Principles and techniques of blood pressure measurement

Machine learning models based on FEM simulation of hoop mode vibrations to enable ultrasonic cuffless measurement of blood pressure

Blood pressure (BP) is one of the vital physiological parameters, and its measurement is done routinely for almost all patients who visit hospitals. Cuffless BP measurement has been of great research interest over the last few years. In this paper, we aim to establish a method for cuffless measurement of BP using ultrasound. In this method, the arterial wall is pushed with an acoustic radiation force impulse (ARFI). After the completion of the ARFI pulse, the artery undergoes impulsive unloading which stimulates a hoop mode vibration. We designed two machine learning (ML) models which make it possible to estimate the internal pressure of the artery using ultrasonically measurable parameters. To generate the training data for the ML models, we did extensive finite element method (FEM) eigen frequency simulations for different tubes under pressure by sweeping through a range of values for inner lumen diameter (ILD), tube density (TD), elastic modulus, internal pressure (IP), tube length, and Poisson's ratio. Through image processing applied on images of different eigen modes supported for each simulated case, we identified its hoop mode frequency (HMF). Two different ML models were designed based on the simulated data. One is a four-parameter model (FPM) that takes tube thickness (TT), TD, ILD, and HMF as the inputs and gives out IP as output. Second is a three-parameter model (TPM) that takes TT, ILD, and HMF as inputs and IP as output. The accuracy of these models was assessed using simulated data, and their performance was confirmed through experimental verification on two arterial phantoms across a range of pressure values. The first prediction model (FPM) exhibited a mean absolute percentage error (MAPE) of 5.63% for the simulated data and 3.68% for the experimental data. The second prediction model (TPM) demonstrated a MAPE of 6.5% for simulated data and 8.73% for experimental data. We were able to create machine learning models that can measure pressure within an elastic tube through ultrasonically measurable parameters and verified their performance to be adequate for BP measurement applications. This work establishes a pathway for cuffless, continuous, real-time, and non-invasive measurement of BP using ultrasound.

Quantitative analysis of the effect of clothing on the oscillometric waveform envelope and oscillometric blood pressure measurements

Purpose

To ensure accurate blood pressure (BP) measurement, it is important to follow guidelines, such as wearing the cuff on the bare arm. However, this recommendation is often challenging due to patients being dressed. This study quantitatively evaluates how wearing a cuff over clothing impacts BP accuracy using oscillometric waveform analysis.

Methods

BP was measured under three conditions: thick sleeve (3.5 mm), thin sleeve (1.5 mm), and bare arm. Oscillometric waveform envelopes (OMWE) were analyzed to extract features like maximum amplitude, width, and slope for each condition. BP measurements and extracted features from the bare arm condition were compared with those from each sleeve condition.

Results

The mean systolic blood pressure (SBP) and pulse pressure (PP) increased by 11.73 and 10.04 mmHg under thick sleeve conditions. These also increased by 4.308 and 4.731 mmHg under thin sleeve conditions (Thick: p < 0.001, Thin: p < 0.05). The mean of mean arterial pressure (MAP) and OMWE width increased by 5.039 and 5.059 mmHg under thick sleeve conditions (Thick: p < 0.025). The mean of maximum amplitude of OMWE under thick and thin sleeves decreased by 0.9428 and 0.4017 mmHg (Thick, Thin: p < 0.001). Diastolic blood pressure (DBP) increased under thick sleeve conditions; however, this was not statistically significant.

Conclusion

Wearing the cuff over clothing altered OMWE morphology, resulting in a lower, flatter shape similar to that seen in hypertensives. This significantly affected BP readings, particularly SBP. Therefore, following guidelines for cuff placement on bare arms is crucial for accurate BP measurement.

Trial registration number and date

Clinical Research Information Service (CRIS) KCT0008511, 22.05.2023.

Structural, material and functional organisation of centres performing paediatric anaesthesia

OBJECTIVE

The French Society of Anesthesiology and Critical Care (Société Française d'Anesthésie et de Réanimation (SFAR)) and the French association of paediatric intensive care anaesthetists (Association des Anesthésistes Réanimateurs Pédiatriques d'Expression Française (ADARPEF)) have joined forces to provide guidelines for professional practice on the structural, material, and functional organisation of centres performing pediatric anesthesia.

DESIGN

A consensus committee of 16 experts from the SFAR and the ADARPEF was convened. The experts declared no conflict of interest before and throughout the process. The entire guidelines process was conducted independently of any industry funding. The authors were asked to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide the assessment of the quality of evidence.

METHODS

Four fields were defined: (1) structure and logistics; (2) equipment and materials; (3) training; and (4) functional organisation. For each field, the objective of the recommendations was to answer a number of questions formulated according to the PICO model (population, intervention, comparison, and outcomes). Based on these questions, an extensive bibliographic search was carried out on works published from 2000 to 2022, using predefined keywords according to PRISMA guidelines and analyzed using the GRADE® methodology. Because of the very small number of studies that could provide the necessary power for the most important endpoint (i.e., morbidity), it was decided, before drafting the recommendations, to adopt a Recommendations for Professional Practice (RPP) format rather than a Formalised Recommendations of Experts (RFE) format. The recommendations were formulated according to the GRADE® methodology, before being voted on by all the experts according to the GRADE grid method.

RESULTS

The experts' synthesis work and the application of the GRADE® method resulted in 34 recommendations dealing with the structural, material and functional organization of centers performing pediatric anaesthesia. After three rounds of rating and several amendments, an agreement was reached on all the recommendations.

CONCLUSIONS

Strong agreement exists among the experts to provide recommendations aimed at improving the structural, material and functional organization of centers performing paediatric anaesthesia.

Adherence to proper blood pressure measurements among interns at the university of Gondar specialized referral hospital

Introduction

Blood pressure is a lateral force exerted on the wall of arteries and is critical for the normal distribution of blood containing nutrients and oxygen to metabolic tissues. It is one of the vital signs often measured by interns, nurses, and physicians at doctor's offices, at bedside, and possibly at home. Accurate blood pressure measurement is essential for proper diagnosis and management of patients, especially those with hypertension. The aim of this cross-sectional survey study is to assess the practice of measuring blood pressure by interns.

Methods

This study was conducted in the form of a survey administered through face-to-face interviews. All the interns at the Univeristy of Gondar Specialized Referral Hospital were approached. The survey included questions about devices used, patient's information, and blood pressure measurement techniques. Epi-Data version 3.1 was used for data entry and exported to STATA 17 for data management and analysis. The Chi-square test was checked to assess the eligibility of variables for logistic regression. Finally, in the multivariable binary logistic regression analysis, variables with P-value < 0.05 were considered to be statistically significantly associated. The Adjusted Odds Ratio (AOR) with 95% CI was reported to declare the statistical significance and strength of association between blood pressure measurement and independent variables.

Result

The magnitude of appropriate measurement of blood pressure among interns was 10.1 (95% CI: 7.19, 13.9). A total of 318 interns participated in the current study. Of these study participants, 65.4% (208) were males. A increase in participants age (AOR: 1.48, 95% CI: 1.09, 2.01), being male interns (AOR: 5.51, 95% CI: 1.51, 8.97), and having patients who were familiar with the procedure (AOR: 2.95, 95% CI: 1.19, 7.03) were factors significantly associated with appropriate adherence to blood pressure measurement.

Conclusion and recommendation

Only 10% of six-year medical students (Interns) were successful in appropriately assessing blood pressure. Age, being male, and patient understanding were factors significantly associated to the adherence of blood pressure measurement. Considering the frequency of BP measurement and the impact of hypertension on morbidity and mortality, efforts are needed to maximize the quality of BP measurement by health professionals. This process should begin early during training and be consistent throughout their clinical practice, supplemented by ongoing education.

A Deep Convolution Method for Hypertension Detection from Ballistocardiogram Signals with Heat-Map-Guided Data Augmentation

Hypertension (HPT) is a chronic disease characterized by the consistent elevation of arterial blood pressure, which is considered to be a significant risk factor for conditions such as stroke, coronary artery disease, and heart failure. The detection and continuous monitoring of HPT can be a demanding process. As a non-contact measuring method, the ballistocardiography (BCG) signal characterizes the repetitive body motion resulting from the forceful ejection of blood into the major blood vessels during each heartbeat. Therefore, it can be applied for HPT detection. HPT detection with BCG signals remains a challenging task. In this study, we propose an end-to-end deep convolutional model BH-Net for HPT detection through BCG signals. We also propose a data augmentation scheme by selecting the J-peak neighborhoods from the BCG time sequences for hypertension detection. Rigorously evaluated via a public data-set, we report an average accuracy of 97.93% and an average F1-score of 97.62%, outperforming the comparative state-of-the-art methods. We also report that the performance of the traditional machine learning methods and the comparative deep learning models was improved with the proposed data augmentation scheme.

Video-based estimation of blood pressure

In this work, we propose a non-contact video-based approach that estimates an individual's blood pressure. The estimation of blood pressure is critical for monitoring hypertension and cardiovascular diseases such as coronary artery disease or stroke. Estimation of blood pressure is typically achieved using contact-based devices which apply pressure on the arm through a cuff. Such contact-based devices are cost-prohibitive as well as limited in their scalability due to the requirement of specialized equipment. The ubiquity of mobile phones and video-based capturing devices motivates the development of a non-contact blood pressure estimation method-Video-based Blood Pressure Estimation (V-BPE). We leverage the time difference of the blood pulse arrival at two different locations in the body (Pulse Transit Time) and the inverse relation between the blood pressure and the velocity of blood pressure pulse propagation in the artery to analytically estimate the blood pressure. Through statistical hypothesis testing, we demonstrate that Pulse Transit Time-based approaches to estimate blood pressure require knowledge of subject specific blood vessel parameters, such as the length of the blood vessel. We utilize a combination of computer vision techniques and demographic information (such as the height and the weight of the subject) to capture and incorporate the aforementioned subject specific blood vessel parameters into our estimation of blood pressure. We demonstrate the robustness of V-BPE by evaluating the efficacy of blood pressure estimation in demographically diverse, outside-the-lab conditions. V-BPE is advantageous in three ways; 1) it is non-contact-based, reducing the possibility of infection due to contact 2) it is scalable, given the ubiquity of video recording devices and 3) it is robust to diverse demographic scenarios due to the incorporation of subject specific information.

