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Attractor reconstruction is a new way to quantify the morphology of a cardiovascular waveform by plotting all data points in the three-dimensional phase space, generating a trajectory of overlapping loops. The aim of this study is to show the feasibility of an automatic approach to quantify pulse wave attractors from a device-guided breathing study, and to link attractor features to pulse waveform features. The recently developed feature extraction technique is applied to arterial pulse waveform data of 30 patients with treated hypertension. The patients performed a device-guided slow breathing exercise. The generated attractors were categorized into three different shapes: triangular attractors, bent attractors and attractors with overlapping arms. The average height of the attractors continuously and progressively dropped from 41.8 [35.4, 55.1] AU to 34.5 [25.4, 47.3] AU (p < 0.001) during the breathing exercise. We have shown that the novel approach to quantify pulse wave attractors is feasible and can be used to detect changes in the morphology of arterial pulse waveforms. Device-guided slow breathing exercise has a shrinking effect on the average height of the attractors, which may indicate a reduction in blood pressure. [ABSTRACT FROM AUTHOR]

Medical devices are subject to strict regulatory and approval processes to enter the market and to be used by operators and patients. These are needed to guarantee the users' safety. The diferent activities of these processes have important implications for all involved stakeholders and for the whole lifecycle of a medical device. The aim of this work is to provide an overview of some key aspects of the new EU Medical Device Regulation and to show why researchers, innovators and clinicians should care about it. Awareness of regulatory requirements can improve the innovation process and its efciency in terms of both social and ethical impact, but this awareness needs to be raised in the upcoming months and years. One can shortly say "yes, one needs to take care" of the new EU Medical Device Regulation. First and foremost, it is crucial for the sake of the users' safety, which is the regulation's intrinsic goal. Second, it should not just be seen as an obstacle for new innovations in the medical domain, but as a chance as it can provide new opportunities. [ABSTRACT FROM AUTHOR]

Background: Assistive technologies have the potential to facilitate everyday life of people with dementia and their families. Close collaboration with affected people and interdisciplinary research are essential to understand and address the needs of prospective users. In this study, we present the results of the evaluation of such an assistive system prototype. Aims: Challenges from the patient and caregiver side, technical and design problems and acceptance and usability with regard to our special target group were evaluated. Methods: MEMENTO, a system of two e-ink tablets and a smartwatch, was tested in the domestic environment of dementia patients. Thirty participants from Italy, Spain and Austria took part in a 3-month field trial and compared the MEMENTO system to traditional strategies in everyday life. Quantitative and qualitative data were collected and frequency of use of the system was monitored. Results: There were no significant changes in quantitative measurements, such as activities of daily living and caregiver burden over the duration of the 3-month field trial. More frequent usage was significantly correlated with positive attitude towards technology (r = 0.723, p < 0.05), but not with age. The design of the system was positively emphasized, reducing fear of the technology on the one hand and stigmatization on the other. Conclusion: We show that a positive attitude towards technology is the essential variable for successful implementation of such systems, regardless of age. Participants showed great interest in digital solutions and agreed that technological systems will help in maintaining independency of persons with cognitive dysfunction in the future. [ABSTRACT FROM AUTHOR]

In December 2019, an outbreak of pneumonia caused by a novel Coronavirus (COVID-19) spread rapidly worldwide. Although the clinical manifestations of COVID-19 are dominated by respiratory symptoms, the cardiovascular system is extensively affected at multiple levels. Due to the unprecedented consequences of the COVID-19 pandemic, the ARTERY society decided to launch the Covid-19 effects on ARTErial StIffness and vascular AgeiNg (CARTESIAN) study — the first international multicentre study into the effects of COVID-19 on non-invasive biomarkers of vascular ageing. The main study objective is to evaluate the presence of Early Vascular Ageing (EVA) 6 and 12 months after COVID-19 infection. Secondary objectives are to study the effect of COVID-19 disease severity on EVA, to investigate the role of psychosocial factors in COVID-19 induced EVA, and to investigate the potential modifying effect of comorbidities and chronic treatments. In the CARTESIAN study, a broad array of cardiovascular measurements, including carotid-femoral pulse wave velocity, central blood pressure, carotid ultrasound, brachial flow-mediated dilatation, will be performed. To date, 43 centres from 21 countries have agreed to participate, with an expected study population of >2500 individuals. To our knowledge, CARTESIAN will be the first study to provide insight into the relationship between COVID-19, its severity, and early vascular ageing in a large cohort, potentially enabling future care and diagnostics to be more focused on the most vulnerable. [ABSTRACT FROM AUTHOR]

