Blood Pressure Monitoring Device Research Articles

A novel cuffless blood pressure monitoring device in hypertension care

Background: Hypertension management is challenged by the dynamic nature of blood pressure (BP) fluctuations. These fluctuations are influenced by factors such as physical activity, emotional changes, and sleep patterns. Traditional guidelines focus on static measurements taken in clinical settings. However, these readings may not accurately represent an individual’s typical BP levels. This approach can lead to misdiagnoses, such as white coat or masked hypertension, resulting in either unnecessary treatment or missed diagnoses.Current Concepts: Recent global hypertension guidelines emphasize the importance of home BP monitoring and 24-hour ambulatory BP measurements for more accurate diagnoses and treatment plans. However, several barriers exist, such as the high cost of ambulatory BP devices and practical challenges associated with home BP monitoring, which limit their widespread utilization. Despite these challenges, integrating BP measurements into mobile devices offers a promising approach to monitoring BP outside the clinical setting. Various innovative approaches have been developed, including smartwatches utilizing photoplethysmography sensors and machine learning algorithms. However, their accuracy and the need for periodic calibration are areas of concern.Discussion and Conclusion: Mobile device BP monitoring represents a significant advancement in hypertension management, offering the potential for continuous, convenient, and less intrusive monitoring. Despite these potential benefits, challenges such as device accuracy verification, large-scale data interpretation, and calibration must be addressed. The future of hypertension management will likely rely on these technologies, along with traditional methods, to provide better insight into individual BP profiles. This integration promises to improve hypertension diagnosis, management, and ultimately patient outcomes, although further research and development are necessary to overcome the current limitations.

Real-time monitoring system for blood pressure monitoring based on internet of things

Real-time monitoring system for blood pressure monitoring based on internet of things

FEASIBILITY OF WATCH-TYPE CUFF-LESS BLOOD PRESSURE MEASUREMENT DEVICE IN DAILY BLOOD PRESSURE MONITORING

Objective: Cuff-less blood pressure (BP) measurement devices integrated into smartwatches have gained prominence for daily monitoring, yet limited studies provide the analysis of real-world BP data collected by such devices. In this study, we evaluated the feasibility of photoplethysmographic BP measuring smartwatch by analyzing data collected in real-world. Design and method: The campaign, “Smartwatch Blood Pressure Monitoring Challenge with Korean Hypertension Society”, was held in June 1-14, 2023 and 896 participants reported 35592 BP values measured by smartwatch (Samsung Galaxy Watch 6, approved in Korean Ministry of Food and Drug Safety). Participants were instructed to measure BP daily, in the morning (5AM-8AM) and evening (6PM-9PM) for two weeks, with initial calibration and re-calibration after the first week. We evaluated 1) BP difference between before and after re-calibration, and 2) difference in morning and evening BP. We also evaluated the determining factors of the BP differences. Results: Morning and evening BP values showed significant difference, higher in the evening by 1.42±5.25 mmHg (p<0.05). However, the diurnal variation was much smaller than reported in other studies using conventional BP monitoring devices. ANOVA identified significant variables for evening-morning differences, including basal metabolic rate, skeletal muscle mass, total body water, average systolic BP (SBP), diastolic BP (DBP), and heart rate in the morning (p < 0.01 in both ITT and PP). Participants who have evening-morning difference higher than the third quartile, where evening SBP was significantly higher than morning SBP, exhibited smaller variable sizes. Turkey’s Honest Significant Difference showed that this relationship is statistically significant between Q1-Q4 and Q2-Q4 in all variables. The calibration stability was assessed by the difference in average BP before and after calibration, resulting in an SBP difference of 4.64±4.73 mmHg and DBP of 3.66±3.62 mmHg, smaller than a 2021 campaign (6.8±5.6mmHg). When the difference of average was measured between same period of time (morning versus morning and evening versus evening), SBP of 5.39±5.22 mmHg and DBP of 4.3±3.99 mmHg. Conclusions: In conclusion, watch-based devices may not detect clinical-level BP variability, but refining calibration protocols offers improvement potential.

Assessing Priorities in a Statewide Cardiovascular and Diabetes Health Collaborative Based on the Results of a Needs Assessment: Cross-Sectional Survey Study.

