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Search results for: heart rate variability
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Insight into heart regeneration
PublicationThe mammalian heart is thought to be incapable of regeneration because of the limited ability of cardiomyocytes. to proliferate. However, it has been recently shown that the neonatal murine heart is able to restore its normal function after coronary artery ligation or even partial resection. Unfortunately, this feature is lost in a few days after birth, although lower vertebrates as zebrafish or newt, retain this ability until adulthood. Therefore,...
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A System for Heart Sounds Classification
PublicationThe future of quick and efficient disease diagnosis lays in the development of reliable non-invasive methods. As for the cardiac diseases – one of the major causes of death around the globe – a concept of an electronic stethoscope equipped with an automatic heart tone identification system appears to be the best solution. Thanks to the advancement in technology, the quality of phonocardiography signals is no longer an issue. However,...
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A machine learning approach to classifying New York Heart Association (NYHA) heart failure
PublicationAccording to the European Society of Cardiology, globally the number of patients with heart failure nearly doubled from 33.5 million in 1990 to 64.3 million in 2017, and is further projected to increase dramatically in this decade, still remaining a leading cause of morbidity and mortality. One of the most frequently applied heart failure classification systems that physicians use is the New York Heart Association (NYHA) Functional...
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Measuring pulse rate with a webcam — A non-contact method for evaluating cardiac activity
PublicationIn this paper the simple and robust method of measuring the pulse rate is presented. Elaborated algorithm allows for efficient pulse rate registration directly from face image captured from webcam. The desired signal was obtained by proper channel selection and principal component analysis. A developed non-contact method of heart rate monitoring is shown in the paper. The proposed technique may have a great value in monitoring...
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Ionosphere variability II: Advances in theory and modeling
PublicationThis paper aims to provide an overview on recent advances in ionospheric modeling capabilities, with the emphasis in the efforts relevant to electron density variability. The discussion spans a wide range of model formulations (e.g., from purely empirical to physics-based ones and data-driven approaches) seeking for advances or gaps with regard to present challenges. This discussion is further supported by consideration of the...
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Measuring Pulse Rate with a Webcam
PublicationIn this paper a simple method of measuring the pulse rate is presented. Elaborated algorithm allows for efficient pulse rate registration directly from face images captured from a webcam. The desired signal is obtained by proper channel selection and principal component analysis. To determine the accuracy of the method an ECG signal is collected together with a video recordings. The effectiveness of the algorithm is considered...
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The instantaneous frequency rate spectogram
PublicationAn accelerogram of the instantaneous phase of signal components referred to as an instantaneous frequency rate spectrogram (IFRS) is presented as a joint time-frequency distribution. The distribution is directly obtained by processing the short-time Fourier transform (STFT) locally. A novel approach to amplitude demodulation based upon the reassignment method is introduced as a useful by-product. Additionally, an estimator of energy...
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Interannual Variability of the GNSS Precipitable Water Vapor in the Global Tropics
PublicationThis paper addresses the subject of inter-annual variability of the tropical precipitable water vapor (PWV) derived from 18 years of global navigation satellite system (GNSS) observations. Non-linear trends of retrieved GNSS PWV were investigated using the singular spectrum analysis (SSA) along with various climate indices. For most of the analyzed stations (~49%) the GNSS PWV anomaly was related to the El Niño Southern Oscillation...
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Ionosphere variability I: Advances in observational, monitoring and detection capabilities
PublicationThe paper aims to review recent advances regarding the observational and monitoring capabilities of the ionization conditions in the Earth's upper atmosphere. The analysis spans both ground and space-based experiments, seeking for new installations and/or missions, new or upgraded instrumentation and/or observational network establishments as means for advancing current understanding and prediction ability of the ionosphere variability....
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Invasive Assessment of the Myocardial Microcirculation during Beating Heart Coronary Artery Bypass Grafting
PublicationCoronary artery bypass grafting may be associated with several cardiac complications, including ischemia, acute myocardial infarction, arrhythmias, or hemodynamic instability. Accumulating evidence suggests that well-developed coronary collateral circulation may protect against adverse effects, including myocardial ischemia. Assessment of myocardial microvascular perfusion is, therefore, of great clinical interest in beating heart...
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Denitrifcation rate in the mainstream deammonification
PublicationThe conventional processes of biological nitrogen removal based on nitrification and denitrification does not fit properly into the concept of the circular economy. As the alternative one should consider the deammonification process, which is a combination of partial nitrification (nitritation) and Anammox processes. It consists of removing ammonium nitrogen from wastewater under anaerobic conditions by a group of autotrophic microorganisms....