Vital signs-based healthcare kiosks for screening chronic and infectious diseases: a systematic review

BACKGROUND

Increasing demands, such as the COVID-19 pandemic, have presented substantial challenges to global healthcare systems, resulting in staff shortages and overcrowded emergency rooms. Health kiosks have emerged as a promising solution to improve overall efficiency and healthcare accessibility. However, although kiosks are commonly used worldwide for access to information and financial services, the health kiosk industry, valued at $800 million, accounts for just 1.9% of the $42 billion global kiosk market. This review aims to bridge the research-to-practice gap by examining the development of health kiosk technology from 2013 to 2023.

METHODS

We conducted a systematic search across PubMed, IEEE Xplore, and Google Scholar databases, identifying 5,537 articles, with 36 studies meeting inclusion criteria for detailed analysis. We evaluated each study based on kiosk purpose, targeted diseases, measured vital signs, and user demographics, along with an assessment of limitations in participant selection and data reporting.

RESULTS

The findings reveal that blood pressure is the most frequently measured vital sign, utilized in 34% of the studies. Furthermore, cardiovascular disease detection emerges as the primary motivation in 56% of the included studies. The United States, India, and the United Kingdom are notable contributors, accounting for 43% of the reviewed articles. Our assessment reveals considerable limitations in participant selection and data reporting in many studies. Additionally, several research gaps remain, including a lack of performance testing, user experience evaluation, clinical intervention, development standardization, and inadequate sanitization protocols.

CONCLUSIONS

This review highlights health kiosks' potential to ease the burden on healthcare system and expand accessibility. However, widespread adoption is hindered by technical, regulatory, and financial challenges. Addressing these barriers could enable health kiosks to play a greater role in early disease detection and healthcare delivery.

Cuff-based blood pressure measurement: challenges and solutions

OBJECTIVE

Accurate measurement of arterial blood pressure (BP) is crucial for the diagnosis, monitoring, and treatment of hypertension. This narrative review highlights the challenges associated with conventional (cuff-based) BP measurement and potential solutions. This work covers each method of cuff-based BP measurement, as well as cuffless alternatives, but is primarily focused on ambulatory BP monitoring.

RESULTS

Manual BP measurement requires stringent training and standardized protocols which are often difficult to ensure in stressful and time-restricted clinical office blood pressure monitoring (OBPM) scenarios. Home Blood pressure monitoring (HBPM) can identify white-coat and masked hypertension but strongly depends on patient adherence to measurement techniques and procedure. The widespread use of nonvalidated automated HBPM devices raises further concerns about measurement accuracy. Ambulatory blood pressure measurement (ABPM) may be used in addition to OBPM. It is recommended to diagnose white-coat and masked hypertension as well as nocturnal BP and dipping, which are the BP values most predictive for major adverse cardiac events. Nonetheless, ABPM is limited by its non-continuous nature and susceptibility to measurement artefacts. This leads to poor overall reproducibility of ABPM results, especially regarding clinical parameters such as BP variability or dipping patterns.

CONCLUSIONS

Cuff-based BP measurement, despite some limitations, is vital for cardiovascular health assessment in clinical practice. Given the wide range of methodological limitations, the paradigm's potential for improvement is not yet fully realized. There are impactful and easily incorporated opportunities for innovation regarding the enhancement of measurement accuracy and reliability as well as the clinical interpretation of the retrieved data. There is a clear need for continued research and technological advancement to improve BP measurement as the premier tool for cardiovascular disease detection and management.

Clinical validation of a wearable ultrasound sensor of blood pressure

Options for the continuous and non-invasive monitoring of blood pressure are limited. Cuff-based sphygmomanometers are widely available, yet provide only discrete measurements. The clinical gold-standard approach for the continuous monitoring of blood pressure requires an arterial line, which is too invasive for routine use. Wearable ultrasound for the continuous and non-invasive monitoring of blood pressure promises to elevate the quality of patient care, yet the isolated sonographic windows in the most advanced prototypes can lead to inaccurate or error-prone measurements, and the safety and performance of these devices have not been thoroughly evaluated. Here we describe validation studies, conducted during daily activities at home, in the outpatient clinic, in the cardiac catheterization laboratory and in the intensive care unit, of the safety and performance of a wearable ultrasound sensor for blood pressure monitoring. The sensor has closely connected sonographic windows and a backing layer that improves the sensor's accuracy and reliability to meet the highest requirements of clinical standards. The validation results support the clinical use of the sensor.

Commercial Wearables for the Management of People with Autism Spectrum Disorder: A Review

Autism Spectrum Disorder (ASD) necessitates comprehensive management, addressing complex challenges in social communication, behavioral regulation, and sensory processing, for which wearable technologies offer valuable tools to monitor and support interventions. Therefore, this review explores recent advancements in wearable technology, categorizing devices based on executive function, psychomotor skills, and the behavioral/emotional/sensory domain, highlighting their potential to improve ongoing management and intervention. To ensure rigor and comprehensiveness, the review employs a PRISMA-based methodology. Specifically, literature searches were conducted across diverse databases, focusing on studies published between 2014 and 2024, to identify the most commonly used wearables in ASD research. Notably, 55.45% of the 110 devices analyzed had an undefined FDA status, 23.6% received 510(k) clearance, and only a small percentage were classified as FDA Breakthrough Devices or in the submission process. Additionally, approximately 50% of the devices utilized sensors like ECG, EEG, PPG, and EMG, highlighting their widespread use in real-time physiological monitoring. Our work comprehensively analyzes a wide array of wearable technologies, including emerging and advanced. While these technologies have the potential to transform ASD management through real-time data collection and personalized interventions, improved clinical validation and user-centered design are essential for maximizing their effectiveness and user acceptance.

Zero End-Digit Preference in Blood Pressure and Implications for Cardiovascular Disease Risk Prediction-A Study in New Zealand

Background/Objectives: Blood pressure (BP) readings are often rounded to the nearest zero end-digit. Guidelines permit rounding to the closest 2 mmHg. This paper investigated the effect of rounding systolic blood pressure (SBP) values on the prediction of cardiovascular disease (CVD) risk among the New Zealand population. A total of 427,299 individuals received opportunistic cardiovascular disease risk assessments at primary care facilities in New Zealand. Method: A total of 292,122 SBP readings possessed a non-zero terminal digit. These were rounded to the nearest zero end-digit. A survival model estimating a 5-year CVD risk was applied to both datasets, i.e., with and without rounding. Hazard ratios and misclassification rates were analysed to emphasise the notable differences. Financial impact was assessed by examining healthcare expenditures. Results: In total, 32% of SBP values exhibited a terminal digit of zero, and 2.85% and 4.24% of men were misclassified as moderate and high risk, respectively, while approximately 3.21% of women were misclassified into the same risk categories. Likewise, 1.19% and 0.47% of men, as well as 0.62% and 0.20% of women, were misclassified into the low and moderate risk categories, respectively. Conclusions: Precisely measuring SBP is crucial in accurately assessing CVD risk and managing healthcare resources effectively.

Metabolically healthy obesity: from epidemiology and mechanisms to clinical implications

The concept of metabolic health, particularly in obesity, has attracted a lot of attention in the scientific community, and is being increasingly used to determine the risk of cardiovascular diseases and diabetes mellitus-related complications. This Review assesses the current understanding of metabolically healthy obesity (MHO). First, we present the historical evolution of the concept. Second, we discuss the evidence for and against its existence, the usage of different definitions of MHO over the years and the efforts made to provide novel definitions of MHO. Third, we highlight epidemiological data with regard to cardiovascular risk in MHO, which is estimated to be moderately elevated using widely used definitions of MHO when compared with individuals with metabolically healthy normal weight, but potentially not elevated using a novel definition of MHO. Fourth, we discuss novel findings about the physiological mechanisms involved in MHO and how such knowledge helps to identify and characterize both people with MHO and those with metabolically unhealthy normal weight. Finally, we address how the concept of MHO can be used for risk stratification and treatment in clinical practice.

The Liquid Metal Age: A Transition From Hg to Ga

This review offers an illuminating journey through the historical evolution and modern-day applications of liquid metals, presenting a comprehensive view of their significance in diverse fields. Tracing the trajectory from mercury applications to contemporary innovations, the paper explores their pivotal role in industry and research. The analysis spans electrical switches, mechanical applications, electrodes, chemical synthesis, energy storage, thermal transport, electronics, and biomedicine. Each section examines the intricacies of liquid metal integration, elucidating their contributions to technological advancements and societal progress. Moreover, the review critically appraises the challenges and prospects inherent in liquid metal applications, addressing issues of recycling, corrosion management, device stability, economic feasibility, translational hurdles, and market dynamics. By delving into these complexities, the paper advances scholarly understanding and offers actionable insights for researchers, engineers, and policymakers. It aims to catalyze innovation, foster interdisciplinary collaboration, and promote liquid metal-enabled solutions for societal needs. Through its comprehensive analysis and forward-looking perspective, this review serves as a guide for navigating the landscape of liquid metal applications, bridging historical legacies with contemporary challenges, and highlighting the transformative potential of liquid metals in shaping future technologies.