The Ohio Cardiovascular and Diabetes Health Collaborative (Cardi-OH) unites general and subspecialty medical staff at the 7 medical schools in Ohio with community and public health partnerships to improve cardiovascular and diabetes health outcomes and eliminate disparities in Ohio's Medicaid population. Although statewide collaboratives exist to address health improvements, few deploy needs assessments to inform their work. Cardi-OH conducts an annual needs assessment to identify high-priority clinical topics, screening practices, policy changes for home monitoring devices and referrals, and preferences for the dissemination and implementation of evidence-based best practices. The results of the statewide needs assessment could also be used by others interested in disseminating best practices to primary care teams. A cross-sectional survey was distributed electronically via REDCap (Research Electronic Data Capture; Vanderbilt University) to both Cardi-OH grant-funded and non-grant-funded members (ie, people who have engaged with Cardi-OH but are not funded by the grant). In total, 88% (103/117) of Cardi-OH grant-funded members and 8.14% (98/1204) of non-grant-funded members completed the needs assessment survey. Of these, 51.5% (53/103) of Cardi-OH grant-funded members and 47% (46/98) of non-grant-funded members provided direct clinical care. The top cardiovascular medicine and diabetes clinical topics for Cardi-OH grant-funded members (clinical and nonclinical) were lifestyle prescriptions (50/103, 48.5%), atypical diabetes (38/103, 36.9%), COVID-19 and cardiovascular disease (CVD; 38/103, 36.9%), and mental health and CVD (38/103, 36.9%). For non-grant-funded members, the top topics were lifestyle prescriptions (53/98, 54%), mental health and CVD (39/98, 40%), alcohol and CVD (27/98, 28%), and cardiovascular complications (27/98, 28%). Regarding social determinants of health, Cardi-OH grant-funded members prioritized 3 topics: weight bias and stigma (44/103, 42.7%), family-focused interventions (40/103, 38.8%), and adverse childhood events (37/103, 35.9%). Non-grant-funded members' choices were family-focused interventions (51/98, 52%), implicit bias (43/98, 44%), and adverse childhood events (39/98, 40%). Assessment of other risk factors for CVD and diabetes across grant- and non-grant-funded members revealed screening for social determinants of health in approximately 50% of patients in each practice, whereas some frequency of depression and substance abuse screening occurred in 80% to 90% of the patients. Access to best practice home monitoring devices was challenging, with 30% (16/53) and 41% (19/46) of clinical grant-funded and non-grant-funded members reporting challenges in obtaining home blood pressure monitoring devices and 68% (36/53) and 43% (20/46) reporting challenges with continuous glucose monitors. Cardi-OH grant- and non-grant-funded members shared the following high-priority topics: lifestyle prescriptions, CVD and mental health, family-focused interventions, alcohol and CVD, and adverse childhood experiences. Identifying high-priority educational topics and preferred delivery modalities for evidence-based materials is essential for ensuring that the dissemination of resources is practical and useful for providers.

A Direct Assessment of Noninvasive Continuous Blood Pressure Monitoring in the Emergency Department and Intensive Care Unit

IntroductionNoninvasive continuous blood pressure monitoring has the potential to improve patient treatment in the hospital setting. Such noninvasive devices can be applied earlier in the treatment process to empower nurses and clinicians to react more quickly to patient deterioration with the added benefit of eliminating the risks associated with invasive monitoring. However, emerging technologies must be capable of reproducing current clinical measures for medical decision making. MethodsThis study aimed to determine the usability and willingness of nurses to implement a noninvasive continuous blood pressure monitoring device. The secondary aim directly compared the systolic blood pressure, diastolic blood pressure, and mean arterial pressure values recorded by the device (VitalStream; CareTaker Medical LLC, Charlottesville, VA) with the “gold standard” brachial cuff and arterial line measures recorded in the emergency department and intensive care unit settings. ResultsVitalStream was similarly received by nurses in the emergency department and intensive care setting, but ultimately had greater promotion from emergency nurses. Despite some statistical similarity between measurement methodologies, all direct comparisons were found to not meet the Association for the Advancement of Medical Instrumentation 2008 and Association for the Advancement of Medical Instrumentation / European Society of Hypertension / International Organization for Standardization 2019 consensus statement criteria for acceptable blood pressure measure differences between the VitalStream and “gold standard” clinical measures. In all instances, the standard deviation of the Bland-Altman bias exceeded 8 mm Hg with less than 85% of paired differences falling within 10 mm Hg of the “gold standard.” DiscussionTaken together, the tested device requires additional postprocessing for medical decision making in trauma or emergent care.