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Importance of ventilation in modulating interaction between sympathetic drive and cardiovascular variability
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Sample Rate Conversion with Fluctuating Resampling Ratio
PublicationIn this paper a sample rate conversion with continuouslychanging resampling ratio has been presented. The proposed implementation is based on variable fractional delay filter implemented using a Farrow structure. It have been demonstrated that using the proposed approach instantaneous resampling ratio can be freely changed. This allows for simulation of audio recored on magnetic tape with nonuniform velocity as well as removal...
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Estimation of respiration rate using an accelerometer and thermal camera in eGlasses
PublicationRespiration rate is a very important vital sign. Different methods of respiration rate measurement or estimation have been developed. However, especially interesting are those that enable remote and unobtrusive monitoring. In this study, we investigated the use of smart glasses for the estimation of respiration rate especially useful for indoors applications. Two methods were analyzed. The first one is based on measurements of...
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Sample Rate Conversion with Fluctuating Resampling Ratio
PublicationIn this paper a sample rate conversion with continuously changing resampling ratio has been presented. The proposed implementation is based on variable fractional delay filter implemented using a Farrow structure. It have been demonstrated that using the proposed approach instantaneous resampling ratio can be freely changed. This allows for simulation of audio recored on magnetic tape with nonuniform velocity as well as removal...
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Evaluation of Respiration Rate Using Thermal Imaging in Mobile Conditions
PublicationRespiratory rate is very important vital sign that should be measured and documented in many medical situations. The remote measurement of respiration rate can be especially valuable for medical screening purposes (e.g. severe acute respiratory syndrome (SARS), pandemic influenza, etc.). In this chapter we present a review of many different studies focused on the measurements and estimation of respiration rate using thermal imaging...
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The accuracy of pulse rate estimation from the sequence of face images
PublicationThe goal of this paper is to analyze the accuracy of pulse rate estimation from the sequence of face images. Simulated and real signals were used to evaluate two pulse rate estimators; one for frequency domain and the second one for time domain using the autocorrelation function. The results show that the mean difference between the reference measurements and estimated pulse rate values are about 2bpm. In the analysis of short...
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The non-invasive evaluation of heart function in patients with an acute myocardial infarction: The role of impedance cardiography
PublicationBackground: The purpose of this study was to analyze hemodynamic changes in patients treated with percutaneous coronary intervention (PCI) at an early stage of acute myocardial infarction (AMI) and at one-month follow-up. Methods: Patients with AMI (n = 27) who underwent PCI were analyzed using impedance cardiography (ICG). ICG data were collected continuously (beat by beat) during the whole PCI procedure and thereafter at every...
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Detection of low- and high-frequency rhythms in the variability of skin sympathetic nerve activity
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Employing Blended E-Learning to Improve Rate of Assignments Handing-In
PublicationIt has been observed that students hand in homework assignments at a notably low rate in introductory C programming course. A survey has revealed that the real issue was not student learning but instructor work organization. Based on survey results, the physical course has been complemented with an e-learning component to guide the homework process. Assignment handing-in rate significantly improved, as e-learning allowed the homework...
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Evaluation of respiration rate and pattern using a portable thermal camera
PublicationThe goal of this paper was to analyze the accuracy of the proposed method for the evaluation of respiration rate and respiration rhythm patterns (e.g. inspiration slope) using the portable and mobile thermal camera module that could be a part of smart glasses. Parameters were analyzed for 12 volunteers in two experiments, when subjects speak and do not speak. The pressure, chest belt was used as a reference measurement method....
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Chirp-rate estimation of FM signals in the time-frequency domain
PublicationNovel dynamic representations of a complex signal in the time-frequency domain including: a channelized instantaneous complex frequency (CICF), a complex local group delay (CLGD) and a channelized instantaneous chirp-rate (CICR) are introduced. The proposed approach is based on the use of the gradient of the short-time Fourier transform complex phase. An interpretation of the newly-introduced distributions especially of the CICR...
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The PARAGON-Heart failure trial – another disappointment for heart failure patients with hypertension and preserved ejection fraction
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Sonar Pulse Detection Using Chirp Rate Estimation and CFAR Algorithms
PublicationThis paper presents a new approach to sonar pulse detection. The method uses chirp rate estimators and algorithms for the adaptive threshold, commonly used in radiolocation. The proposed approach allows detection of pulses of unknown parameters, which may be used in passive hydrolocation or jamming detection in underwater communication. Such an analysis is possible thanks to a new kind of imaging, which presents signal energy in...
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Systematic Literature Review on Click Through Rate Prediction
PublicationThe ability to anticipate whether a user will click on an item is one of the most crucial aspects of operating an e-commerce business, and clickthrough rate prediction is an attempt to provide an answer to this question. Beginning with the simplest multilayer perceptrons and progressing to the most sophisticated attention networks, researchers employ a variety of methods to solve this issue. In this paper, we present the findings...
