scholarly journals Assessing hemodynamics from the photoplethysmogram to gain insights into vascular age: A review from VascAgeNet

2021 ◽  
Author(s):  
Peter H. Charlton ◽  
Birutė Paliakaitė‬‬‬ ◽  
Kristjan Pilt ◽  
Martin Bachler ◽  
Serena Zanelli ◽  
...  
Keyword(s):  
Pulse Wave ◽  
Pulse Transit Time ◽  
Time Measurement ◽  
Future Research ◽  
Full Potential ◽  
Vascular Ageing ◽  
Vascular Age ◽  
Repeatability And Reproducibility ◽  
Consumer Devices ◽  
Pulse Arrival

The photoplethysmogram (PPG) signal is widely measured by clinical and consumer devices, and it is emerging as a potential tool for assessing vascular age. The shape and timing of the PPG pulse wave are both influenced by normal vascular ageing, changes in arterial stiffness and blood pressure, and atherosclerosis. This review summarises research into assessing vascular age from the PPG. Three categories of approaches are described: (i) those which use a single PPG signal (based on pulse wave analysis); (ii) those which use multiple PPG signals (such as pulse transit time measurement); and (iii) those which use PPG and other signals (such as pulse arrival time measurement). Evidence is then presented on the performance, repeatability and reproducibility, and clinical utility of PPG-derived parameters of vascular age. Finally, the review outlines key directions for future research to realise the full potential of photoplethysmography for assessing vascular age.

scholarly journals Vascular ageing in elderly patients with metabolic syndrome

2020 ◽  
pp. 74-80
Author(s):  
S. V. Nedogoda ◽  
V. V. Tsoma ◽  
E. V. Chumachek ◽  
V. O. Smirnova ◽  
R. V. Palashkin
Keyword(s):  
Metabolic Syndrome ◽  
Arterial Wall ◽  
Pulse Wave ◽  
Propagation Rate ◽  
Convincing Evidence ◽  
Cumulative Exposure ◽  
Vascular Aging ◽  
Pulse Wave Propagation ◽  
Vascular Ageing ◽  
Vascular Age

Vascular aging is associated with increased arterial stiffness, vascular remodeling, and increased pulse wave propagation rate. This process can be accelerated by cumulative exposure to various factors that damage the arterial wall: arterial hypertension, hyperglycemia, dyslipidemia, smoking, etc. At present, there is no convincing evidence of the preferential effect of certain components of metabolic syndrome that have the greatest impact on the acceleration of vascular aging in older patients. In  this regard, a  non-interactive study was conducted to  calculate vascular age and compare it with passport age in patients over 65 years of age with metabolic syndrome (MS) and obesity, assessing the greatest contribution to vascular ageing in a given age group of different MS components. The study showed that at different age periods MS components have different specific weights in the formation of early vascular aging.

scholarly journals Recommendations for determining the validity of consumer wearable and smartphone step count: expert statement and checklist of the INTERLIVE network

2020 ◽  
pp. bjsports-2020-103147
Author(s):  
William Johnston ◽  
Pedro B Judice ◽  
Pablo Molina García ◽  
Jan M Mühlen ◽  
Esben Lykke Skovgaard ◽  
...  
Keyword(s):  
Physical Activity ◽  
Literature Review ◽  
Systematic Literature Review ◽  
Best Practice ◽  
Well Being ◽  
Future Research ◽  
Full Potential ◽  
Step Counter ◽  
Research Activities ◽  
Consumer Devices