Abstract P310: Preference for Home Blood Pressure Monitoring versus Ambulatory Blood Pressure Monitoring for Measuring Sleep Blood Pressure: The BetterBP Study

Background: Home blood pressure (BP) monitoring (HBPM) devices have been adapted as an alternative to ambulatory BP monitoring devices (ABPM) for measuring sleep BP. We evaluated participants' preference for using HBPM versus ABPM to monitor sleep BP in the BetterBP study. Methods: Participants in the BetterBP study (N=591) completed one night of HBPM (3 measurements total) and 24 hours of ABPM (measurements every 30 minutes) in random order. After completing both procedures, participants were asked about the side effects experienced, willingness to again perform HBPM for one night versus ABPM for 24 hours to monitor sleep BP, and overall preference for HBPM versus ABPM for monitoring BP. We used McNemar’s test to evaluate differences between devices. Results: Among all 591 participants, the mean age was 39 years old, and 63% were women. Additionally, 49% were non-Hispanic, White; 21% were non-Hispanic, Black; 15% were non-Hispanic, Asian; and 7% were Hispanic. Interference of normal sleeping pattern was less common for HBPM compared with ABPM (46% versus 57%; p<0.001). Overall, 7% and 6% of participants reported removing the HBPM and ABPM device, respectively, due to disturbance while sleeping (p=0.88). Also, 27% of participants reported pain while undergoing HBPM for one night compared to 47% for ABPM (p<0.001); 43% had irritation while undergoing HBPM for one night compared to 68% for ABPM (p<0.001); and 12% had bruising while undergoing HBPM compared to 23% for ABPM (p<0.001). For the willingness to perform one night of HBPM versus ABPM to monitor sleep BP, 80% were very or completely willing to use HBPM compared to 60% who were very or completely willing to use ABPM ( Table , p<0.001). For overall preference, 71% of participants preferred HBPM, 24% preferred ABPM, and 5% did not prefer either HPBM or ABPM. Conclusion: Participants reported fewer side effects and greater tolerability with HBPM than ABPM and preferred one night of HBPM over 24 hours of ABPM to monitor sleep BP.

Validation of the Meditech ABPM-06 24-hour blood pressure monitoring system in a pediatric population according to International Organization for Standardization Protocol 81060-2:2018.

Ambulatory blood pressure monitoring (ABPM) devices play a crucial role in diagnosing hypertension, not only in adults but also in pediatric patients. ABPM-06, the latest oscillometric device from Meditech Ltd. (Budapest, Hungary), is the focus of this study. The objective was to validate the ABPM-06 device using the International Organization for Standardization (ISO) 81060-2 : 2018 standard. A total of 86 healthy patients, consisting of 34 males and 52 females, aged between 3 and 17 years, were enrolled in this study. During the ambulatory phase, a total of 50 patients were enrolled, with 35 patients falling within the 3- to 12-year-old age range and 15 patients aged between 12 and 17 years. Additionally, for the dynamic test, 36 patients were selected, comprising of 10 individuals aged 3-12 years and 26 patients aged 12-17 years. These patients were recruited from the outpatient clinics of the Department of Pediatrics at Albert Szent-Györgyi University in Szeged, Hungary. The validation process involved utilizing the same-arm sequence protocol, both in resting positions and during stress testing. The ABPM-06 performed well in both clinical and ambulatory validations. In terms of validation criterion 1, the mean ± SD of the differences between the test device and reference blood pressure readings was -1.3 ± 3.5 mmHg for systolic and -0.1 ± 2.3 mmHg for diastolic, in children under the age of 12 years. For those over the age of 12 years, the mean ± SD of the differences was -2.8 ± 4.6 mmHg for systolic and -0.5 ± 2.7 mmHg for diastolic. Regarding the ambulatory validation, for children under 12 years old, the mean ± SD of the differences was -1.3 ± 3.5 mmHg for systolic and -0.1 ± 2.3 mmHg for diastolic. In the age group above 12 years, the mean ± SD of the differences was -2.8 ± 4.6 mmHg for systolic and -0.5 ± 2.7 mmHg for diastolic. Both tests successfully met the established criteria regarding the mean and SD values of the differences between the device readings and the observed SBP and DBP measurements. The ABPM-06 oscillometric device fully adheres to the ISO 81060-2 : 2018 standard requirements for ABPM determination in the pediatric population (ages 3-17 years). Consequently, this ABPM device proves to be suitable for effectively managing hypertension in children and adolescents.

