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multiscale entropy

Imtiaz Awan, Wajid Aziz, Imran Hussain Shah, Nazneen Habib, Jalal S Alowibdi, Sharjil Saeed, Malik Sajjad Ahmed Nadeem, Syed Ahsin Ali Shah
Considerable interest has been devoted for developing a deeper understanding of the dynamics of healthy biological systems and how these dynamics are affected due to aging and disease. Entropy based complexity measures have widely been used for quantifying the dynamics of physical and biological systems. These techniques have provided valuable information leading to a fuller understanding of the dynamics of these systems and underlying stimuli that are responsible for anomalous behavior. The single scale based traditional entropy measures yielded contradictory results about the dynamics of real world time series data of healthy and pathological subjects...
2018: PloS One
Xiaoling Chen, Ping Xie, Yuanyuan Zhang, Yuling Chen, Fangmei Yang, Litai Zhang, Xiaoli Li
Recently, functional corticomuscular coupling (FCMC) between the cortex and the contralateral muscle has been used to evaluate motor function after stroke. As we know, the motor-control system is a closed-loop system that is regulated by complex self-regulating and interactive mechanisms which operate in multiple spatial and temporal scales. Multiscale analysis can represent the inherent complexity. However, previous studies in FCMC for stroke patients mainly focused on the coupling strength in single-time scale, without considering the changes of the inherently directional and multiscale properties in sensorimotor systems...
2018: Frontiers in Neurology
Priyalakshmi Sheela, Subha D Puthankattil
Autism Spectrum Disorders (ASD) comprise all pervasive neurodevelopmental diseases marked by deficits in social and communication skills, delayed cognitive development, restricted and repetitive behaviors. The core symptoms begin in early childhood, may continue life-long resulting in poor performance in adult stage. Event-related potential (ERP) is basically a time-locked electroencephalogram signal elicited by various stimuli, related to sensory and cognitive processes. The various ERP based techniques used for the study of ASD are considered in this review...
May 12, 2018: International Journal of Developmental Neuroscience
Hongyun Liu, Zhao Yang, Fangang Meng, Lei Huang, Wei Qu, Hongwei Hao, Jianguo Zhang, Luming Li
OBJECTIVE: Vagus nerve stimulation (VNS) is an adjunctive treatment in drug-resistant epilepsy. The alterations in heart rate dynamics through VNS are not well understood. This study aimed to determine changes in heart rhythm complexity in association with VNS and to relate the findings to the outcome of VNS treatment in patients with drug-resistant epilepsy. METHODS: We prospectively analyzed 32 patients with drug-resistant epilepsy, who underwent VNS implantation, and 32 age- and sex-matched healthy control subjects...
April 26, 2018: Epilepsy & Behavior: E&B
Kiyoumars Roushangar, Farhad Alizadeh, Jan Adamowski
Understanding precipitation on a regional basis is an important component of water resources planning and management. The present study outlines a methodology based on continuous wavelet transform (CWT) and multiscale entropy (CWME), combined with self-organizing map (SOM) and k-means clustering techniques, to measure and analyze the complexity of precipitation. Historical monthly precipitation data from 1960 to 2010 at 31 rain gauges across Iran were preprocessed by CWT. The multi-resolution CWT approach segregated the major features of the original precipitation series by unfolding the structure of the time series which was often ambiguous...
April 27, 2018: Environmental Research
S P Arunachalam, S Kapa, S K Mulpuru, P A Friedman, E G Tolkacheva
Analysis of biomedical signals can yield invaluable information for prognosis, diagnosis, therapy evaluation, risk assessment, and disease prevention which is often recorded as short time series data that challenges existing complexity classification algorithms such as Shannon entropy (SE) and other techniques. The purpose of this study was to improve previously developed multiscale entropy (MSE) technique by incorporating nearest-neighbor moving-average kernel, which can be used for analysis of nonlinear and non-stationary short time series physiological data...
2018: Journal of Healthcare Engineering
Matt McKenzie, Sung Min Ha, Aravind Rammohan, Ravi Radhakrishnan, N Ramakrishnan
We utilize a multiscale modeling framework to study the effect of shape, size, and ligand composition on the efficacy of binding of a ligand-coated particle to a substrate functionalized with the target receptors. First, we show how molecular dynamics along with steered molecular dynamics calculations can be used to accurately parameterize the molecular-binding free energy and the effective spring constant for a receptor-ligand pair. We demonstrate this for two ligands that bind to the α5 β1 -domain of integrin...
April 24, 2018: Biophysical Journal
Xuanyu Li, Zhaojun Zhu, Weina Zhao, Yu Sun, Dong Wen, Yunyan Xie, Xiangyu Liu, Haijing Niu, Ying Han
Multiscale entropy (MSE) analysis is a novel entropy-based analysis method for quantifying the complexity of dynamic neural signals and physiological systems across multiple temporal scales. This approach may assist in elucidating the pathophysiologic mechanisms of amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD). Using resting-state fNIRS imaging, we recorded spontaneous brain activity from 31 healthy controls (HC), 27 patients with aMCI, and 24 patients with AD. The quantitative analysis of MSE revealed that reduced brain signal complexity in AD patients in several networks, namely, the default, frontoparietal, ventral and dorsal attention networks...