Relationships between sensory processing patterns and metabolic risk factors among community dwelling people with metabolic syndrome: A cross-sectional and correlational research design

BACKGROUND

Metabolic Syndrome (MetS) increases the risk of other serious health problems, particularly cardiovascular diseases and stroke. Sensory processing patterns (SPPs) are internal factors shaping behaviors and emotions, both healthy and unhealthy. There is a lack of studies directly examining the relationship between the SPPs and metabolic risk factors.

METHOD

This study aimed to investigate SPPs and their association with metabolic risk factors in individuals with metabolic syndrome (MetS). One hundred and seventeen individuals with MetS completed questionnaires on demographic characteristics and the Thai Sensory Patterns Assessment-adult version. Data on metabolic risk factors, including fasting blood glucose, blood pressure, and waist circumference, were collected.

RESULTS

The findings revealed high arousal levels in proprioceptive and auditory senses among the participants. The fasting blood glucose was significantly correlated with a preference in the tactile sense (r = -0.150, P<0.05), while waist circumference was associated with arousal level in the auditory and smell-taste senses (r = 0.140, -0.160, P<0.05). Moreover, the GLMM revealed that fasting blood glucose was associated with preferences in tactile, vestibular, and proprioceptive senses (r = -0.481, 0.726, -0.386, P<0.05). Furthermore, diastolic blood pressure was associated with preferences in vestibular sense (r = 0.099; P<0.05).

CONCLUSION

The SPPs might be related to metabolic risk factors, so it is important to recognize how individual SPPs relate to metabolic risk factors. However, further studies using a larger sample may be needed to deeply explore the mechanisms underlying these associations.

Impact of Concurrent Exercise Training on Cardiac Autonomic Modulation, Metabolic Profile, Body Composition, Cardiorespiratory Fitness, and Quality of Life in Type 2 Diabetes with Cardiac Autonomic Neuropathy: A Randomized Controlled Trial

Background: Type 2 diabetes mellitus (T2DM) often leads to cardiac autonomic neuropathy (CAN), a severe complication affecting cardiovascular health. Exercise training is a proven intervention for improving metabolic control and cardiovascular health in T2DM, but the effects of concurrent exercise training (CET), combining aerobic and resistance exercises, on CAN are not fully understood. Objective: This randomized controlled trial investigates the impact of a structured CET program on cardiac autonomic modulation, metabolic profile, body composition, cardiorespiratory fitness (CRF), and quality of life (QoL) in individuals with T2DM and CAN. Methods: A total of 96 participants, aged 35-70 years, with T2DM and CAN, were randomized into CET (n = 48) and control (n = 48) groups. The CET group engaged in combined aerobic and resistance training three times per week for 13 weeks, while the control group received standard care. Primary outcomes included heart rate variability (HRV) and heart rate recovery (HRR). Secondary outcomes were metabolic profile, body composition, CRF, and QoL, which were assessed using standardized protocols and validated questionnaires. The trial was registered with the Clinical Trials Registry-India (CTRI/2021/09/036711). Results: Significant improvements were noted in the CET group compared to controls. HRV metrics (SDNN, RMSSD, pNN50, TP, LF power, HF power, and LF/HF ratio) and HRR metrics (HRR30s, HRR1, HRR2, and HRR3) all showed significant enhancements (p < 0.01). The CET group also exhibited substantial reductions in fasting blood glucose, postprandial blood glucose, HbA1c, waist circumference, hip circumference, and percentage body fat (p < 0.01). Improvements were observed in lipid profile markers and CRF (VO2max) (p < 0.01). QoL scores improved significantly in the CET group as per the ADDQoL-19 (p < 0.01). Conclusions: CET significantly enhances cardiac autonomic modulation, metabolic profile, body composition, CRF, and QoL in individuals with T2DM and CAN. These findings support the integration of CET into standard T2DM management to improve clinical outcomes and QoL. Further research is needed to explore the long-term benefits and broader applicability of CET in diverse diabetic populations.

Regional and socio-demographic variation in laboratory-based predictions of 10-year cardiovascular disease risk among adults in north and south India

OBJECTIVE

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in India. There is no laboratory-based CVD risk data among Indians from different regions and backgrounds. This study estimated laboratory-based 10-year CVD risk across different population sub-groups.

METHODS

Data from UDAY derived from cross-sectional surveys of rural and urban populations of northern (Haryana) and southern (Andhra Pradesh) India were analysed. World Health Organization/International Society of Hypertension laboratory-based equations calculated 10-year CVD risk among participants without CVD history. Wilcoxon rank sum test analyzed average CVD risk across subgroups. Chi-square test compared population proportions in different CVD risk categories. Regression analysis assessed the association between CVD risk and participant characteristics.

RESULTS

The mean (SD) age of the participants (n = 8448) was 53.2 (9.2) years. Males in Haryana had increased CVD risk compared to those in Andhra Pradesh (p < 0.01). In both states, female gender was shown to have a protective effect on CVD risk (p < 0.01). Age correlated with increased risk (p < 0.01). Education level did not affect CVD risk however employment status may have. Hypertension, diabetes, hyperlipidemia, smoking, and insufficient exercise were associated with increased CVD risk (p < 0.01). Residence (urban versus rural) and wealth index did not largely affect CVD risk.

CONCLUSION

Minor differences exist in the distribution of laboratory-based CVD risk across Indian population cohorts. CVD risk was similar in urban wealthy participants and rural poor and working-class communities in northern and southern India. Public health efforts need to target all major segments of the Indian population to curb the CVD epidemic.

The impact of sphygmomanometer placement and cuff placement on blood pressure measurements

Background

Hypertension is the most significant global risk factor for mortality and morbidity, making standardized blood pressure measurement crucial.

Objectives

To investigate whether the location of blood pressure monitors and the positioning of cuffs yield differing results in blood pressure measurements.

Methods

Patients admitted to the Affiliated Hospital of Jiujiang College between 1 January 2022 and 30 June 2023 were enrolled in this study and randomly allocated into four groups. These groups were defined based on the positioning of monitoring equipment as follows: varied placements of cuffs on automatic blood pressure monitors, different heights for mercury column blood pressure monitors, varied heights for automatic blood pressure monitors, and different orientations for the cuff airbag tubes on electrocardiogram monitors. Blood pressure was measured and recorded for each group, followed by an analysis of the variations in readings across the different setups.

Results

In the first cohort of 763 individuals, mean systolic blood pressure measured at the standard upper arm site was 128.8 ± 10.5 mmHg, compared to 125.3 ± 10.4 mmHg at the elbow fossa. The corresponding diastolic pressures were 79.2 ± 10.7 and 75.0 ± 10.6 mmHg, respectively. The difference in systolic pressure between these positions was significant at 3.48 ± 3.22 mmHg (t₁ = 29.91, p₁ < 0.001) and for diastolic pressure at 4.23 ± 1.31 mmHg (t₂ = 88.98, p₂ < 0.001). For the subsequent groups, involving 253, 312, and 225 individuals, respectively, blood pressure measurements were analyzed and compared across different methods within each group. All p-values exceeded 0.05, indicating no statistically significant differences.

Conclusions

Blood pressure values measured at the elbow fossa position using an upper arm-type automatic sphygmomanometer were found to be lower than those measured at the upper arm position, with a difference of 3.48 mmHg for systolic and 4.23 mmHg for diastolic pressures. It is therefore essential to position the cuff correctly, specifically 2-3 cm above the elbow fossa, when utilizing an upper arm-type automatic sphygmomanometer for blood pressure monitoring. Conversely, the placement of the mercury column sphygmomanometer and the automated sphygmomanometer at varying heights had no significant effect on blood pressure readings. Similarly, the orientation of the electrocardiogram's cuffed balloon tube, whether facing upward or downward, did not influence blood pressure measurement outcomes.

Accuracy, precision, and interobserver and intraobserver agreements related to pressure-measurement devices

OBJECTIVE

To evaluate the accuracy, precision, and observer agreement of three pressure measurement devices.

STUDY DESIGN

In vitro model study.

SAMPLE POPULATION

Water manometer with built-in gauge (WMg), arterial pressure transducer (APT), and Compass CT (CCT).

METHODS

The model was set to five predetermined pressures (4, 8, 13, 17, and 24 cm H2O) using a water manometer with a ruler (WMr) as the gold standard. Each device was tested at each pressure in a randomized order by three investigators. Bland-Altman plots were used to assess agreement between devices. Intraclass correlation coefficients (ICC) were calculated for interobserver and intraobserver agreements.

RESULTS

The mean differences (cm H2O) ± SEM in comparison with the set pressure were -0.020 ± 0.010 (WMg), -0.390 ± 0.077 (APT), and -1.267 ± 0.213 (CCT). Pressures measured by WMg did not differ from those measured by WMr. Pressures measured by all devices did not differ from each other (p > .062 for all comparisons). Interobserver agreement was excellent (1.000), and intraobserver agreement was excellent (0.985, 0.990, 0.998 for each observer).

CONCLUSION

Compared to the WMr, the WMg was the most accurate and precise, followed by the APT; the CCT was the least accurate and precise. Interobserver and intraobserver agreements for all three devices were excellent.

CLINICAL SIGNIFICANCE

The largest mean difference of all devices was within 1.3 cm H2O of the set pressure, indicating possible clinical utility of any of the devices. However, WMr or WMg should be considered first due to their high precision and accuracy.

Simultaneous 24-h ambulatory blood pressure measurement on both arms: a consideration for improving hypertension management

OBJECTIVE

Arterial hypertension is one of the common treatment goals in today's medicine. 24-h ambulatory blood pressure measurement (ABPM) performed by oscillometric cuff-based devices is considered as the gold standard in hypertension diagnostics. This study aims at examining the measurement accuracy of a widely used, ABPM device.