Value and Variability of Pulse Shape Indicator for Estimating Mean Arterial Pressure in the Radial and Femoral Arteries.

The form factor (FF) is a pulse shape indicator that corresponds to the fraction of pulse pressure added to diastolic blood pressure to estimate the time-averaged mean arterial pressure (MAP). Our invasive study assessed the FF value and variability at the radial and femoral artery levels and evaluated the recommended fixed FF value of 0.33. Hemodynamically stable patients were prospectively included in 2 intensive care units. FF was documented at baseline and during dynamic maneuvers. A total of 632 patients (64±16 years of age, 66% men, MAP=81±14 mm Hg) were included. Among them, 355 (56%) had a radial catheter and 277 (44%) had a femoral catheter. The FF was 0.34±0.06. In multiple linear regression, FF was influenced by biological sex (P<0.0001) and heart rate (P=0.04) but not by height, weight, or catheter location. The radial FF was 0.35±0.06, whereas the femoral FF was 0.34±0.05 (P=0.08). Both radial and femoral FF were higher in women than in men (P<0.05). When using the 0.33 FF value to estimate MAP, the error was -0.4±4.0 mm Hg and -0.1±2.9 mm Hg at the radial and femoral level, respectively, and the MAP estimate still demonstrated high accuracy and good precision even after changes in norepinephrine dose, increase in positive end-expiratory pressure level, fluid administration, or prone positioning (n=218). Despite higher FF in women and despite interindividual variability in FF, using a fixed FF value of 0.33 yielded accurate and precise estimations of MAP. This finding has potential implications for blood pressure monitoring devices and the study of pulse wave amplification.

Photoplethysmography for Assessing Microcirculation in Hypertensive Patients After Taking Antihypertensive Drugs: A Review.

High blood pressure (BP) is a common disease and is associated with many chronic diseases. Measuring BP is essential for the treatment and management of many diseases, and therefore there is a growing need for a non-invasive, sleeveless and continuous BP monitoring device. With the development of technology, pulse waveform analysis using photoplethysmography (PPG) has become more feasible for evaluating BP. This study aimed to evaluate the changes of vascular elasticity and blood volume over time by using the characteristic parameters extracted by PPG. We reviewed the latest progress and literature on the observation of capillary network characteristics in hypertensive and non-hypertensive patients by PPG, the influence of different drugs on microcirculation characteristics in hypertensive patients with PPG, and further explored the key relationship between microcirculation and hypertension. We found that the PPG waveform produced by the fingertips of hypertensive patients is very different from that of healthy people, and the PPG waveform changes significantly during diastolic period after antihypertensive treatment. With the rapid development of medical technology, people can get more intuitive microcirculation image data, which provides beneficial help for the comprehensive understanding of hypertension.

Feasibility and Effectiveness of a Ring-Type Blood Pressure Measurement Device Compared With 24-Hour Ambulatory Blood Pressure Monitoring Device.