Consumer wearable and smartphone devices provide an accessible means to objectively measure physical activity (PA) through step counts. With the increasing proliferation of this technology, consumers, practitioners and researchers are interested in leveraging these devices as a means to track and facilitate PA behavioural change. However, while the acceptance of these devices is increasing, the validity of many consumer devices have not been rigorously and transparently evaluated. The Towards Intelligent Health and Well-Being Network of Physical Activity Assessment (INTERLIVE) is a joint European initiative of six universities and one industrial partner. The consortium was founded in 2019 and strives to develop best-practice recommendations for evaluating the validity of consumer wearables and smartphones. This expert statement presents a best-practice consumer wearable and smartphone step counter validation protocol. A two-step process was used to aggregate data and form a scientific foundation for the development of an optimal and feasible validation protocol: (1) a systematic literature review and (2) additional searches of the wider literature pertaining to factors that may introduce bias during the validation of these devices. The systematic literature review process identified 2897 potential articles, with 85 articles deemed eligible for the final dataset. From the synthesised data, we identified a set of six key domains to be considered during design and reporting of validation studies: target population, criterion measure, index measure, validation conditions, data processing and statistical analysis. Based on these six domains, a set of key variables of interest were identified and a ‘basic’ and ‘advanced’ multistage protocol for the validation of consumer wearable and smartphone step counters was developed. The INTERLIVE consortium recommends that the proposed protocol is used when considering the validation of any consumer wearable or smartphone step counter. Checklists have been provided to guide validation protocol development and reporting. The network also provide guidance for future research activities, highlighting the imminent need for the development of feasible alternative ‘gold-standard’ criterion measures for free-living validation. Adherence to these validation and reporting standards will help ensure methodological and reporting consistency, facilitating comparison between consumer devices. Ultimately, this will ensure that as these devices are integrated into standard medical care, consumers, practitioners, industry and researchers can use this technology safely and to its full potential.

scholarly journals Methodological Considerations for a Vascular Function Test Battery

2019 ◽  
Vol 40 (09) ◽  
pp. 601-608
Author(s):  
Rachel Kimble ◽  
Karen M. Keane ◽  
John K. Lodge ◽  
Glyn Howatson
Keyword(s):  
Vascular Function ◽  
Pulse Wave ◽  
Augmentation Index ◽  
Careful Consideration ◽  
Test Battery ◽  
Doppler Imaging ◽  
Stiffness Index ◽  
Future Research ◽  
Reflection Index ◽  
Repeatability And Reproducibility

AbstractThere is a dearth of information regarding the reliability of non-invasive measures of vascular function taken in a single testing session. This study aimed to determine the test-retest reliability of a test battery of vascular function measures: automated blood pressure (BP), laser Doppler imaging with iontophoresis (LDI), digital volume pulse (DVP), pulse wave velocity (PWV), augmentation index (AIx) measured by pulse wave analysis (PWA) and flow-mediated dilation (FMD) taken within and between sessions. Measures were taken in 21 non-smoking males intra-session and again inter-session (one week apart) to determine repeatability and reproducibility, respectively. There was moderate to excellent repeatability (ICC: 0.53–0.93; CV=2.2–18.1%) and reproducibility (ICC: 0.71–0.96; CV 1.9–14.2%) for BP, DVP stiffness index, PWV, AIx, AIx normalised to heart rate (75 bpm), absolute and percentage FMD. Repeatability of the DVP reflection index was moderate (ICC: 0.64; CV=9.5%) but there was poor reproducibility (ICC: 0.17; CV=15.1%). Moreover, the repeatability and reproducibility of the LDI measures ranged from poor to good (ICC: 0.31–0.84; CV=28.4–36.7%). These data indicated that there was considerable variability in the repeatability and reproducibility of measurements of endothelial function and arterial stiffness taken in a battery of measurements, which needs careful consideration in future research designs.

scholarly journals Multi-Site Photoplethysmography Technology for Blood Pressure Assessment: Challenges and Recommendations

2019 ◽  
Vol 8 (11) ◽  
pp. 1827 ◽  
Author(s):  
Chan ◽  
Cooper ◽  
Hosanee ◽  
Welykholowa ◽  
Kyriacou ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Pulse Wave ◽  
Blood Pressure Monitoring ◽  
New Technology ◽  
Pulse Transit Time ◽  
Time Of Day ◽  
White Coat Hypertension ◽  
Future Research ◽  
Site Location ◽  
Arterial Blood