METHODS

Fifty-two young and healthy participants underwent simultaneous 24-h ABPM on the left and the right upper arm using two Boso/A&D TM-2430 oscillometric cuff-based devices. Pressure curves of the cuffs, as well as hydrostatic pressure difference between the cuffs were recorded.

RESULTS

The mean differences between both simultaneous measurements were 1.16 mmHg with limits of agreement of 36.23 mmHg for SBP and 1.32 mmHg with limits of agreement of 32.65 mmHg for DBP. Excluding measurements where the pressure curves were disturbed and correcting for hydrostatic pressure difference between the cuffs, reduced the measurement error. However, limits of agreement remained around 20 mmHg. There were large differences in hypertension grading and dipping pattern classification between simultaneous measurements on the left and right arm.

CONCLUSION

The cuff-based ABPM device reveals notable measurement uncertainties, influencing hypertension grading, dipping pattern classification and blood pressure variability. These effects are attributed in part to disturbances during cuff deflation and hydrostatic influences. Nonetheless, ABPM has shown its clinical values in several studies, while this study underscores its still unlocked potential to improve hypertension management.

A Survey on Blood Pressure Measurement Technologies: Addressing Potential Sources of Bias

Regular blood pressure (BP) monitoring in clinical and ambulatory settings plays a crucial role in the prevention, diagnosis, treatment, and management of cardiovascular diseases. Recently, the widespread adoption of ambulatory BP measurement devices has been predominantly driven by the increased prevalence of hypertension and its associated risks and clinical conditions. Recent guidelines advocate for regular BP monitoring as part of regular clinical visits or even at home. This increased utilization of BP measurement technologies has raised significant concerns regarding the accuracy of reported BP values across settings. In this survey, which focuses mainly on cuff-based BP monitoring technologies, we highlight how BP measurements can demonstrate substantial biases and variances due to factors such as measurement and device errors, demographics, and body habitus. With these inherent biases, the development of a new generation of cuff-based BP devices that use artificial intelligence (AI) has significant potential. We present future avenues where AI-assisted technologies can leverage the extensive clinical literature on BP-related studies together with the large collections of BP records available in electronic health records. These resources can be combined with machine learning approaches, including deep learning and Bayesian inference, to remove BP measurement biases and provide individualized BP-related cardiovascular risk indexes.

An Unusual High Bifurcation of the Brachial Artery: A Cadaveric Case Report

The human vascular system exhibits a remarkable degree of anatomical variability, with deviations from conventional arterial branching patterns occasionally encountered. Among these variations, the atypical bifurcation has drawn attention for its infrequent occurrence and potential clinical implications. This study investigates the rare anatomical variation of high bifurcation seen during cadaver dissection in the brachial artery. It emphasizes the relevance of understanding such variations in established vascular anatomy and their clinical implications. Detailed findings from the dissection of the upper limbs, which reveal a high bifurcation in a 40-year-old male cadaver, are presented. The report highlights unique anatomical variations, including a superficial path. The conclusion underscores the rarity of this high bifurcation and its potential impact on medical procedures. It stresses the importance of healthcare professionals being aware of and prepared for such anatomical variations for optimal patient care. In order to manage potential difficulties during medical operations affecting the circulatory system and eventually enhance patient outcomes, it is necessary to understand these deviations.

Predictors of Cardiac Autonomic Dysfunction in Obesity-Related Hypertension

INTRODUCTION

Cardiac Autonomic Dysfunction (CAD) is an overlooked cardiovascular risk factor in individuals with obesity-related hypertension. Despite its clinical significance, there is a notable lack of clarity regarding the pathophysiological correlates involved in its onset and progression.

AIM

The present study aimed to identify potential predictors of CAD in obesity-related hypertension.

METHODS

A total of 72 participants (34 men and 38 women) were enrolled. Comprehensive evaluations were conducted, including cardiac autonomic function assessments, body composition estimation and biochemical analysis. Participants were categorized as CAD-positive or CAD-negative based on Ewing's criteria for autonomic dysfunction. Univariate logistic regression analysis was performed to identify potential predictors for CAD. Multivariate logistic regression models were further constructed by adjusting clinically relevant covariates to identify independent predictors of CAD.

RESULTS

Multivariate logistic regression analysis revealed that resting heart rate (HRrest), (odds ratio, confidence interval: 0.85, 0.78-0.93; p = 0.001) and percentage body fat (BF%), (odds ratio, confidence interval: 0.78, 0.64-0.96; p = 0.018) were significant independent predictors of CAD. Receiver Operating Characteristic curve analysis depicted optimal cut-off values for HRrest and BF% as > 74.1 bpm and > 33.6%, respectively. Multicolinearity analysis showed variance inflation factors (VIF) below the cautionary threshold of 3.

CONCLUSIONS

The HRrest and BF% emerged as significant independent predictors of CAD in obesity-related hypertension. Therapeutic strategies should target HRrest < 74.1 bpm and BF% < 33.6% to mitigate CAD risk in this population. Future trials are required to establish causal relationships and may consider additional confounding variables in obesity-related hypertension.

Smartphone-Based versus Non-Invasive Automatic Oscillometric Brachial Cuff Blood Pressure Measurements: A Prospective Method Comparison Volunteer Study

Introduction: Mobile health diagnostics have demonstrated effectiveness in detecting and managing chronic diseases. This method comparison study aims to assess the accuracy and precision of the previously evaluated OptiBP™ technology over a four-week study period. This device uses optical signals recorded by placing a patient's fingertip on a smartphone's camera to estimate blood pressure (BP). Methods: In adult participants without cardiac arrhythmias and minimal interarm blood pressure difference (systolic arterial pressure (SAP) < 15 mmHg or diastolic arterial pressure (DAP) < 10 mmHg), three pairs of 30 s BP measurements with the OptiBP™ (test method) were simultaneously compared using three pairs of measurements with the non-invasive oscillometric brachial cuff (reference method) on the opposite arm over a period of four consecutive weeks at a rate of two measurements per week (one in the morning and one in the afternoon). The agreement of BP values between the two technologies was analyzed using Bland-Altman and error grid analyses. The performance of the smartphone application was investigated using the International Organization for Standardization (ISO) definitions, which require the bias ± standard deviation (SD) between two technologies to be lower than 5 ± 8 mmHg. Results: Among the 65 eligible volunteers, 53 participants had adequate OptiBP™ BP values. In 12 patients, no OptiBP™ BP could be measured due to inadequate signals. Only nine participants had known chronic arterial hypertension and 76% of those patients were treated. The mean bias ± SD between both technologies was -1.4 mmHg ± 10.1 mmHg for systolic arterial pressure (SAP), 0.2 mmHg ± 6.5 mmHg for diastolic arterial pressure (DAP) and -0.5 mmHg ± 6.9 mmHg for mean arterial pressure (MAP). Error grid analyses indicated that 100% of the pairs of BP measurements were located in zones A (no risk) and B (low risk). Conclusions: In a cohort of volunteers, we observed an acceptable agreement between BP values obtained with the OptiBPTM and those obtained with the reference method over a four-week period. The OptiBPTM fulfills the ISO standards for MAP and DAP (but not SAP). The error grid analyses showed that 100% measurements were located in risk zones A and B. Despite the need for some technological improvements, this application may become an important tool to measure BP in the future.

Performance of wearable watch-type home blood pressure measurement devices in a real-world clinical sample

BACKGROUND

Independent testing of home blood pressure (BP) measurement (HBPM) devices is often lacking, particularly among older and multi-morbid patients.

METHODS

We studied the Bpro G2 (using tonometry), Omron HeartGuide (using occlusive oscillometric technology), and Heartisans (using photoplethysmography) wrist watch HBPM devices against a gold standard brachial sphygmomanometer. To test device performance, we used the ISO81060-2 protocol (though this protocol cannot formally validate cuffless devices). We also used linear mixed models to compare adjusted longitudinal BP measurements between devices. Finally, as a surrogate for usability, we recorded instances of device failure where no BP measurement was returned.

RESULTS

We enrolled 128 participants (median [Q1-Q3] age 53 [40-65] years, 51% male, 46% on antihypertensive drugs), of whom 100 were suitable for the primary analysis. All three devices had mean BP values within 5 mmHg of sphygmomanometry. However, due to insufficient reliability (e.g., wider than accepted standard deviations of mean BP), none of the three devices passed all criteria required by the ISO81060-2 protocol. In adjusted longitudinal analyses, the Omron device also systematically underestimated systolic and diastolic BP (- 8.46 mmHg; 95% CI 6.07, 10.86; p < 0.001; and - 2.53 mmHg; 95% CI - 4.03, - 1.03; p = 0.001; respectively). Nevertheless, compared to the Omron device, BPro and Heartisans devices had increased odds of failure (BPro: odds ratio [OR] 5.24; p < 0.0001; Heartisans: OR 5.61; p < 0.001).

CONCLUSIONS

While we could not formally validate the cuffless devices, our results show that wearable technologies will require improvements to offer reliable BP assessment. This study also highlights the need for validation protocols specifically designed for cuffless BP measurement technologies.

Effects of boron citrate supplementation on cardiometabolic factors, inflammatory biomarkers and anthropometric measures in obese patients: study protocol for a randomised, double-blind clinical trial

INTRODUCTION

Obesity is a chronic disease with serious health consequences, but weight loss is difficult to maintain through lifestyle intervention alone. The efficacy and safety of boron citrate (BC), a novel therapeutic approach, in patients with obesity are not known. The current trial will take place to determine the effects of BC supplementation on cardiometabolic factors, inflammatory biomarkers, anthropometric measures and body composition in obese patients.