This study aimed to evaluate the applicability and precision of a ring-type cuffless blood pressure (BP) measurement device, CART-I Plus, compared to conventional 24-hour ambulatory BP monitoring (ABPM). Forty patients were recruited, and 33 participants were included in the final analysis. Each participant wore both CART-I Plus and ABPM devices on the same arm for approximately 24 hours. BP estimation from CART-I Plus, derived from photoplethysmography (PPG) signals, were compared with the corresponding ABPM measurements. The CART-I Plus recorded systolic blood pressure (SBP)/diastolic blood pressure (DBP) values of 131.4±14.1/81.1±12.0, 132.7±13.9/81.9±11.9, and 128.7±14.6/79.3±12.2 mmHg for 24-hour, daytime, and nighttime periods respectively, compared to ABPM values of 129.7±11.7/84.4±11.2, 131.9±11.6/86.3±11.1, and 124.5±13.6/80.0±12.2 mmHg. Mean differences in SBP/DBP between the two devices were 1.74±6.69/-3.24±6.51 mmHg, 0.75±7.44/-4.41±7.42 mmHg, and 4.15±6.15/-0.67±5.23 mmHg for 24-hour, daytime, and nighttime periods respectively. Strong correlations were also observed between the devices, with r=0.725 and r=0.750 for transitions in SBP and DBP from daytime to nighttime, respectively (both p<0.001). The CART-I Plus device, with its unique ring-type design, shows promising accuracy in BP estimation and offers a potential avenue for continuous BP monitoring in clinical practice. ClinicalTrials.gov Identifier: NCT06084065.

Novel Pulse Waveform Index by Ambulatory Blood Pressure Monitoring and Cardiac Function: A Pilot Study

BackgroundA simple ambulatory measure of cardiac function could be helpful for monitoring heart failure patients. ObjectivesThe purpose of this paper was to determine whether a novel pulse waveform analysis using data obtained by our developed multisensor-ambulatory blood pressure monitoring (ABPM) device, the 'Sf/Am' ratio, is associated with echocardiographic left ventricular ejection fraction (LVEF). MethodsMultisensor-ABPM was conducted twice at baseline in 20 heart failure (HF) patients with HF-reduced LVEF or HF-preserved LVEF (median age 66 years, male 65%) and over a 6- to 12-month follow-up after patient-tailored treatment. We assessed the changes in the pulse waveform index Sf/Am and LVEF that occurred between the baseline and follow-up. The Sf/Am consists of the area of the ejection part in the square forward wave (Sf) and the amplitude of the measured wave (Am). We divided the patients into the recovered (n = 11) and not-recovered (n = 9) groups defined by a ≥10% increase in LVEF. ResultsAlthough the ambulatory BP levels and variabilities did not change in either group, the Sf/Am increased significantly in the recovered group (baseline 21.4 ± 4.5; follow-up, 25.6 ± 3.7, P = 0.004). The not-recovered group showed no difference between the baseline and follow-up. The follow-up/baseline Sf/Am ratio was significantly associated with the LVEF ratio (r = 0.469, P = 0.037). The Sf/Am was significantly correlated with the LVEF in overall measurements (n = 40, r = 0.491, P = 0.001). ConclusionsThese results demonstrated that a novel noninvasive pulse waveform index, the Sf/Am measured by multisensor-ABPM is associated with LVEF. The Sf/Am may be useful for estimating cardiac function.

Agreement Between Guideline Thresholds Using an "All-in-One" Device to Measure Office, Home, and Ambulatory Blood Pressures.

Blood pressure (BP) thresholds for diagnosing and managing hypertension vary for office, home, and ambulatory readings, and between guideline documents. This analysis determined corresponding office, home, and ambulatory BP thresholds using baseline data from the HI-JAMP (Home-Activity Information and Communication Technology-Based Japan Ambulatory Blood Pressure Monitoring Prospective) study, which used a validated "all-in-one" BP monitoring device. Data from 2322 treated patients with hypertension who underwent office BP measurement, then 24-hour ambulatory BP monitoring, then home BP monitoring for 5 days were analyzed. Corresponding BP thresholds for office, home, and ambulatory measurements were determined using Deming regression. Values equivalent to office systolic BP (SBP) of 120 and 140 mm Hg were as follows: 115.9 and 127.7 mm Hg for 24-hour ambulatory SBP; 120.8 and 134.0 mm Hg for daytime ambulatory SBP; 104.9 and 117.9 mm Hg for nighttime ambulatory SBP; and 122.0 and 134.2 mm Hg for morning-evening average home SBP. Deming regression showed that morning-evening average home SBP and daytime ambulatory SBP were almost the same (home SBP=0.99×daytime ambulatory SBP+0.27 mm Hg; r=0.627). Morning-evening average home SBP values of 120 and 135 mm Hg were equivalent to daytime ambulatory SBP values of 119.1 and 133.9 mm Hg, respectively. A home SBP threshold of 130 mm Hg corresponded to 24-hour and nighttime ambulatory SBP values of 123.5 and 113.6 mm Hg, whereas a home SBP threshold of 135 mm Hg corresponded to 24-hour and nighttime ambulatory SBP values of 128.0 and 119.2 mm Hg. Ambulatory and home BP thresholds in this analysis were similar to those proposed by existing guidelines. The similarity between the home BP and daytime ambulatory BP thresholds was a clinically relevant finding.

