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Scientific Reports Jan 2022Continuous monitoring of blood pressure (BP) is essential for the prediction and the prevention of cardiovascular diseases. Cuffless BP methods based on non-invasive...
Continuous monitoring of blood pressure (BP) is essential for the prediction and the prevention of cardiovascular diseases. Cuffless BP methods based on non-invasive sensors integrated into wearable devices can translate blood pulsatile activity into continuous BP data. However, local blood pulsatile sensors from wearable devices suffer from inaccurate pulsatile activity measurement based on superficial capillaries, large form-factor devices and BP variation with sensor location which degrade the accuracy of BP estimation and the device wearability. This study presents a cuffless BP monitoring method based on a novel bio-impedance (Bio-Z) sensor array built in a flexible wristband with small-form factor that provides a robust blood pulsatile sensing and BP estimation without calibration methods for the sensing location. We use a convolutional neural network (CNN) autoencoder that reconstructs an accurate estimate of the arterial pulse signal independent of sensing location from a group of six Bio-Z sensors within the sensor array. We rely on an Adaptive Boosting regression model which maps the features of the estimated arterial pulse signal to systolic and diastolic BP readings. BP was accurately estimated with average error and correlation coefficient of 0.5 ± 5.0 mmHg and 0.80 for diastolic BP, and 0.2 ± 6.5 mmHg and 0.79 for systolic BP, respectively.
Topics: Adult; Arterial Pressure; Biosensing Techniques; Blood Pressure Determination; Electric Impedance; Equipment Design; Humans; Neural Networks, Computer; Predictive Value of Tests; Pulsatile Flow; Reproducibility of Results; Signal Processing, Computer-Assisted; Time Factors; Transducers; Wearable Electronic Devices; Wrist; Young Adult
PubMed: 35013376
DOI: 10.1038/s41598-021-03612-1 -
Oxidative Medicine and Cellular... 2022Blood pressure (BP) is a basic determinant for organ blood flow supply. Insufficient blood supply will cause tissue hypoxia, provoke cellular oxidative stress, and to... (Review)
Review
Blood pressure (BP) is a basic determinant for organ blood flow supply. Insufficient blood supply will cause tissue hypoxia, provoke cellular oxidative stress, and to some extent lead to organ injury. Perioperative BP is labile and dynamic, and intraoperative hypotension is common. It is unclear whether there is a causal relationship between intraoperative hypotension and organ injury. However, hypotension surely compromises perfusion and causes harm to some extent. Because the harm threshold remains unknown, various guidelines for intraoperative BP management have been proposed. With the pending definitions from robust randomized trials, it is reasonable to consider observational analyses suggesting that mean arterial pressures below 65 mmHg sustained for more than 15 minutes are associated with myocardial and renal injury. Advances in machine learning and artificial intelligence may facilitate the management of hemodynamics globally, including fluid administration, rather than BP alone. The previous mounting studies concentrated on associations between BP targets and adverse complications, whereas few studies were concerned about how to treat and multiple factors for decision-making. Hence, in this narrative review, we discussed the way of BP measurement and current knowledge about baseline BP extracting for surgical patients, highlighted the decision-making process for BP management with a view to providing pragmatic guidance for BP treatment in the clinical settings, and evaluated the merits of an automated blood control system in predicting hypotension.
Topics: Arterial Pressure; Artificial Intelligence; Blood Pressure; Humans; Hypotension; Myocardium
PubMed: 35860431
DOI: 10.1155/2022/5916040 -
Ugeskrift For Laeger Apr 2023
Topics: Humans; Blood Pressure; Blood Pressure Determination
PubMed: 37057697
DOI: No ID Found -
The Lancet. Public Health Feb 2017
Topics: Blood Pressure; Blood Pressure Determination; Ethanol
PubMed: 29253394
DOI: 10.1016/S2468-2667(17)30009-9 -
JAMA Network Open Jun 2022Women are at higher risk of cardiovascular events than men with similar blood pressure (BP). Whether this discrepancy in risk is associated with the accuracy of brachial...
IMPORTANCE
Women are at higher risk of cardiovascular events than men with similar blood pressure (BP). Whether this discrepancy in risk is associated with the accuracy of brachial cuff BP measurements is unknown.
OBJECTIVES
To examine the difference in brachial cuff BP accuracy in men and women compared with invasively measured aortic BP and to evaluate whether noninvasive central BP estimation varies with sex.
DESIGN, SETTING, AND PARTICIPANTS
This cross-sectional study enrolled 500 participants without severe aortic stenosis or atrial fibrillation from January 1 to December 31, 2019, who were undergoing nonurgent coronary angiography at a tertiary care academic hospital.
EXPOSURES
Simultaneous measurements of invasive aortic BP and noninvasive BP.