METHODS AND ANALYSIS

This double-blind, placebo-controlled, randomised clinical trial will involve 60 eligible obese participants aged 18-60 years. Participants will randomly be allocated to receive either BC capsules (containing 10 mg of boron) in the intervention group or placebo capsules (containing 10 mg of maltodextrin) in the placebo group for 12 weeks. Moreover, physical activity and dietary recommendations will be provided for both groups. To assess the dietary intakes of participants, a 3-day food record (2 days of the week and 1 day of the weekend) will be filled. Cardiometabolic factors, inflammatory biomarkers including tumour necrosis factor α, C reactive protein, interleukin-6 and interleukin-10 levels, anthropometric measures and body composition will be assessed at the baseline and end of the intervention. The findings of this study will provide evidence for the effectiveness of BC in the management of obesity.

ETHICS AND DISSEMINATION

There are so far no reported adverse effects associated with the use of boron. This trial was approved by the Ethics Committee of Tabriz University of Medical Sciences (approval number: IR.TBZMED.REC.1401.350). Positive as well as negative findings will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

IRCT20220806055624N1.

Recent Advances of Nanogenerator Technology for Cardiovascular Sensing and Monitoring

Cardiovascular sensing and monitoring is a widely used function in cardiovascular devices. Nowadays, achieving desired flexibility, wearability and implantability becomes a major design goal for the advancement of this family of devices. As an emerging technology, nanogenerator (NG) offers an intriguing promise for replacing the battery, an essential obstacle toward tissue-like soft electronics. This article reviews most recent advancements in NG technology for advanced cardiovascular sensing and monitoring. Based on the application targets, the discuss covers implantable NGs on hearts, implantable NGs for blood vessel grafts and patches, and wearable NGs with various sensing functions. The applications of NGs as a power source and as an electromechanical sensing element are both discussed. At the end, current challenges in this direction and future research perspectives are elaborated. This emerging and impactful application direction reviewed in this article is expected to inspire many new research and commercialization opportunities in the field of NG technology.

BCG Signal Quality Assessment Based on Time-Series Imaging Methods

This paper describes a signal quality classification method for arm ballistocardiogram (BCG), which has the potential for non-invasive and continuous blood pressure measurement. An advantage of the BCG signal for wearable devices is that it can easily be measured using accelerometers. However, the BCG signal is also susceptible to noise caused by motion artifacts. This distortion leads to errors in blood pressure estimation, thereby lowering the performance of blood pressure measurement based on BCG. In this study, to prevent such performance degradation, a binary classification model was created to distinguish between high-quality versus low-quality BCG signals. To estimate the most accurate model, four time-series imaging methods (recurrence plot, the Gramain angular summation field, the Gramain angular difference field, and the Markov transition field) were studied to convert the temporal BCG signal associated with each heartbeat into a 448 × 448 pixel image, and the image was classified using CNN models such as ResNet, SqueezeNet, DenseNet, and LeNet. A total of 9626 BCG beats were used for training, validation, and testing. The experimental results showed that the ResNet and SqueezeNet models with the Gramain angular difference field method achieved a binary classification accuracy of up to 87.5%.

The burden of non-communicable diseases among people living with HIV in Sub-Saharan Africa: a systematic review and meta-analysis

Background

Non-communicable diseases (NCDs) are increasing among people living with HIV (PLHIV), especially in Sub-Saharan Africa (SSA). We determined the prevalence of NCDs and NCD risk factors among PLHIV in SSA to inform health policy makers.

Methods

We conducted a systematic review and meta-analysis on the prevalence of NCDs and risk factors among PLHIV in SSA. We comprehensively searched PubMed/MEDLINE, Scopus, and EBSCOhost (CINAHL) electronic databases for sources published from 2010 to July 2023. We applied the random effects meta-analysis model to pool the results using STATA. The systematic review protocol was registered on PROSPERO (registration number: CRD42021258769).

Findings

We included 188 studies from 21 countries in this meta-analysis. Our findings indicate pooled prevalence estimates for hypertension (20.1% [95% CI:17.5-22.7]), depression (30.4% [25.3-35.4]), diabetes (5.4% [4.4-6.4]), cervical cancer (1.5% [0.1-2.9]), chronic respiratory diseases (7.1% [4.0-10.3]), overweight/obesity (32.2% [29.7-34.7]), hypercholesterolemia (21.3% [16.6-26.0]), metabolic syndrome (23.9% [19.5-28.7]), alcohol consumption (21.3% [17.9-24.6]), and smoking (6.4% [5.2-7.7]).

Interpretation

People living with HIV have a high prevalence of NCDs and their risk factors including hypertension, depression, overweight/obesity, hypercholesterolemia, metabolic syndrome and alcohol consumption. We recommend strengthening of health systems to allow for improved integration of NCDs and HIV services in public health facilities in SSA. NCD risk factors such as obesity, hypercholesterolemia, and alcohol consumption can be addressed through health promotion campaigns. There is a need for further research on the burden of NCDs among PLHIV in most of SSA.

Funding

This study did not receive any funding.

Standardized protocol of blood pressure measurement and quality control program for the Korea National Health and Nutrition Examination Survey

Accurate blood pressure (BP) measurement is crucial for hypertension detection and management. The Korea National Health and Nutrition Examination Survey (KNHANES) assesses the health of Koreans using representative cross-sectional data. BP measurements were historically done with mercury sphygmomanometers for participants aged ≥10 years. However, KNHANES transitioned to Greenlight 300TM (mercury-free auscultatory device) in 2020 for participants aged ≥6 years and used dual devices (Microlife WatchBP Office AFIB and Greenlight) in 2021-2022. To ensure consistency, KNHANES will adopt Microlife as the unified BP device with Greenlight for device validation from 2023. Under the new protocol, participants aged ≥6 years will have their BP measured three times at 30-second intervals after a 5-minute rest under ambient temperature (20-25℃) and noise ≤65 dB. The average of the 2nd and 3rd readings will be used as the representative BP value. The quality control (QC) program involves four trained examiners passing the "quality control and assurance of BP measurement program" three times annually, and undergoing "video monitoring of weekly calibration process" once a year. Additionally, the QC team will conduct "on-site evaluations of BP measurement" at mobile examination centers three times a year. A Five-Step QC process for BP devices was also developed. This document outlines the standardized BP measurement protocol and rigorous QC program in KNHANES, aiming to ensure accurate and reliable BP data for epidemiological research and public health policymaking in South Korea.

B3X: a novel efficient algorithm for accurate automated auscultatory blood pressure estimation

Objective.The auscultatory technique is still considered the most accurate method for non-invasive blood pressure (NIBP) measurement, although its reliability depends on operator's skills. Various methods for automated Korotkoff sounds analysis have been proposed for reliable estimation of systolic (SBP) and diastolic (DBP) blood pressures. To this aim, very complex methodologies have been presented, including some based on artificial intelligence (AI). This study proposes a relatively simple methodology, named B3X, to estimate SBP and DBP by processing Korotkoff sounds recordings acquired during an auscultatory NIBP measurement.Approach.The beat-by-beat change in morphology of adjacent Korotkoff sounds is evaluated via their cross-correlation. The time series of the beat-by-beat cross-correlation and its first derivative are analyzed to locate the timings of SBP and DBP values. Extensive tests were performed on a public database of 350 annotated measurements, and the performance was evaluated according to the BHS, AAMI/ANSI, and International Organization for Standardization (ISO) quality standards.Main results.The proposed approach achieved 'A' scores for SBP and DBP in the BHS grading system, and passed the quality tests of AAMI/ANSI and ISO standards. The B3X algorithm outperformed two well-established algorithms for oscillometric NIBP measurement in both SBP and DBP estimation. It also outperformed four AI-based algorithms in DBP estimation, while providing comparable performance for SBP, at the cost of a much lower computational burden. The full code of the B3X algorithm is provided in a public repository.Significance.The very good performances ensured by the proposed B3X algorithm, at a low computational cost and without the need for parameter training, support its direct implementation into clinical blood pressure (BP) monitoring devices. The results of this study pave the way for solving/overcoming the trade-off between the accuracy of the auscultatory technique and the objectivity of oscillatory measurements, by bringing an automated auscultatory BP measurement method in clinical practice.

Non-Invasive Estimation of Central Systolic Blood Pressure by Radial Tonometry: A Simplified Approach

BACKROUND

Central systolic blood pressure (cSBP) provides valuable clinical and physiological information. A recent invasive study showed that cSBP can be reliably estimated from mean (MBP) and diastolic (DBP) blood pressure. In this non-invasive study, we compared cSBP calculated using a Direct Central Blood Pressure estimation (DCBP = MBP2/DBP) with cSBP estimated by radial tonometry.

METHODS

Consecutive patients referred for cardiovascular assessment and prevention were prospectively included. Using applanation tonometry with SphygmoCor device, cSBP was estimated using an inbuilt generalized transfer function derived from radial pressure waveform, which was calibrated to oscillometric brachial SBP and DBP. The time-averaged MBP was calculated from the radial pulse waveform. The minimum acceptable error (DCBP-cSBP) was set at ≤5 (mean) and ≤8 mmHg (SD).

RESULTS

We included 160 patients (58 years, 54%men). The cSBP was 123.1 ± 18.3 mmHg (range 86-181 mmHg). The (DCBP-cSBP) error was -1.4 ± 4.9 mmHg. There was a linear relationship between cSBP and DCBP (R2 = 0.93). Forty-seven patients (29%) had cSBP values ≥ 130 mmHg, and a DCBP value > 126 mmHg exhibited a sensitivity of 91.5% and specificity of 94.7% in discriminating this threshold (Youden index = 0.86; AUC = 0.965).