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On Sample Rate Conversion Based on Variable Fractional Delay Filters
PublicationThe sample rate conversion algorithm based on variable fractional delay filters is often used if the resampling ratio cannot be expressed as the ratio of small integer numbers or if it is not constant. The main advantage of such solution is that it allows for arbitrary resampling ratios which can even be changed during the resampling process. In this paper a discussion on influence of different approaches to fractional filter...
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Residue-Pole Methods for Variability Analysis of S-parameters of Microwave Devices with 3D FEM and Mesh Deformation
PublicationThis paper presents a new approach for variability analysis of microwave devices with a high dimension of uncertain parameters. The proposed technique is based on modeling an approximation of system by its poles and residues using several modeling methods, including ordinary kriging, Adaptive Polynomial Chaos (APCE), and Support Vector Machine Regression (SVM). The computational cost is compared with the traditional Monte-Carlo...
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Rationale and design of Mind-HF: randomized trial of the original Mindfulness-Based Heart Training for patients with heart failure
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The Comparison of the Crypto- and Fiat Currencies’ Exchange Rate Volatility in The Years 2015–2017
PublicationThe article describes the issues related to exchange rate volatility of crypto- and fiat currencies. The first part presents the issue of exchange rate volatility as well as methods of its evaluation and criteria of the conducted research. In the next part the author presented the essence of currencies and the main currency i.e. fiat money in the global economy in terms of the volume of transactions on the FOREX market. Then the...
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Determining the Seasonal Variability of the Territorial Sea Baseline in Poland (2018–2020) Using Integrated USV/GNSS/SBES Measurements
PublicationThe Territorial Sea Baseline (TSB) allows coastal states to define the maritime boundaries, such as: contiguous zone, continental shelf, exclusive economic zone and territorial sea. Their delimitations determine what rights (jurisdiction and sovereignty) a given coastal state is entitled to. For many years, the problem of delimiting baseline was considered in two aspects: legal (lack of clear-cut regulations and different interpretations)...
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APPLICATION OF ENTROPY-BASED METHODS TO DISTINGUISH HEALTHY INDIVIDUALS WITH NORMAL SINUS RHYTHM FROM PATIENTS WITH CONGESTIVE HEART FAILURE
PublicationIn this paper, we examined whether entropy-based methods are able to differentiate healthy individuals from patients with congestive heart failure. To this aim, we applied two methods: Permutation Entropy and Block Entropy. Long-term ECG recordings (75 000 RR intervals) were analyzed. The results proved that both methods can distinguish those groups on condition that the parameters are appropriately chosen.
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Entropic Measures of Complexity of Short-Term Dynamics of Nocturnal Heartbeats in an Aging Population
PublicationTwo entropy-based approaches are investigated to study patterns describing differences in time intervals between consecutive heartbeats. The first method explores matrices arising from networks of transitions constructed following events represented by a time series. The second method considers distributions of ordinal patterns of length three, whereby patterns with repeated values are counted as different patterns. Both methods provide...
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Systems, environments, and soliton rate equations: A non-Kolmogorovian framework for population dynamics
PublicationSoliton rate equations are based on non-Kolmogorovian models of probability and naturally include autocatalytic processes. The formalism is not widely known but has great unexplored potential for applications to systems interacting with environments. Beginning with links of contextuality to non- Kolmogorovity we introduce the general formalism of soliton rate equations and work out explicit examples of subsystems interacting with...
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Sample Rate Conversion Based on Frequency Response Masking Filter
PublicationThe sample rate conversion with high resampling ratios requires low-pass digital filters with very narrow transition band which results in high computational complexity and makes filter design problematic. Therefore in this work we propose to use the FRM method, which breaks the filter with a narrow transition band into a group of filters with reduced design requirements. These decreases the number of non-zero coefficients and...
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The variability of Hg concentration and composition of marine phytoplankton
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The variability of macrophyte metrics used in river monitoring
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Altered Cardiovascular Variability in Obstructive Sleep Apnea
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Cardiovascular variability characteristics in obstructive sleep apnea
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Evaluation of a company’s image on social media using the Net Sentiment Rate
PublicationVast amounts of new types of data are constantly being created as a result of dynamic digitization in all areas of our lives. One of the most important and valuable categories for business is data from social networks such as Facebook. Feedback resulting from the sharing of thoughts and emotions, expressed in comments on various products and services, is becoming the key factor on which modern business is based. This feedback is...