VascAgeNet is a new European network which will join forces in order to refine, harmonize and promote the vascular ageing concept. It aims to bring innovations in cardiovascular research from bench to bedside and to establish assessment of vascular ageing in clinical practice. The interdisciplinary, inter-country and intersectional approach will enable all important players at the different stages of the innovation process to come together, as recommended in the triple or quadruple helix model of innovation, in order to guarantee best solutions. This is deemed necessary in order for economic and revolutionary solutions to be fit for wide-spread clinical use, especially in low-income and inclusiveness target countries. Thus, a clear case exists for a strong collaboration between science and industry, to foster innovations and breakthroughs in vascular ageing in order to improve clinical practice and to reduce the burden of cardiovascular diseases globally. [ABSTRACT FROM AUTHOR]

Cardiovascular Disease (CVD) is the leading cause of morbidity and mortality worldwide, regardless of gender, ethnicity or income. Evidence that vascular age, as opposed to chronological age, is better related to the prognosis of CVD is convincing. Despite recent technological advances for the measurement of vascular ageing, unmet needs remain which currently limit the assessment of vascular ageing in routine clinical practice. These unmet needs include: (1) lack of easy-to-use, affordable techniques/devices, (2) insufficient validation in clinical settings, (3) fragmentation of expertise in few research laboratories globally, and (4) lack of investigator/research driven intervention studies and head-to-head comparisons between different measurement techniques. This paper summarises how a recently awarded European COoperation in Science and Technology (COST) Action on Vascular Ageing (VascAgeNet) will address these unmet needs. The broad aim of the COST Action VascAgeNet is to establish a network which will work to refine, harmonize and promote the use of vascular ageing biomarkers, in order to improve clinical practice and to reduce the burden of CVD globally. [ABSTRACT FROM AUTHOR]

Background: Steady state hemodynamics [Stroke Volume - SV, cardiac output, peripheral resistance (Rp)] have attracted researchers in hypertension for decades. However, due to technical difficulties, they never entered clinical medicine. Objective: To investigate the performance of a model-based algorithm, utilizing brachial pressure waveforms obtained with a cuff, to estimate stroke volume. The model combines a modified three-element like Windkessel system and transmission line theory. Participants and Methods: In study 1, 97 patients with reperfused acute myocardial infarction and two healthy controls underwent cardiac magnetic resonance imaging (1.5 Tesla Magnetom, Siemens, Germany), and SV was measured with standard protocols from short axis cine images (11 slices). In study 2, 19 healthy individuals (12 females) had SVs measured with inert gas rebreathing at rest, and during light exercise (20 watts) on a bicycle ergometer. In both studies, model-based SV, estimated with a brachial cuff, was the comparator. Results: In study 1, both SVs were moderately correlated (r = 0.54, p < 0.001). Using the method of Bland–Altman, mean difference between both methods was 8.7 ml (1.96 limits of agreement were 36.7 and –19.3 ml), with no systematic bias. In study 2, both SVs were moderately correlated at rest (r = 0.63, p = 0.004) and at light exercise (r = 0.70, p = 0.0057). Using the method of Bland-Altman, mean difference between both methods was 8.6 ml (1.96 limits of agreement were 39.2 and –22.0 ml) at rest, and 42.7 ml (1.96 limits of agreement were 95.4 and –10.1 ml) at light exercise. Conclusion: Brachial oscillometry and mathematical modeling provide a reasonable estimate of SV under static conditions, which may be a useful addition to 24-h measurements of blood pressure and pulsatile hemodynamics. [ABSTRACT FROM AUTHOR]