CONCLUSIONS

Using the DCBP formula, radial tonometry allows for the robust estimation of cSBP without the need for a generalized transfer function. This finding may have implications for risk stratification.

Toward Real-Time Blood Pressure Monitoring via High-Fidelity Iontronic Tonometric Sensors with High Sensitivity and Large Dynamic Ranges

Continuous, noninvasive blood pressure (CNIBP) monitoring provides valuable hemodynamic information that renders detection of the early onset of cardiovascular diseases. Wearable mechano-electric pressure sensors that mount on the skin are promising candidates for monitoring continuous blood pressure (BP) pulse waveforms due to their excellent conformability, simple sensing mechanisms, and convenient signal acquisition. However, it is challenging to acquire high-fidelity BP pulse waveforms since it requires highly sensitive sensors (sensitivity larger than 4 × 10-5 kPa-1 ) that respond linearly with pressure change over a large dynamic range, covering the typical BP range (5-25 kPa). Herein, this work introduces a high-fidelity, iontronic-based tonometric sensor (ITS) with high sensitivity (4.82 kPa-1 ), good linearity (R2 > 0.995), and a large dynamic range (up to 180% output change) over a broad working range (0 to 38 kPa). Additionally, the ITS demonstrates a low limit of detection at 40 Pa, a fast load response time (35 ms) and release time (35 ms), as well as a stable response over 5000 load per release cycles, paving ways for potential applications in human-interface interaction, electronic skins, and robotic haptics. This work further explores the application of the ITS in monitoring real-time, beat-to-beat BP by measuring the brachial and radial pulse waveforms. This work provides a rational design of a wearable pressure sensor with high sensitivity, good linearity, and a large dynamic range for real-time CNIBP monitoring.

VidBP: Detecting Blood Pressure from Facial Videos with Personalized Calibration

Recent studies have found that blood volume pulse (BVP) in facial videos contains features highly correlated to blood pressure (BP). However, the mapping from BVP features to BP varies from person to person. To address this issue, VidBP has been proposed as a BP detector that can be calibrated based on an individual's data. VidBP is pre-trained on a large dataset to extract BP-related features from BVP. Then, BVP samples and BP labels of an individual are fed into the pre-trained VidBP to create a personal dictionary of BP-related features. When estimating the individual's BP, the current BP-related feature is compared to the features saved in the dictionary, and the BP labels of the similar features are considered as the BP estimate. The performance of VidBP was evaluated on 640 samples of 16 subjects, and it demonstrated significantly lower errors in BP estimation compared to state-of-the-art methods. The personalized calibration of VidBP is a significant advantage, enabling it to better capture the unique mapping from BVP features to BP for each individual.Clinical relevance This study reports a feasible method to estimate BP from facial videos, providing a convenient and cost-effective way for home BP monitoring.

Food consumption by degree of processing is associated with nocturnal dipping and blood pressure variability: The ELSA-Brasil study

BACKGROUND AND AIMS

Ambulatory blood pressure monitoring (ABPM) allows the assessment of cardiovascular risk markers that cannot be obtained by casual measurements; however, the evidence on the association between food consumption and blood pressure (BP) assessed by ABPM is scarce. We aimed to evaluate the association between food consumption by degree of processing and ambulatory BP.

METHODS AND RESULTS

Cross-sectional analysis (2012-2014) of data from a subsample (n = 815) of ELSA-Brasil cohort participants who performed 24-h ABPM was conducted. Systolic (SBP) and diastolic (DBP) BP means and variability during the 24 h and subperiods (sleep and wake), nocturnal dipping, and morning surge were evaluated. Food consumption was classified according to NOVA. Associations were tested by generalized linear models. The consumption of unprocessed, minimally processed foods, and culinary ingredients (U/MPF&CI) was 63.1% of daily caloric intake, 10.8% of processed (PF), and 24.8% of ultraprocessed (UPF). A negative association was found between U/MPF&CI consumption and extreme dipping (T2: odds ratio [OR] = 0.56, 95% confidence interval [CI] = 0.55-0.58; T3: OR = 0.55; 95% CI = 0.54-0.57); and between UPF consumption and nondipping (T2: OR = 0.68, 95% CI = 0.55-0.85) and extreme dipping (T2: OR = 0.63, 95% CI = 0.61-0.65; T3: OR = 0.95, 95% CI = 0.91-0.99). There was a positive association between PF consumption and extreme dipping (T2: OR = 1.22, 95% CI = 1.18-1.27; T3: OR = 1.34, 95% CI = 1.29-1.39) and sleep SBP variability (T3: Coef = 0.56, 95% CI = 0.03-1.10).

CONCLUSIONS

The high consumption of PF was associated with greater BP variability and extreme dipping, while the U/MPF&CI and UPF consumption were negatively associated with alterations in nocturnal dipping.

The clinical manifestation and outcome of COVID-19 in patients with a history of ischemic heart disease; a retrospective case-control study

INTRODUCTION

Coronary artery disease (CAD) is considered an independent risk factor for COVID-19. However, no study has specifically examined the clinical manifestations and outcomes of COVID-19 in patients with ischemic heart disease (IHD).

METHODS

In a retrospective case-control study between 20 March 2020 to 20 May 2020, the medical record of 1611 patients with laboratory-confirmed SARS-CoV-2 infection was reviewed. IHD was defined as a history of an abnormal coronary angiography, coronary angioplasty, coronary artery bypass graft (CABG), or chronic stable angina. Demographic data, past medical history, drug history, symptoms, vital signs, laboratory findings, outcome, and death were investigated from medical records.

RESULTS

1518 Patients (882 men (58.1%)) with a mean age of 59.3 ± 15.5 years were included in the study. Patients with IHD (n = 300) were significantly less likely to have fever (OR: 0.170, 95% CI: 0.34-0.81, P < 0.001), and chills (OR: 0.74, 95% CI: 0.45-0.91, P < 0.001). Patients with IHD were 1.57 times more likely to have hypoxia (83.3% vs. 76%, OR: 1.57, 95% CI: 1.13-2.19, P = 0.007). There was no significant difference in terms of WBC, platelets, lymphocytes, LDH, AST, ALT, and CRP between the two groups (P > 0.05). After adjusting for demographic characteristics, comorbidities and vital signs, the risk factors for mortality of these patients were older age (OR: 1.04 and 1.07) and cancer (OR: 1.03, and 1.11) in both groups. In addition, in the patients without IHD, diabetes mellitus (OR: 1.50), CKD (OR: 1.21) and chronic respiratory diseases (OR: 1.48) have increased the odds of mortality. In addition, the use of anticoagulants (OR: 2.77) and calcium channel blockers (OR: 2.00) has increased the odds of mortality in two groups.

CONCLUSION

In comparison with non-IHD, the symptoms of SARS-CoV-2 infection such as fever, chills and diarrhea were less common among patients with a history of IHD. Also, older age, and comorbidities (including cancer, diabetes mellitus, CKD and chronic obstructive respiratory diseases) have been associated with a higher risk of mortality in patients with IHD. In addition, the use of anticoagulants and calcium channel blockers has increased the chance of death in two groups without and with IHD.

Continuous Monitoring of Blood Pressure and Vascular Hemodynamic Properties With Miniature Extravascular Hall-Based Magnetic Sensor

Continuous measurement of vascular and hemodynamic parameters could improve monitoring of disease progression and enable timely clinical decision making and therapy surveillance in patients suffering from cardiovascular diseases. However, no reliable extravascular implantable sensor technology is currently available. Here, we report the design, characterization, and validation of an extravascular, magnetic flux sensing device capable of capturing the waveforms of the arterial wall diameter, arterial circumferential strain, and arterial pressure without restricting the arterial wall. The implantable sensing device, comprising a magnet and a magnetic flux sensing assembly, both encapsulated in biocompatible structures, has shown to be robust, with temperature and cyclic-loading stability. Continuous and accurate monitoring of arterial blood pressure and vascular properties was demonstrated with the proposed sensor in vitro with a silicone artery model and validated in vivo in a porcine model mimicking physiologic and pathologic hemodynamic conditions. The captured waveforms were further used to deduce the respiration frequency, the duration of the cardiac systolic phase, and the pulse wave velocity. The findings of this study not only suggest that the proposed sensing technology is a promising platform for accurate monitoring of arterial blood pressure and vascular properties, but also highlight the necessary changes in the technology and the implantation procedure to allow the translation of the sensing device in the clinical setting.

The Influence of FAM13A and PPAR-γ2 Gene Polymorphisms on the Metabolic State of Postmenopausal Women

Recently, we have observed two significant pandemics caused by communicable (COVID-19) and non-communicable factors (obesity). Obesity is related to a specific genetic background and characterized by immunogenetic features, such as low-grade systemic inflammation. The specific genetic variants include the presence of polymorphism of the Peroxisome Proliferator-Activated Receptors gene (PPAR-γ2; Pro12Ala, rs1801282, and C1431T, rs3856806 polymorphisms), β-adrenergic receptor gene (3β-AR; Trp64Arg, rs4994), and Family With Sequence Similarity 13 Member A gene (FAM13A; rs1903003, rs7671167, rs2869967). This study aimed to analyze the genetic background, body fat distribution, and hypertension risk in obese metabolically healthy postmenopausal women (n = 229, including 105 lean and 124 obese subjects). Each patient underwent anthropometric and genetic evaluations. The study has shown that the highest value of BMI was associated with visceral fat distribution. The analysis of particular genotypes has revealed no differences between lean and obese women except for FAM13A rs1903003 (CC), which was more prevalent in lean patients. The co-existence of the PPAR-γ2 C1431C variant with other FAM13A gene polymorphisms [rs1903003(TT) or rs7671167(TT), or rs2869967(CC)] was related to higher BMI values and visceral fat distribution (WHR > 0.85). The co-association of FAM13A rs1903003 (CC) and 3β-AR Trp64Arg was associated with higher values of systolic (SBP) and diastolic blood pressure (DBP). We conclude that the co-existence of FAM13A variants with C1413C polymorphism of the PPAR-γ2 gene is responsible for body fat amount and distribution.

