Quadratic time was included to account for non-linear change in SBP. Two interaction terms (immigration history x linear time and immigration history x quadratic time) were included to assess differences in SBP change by nativity. Results: The study included 1598 participants after exclusions. The figure shows the predicted average SBP by immigration history over the study period, derived from the mixed linear model. Compared to US-B, the FB<30 and FB30+ experienced an average of 7.3 (95% CI 2.0-12.7) and 7.9 (95% CI 2.2-13.5) mmHg increase in SBP over the study period, respectively. Conclusions: In contrast to current literature, immigrants appeared to be at greater risk for adverse cardiovascular risk factors.

Elimination of Multicollinearity in Continuous Non-Invasive Blood Pressure Approximation by Information Criterion

2021 ◽  
Vol 11 (1) ◽  
pp. 53-62
Author(s):  
S. Sree Niranjanaa Bose ◽  
A. Kandaswamy
Keyword(s):  
Blood Pressure ◽  
Information Criterion ◽  
Absolute Error ◽  
Medical Instrumentation ◽  
Ensemble Model ◽  
Single Model ◽  
Invasive Blood Pressure ◽  
Non Invasive ◽  
Error Measures ◽  
Electrocardiogram Ecg

Continuous and unobtrusive method of measuring blood pressure has been gaining more attention in the healthcare community. With the application of data analysis techniques in biosignals like Electrocardiogram (ECG) and Photoplethysmogram (PPG), several predictors are obtained that correlates well with the blood pressure. But the BP approximation regression models formed using these predictors suffers from multicollinearity (higher correlation between predictors). The article proposes the use of information criterion-based model ensemble approach to reduce the effect of multicollinearity in the continuous BP estimation. The study focuses on forming pool of candidate models from feature subsets. The best performing models are selected based on information criterion and combined to form the ensemble model. Experiments with performed with MIMIC-II dataset that consists of 104 records with simultaneously recorded PPG and arterial BP. The results suggest that the technique achieves Mean Absolute Error (MAE) of 5.81 mm Hg and 3.35 mm Hg for systolic and diastolic BP and Root Mean Square Error (RMSE) of 6.08 mm Hg and 4.12 mm Hg for systolic and diastolic BP respectively. The error measures conform to the standards set by American Association of Medical Instrumentation (AAMI). The method reveals that the ensemble model based on information criterion outperforms well compared to the usage of single model.

scholarly journals A novel art of continuous non-invasive blood pressure measurement

2019 ◽  
Author(s):  
Jürgen Fortin ◽  
Dorothea Rogge ◽  
Christian Fellner ◽  
Doris Flotzinger ◽  
Julian Grond ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Pressure Monitoring ◽  
Blood Pressure Measurement ◽  
Wearable Sensors ◽  
Pulse Transit Time ◽  
Control Technique ◽  
Volume Control ◽  
Flow Monitoring ◽  
Non Invasive ◽  
Arterial Blood

AbstractWearable sensors to continuously measure blood pressure (BP) and derived cardiovascular variables have the potential to revolutionize patient monitoring. Current wearable methods analyzing time components (e.g., pulse transit time) still lack clinical accuracy, whereas existing technologies for direct BP measurement are too bulky. Here we present a new art of continuous non-invasive arterial blood pressure monitoring (CNAP2GO). It directly measures BP by using a new “volume control technique” and could be used for small wearable sensors integrated in a finger ring. As a software prototype, CNAP2GO showed excellent BP measurement performance in comparison with invasive BP in 46 patients having surgery. The resulting pulsatile BP signal carries information to derive cardiac output and other hemodynamic variables. We show that CNAP2GO can be miniaturized for wearable approaches. CNAP2GO potentially constitutes the breakthrough for wearable sensors for blood pressure and flow monitoring in both ambulatory and in-hospital clinical settings.

scholarly journals Imputation of the continuous arterial line blood pressure waveform from non-invasive measurements using deep learning

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brian L. Hill ◽  
Nadav Rakocz ◽  
Ákos Rudas ◽  
Jeffrey N. Chiang ◽  
Sidong Wang ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Deep Learning ◽  
Diastolic Blood Pressure ◽  
Standard Of Care ◽  
Mean Difference ◽  
Arterial Line ◽  
Current Standard ◽  
Mortality And Morbidity ◽  
Non Invasive ◽  
Arterial Blood