Hypertension is one of the most prevalent diseases and is often called the “silent killer” because there are usually no early symptoms. Hypertension is also associated with multiple morbidities, including chronic kidney disease and cardiovascular disease. Early detection and intervention are therefore important. The current routine method for diagnosing hypertension is done using a sphygmomanometer, which can only provide intermittent blood pressure readings and can be confounded by various factors, such as white coat hypertension, time of day, exercise, or stress. Consequently, there is an increasing need for a non-invasive, cuff-less, and continuous blood pressure monitoring device. Multi-site photoplethysmography (PPG) is a promising new technology that can measure a range of features of the pulse, including the pulse transit time of the arterial pulse wave, which can be used to continuously estimate arterial blood pressure. This is achieved by detecting the pulse wave at one body site location and measuring the time it takes for it to reach a second, distal location. The purpose of this review is to analyze the current research in multi-site PPG for blood pressure assessment and provide recommendations to guide future research. In a systematic search of the literature from January 2010 to January 2019, we found 13 papers that proposed novel methods using various two-channel PPG systems and signal processing techniques to acquire blood pressure using multi-site PPG that offered promising results. However, we also found a general lack of validation in terms of sample size and diversity of populations.

scholarly journals Leveraging the potential of machine learning for assessing vascular ageing: state-of-the-art and future research

2021 ◽  
Author(s):  
Vasiliki Bikia ◽  
Terence Fong ◽  
Rachel E Climie ◽  
Rosa- Maria Bruno ◽  
Bernhard Hametner ◽  
...  
Keyword(s):  
Machine Learning ◽  
Risk Factors ◽  
Clinical Utility ◽  
State Of The Art ◽  
Future Research ◽  
New Techniques ◽  
Age Assessment ◽  
Vascular Ageing ◽  
Vascular Age ◽  
Basic Approaches

Abstract Vascular ageing biomarkers have been found to be predictive of cardiovascular risk independently of classical risk factors, yet are not widely used in clinical practice. In this review we present two basic approaches for using machine learning (ML) to assess vascular age: parameter estimation and risk classification. We then summarize their role in developing new techniques to assess vascular ageing quickly and accurately. We discuss the methods used to validate ML-based markers, the evidence for their clinical utility, and key directions for future research. The review is complemented by case studies of the use of ML in vascular age assessment which can be replicated using freely available data and code.

EVALUATION OF THE VESSEL AGE BY APPLYING THE ACCELERATION PLETHYSMOGRAM ANALYSIS

2021 ◽  
pp. 61-67
Author(s):  
Елизавета Александровна Молчанова ◽  
Петр Вячеславович Лужнов
Keyword(s):  
Blood Vessels ◽  
Pulse Wave ◽  
Vascular System ◽  
Vascular Wall ◽  
Second Derivative ◽  
Contour Analysis ◽  
Physiological Factors ◽  
Vascular Age ◽  
Relationship Of ◽  
The Relationship

В работе приведены понятия жесткости, эластичности и тонуса сосудов, а также же их взаимосвязь с общим состоянием сосудистой стенки. Описан индекс, объединяющий влияние вышеперечисленных факторов на состояние сосудистой системы и дающий представление о возрасте сосудов пациента, а также показана связь этого индекса с возрастом человека. Представлен обзор способов определения возраста сосудов с помощью контурного анализа пульсовой волны. Среди предложенных способов был выделен подход на основе контурного анализа сигнала пульсовой волны, а также ее второй производной. В данном исследовании проводилась разработка алгоритма расчета показателя возраста сосудов (VA), базирующаяся на анализе сигнала и его второй производной. При этом особое внимание уделялось физической интерпретации параметров, входящих в состав расчетной формулы. С помощью представленного алгоритма в группе из трех испытуемых был определен сосудистый возраст. Из анализа полученных результатов было выявлено влияние физиологических факторов на значение возраста сосудов. Предложены методики, позволяющие исключить влияние этих факторов на значения показателя VA и тем самым получить более точные результаты. Также представлены стратегии дальнейшего развития исследований в этом направлении In The paper presents the concepts of rigidity, elasticity and tone of blood vessels, as well as their relationship with the general state of the vascular wall. An index is described that combines the influence of the above factors on the state of the vascular system and gives an idea of the age of the patient's vessels, and also shows the relationship of this index with the age of a person. An overview of the methods for determining the age of blood vessels using the contour analysis of the pulse wave is presented. Among the proposed methods, an approach based on the contour analysis of the pulse wave signal, as well as its second derivative, was singled out. In this study, an algorithm was developed for calculating the indicator of vascular age (VA), based on the analysis of the signal and its second derivative. In this case, special attention was paid to the physical interpretation of the parameters included in the calculation formula. Using the presented algorithm, vascular age was determined in a group of three subjects. From the analysis of the results obtained, the influence of physiological factors on the value of the age of the vessels was revealed. Methods are proposed that allow to exclude the influence of these factors on the values of the VA indicator and thereby obtain more accurate results. Also presented are strategies for the further development of research in this direction

scholarly journals Biomass valorisation over metal-based solid catalysts from nanoparticles to single atoms