Background: Regulation is part of the technology innovation process and has a key role within the lifecycle of a medical device aiming at ensuring effectiveness and safety for users (1). Ever-increasing regulatory requirements (e.g., the Regulation MDR (EU) 2017/745) impact on the development of novel and already approved systems (2, 3). Debating and raising awareness is important since it can improve the transfer of knowledge and expertise among the relevant stakeholders. Thus, the implementation of a survey to explore knowledge and perception of the regulatory framework of medical devices for the assessment of vascular age can be helpful for the involved community. Methods: A multidisciplinary team including clinicians, researchers and developers from VascAgeNet was established to design and implement a digital questionnaire. A secure, open-source, two-factor authentication system for generation, distribution, and data collection of the survey supported by the European Commission (EUSurvey, https://ec. europa. eu/eusur vey) was adopted. Results: The questionnaire has received ethical clearance by National Council of Research, Italy (Notification 0063984/2021) and University College London (17999/002) Research Ethics Committees and is being distributed digitally (e.g., within VascAgeNet, Artery Society etc.). The anonymous questionnaire is available at https://ec. europa. eu/eusur vey/runner/REGUL ATORY Surve y2022 or by scanning the QR code below, it takes approximately 10 min to complete. Conclusions: A survey related to regulation and medical devices for vascular ageing assessment has been developed and is available for the community. The results could inspire concrete actions reducing gap between research and clinical practice. [ABSTRACT FROM AUTHOR]

Introduction: Vascular Age (VA) can assess cardiovascular disease risk, independently of chronological age, however it is not yet widely applied in routine clinical practice. A quantitative questionnaire was developed to assess current knowledge gaps related to VA and barriers to implementation in routine practice in both research and clinical settings. Methods: Using a stepwise mixed-methods approach, a quantitative questionnaire was constructed. The 22-item anonymous survey was based on a previous qualitative analysis including 80 participants with multiple scientific backgrounds, and included questions on perceptions/beliefs, knowledge, and implementation of VA. The survey was disseminated to clinicians and researchers world-wide, via social media and targeted emails from well-known societies (including Artery, ESH, ISH, ESC). Results: 276 (50% female) completed the questionnaire, 46% were clinicians, 33% researchers, 10% students. Clinical specialties included cardiology (36%), internal medicine (22%) and General Practice (10%). While 84% of clinicians and researchers rate VA importance as high or very high (Table), only 11% of clinicians measure VA in clinical settings. Limiting factors include cost, lack of guidelines and lack of knowledge. Discussion: These results show that implementation of VA is very low in clinical settings and awareness of VA needs to be improved via planned targeted awareness strategies and educational material. [ABSTRACT FROM AUTHOR]

Ant clustering algorithms are a robust and flexible tool for clustering data that have produced some promising results. This paper introduces two improvements that can be incorporated into any ant clustering algorithm: kernel function similarity weights and a similarity memory model replacement scheme. A kernel function weights objects within an ant’s neighborhood according to the object distance and provides an alternate interpretation of the similarity of objects in an ant’s neighborhood. Ants can hill-climb the kernel gradients as they look for a suitable place to drop a carried object. The similarity memory model equips ants with a small memory consisting of a sampling of the current clustering space. We test several kernel functions and memory replacement schemes on the Iris, Wisconsin Breast Cancer, and Lincoln Lab network intrusion datasets. Compared to a basic ant clustering algorithm, we show that kernel functions and the similarity memory model increase clustering speed and cluster quality, especially for datasets with an unbalanced class distribution, such as network intrusion. [ABSTRACT FROM AUTHOR]

Introduction: Microgravity in space is known to cause major alterations in the cardiovascular system. Left ventricular ejection time (LVET) can be measured by the time from the onset point of the pressure wave to the incisura of the dicrotic notch. The aim of this study was to simulate microgravity by head-down tilt bedrest (HDT) to examine changes in LVET in female and male subjects. Methods: 24 healthy subjects (16 males and 8 females, height 176 ± 7 cm, weight 77 ± 6 kg, age 37 ± 10 years) were enrolled in a HDT study. The bed rest study applied strict –6° HDT for 60 days. Pulse wave measurements were taken using an oscillometric pressure cuff on the brachial artery. LVET index (LVETi) was calculated according to Weissler et al [1]. LVETis of different measurement times were compared using repeated measures ANOVA with post-hoc analysis using paired t-tests and Bonferroni correction. Results: Figure shows a decrease of LVETi during bed rest, followed by a sharp rise of LVETi after bed rest. Repeated measures ANOVA confirmed significant differences between measurement times. The increase of LVETi from each HDT measurement day to 4 days after HDT (R + 4) was significant (p < 0.001). There were no significant differences comparing male and female subjects. Discussion/Conclusion: Overall, we conclude that LVETi decreased during HDT and reached four days after bed rest a similar level as before for both female and male subjects. As LVETi removes heart rate induced effects on LVET, the change in LVETi might be a result of change in ventricular ejection and afterload. [ABSTRACT FROM AUTHOR]