AbstractIn two-thirds of intensive care unit (ICU) patients and 90% of surgical patients, arterial blood pressure (ABP) is monitored non-invasively but intermittently using a blood pressure cuff. Since even a few minutes of hypotension increases the risk of mortality and morbidity, for the remaining (high-risk) patients ABP is measured continuously using invasive devices, and derived values are extracted from the recorded waveforms. However, since invasive monitoring is associated with major complications (infection, bleeding, thrombosis), the ideal ABP monitor should be both non-invasive and continuous. With large volumes of high-fidelity physiological waveforms, it may be possible today to impute a physiological waveform from other available signals. Currently, the state-of-the-art approaches for ABP imputation only aim at intermittent systolic and diastolic blood pressure imputation, and there is no method that imputes the continuous ABP waveform. Here, we developed a novel approach to impute the continuous ABP waveform non-invasively using two continuously-monitored waveforms that are currently part of the standard-of-care, the electrocardiogram (ECG) and photo-plethysmogram (PPG), by adapting a deep learning architecture designed for image segmentation. Using over 150,000 min of data collected at two separate health systems from 463 patients, we demonstrate that our model provides a highly accurate prediction of the continuous ABP waveform (root mean square error 5.823 (95% CI 5.806–5.840) mmHg), as well as the derived systolic (mean difference 2.398 ± 5.623 mmHg) and diastolic blood pressure (mean difference − 2.497 ± 3.785 mmHg) compared to arterial line measurements. Our approach can potentially be used to measure blood pressure continuously and non-invasively for all patients in the acute care setting, without the need for any additional instrumentation beyond the current standard-of-care.

Abstract 15385: A Tapered BP Cuff More Accurately Measures Systolic Blood Pressure Than Does a Standard Rectangular BP Cuff Over a Range of Arm Circumferences

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Sean T Gloth ◽  
Daniel I Ambinder ◽  
Glenn Whitman ◽  
Steven P Schulman ◽  
Jeffrey A Brinker ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Risk Factor ◽  
Systolic Blood Pressure ◽  
Radial Artery ◽  
Mean Difference ◽  
Non Invasive ◽  
Arm Circumference ◽  
Significant Difference ◽  
Two Measures ◽  
Continuous Range

Introduction: Systolic blood pressure (BP) is an important risk factor for cardiovascular outcomes. However, non-invasive measures obtained using a standard rectangular cuff (RC) are accurate only when the width of the cuff is ~40% of the arm circumference (AC). This ideal Ratio (IR) is met for the medium standard rectangular cuff at an AC of 30 cm. Hypothesis: A tapered cuff (TC) designed to maintain the IR over a range of ACs more accurately measures systolic BP than does a standard rectangular cuff. Methods: Twenty-two measures of BP using the RC and the TC were compared in seven patients with ACs of 30 cm. In addition, twenty-seven measures of SBP using the RC and the TC were compared with radial artery pressures in 12 patients with clinically placed arterial lines and arm circumferences ranging from 24 cm to 38 cm. Results: When ACs were 30 cm, there was no significant difference between the RC and SC systolic pressures (mean ± SD difference of 1.3 mmHg ± 0.8, p=.78) and they correlated with one another, R 2 of 0.99. However, over a range of ACs, the RC systolic pressures significantly differed from the arterial pressures (mean difference ± SD of 11 ± 4 mmHg, p=.005), and did not correlate with the arterial readings (Panel A) , whereas the TC systolic pressures did not differ from the arterial pressures (mean difference ± SD of 2 ± 1.3 mmHg, p=.18) and did correlate with the arterial readings (Panel B). Conclusion: Systolic BPs obtained with a TC which maintains the IR over a continuous range of arm circumferences are more accurate than are those obtained with a RC.

scholarly journals Measurement of Blood Pressure by Ultrasound—The Applicability of Devices, Algorithms and a View in Local Hemodynamics

Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2255
Author(s):  
Moritz Meusel ◽  
Philipp Wegerich ◽  
Berit Bode ◽  
Elena Stawschenko ◽  
Kristina Kusche-Vihrog ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Detailed Comparison ◽  
Vessel Diameter ◽  
Deep Tissue ◽  
Steady State Condition ◽  
Non Invasive ◽  
The Us ◽  
Invasive Arterial Pressure ◽  
The Right ◽  
Main Effects

Objective: Due to ongoing technical progress, the ultrasonic measurement of blood pressure (BP) as an alternative to oscillometric measurement (NIBP) or the continuous non-invasive arterial pressure method (CNAP) moves further into focus. The US method offers several advantages over NIBP and CNAP, such as deep tissue penetration and the utilization of different arterial locations. Approach: Ten healthy subjects (six female, aged 30.9 ± 4.6 years) volunteered in our investigation. In the ultrasonic BP measurement, we differentiated between the directly measured (pulsatile diastolic and systolic vessel diameter) and indirectly calculated variables at three different artery locations on both arms, with two different ultrasound devices in the transversal and longitudinal directions of the transducer. Simultaneously, NIBP monitoring served as reference BP, while CNAP monitored the steady state condition of the arm under investigation. The Moens–Korteweg algorithm (MKE) and the algorithm of the working group of San Diego (SanD) were selected for the indirectly calculated ultrasonic BP data. Main results: With US, we were able to measure the BP at each selected arterial position. Due to the investigation setup, we found small but significant interactions of the main effects. Bland and Altman analysis revealed that US-BP measurement was similar to NIBP, with superior accuracy when compared to the established CNAP method. In addition, US-BP measurement showed that the measurement accuracy of both arms can be regarded as identical. In a detailed comparison of the selected arterial vascular sections, systematic discrepancies between the right and left arm could be observed. Conclusion: In our pilot study, we measured BP effectively and accurately by US using two different devices. Our findings suggest that ultrasonic BP measurement is an adequate alternative for live and continuous hemodynamic monitoring.

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