Association of estimated white matter hyperintensity age with cognition in hypertensive elderly

AbstractBackgroundHypertension is associated with white matter hyperintensity (WMH) and cognitive impairment. Further, WMH is associated with cognitive impairment including executive, attention and visuospatial functions. The aim of this study was to investigate the effects of controlled hypertension (cHT) and previously developed concept, ‘WMH age’ on cognitive function and the mediating role of WMH in the effect of cHT on cognitive impairment.MethodWe enrolled 855 Koreans without dementia aged 60 years or older, 326 of whom completed 2‐year follow‐up assessment. We measured their blood pressure thrice in a sitting position using an automated blood pressure monitoring device. We estimated ‘WMH age’ of every participant using previously developed WMH probability map of healthy older Koreans. We analyzed the mediating effect of WMH age in the association of cHT and cognitive function using the PROCESS Macro model.ResultOld WMH age was associated with a faster decline in the Mini‐Mental Status Examination (MMSE; p = .003), Consortium to Establish a Registry for Alzheimer’s Disease total score (CERAD‐TS; p = .003), and Frontal Assessment Battery (FAB; p = .007). Old WMH age showed an approximately‐six times higher risk of incident mild cognitive impairment (OR = 6.47, 95% CI = 1.37 – 9.50, p = .024) compared to young or normal WMH age over the 2‐year follow‐up period in the cHT group. WMH age mediated the effects of cHT on the MMSE, CERAD‐TS, and FAB scores at baseline and two‐year follow‐up period.ConclusionWMH mediates the adverse effect of hypertension on cognitive function. Elders with cHT who have older WMH age may be at a higher risk of cognitive decline.

3D Printing of Polyvinylidene Fluoride‐Based Piezoelectric Sensors for Noninvasive Continuous Blood Pressure Monitoring

The successful fabrication and application of 3D‐printed piezoelectric sensors, made from polyvinylidene fluoride‐barium titanate nanocomposites, for continuous blood pressure (BP) monitoring, is presented. The sensors are fabricated using direct‐ink write 3D printing technique possessing excellent flexibility, rendering them ideal for wearable applications. Key printing parameters, such as nozzle size and pressure, are optimized to achieve a β‐phase of 70% and an overall crystallinity of 48.3%. The sensors are characterized under dynamic pressures and show excellent linearity with a coefficient of determination (R2) of 0.99 and a pressure sensitivity of 0.024 V kPa−1, and demonstrate durability over 3600 cycles. The performance of our piezoelectric sensors is compared with a standard BP monitoring device for a subject, and a strong correlation with a standard deviation of 3.87 and 0.63 mmHg for sytolic BP and diastolic BP, respectively, is found. The development of sensors through 3D printing, as demonstrated in this study, represents a significant scientific advancement in the field of personalized healthcare. This novel approach enables the creation of customized wearable devices tailored for real‐time health monitoring of BP and heart rate.

Performance of a cuffless blood pressure monitor in the adult and elderly population - a comparative validation study