Cholinergic nerve contribution to cutaneous active vasodilation during exercise is similar to whole body passive heating

Sympathetic cholinergic nerve cotransmission is widely accepted as the mechanism of cutaneous active vasodilation (CAVD) during whole body passive heating (passive heating). However, recent research suggests that there may be mechanistic differences in CAVD to heating, depending on the modality of thermal loading. It is unknown whether sympathetic cholinergic cotransmission explains CAVD during exercise. This study sought to confirm the role of cholinergic nerves in CAVD during passive heating and expand these findings to exercise. It was hypothesized that CAVD during both exercise and passive heating would be abolished by cholinergic nerve blockade. Eight young (18-30 yr) recreationally active individuals exercised (1 h seated cycling at 60% V̇o2peak) and were passively heated (∼1 h seated passive heating with mean skin temperature clamped at 39°C by water-perfused suit), in randomized order on separate days. Cholinergic nerves were blocked via Botox ∼2 wk prior to the study. Skin blood flow was assessed using laser Doppler flowmetry and expressed as percent of maximum cutaneous vascular conductance (%CVCmax). At the end of exercise/passive heating, internal temperature had increased by ∼0.7°C. The %CVCmax at the Botox-treated sites (exercise: 19 ± 6 and passive heating: 15 ± 14%CVCmax) was significantly less (P < 0.001) than at the untreated sites (exercise: 35 ± 11 and passive heating: 38 ± 6%CVCmax), but there were no differences between exercise and passive heating (modality, P = 0.909; modality-Botox interaction, P = 0.230). We conclude that CAVD during both exercise and passive heating is mediated by sympathetic cholinergic nerves, a critical thermoregulatory mechanism that appears to be independent of the thermal loading modality.NEW & NOTEWORTHY Our study establishes the primacy of cholinergic nerves to cutaneous active vasodilation during exercise and confirms this model during passive heating using a crossover study design. In addition, the mode of heating, whether passive or exercise induced, did not change the sensitivity of the cholinergic component of the thermoeffector response to increased internal temperature. Thus, cutaneous active vasodilator nerves are responsible for similar skin blood flow responses regardless of how thermal loading is accomplished.

Agreement of high-definition oscillometry at two cuff locations with invasively measured arterial blood pressures in anaesthetised cheetahs

OBJECTIVES

To evaluate the agreement between high-definition oscillometry (HDO) used on the metatarsus or tail base with invasive arterial blood pressures measured in the dorsal pedal artery in anaesthetised cheetahs.

STUDY DESIGN

Prospective clinical study.

ANIMALS

A group of 13 captive adult cheetahs.

METHODS

Cheetahs were immobilised with medetomidine (32-45 μg kg^-1) and tiletamine/zolazepam (0.93-1.39 mg kg^-1) administered intramuscularly, and anaesthesia was maintained with either isoflurane in oxygen or continuous propofol infusion. Invasive blood pressure was measured via a 20 gauge intra-arterial catheter in the dorsal pedal artery in the metatarsus and used as a reference method for pressures simultaneously estimated using HDO on the contralateral metatarsus and tail base. Bland-Altman plots (for repeated measurements) and criteria defined by the American College of Veterinary Internal Medicine (ACVIM) were used to compare agreement according to the anatomical location of the cuff, the anaesthetic maintenance agent and magnitude of the blood pressure.

RESULTS

A total of 147 paired measurements were obtained with HDO on the metatarsus and 135 on the tail. Agreement with invasive pressures was better when HDO was used on the tail (rather than on the metatarsus) with all ACVIM criteria being met. Mean bias (a positive bias meaning that HDO overestimated the invasively measured pressures) ± standard deviation of differences for systolic, diastolic and mean arterial pressures were -7.0 ± 13.9, 4.2 ±12.1 and 4.6 ±11.2 mmHg, respectively, for HDO on the tail, and -11.9 ±15.1, 2.8 ±16.5 and 2.1 ±13.2 mmHg, respectively, for HDO on the metatarsus. Agreement was better during isoflurane anaesthesia than propofol, and at lower blood pressures than at higher.

CONCLUSIONS AND CLINICAL RELEVANCE

When used on the tail base of anaesthetised cheetahs, HDO met the ACVIM validation criteria for a noninvasive device, as compared to invasively measured pressures in the dorsal pedal artery.

The effects of royal jelly supplementation on oxidative stress, inflammatory mediators, mental health, cognitive function, quality of life, and clinical outcomes of patients with ischemic stroke: study protocol for a randomized controlled trial

BACKGROUND

Stroke is a debilitating disease that affects over 15 million people worldwide each year, resulting in the death of one-third of those people and severe disability in two-thirds of survivors. Previous studies reported various health benefits of Royal jelly in the context of its anti-inflammatory properties. We will aim to investigate the effects of royal jelly supplementation on oxidative stress, inflammatory mediators, mental health, cognitive function, quality of life, and clinical outcomes of patients with ischemic stroke.

METHODS

The present study will be a triple-blind randomized placebo trial. Patients who meet our eligibility criteria will be assigned to the intervention or the control groups to receive allocated intervention for 12 weeks. Individuals of the intervention group will consume 1000 mg of Royal jelly dragee daily after breakfast. Subjects of the control group will receive a placebo dragee identical to the Royal jelly dragee. The severity of the stroke, cognitive function, mental health, quality of life, clinical outcomes, and biochemical measures will be assessed at baseline and post-intervention.

DISCUSSION

The current study is designed to investigate the effectiveness and safety of royal jelly supplementation in a randomized, parallel, two-arms, single-center, triple-blind, placebo-controlled manner. This study will provide evidence as a phase III clinical trial.

TRIAL REGISTRATION

IRCT20180818040827N4, registered on 16 October 2021. https://www.irct.ir/trial/59275.

Adverse Effects of Chewing Khat (Catha edulis): A Community-based Study in Ethiopia

Objectives

The purpose of this study was to assess the effects of habitual chewing of khat (Catha edulis) on blood pressure, body mass index, and physiological aspects of sexuality among residents of an Ethiopian town.

Methods

A statistically determined and randomly selected sample of khat-chewing individuals in the town of Hosanna in Southern Ethiopia were included in the study. We used physical measurements and a self-administered questionnaire to collect the data, which was statistically analyzed.

Results

The participants comprised a total of 420 with mean age = 28.7±5.7 years; 336 (80.0%) were male. Nearly half (201; 47.9%) were in the age-group 30-34 years. The adverse effects of khat use were assessed from the median score of each outcome, namely, physical problems, abuse potential, and social effects. Having a score above the median on each of the three target outcomes was equated with the presence of adverse effects. Adverse effects were reported among 341 of 420 (81.2%) participants, of whom 277 of 341 (81.2%) were male and 64 of 341 (18.8%) were female. The reported adverse effects were significantly higher among those who co-used tobacco, coffee, or tea with khat, with adjusted odds ratio = 4.8; CI: 2.86-8.22.

Conclusions

Khat chewing was found to have a significant adverse effect on the health of individuals who indulged in it. This finding implies the need for urgent intervention from health authorities.

Intensive care photoplethysmogram datasets and machine-learning for blood pressure estimation: Generalization not guarantied

The large MIMIC waveform dataset, sourced from intensive care units, has been used extensively for the development of Photoplethysmography (PPG) based blood pressure (BP) estimation algorithms. Yet, because the data comes from patients in severe conditions-often under the effect of drugs-it is regularly noted that the relationship between BP and PPG signal characteristics may be anomalous, a claim that we investigate here. A sample of 12,000 records from the MIMIC waveform dataset was stacked up against the 219 records of the PPG-BP dataset, an alternative public dataset obtained under controlled experimental conditions. The distribution of systolic and diastolic BP data and 31 PPG pulse morphological features was first compared between datasets. Then, the correlation between features and BP, as well as between the features themselves, was analysed. Finally, regression models were trained for each dataset and validated against the other. Statistical analysis showed significant p < 0.001 differences between the datasets in diastolic BP and in 20 out of 31 features when adjusting for heart rate differences. The eight features showing the highest rank correlation ρ   >   0.40 to systolic BP in PPG-BP all displayed muted correlation levels ρ   <   0.10 in MIMIC. Regression tests showed twice higher baseline predictive power with PPG-BP than with MIMIC. Cross-dataset regression displayed a practically complete loss of predictive power for all models. The differences between the MIMIC and PPG-BP dataset exposed in this study suggest that BP estimation models based on the MIMIC dataset have reduced predictive power on the general population.

Advancement in the Cuffless and Noninvasive Measurement of Blood Pressure: A Review of the Literature and Open Challenges

Hypertension is a chronic condition that is one of the prominent reasons behind cardiovascular disease, brain stroke, and organ failure. Left unnoticed and untreated, the deterioration in a health condition could even result in mortality. If it can be detected early, with proper treatment, undesirable outcomes can be avoided. Until now, the gold standard is the invasive way of measuring blood pressure (BP) using a catheter. Additionally, the cuff-based and noninvasive methods are too cumbersome or inconvenient for frequent measurement of BP. With the advancement of sensor technology, signal processing techniques, and machine learning algorithms, researchers are trying to find the perfect relationships between biomedical signals and changes in BP. This paper is a literature review of the studies conducted on the cuffless noninvasive measurement of BP using biomedical signals. Relevant articles were selected using specific criteria, then traditional techniques for BP measurement were discussed along with a motivation for cuffless measurement use of biomedical signals and machine learning algorithms. The review focused on the progression of different noninvasive cuffless techniques rather than comparing performance among different studies. The literature survey concluded that the use of deep learning proved to be the most accurate among all the cuffless measurement techniques. On the other side, this accuracy has several disadvantages, such as lack of interpretability, computationally extensive, standard validation protocol, and lack of collaboration with health professionals. Additionally, the continuing work by researchers is progressing with a potential solution for these challenges. Finally, future research directions have been provided to encounter the challenges.