MAIN OUTCOMES AND MEASURES
Sex differences in accuracy were determined by calculating the mean difference between the noninvasive measurements (brachial and noninvasive central BP) and the invasive aortic BP (reference). Linear regression and mediation analyses were performed to identify mediators between sex and brachial cuff accuracy.
RESULTS
This study included 500 participants (145 female [29%] and 355 male [71%]; 471 [94%] White; mean [SD] age, 66 [10] years). Baseline characteristics were similar for both sexes apart from body habitus. Despite similar brachial cuff systolic BP (SBP) (mean [SD], 124.5 [17.7] mm Hg in women vs 124.4 [16.4] in men; P = .97), invasive aortic SBP was higher in women (mean [SD], 130.9 [21.7] in women vs 124.7 [20.1] mm Hg in men; P < .001). The brachial cuff was relatively accurate compared with invasive aortic SBP estimation in men (mean [SD] difference, -0.3 [11.7] mm Hg) but not in women (mean [SD] difference, -6.5 [12.1] mm Hg). Noninvasive central SBP (calibrated for mean and diastolic BP) was more accurate in women (mean [SD] difference, 0.6 [15.3] mm Hg) than in men (mean [SD] difference, 8.3 [14.2] mm Hg). This association of sex with accuracy was mostly mediated by height (3.4 mm Hg; 95% CI, 1.1-5.6 mm Hg; 55% mediation).
CONCLUSIONS AND RELEVANCE
In this cross-sectional study, women had higher true aortic SBP than men with similar brachial cuff SBP, an association that was mostly mediated by a shorter stature. This difference in BP measurement may lead to unrecognized undertreatment of women and could partly explain why women are at greater risk for cardiovascular diseases for a given brachial cuff BP than men. These findings may justify the need to study sex-specific BP targets or integration of sex-specific parameters in BP estimation algorithms.
Topics: Aged; Arterial Pressure; Blood Pressure; Blood Pressure Determination; Brachial Artery; Cross-Sectional Studies; Female; Humans; Male
PubMed: 35671057
DOI: 10.1001/jamanetworkopen.2022.15513 -
Journal of Hypertension Oct 2022Accurate measurement of central blood pressure (BP) using upper arm cuff-based methods is associated with several factors, including determining the level of systolic BP...
OBJECTIVE
Accurate measurement of central blood pressure (BP) using upper arm cuff-based methods is associated with several factors, including determining the level of systolic BP (SBP) amplification. This study aimed to determine the agreement between cuff-based and invasively measured SBP amplification.
METHODS
Patients undergoing coronary angiography had invasive SBP amplification (brachial SBP - central SBP) measured simultaneously with cuff-based SBP amplification using a commercially available central BP device (device 1: Sphygmocor Xcel; n = 171, 70% men, 60 ± 10 years) and a now superseded model of a central BP device (device 2: Uscom BP+; n = 52, 83% men, 62 ± 10 years).
RESULTS
Mean difference (±2SD, limits of agreement) between cuff-based and invasive SBP amplification was 4 mmHg (-12, +20 mmHg, P < 0.001) for device 1 and -2 mmHg (-14, +10 mmHg, P = 0.10) for device 2. Both devices systematically overestimated SBP amplification at lower levels and underestimated at higher levels of invasive SBP amplification, but with stronger bias for device 1 (r = -0.68 vs. r = -0.52; Z = 2.72; P = 0.008). Concordance of cuff-based and invasive SBP amplification across quartiles of invasive SBP amplification was low, particularly in the lowest and highest quartiles. The root mean square errors from regression between cuff-based central SBP and brachial SBP were significantly lower (indicating less variability) than from invasive regression models (P < 0.001).
CONCLUSIONS
Irrespective of the difference from invasive measurements, cuff-based estimates of SBP amplification showed evidence of proportional systematic bias and had less individual variability. These observations could provide insights on how to improve the performance of cuff-based central BP.