Abstract Background Cuffless blood pressure (BP) monitoring devices are emerging as powerful tools for BP monitoring and management of hypertension, particularly in the elderly, in whom prevalence of hypertension is high. Some cuffless BP monitors allow the hourly and daily tracking of blood pressure. It remains unclear, however, whether cuffless devices yield equivalent performance across age categories. Purpose To compare the performance of BP measurements conducted by a cuffless BP monitor in different body positions in adult and elderly participants with a wide range of BP levels. Methods 2 cohorts of patients (adult, 21-65 years; elderly, 65-85 years) were recruited for a prospective clinical study (NCT04027777) between August/2019–March/2022. During 4 visits over a month, systolic/diastolic BP (SBP, DBP) measurements obtained by the investigated cuffless wrist bracelet were compared to the reference measurement – double auscultation – in a sitting, standing and lying position after a unique initial calibration. The two ISO 81060-2 criteria were used for the comparison of BP measurements by the cuffless monitor and auscultation (BP-reading-level – criterion 1; subject-level – criterion 2) in the sitting position (there are no ISO criteria for other body positions). The mean differences on SBP and DBP between cohorts both at BP-reading-level and at subject-level were compared (unpaired t-test). Results 96 adult (38±12 years)/35 elderly (73±6 years) were included in the study. Of those, 84 adult/35 elderly patients were investigated in sitting position; 91 adult/35 elderly in all body positions. SBP and DBP were significantly higher in the elderly cohort (SBP 116.4±20.3 vs. 133.9±17.7 mmHg, P≤0.0001; DBP 74.5±12.0 vs. 77.9±11.7 mmHg, P≤0.0001). The results for the analyses at BP-reading-level and subject-level are shown in Table 1. For the analyses on sitting position at BP-reading-level, SBP and DBP for both cohorts were within ISO targets for mean error and SD. At subject-level, the SD of the mean paired differences per subject were within individual ISO targets for SBP and DBP on both cohorts. Statistically significant differences between cohorts were found only at BP-reading-level for all body positions, although the magnitude of differences were not clinically relevant (Table 1, bold and *). Figure 1 highlights the biases and correlations of SBP and DBP readings between the cuffless BP monitor and auscultation for both adult and elderly cohorts. Conclusions The cuffless BP monitor investigated in the present study yielded equivalent BP measurements compared to auscultation, with similar performance in the adult and elderly populations.Table 1Figure 1

Abstract 15801: Nighttime Hypertension is a Risk Factor for Cardiovascular Events in Stage B Heart Failure Patients

Background: Nighttime blood pressure (BP) was reported to have a stronger association with cardiovascular outcome and hypertensive organ damage than clinic BP, 24-hour BP, and daytime BP in hypertensives. However, the significance of nighttime BP was not established in stage B heart failure (HF) patients. We hypothesized that nighttime BP measured by home BP monitoring device was associated with cardiovascular outcome in stage B HF patients. Method: We used the dataset of Japan Morning Surge-Home Blood Pressure study (J-HOP study), and selected 417 of stage B HF patients. The definition of stage B HF was based on Universal definition of HF. The patients with history of HF hospitalization were excluded. BP was measured on waking, before bedtime and during the night. The cardiovascular event was followed. Result: Mean follow-up period was 6.6±3.8 years, and 59 cardiovascular events were occurred. When nighttime hypertension was defined as nighttime BP &gt;120mmHg, nighttime HT group showed higher BMI, serum creatinine, HbA1c, and higher prevalence of diabetes, atrial fibrillation, and chronic kidney disease, and lower HDL-cholesterol than nighttime normotension (NT) group. With regard to BP, nighttime HT group, clinic BP, home morning BP, home evening BP, and home nighttime BP were higher in nighttime HT group than in nighttime NT group. In Kaplan-Meier analysis, nighttime HT group had a higher incident of cardiovascular event than nighttime NT group (P&lt;0.01). In Cox multivariate analysis, nighttime HT was significant predictor for cardiovascular event adjusting by significant variables (Hazard ratio 1.84, 95% Confidence interval: 1.01-3.36, P=0.046). Conclusions: Nighttime HT was a prognostic factor in stage B HT patients. Nighttime BP was a therapeutic target to improve the outcome in stage B HT patients.

WATCH-BPM-Comparison of a WATCH-Type Blood Pressure Monitor with a Conventional Ambulatory Blood Pressure Monitor and Auscultatory Sphygmomanometry.