Background: Association of Ambulatory Blood Pressure Monitoring (ABPM) with mortality depends on cardiac function in hemodialysis patients. Evidence for the predictive power of central Systolic Pressure (cSBP) is inconclusive. Thus, this study aimed to investigate the additional information of ambulatory cSBP in risk prediction in a cohort of hemodialysis patients. Methods: Within the ISAR-study cohort, 344 hemodialysis patients underwent 24 h ABPM on the dialysis day. All-cause and cardiovascular mortality served as endpoints. Risk prediction was performed using Cox regression in patients with or without atrial fibrillation (AF) or heart failure (HF) for peripheral (pSBP) and central systolic pressure calibrated with peripheral systolic and diastolic pressure (cSBP1) or peripheral mean and diastolic pressure (cSBP2). Results: During a mean follow-up of 37.6 (17.5 SD) months, 115 patients died, of whom 47 due to cardiovascular reasons.Inpatients with AF or HF, a negative association to mortality could be observed, independent of pressure location and calibration (see Table). In patients without AF or HF, these associations were to the opposite directions and cSBP2 was superior to pSBP and cSBP1 for all-cause (pSBP: HR = 1.01, p = 0.30; cSBP1: HR = 1.00, p = 0.77; cSBP2: HR = 1.01, p = 0.06) and cardiovascular (pSBP: HR = 1.03, p = 0.02; cSBP1: HR = 1.02, p = 0.06; cSBP2: HR = 1.03, p = 0.003) mortality. This circumstance was confirmed in multivariable analysis combining pSBP and differences between pSBP and cSBP (see Table). Conclusions: This study provides evidence for the additional information of central systolic blood pressure and its dependency on calibration in risk prediction in hemodialysis patients. Further studies are needed to confirm these findings. AForHF (n = 105) noAForHF (n =239) HR P HR P All-cause Mortality 59 events 56 events pSBP 0 97 (0 96, 0 98) <0 001 1 01 (0 99. 1 03) 030 Univariate CSBP1 0.97 (0.95, 0.98) <0.001 1.00(0.98, 1.02) 0.77 CSBP2 0.97 (0.96, 0.99) <0.001 1.01 (1.00,1.03) 006 pSBP-cSBP1 0.93(0.85,1.01) 0.09 1.10(1.04,1.17) <0.001 PSBP-CSBP2 1.01(0.97, 1.05) 0.59 0.95(0.91, 0.98) 0.005 pSBP 0.97(0 95,0.99) <0.001 1.00(0.98,1.01) 0.60 Multivariable pSBP-cSBP1 1.01 (0.92, 1.12) 0.80 1.11 (1.04,1.19) 0.002 pSBP 0.97 (0.96, 0.98) <0.001 1.00 (0.99, 1.02) 0.79 PSBP-CSBP2 1 00 (0 96, 1 04) 083 0 95(0 91.0 99) 0009 Cardiovascular Mortality 20 events 27 events pSBP 0 95 (0 93, 0 98) <0.001 1 03(1 00, 1 05) 0.02 CSBP1 0 95 (0.93, 0.97) <0 001 1 02(1.00, 1.05) 006 Univariate CSBP2 0.96(0.94,0.98) <0.001 1.03(1.01,1.05) 0 003 pSBP-cSBP1 0.86 (0.74, 1.02) 008 1 12(1.03. 1.20) 0 006 pSBP-cSBP2 1.01(0.94, 1.07) 0.87 0.93(0.88, 0.98) 0.006 pSBP 0 95(0 93, 0 98) <0 001 1 02(0 99, 1 04) 0.22 pSBP-cSBP1 0.98(0.81, 1.19) 0.87 1.08(0.98, 1.18) 0.12 pSBP 0.95 (0.93, 0.98) <0.001 1.02(1.00.1.04) 0.12 Multivariable PSBP-CSBP2 0.98(0.91, 1.05) 059 0 94(0.89, 1.00) 0.04 Table: Univariate and multivariable hazard ratios (95% confidence intervals) per mmHg increase and significance levels (p) for all-cause and cardiovascular mortality. Abbreviations: pSBP, peripheral systolic pressure; cSBP, central systolic pressure (1=brachial systolic and diastolic pressure calibration; 2= brachial mean and diastolic pressure calibration); HR, hazard ratio; AF, atrial fibrillation; HF, heart failure. [ABSTRACT FROM AUTHOR]