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Respiratory Rate Estimation Based on Detected Mask Area in Thermal Images
PublicationThe popularity of non-contact methods of measuring vital signs, particularly respiratory rate, has increased during the SARS-COV-2 pandemic. Breathing parameters can be estimated by analysis of temperature changes observed in thermal images of nostrils or mouth regions. However, wearing virus-protection face masks prevents direct detection of such face regions. In this work, we propose to use an automatic mask detection approach...
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The Influent Effects of Flow Rate Profile on thePerformance of Microbial Fuel Cells Model
PublicationThe energy contained in wastewaters has been identified as a promising sustainableenergy resource that could be harvested by using microbial fuel cells (MFC). When dealing with realwastewaters, the MFCs should be able to manage high flow rates and flow rates fluctuations. In thiswork, the short-term effects of the influent flow rate variations on the performance of a microbialfuel cell has been studied. With this aim, the influent...
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Statistical and fractal analysis of human heart dynamics.
PublicationPrzedstawiono sposób obliczania podstawowych i bardziej zaawansowanych (dyskrepancja) wielkości statystycznych do analizy dynamiki ludzkiego serca. Oprócz analizy statystycznej pokazano elementy analizy fraktalnej (wykresy Poincare). Przedstawiona analiza umożliwia wykrywanie patologicznych sytuacji i jest pomocna lekarzom w diagnostyce.
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Temporal Changes in Complexity of Cardiovascular Regulation during Head-Up Tilt Test by Entropic Measures of Fluctuations of Heart Period Intervals and Systolic Blood Pressure
PublicationTemporal changes in complexity of cardiovascular regulation during head-up tilt test by entropic measures of fluctuations of heart period intervals and systolic blood pressure
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Network oscillations modulate interictal epileptiform spike rate during human memory
PublicationEleven patients being evaluated with intracranial electroencephalography for medically resistant temporal lobe epilepsy participated in a visual recognition memory task. Interictal epileptiform spikes were manually marked and their rate of occurrence compared between baseline and three 2 s periods spanning a 6 s viewing period. During successful, but not unsuccessful, encoding of the images there was a significant reduction in...
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Clinical characteristics and medical therapy in randomized clinical trial eligible-and-enrolled vs. eligible-but-not enrolled patients with ischaemic heart failure
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Diurnal variability of atmospheric water vapour, precipitation and cloud top temperature across the global tropics derived from satellite observations and GNSS technique
PublicationThe diurnal cycle of convection plays an important role in clouds and water vapour distribution across the global tropics. In this study, we utilize integrated moisture derived from the global navigation satellite system (GNSS), satellite precipitation estimates from TRMM and merged infrared dataset to investigate links between variability in tropospheric moisture, clouds development and precipitation at a diurnal time scale. Over...
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Relationship between wages, labour productivity and unemployment rate in new EU member countries
PublicationThe main aim of this article is to find out the extent to which relative labour productivity and relative unemployment rate changes determine relative wage changes. We use average annual macro-data for the period 2002-2013 for Poland and other 5 new EU members: Estonia, Hungary, Slovak, Czech Republic and Slovenia. Using Poland as benchmark, rst we examine the correlation between wage, productivity and unemployment rate changes...
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Respiration rate estimation for model predictive control of dissolved oxygen in wastewater treatment plant
PublicationRespiration rate is very important parameter for biological processes in wastewater treatment plant (WWTP). The sequential algorithm for estimate the respiration rate is proposed and investigated. The Kalman filter (KF) is used. Simulation tests for the benchmark WWTP are presented.Respiracja jest bardzo ważnym parametrem dla prawidłowego przebiegu procesów biologicznych w oczyszczalni ścieków. W artykule przedstawiono i zbadano...
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Non-linear strain rate analysis of earthquake-induced pounding between steel buildings
PublicationPast and recent earthquakes have shown that ground motions may cause severe structural damage to civil engineering structures. Earthquake-induced pounding between adjacent buildings has been identified as one of the reasons which intensifies damages. The aim of this paper is to show the results of the detailed nonlinear FEM analysis of earthquake-induced pounding between two steel buildings. The elastic – perfectly plastic material...
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Sensitivity of echo parameters to seafloor properties and depth variability.
PublicationPrzeprowadzono badanie użyteczności wybranych parametrów echa akustycznego, w szczególności wymiaru fraktalnego oraz momentów spektralnych obwiedni, w klasyfikacji dna morskiego, ze szczególnym uwzględnieniem wpływu zmieniającej się głębokości. Wykorzystano numeryczną symulację rozpraszania echa na dnie oraz innych elementów procesu akustycznego sondowania dna, w tym także procedurę kompensacji wpływu zmian głębokości dna na echo.