Smart devices that are able to measure blood pressure (BP) are valuable for hypertension or heart failure management using digital technology. Data regarding their diagnostic accuracy in comparison to standard noninvasive measurement in accordance to Riva-Rocci are sparse. This study compared a wearable watch-type oscillometric BP monitor (Omron HeartGuide), a wearable watch-type infrared BP monitor (Smart Wear), a conventional ambulatory BP monitor, and auscultatory sphygmomanometry. Therefore, 159 consecutive patients (84 male, 75 female, mean age 64.33 ± 16.14 years) performed observed single measurements with the smart device compared to auscultatory sphygmomanometry (n = 109) or multiple measurements during 24 h compared to a conventional ambulatory BP monitor on the upper arm (n = 50). The two BP monitoring devices were simultaneously worn on the same arm throughout the monitoring period. In a subgroup of 50 patients, single measurements were also performed with an additional infrared smart device. The intraclass correlation coefficient (ICC) between the difference and the mean of the oscillometric Omron HeartGuide and the conventional method for the single measurement was calculated for both systole (0.765) and diastole (0.732). This is exactly how the ICC was calculated for the individual mean values calculated over the 24 h long-term measurement of the individual patients for both systole (0.880) and diastole (0.829). The ICC between the infrared device and the conventional method was "bad" for SBP (0.329) and DBP (0.025). Therefore, no further long-term measurements were performed with the infrared device. The Omron HeartGuide device provided comparable BP values to the standard devices for single and long-term measurements. The infrared smart device failed to acquire valid measurement data.

Beat-to-beat continuous blood pressure estimation with optimal feature set of PPG and ECG signals using deep recurrent neural networks

Aim: Continuous blood pressure (BP) monitoring can provide invaluable information for cardiovascular disease (CVD) diagnosis. The purpose of this study is to develop a deep recurrent neural network (RNN) model with an optimal feature set of photoplethysmogram (PPG) and electrocardiogram (ECG) signals for continuous BP estimation. Methods: This paper presents a novel deep recurrent neural network (RNN), which consists of 2-layered bidirectional Long Short-term Memory (Bi-LSTM) and 6-layered LSTM networks. It is used to estimate BP based on the optimal feature set of PPG and ECG signals. In this work, the optimal feature set is determined using five different feature selection methods. Results: The proposed method is evaluated based on 660 subjects from the University of California Irvine (UCI) machine learning repository. The RNN model with optimal feature set achieved root mean square error (RMSE) of 3.223 and 1.781 mmHg for systolic BP (SBP) and diastolic BP (DBP), respectively. It also showed mean absolute error (MAE) of 2.514 and 1.383 mmHg for SBP and DBP, respectively. Regarding the British Hypertension Society (BHS) standard, the results attained grade A for the estimation of SBP and DBP. Conclusion: The experimental results suggest that the proposed deep RNN model with an optimal feature set can improve the performance of BP prediction. Thus, it is possible to further apply our proposed method to develop a wearable device for real-time BP monitoring.

Pearls and pitfalls of cuffless blood pressure monitoring devices

Cuffless blood pressure measuring devices are emerging as alternatives for out-of-office assessment of patients with hypertension. This novel technology promises to deliver continuous or beat-to-beat blood pressure measurement and resolve some of the inconveniences associated with conventional cuff-based devices such as improper cuff fit, discomfort, low adherence to monitoring, and technical challenges. Blood pressure can be estimated based on phenomena related to cardiovascular activity: pulse wave velocity, pulse wave analysis, tonometry, and volume clamping. In this narrative review, we seek to summarize current approaches for nontraditional measurement of blood pressure and discuss some of the benefits and limitations of this technology.

The Promise and Illusion of Continuous, Cuffless Blood Pressure Monitoring.

Blood pressure (BP) fluctuations outside of clinic are increasingly recognized for their role in the development of cardiovascular disease, syncope, and premature death and as a promising target for tailored hypertension treatment. However, current cuff-based BP devices, including home and ambulatory devices, are unable to capture the breadth of BP variability across human activities, experiences, and contexts. Cuffless, wearable BP devices offer the promise of beat-to-beat, continuous, noninvasive measurement of BP during both awake and sleep periods with minimal patient inconvenience. Importantly, cuffless BP devices can characterize BP variability, allowing for the identification of patient-specific triggers of BP surges in the home environment. Unfortunately, the pace of evidence, regulation, and validation testing has lagged behind the pace of innovation and direct consumer marketing. We provide an overview of the available technologies and devices for cuffless BP monitoring, considerations for the calibration and validation of these devices, and the promise and pitfalls of the cuffless BP paradigm.