2020 ◽  
Vol 49 (12) ◽  
pp. 3764-3782 ◽  
Author(s):  
Cecilia Mondelli ◽  
Gökalp Gözaydın ◽  
Ning Yan ◽  
Javier Pérez-Ramírez
Keyword(s):  
Future Research ◽  
Full Potential ◽  
Solid Catalysts ◽  
Single Atoms ◽  
Biomass Valorisation ◽  
Catalyst Efficiency

Metal size and speciation strongly impact catalyst efficiency and robustness in biomass upgrading through redox and acid-mediated reactions, with the full potential of single atoms and low-nuclearity species still to be unlocked by future research.

scholarly journals Introducing Computational Thinking Practices in Learning Science of Elementary Schools [Research-in-Progress]

10.28945/4327 ◽  
2019 ◽  
Keyword(s):  
Science Education ◽  
Problem Solving ◽  
Computational Thinking ◽  
Learning Science ◽  
Future Research ◽  
Full Potential ◽  
Science Program ◽  
Next Generation ◽  
Science Field ◽  
Problem Solving Skills

Aim/Purpose: Science is becoming a computational endeavor therefore Computational Thinking (CT) is gradually being accepted as a required skill for the 21st century science student. Students deserve relevant conceptual learning accessible through practical, constructionist approaches in cross-curricular applications therefore it is required for educators to define, practice and assess practical ways of introducing CT to science education starting from elementary school. Background: Computational Thinking is a set of problem-solving skills evolving from the computer science field. This work-in-progress research assesses the CT skills, along with science concepts, of students participating in a science program in school. The program pertains learning science by modeling and simulating real world phenomenon using an agent-based modeling practice. Methodology: This is an intervention research of a science program. It takes place as part of structured learning activities of 4th and 5th grade classes which are teacher-guided and are conducted in school. Both qualitative and quantitative evaluations are parts of the mixed methods research methodology using a variety of evaluation technique, including pretests and posttests, surveys, artifact-based interviews, in class observations and project evaluations. Contribution: CT is an emerging skill in learning science. It is requiring school systems to give increased attention for promoting students with the opportunity to engage in CT activities alongside with ways to promote a deeper understanding of science. Currently there is a lack of practical ways to do so and lack of methods to assess the results therefore it is an educational challenge. This paper presents a response to this challenge by proposing a practical program for school science courses and an assessment method. Findings: This is a research in progress which finding are based on a pilot study. The researches believe that findings may indicate improved degree of students' science understanding and problem-solving skills. Recommendations for Practitioners: Formulating computer simulations by students can have great potential on learning science with embedded CT skills. This approach could enable learners to see and interact with visualized representations of natural phenomena they create. Although most teachers do not learn about CT in their initial education, it is of paramount importance that such programs, as the one described in this research, will assist teachers with the opportunity to introduce CT into science studies. Recommendation for Researchers: Scientific simulation design in primary school is at its dawn. Future research investment and investigation should focus on assessment of aspects of the full Computational Thinking for Science taxonomy. In addition, to help teachers assess CT skills, new tools and criteria are required. Impact on Society: STEM related professions are lacking the man power required therefore the full potential of the economy of developed countries is not fulfilled. Having students acquire computational thinking skills through formal education may prepare the next generation of world class scientists and attract larger populations to these fields. Future Research: The inclusion of computational thinking as a core scientific practice in the Next Generation Science Standards is an important milestone, but there is still much work to do toward addressing the challenge of CT-Science education to grow a generation of technologically and scientifically savvy individuals. New comprehensive approaches are needed to cope with the complexity of cognitive processes related to CT.

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