Topics: Arm; Arterial Pressure; Blood Pressure; Blood Pressure Determination; Brachial Artery; Female; Humans; Male
PubMed: 36052526
DOI: 10.1097/HJH.0000000000003228 -
Anaesthesiology Intensive Therapy 2022Mean arterial pressure (MAP) is a key haemodynamic variable monitored in critically ill patients. The advantages of oscillometric noninvasive blood pressure (NIBP)... (Meta-Analysis)
Meta-Analysis Review
Mean arterial pressure (MAP) is a key haemodynamic variable monitored in critically ill patients. The advantages of oscillometric noninvasive blood pressure (NIBP) measurement are its easy and fast methodology; however, the accuracy and the precision of this measurement in critically ill patients is constantly debated. We performed a systematic review and meta-analysis of observational studies comparing oscillometric NIBP methods with invasive arterial pressure (IAP) measurements. We included studies of adult critically ill patients, which evaluated MAP in the same patient by both NIBP and IAP at any site. We included only studies comparing simultaneous measurements of arterial pressure by NIBP and IAP, reporting their results using mean difference and SD of agreement. The main outcome was to define the bias of the MAP measured by NIBP over the IAP measurement. The quality of the studies was analysed by the QUADAS 2 tool. Seven studies and 1593 patients were included in the main analysis. The oscillometric NIBP method had a mean value of -1.50 mmHg when compared with IAP (95% CI: -3.34 to 0.35; I2 = 96% for random effects model, P < 0.01). The limits of agreement for MAP varied between -14.6 mmHg and +40.3 mmHg. NIBP had an adequate accuracy regarding MAP measurements by oscillometry. Limits of agreement may thus narrow the clinical applicability in scenarios in which there is a need for a more precise management of blood pressure.
Topics: Adult; Humans; Blood Pressure; Blood Pressure Determination; Oscillometry; Critical Illness; Arterial Pressure
PubMed: 36734453
DOI: 10.5114/ait.2022.123120 -
Journal of Hypertension Oct 2020
Topics: Adolescent; Arterial Pressure; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Humans; Young Adult
PubMed: 32890267
DOI: 10.1097/HJH.0000000000002559 -
Artificial Organs Dec 2022The life expectancy of patients with a continuous flow left ventricular assist device (cf-LVAD) is increasing. Adequate determination and regulation of mean arterial... (Review)
Review
BACKGROUND
The life expectancy of patients with a continuous flow left ventricular assist device (cf-LVAD) is increasing. Adequate determination and regulation of mean arterial pressure (MAP) is important to prevent adverse events. Given the low pulsatility characteristics in these patients, standard blood pressure equipment is inadequate to monitor MAP and not recommended. We provide an overview of currently available noninvasive techniques, using an extensive search strategy in three online databases (Pubmed, Scopus and Google Scholar) to find validation studies using invasive intra-arterial blood pressure measurement as a reference. Mean differences with the reference values smaller than 5 ± 8 mm Hg were considered acceptable.
OBSERVATIONS
After deduplication, screening, and exclusion of incorrect sources, eleven studies remained with 3139 successful MAP measurements in 386 patients. Four noninvasive techniques, using Doppler, pulse oximetry, finger cuff volume clamp, or slow upper arm cuff deflation, were identified and evaluated for validity and success rate in cf-LVAD patients. Here, a comprehensive technical background of the blood pressure measurement methods is provided in combination with a clinical use comparison. Of the reported noninvasive techniques, slow cuff devices performed most optimally (mean difference 1.3 ± 5.2 mm Hg).
CONCLUSIONS
Our results are encouraging and indicate that noninvasive blood pressure monitoring options with acceptable validity and success rate are available. Further technical development and validation is warranted for the growing population of patients on long-term cf-LVAD support.
Topics: Humans; Heart-Assist Devices; Arterial Pressure; Blood Pressure Determination; Arteries; Blood Pressure; Heart Failure
PubMed: 35920238
DOI: 10.1111/aor.14367 -
Sensors (Basel, Switzerland) Aug 2022Blood pressure (BP) monitoring can be performed either invasively via arterial catheterization or non-invasively through a cuff sphygmomanometer. However, for conscious... (Review)
Review
Blood pressure (BP) monitoring can be performed either invasively via arterial catheterization or non-invasively through a cuff sphygmomanometer. However, for conscious individuals, traditional cuff-based BP monitoring devices are often uncomfortable, intermittent, and impractical for frequent measurements. Continuous and non-invasive BP (NIBP) monitoring is currently gaining attention in the human health monitoring area due to its promising potentials in assessing the health status of an individual, enabled by machine learning (ML), for various purposes such as early prediction of disease and intervention treatment. This review presents the development of a non-invasive BP measuring tool called sphygmomanometer in brief, summarizes state-of-the-art NIBP sensors, and identifies extended works on continuous NIBP monitoring using commercial devices. Moreover, the NIBP predictive techniques including pulse arrival time, pulse transit time, pulse wave velocity, and ML are elaborated on the basis of bio-signals acquisition from these sensors. Additionally, the different BP values (systolic BP, diastolic BP, mean arterial pressure) of the various ML models adopted in several reported studies are compared in terms of the international validation standards developed by the Advancement of Medical Instrumentation (AAMI) and the British Hypertension Society (BHS) for clinically-approved BP monitors. Finally, several challenges and possible solutions for the implementation and realization of continuous NIBP technology are addressed.
Topics: Blood Pressure; Blood Pressure Determination; Humans; Machine Learning; Pulse Wave Analysis; Sphygmomanometers
PubMed: 36015956
DOI: 10.3390/s22166195