What is essential remains invisible to the eyes? Blood pressure cuffs colonized by bacterial diversity

Using sphygmomanometers to measure blood pressure is a common practice in the healthcare context. The disinfection and maintenance of these devices is essential in clinical practice to prevent the proliferation of microorganisms. The aim of this study was to determine the presence of pathogenic microorganisms in sphygmomanometer cuffs in the clinical setting. A cross-sectional study was carried out. Five types of healthcare centers, selected through convenience sampling, participated in this study. Samples were collected from the inside of sphygmomanometer cuffs, and labeled and delivered to the laboratory for analysis. The samples were incubated in an oven at 35.5 °C for 24 h. A total CFU count was carried out on the plates that were cataloged as positive. Colonies that showed growth were identified using the matrix-assisted laser desorption/ionization-mass spectrometry technology. Of the total sample, (N = 372), 69.1% were positive and were isolated. In 30.9% (n = 115), no bacterial development was found within 48 h. A total of 257 microorganisms were found. The mean number of colony-forming units was 29.62 (SD = 32.33). The socio-health centers had the highest amount of bacterial contamination in the cuffs. In regards to the type of microorganisms, 31.5% (n = 81) found were Bacillus cereus, followed by 26.8% (n = 69) of Staphylococcus hominis and 9.7% (n = 25) were Pantoea agglomerans, among others. Statistically significant differences were found between the type of microorganism and the hours elapsed since the last disinfection (X²(19) = 44.582; p = 0.001). Statistically significant differences were found between the time elapsed since the last disinfection and the type of sphygmomanometer (X² (2) = 117.752; p = 0.000). Despite the fact that most hospitals and health centers have established infection control policies and protocols, the results of this study indicate the presence of pathogenic microorganisms in blood pressure cuffs in the clinical setting.

Measuring the quality of antenatal care in a context of high utilisation: evidence from Telangana, India

BACKGROUND

Antenatal care coverage has dramatically increased in many low-and middle-income settings, including in the state of Telangana, India. However, there is increasing evidence of shortfalls in the quality of care women receive during their pregnancies. This study aims to examine dimensions of antenatal care quality in Telangana, India using four primary and secondary data sources.

METHODS

Data from two secondary statewide data sources (National Family Health Survey (NFHS-5), 2019-21; Health Management Information System (HMIS), 2019-20) and two primary data sources (a facility survey in 19 primary health centres and sub-centres in selected districts of Telangana; and observations of 36 antenatal care consultations at these facilities) were descriptively analysed.

RESULTS

NFHS-5 data showed about 73% of women in Telangana received all six assessed antenatal care components during pregnancy. HMIS data showed high coverage of antenatal care visits but differences in levels of screening, with high coverage of haemoglobin tests for anaemia but low coverage of testing for gestational diabetes and syphilis. The facility survey found missing equipment for several key antenatal care services. Antenatal care observations found blood pressure measurement and physical examinations had high coverage and were generally performed correctly. There were substantial deficiencies in symptom checking and communication between the woman and provider. Women were asked if they had any questions in 22% of consultations. Only one woman was asked about her mental health. Counselling of women on at least one of the ten items relating to birth preparedness and on at least one of six danger signs occurred in 58% and 36% of consultations, respectively.

CONCLUSION

Despite high coverage of antenatal care services and some essential maternal and foetal assessments, substantial quality gaps remained, particularly in communication between healthcare providers and pregnant women and in availability of key services. Progress towards achieving high quality in both content and experience of antenatal care requires addressing service gaps and developing better measures to capture and improve women's experiences of care.

Non-invasive blood pressure estimation combining deep neural networks with pre-training and partial fine-tuning

Objective. Daily blood pressure (BP) monitoring is essential since BP levels can reflect the functions of heart pumping and vasoconstriction. Although various neural network-based BP estimate approaches have been proposed, they have certain practical shortcomings, such as low estimation accuracy and poor model generalization. Based on the strategy of pre-training and partial fine-tuning, this work proposes a non-invasive method for BP estimation using the photoplethysmography (PPG) signal.Approach. To learn the PPG-BP relationship, the deep convolutional bidirectional recurrent neural network (DC-Bi-RNN) was pre-trained with data from the public medical information mark for intensive care (MIMIC III) database. A tiny quantity of data from the target subject was used to fine-tune the specific layers of the pre-trained model to learn more individual-specific information to achieve highly accurate BP estimation.Main results.The mean absolute error and the Pearson correlation coefficient (r) of the proposed algorithm are 3.21 mmHg and 0.919 for systolic BP, and 1.80 mmHg and 0.898 for diastolic BP (DBP). The experimental results show that our method outperforms other methods and meets the requirements of the Association for the Advancement of Medical Instrumentation standard, and received an A grade according to the British Hypertension Society standard.Significance.The proposed method applies the strategy of pre-training and partial fine-tuning to BP estimation and verifies its effectiveness in improving the accuracy of non-invasive BP estimation.

Temporal fluctuations of cardiovascular parameters after intravitreal injections

BACKGROUND

Despite the effectiveness of intravitreal injection (IVI) of anti-vascular endothelial growth factor in treating retinal diseases, there remains a paucity of evidence on potential systemic risks associated with this procedure. This study aims to investigate cardiovascular parameters and the risk of hypertensive urgency after IVIs.

METHODS

Patients who received IVIs for retinal/macular diseases were enrolled retrospectively. Patients who received cataract surgeries were enrolled as controls. Systolic and diastolic blood pressure (BP) and heart rate were measured 10 minutes before, immediately after, and more than 30 minutes after IVIs and cataract surgery. Multivariate analysis was performed to evaluate risk factors for hypertensive urgency.

RESULTS

Seventy patients who received IVIs and 95 patients who received cataract surgeries were enrolled. A higher preoperative systolic BP was found in the IVI groups than in the control group (147.0 ± 22.9 vs 136.3 ± 21.8 mmHg, respectively). The patients who received IVIs had a higher increase in perioperative systolic BP immediately after the procedure than the controls (17.43 ± 20.53 mmHg vs 9.11 ± 18.92 mmHg, p = 0.009). The IVI procedure (odds ratio [OR] 4.84, p = 0.008), preoperative systolic BP ≥160 mmHg (OR 17.891, p = 0.001, compared to preoperative systolic BP <140 mmHg), and underlying hypertension (OR 3.305, p = 0.041) were risk factors for hypertensive urgency immediately after the IVIs.

CONCLUSION

We found a transient increase in BP after IVIs, which may have been associated with hypertensive urgency and related cardiovascular disorders in older patients and in those with relevant comorbidities. Clinicians should pay more attention to these patients before performing IVIs.

Efficacy of olive leaves extract on the outcomes of hospitalized covid-19 patients: A randomized, triple-blinded clinical trial

Introduction

Since the emergence of the novel coronavirus, herbal medicine has been considered a treatment for COVID-19 patients. This study was done to determine the efficacy of olive leaf extract on the outcomes of COVID-19 patients.

Materials and Methods

This randomized, triple-blinded clinical trial was conducted on hospitalized COVID-19 patients. Using block randomization, eligible patients were allocated to the following groups: intervention A received olive leaf extract (250 mg every 12 hours for five days), intervention B received olive leaf extract (500 mg every 12 hours for five days), and the control group received placebo (every 12 hours for five days). The outcomes (vital signs, laboratory tests, and length of hospitalization) were compared by group.

Results

Of the 150 patients randomized into groups, 141 completed the follow-up and were analyzed. On the fifth day of hospitalization, body temperature (MD=0.34, P<0.001), pulse rate (MD=5.42, P=0.016), respiratory rate (MD=1.66, P=0.001), ESR (MD=13.55, P<0.001), and CRP (MD=15.68, P<0.001) of intervention A were significantly lower than the control group, while oxygen saturation (MD= -1.81, P=0.001) of intervention A was significantly higher than the control group. Furthermore, body temperature (MD=0.30, P=0.001), pulse rate (MD=5.29, P=0.022), respiratory rate (MD=1.41, P=0.006), ESR (MD=14.79, P<0.001), and CRP (MD=16.28, P<0.001) of intervention B were significantly lower than the control group, while oxygen saturation (MD= -2.38, P<0.001) of intervention B was significantly higher than the control group.

Conclusion

Olive leaf extract can improve the clinical status of the patients and decrease the length of hospitalization.

Blood Pressure Measurement: From Cuff-Based to Contactless Monitoring

Blood pressure (BP) determines whether a person has hypertension and offers implications as to whether he or she could be affected by cardiovascular disease. Cuff-based sphygmomanometers have traditionally provided both accuracy and reliability, but they require bulky equipment and relevant skills to obtain precise measurements. BP measurement from photoplethysmography (PPG) signals has become a promising alternative for convenient and unobtrusive BP monitoring. Moreover, the recent developments in remote photoplethysmography (rPPG) algorithms have enabled new innovations for contactless BP measurement. This paper illustrates the evolution of BP measurement techniques from the biophysical theory, through the development of contact-based BP measurement from PPG signals, and to the modern innovations of contactless BP measurement from rPPG signals. We consolidate knowledge from a diverse background of academic research to highlight the importance of multi-feature analysis for improving measurement accuracy. We conclude with the ongoing challenges, opportunities, and possible future directions in this emerging field of research.