April 1, 2018: Biomedical Optics Express
Ahmad Chaddad, Paul Daniel, Tamim Niazi
Purpose: Colorectal cancer (CRC) is markedly heterogeneous and develops progressively toward malignancy through several stages which include stroma (ST), benign hyperplasia (BH), intraepithelial neoplasia (IN) or precursor cancerous lesion, and carcinoma (CA). Identification of the malignancy stage of CRC pathology tissues (PT) allows the most appropriate therapeutic intervention. Methods: This study investigates multiscale texture features extracted from CRC pathology sections using 3D wavelet transform (3D-WT) filter...
2018: Frontiers in Oncology
Lucia Bizovska, Zdenek Svoboda, Eliska Kubonova, Nicolas Vuillerme, Zuzana Hirjakova, Miroslav Janura
PURPOSE: The aim of this study was to compare gait stability and variability between walking conditions and age groups. METHODS: Twenty-six healthy younger and older females participated. Trunk acceleration in the vertical (V), medial-lateral (ML) and anteriorposterior (AP) directions during 5 minutes walking overground and 3 minutes walking on the treadmill at self-selected speed were recorded. Root mean square and standard deviations of acceleration, stride time and its variability, Lyapunov exponents (LE), multiscale entropy (MSE) and harmonic ratios (HR) were computed...
2018: Acta of Bioengineering and Biomechanics
Jia-Ying Wang, Qing-Hao Meng, Bing Luo, Ming Zeng
This article presents a new type of active controlled multiple-fan wind tunnel. The wind tunnel consists of swivel plates and arrays of direct current fans, and the rotation speed of each fan and the shaft angle of each swivel plate can be controlled independently for simulating different kinds of outdoor wind fields. To measure the similarity between the simulated wind field and the outdoor wind field, wind speed and direction time series of two kinds of wind fields are recorded by nine two-dimensional ultrasonic anemometers, and then statistical properties of the wind signals in different time scales are analyzed based on the empirical mode decomposition...
March 2018: Review of Scientific Instruments
Haruki Kasuya, Hiroshi Gotoda, Seiji Yoshida, Shigeru Tachibana
We have intensively studied the dynamic behavior of combustion instability in a cylindrical combustor with an off-center installed coaxial injector. The most interesting discovery in this study is the appearance of a deterministic chaos in a transition from a dynamically stable state to well-developed high-frequency thermoacoustic combustion oscillations with increasing the volume flow rate of nitrogen with which oxygen is diluted. The presence of deterministic chaos is reasonably identified by considering an extended version of the Sugihara-May algorithm [G...
March 2018: Chaos
Teresa S Henriques, Madalena D Costa, Pooja Mathur, Priyam Mathur, Roger B Davis, Murray A Mittleman, Kamal R Khabbaz, Ary L Goldberger, Balachundhar Subramaniam
Complexity measures are intended to assess the cardiovascular system's capacity to respond to stressors. We sought to determine if decreased BP complexity is associated with increased estimated risk as obtained from two standard instruments: the Society of Thoracic Surgeons' (STS) Risk of Mortality and Morbidity Index and the European System for Cardiac Operative Risk Evaluation Score (EuroSCORE II). In this observational cohort study, preoperative systolic, diastolic, mean (MAP) and pulse pressure (PP) time series were derived in 147 patients undergoing cardiac surgery...
March 21, 2018: Journal of Clinical Monitoring and Computing
Karl Kuntzelman, L Jack Rhodes, Lillian N Harrington, Vladimir Miskovic
There is a broad family of statistical methods for capturing time series regularity, with increasingly widespread adoption by the neuroscientific community. A common feature of these methods is that they permit investigators to quantify the entropy of brain signals - an index of unpredictability/complexity. Despite the proliferation of algorithms for computing entropy from neural time series data there is scant evidence concerning their relative stability and efficiency. Here we evaluated several different algorithmic implementations (sample, fuzzy, dispersion and permutation) of multiscale entropy in terms of their stability across sessions, internal consistency and computational speed, accuracy and precision using a combination of electroencephalogram (EEG) and synthetic 1/ƒ noise signals...
March 18, 2018: Brain and Cognition
Espen A F Ihlen, Kimberley S van Schooten, Sjoerd M Bruijn, Jaap H van Dieën, Beatrix Vereijken, Jorunn L Helbostad, Mirjam Pijnappels
Age and age-related diseases have been suggested to decrease entropy of human gait kinematics, which is thought to make older adults more susceptible to falls. In this study we introduce a new entropy measure, called phase-dependent generalized multiscale entropy (PGME), and test whether this measure improves fall-risk prediction in community-dwelling older adults. PGME can assess phase-dependent changes in the stability of gait dynamics that result from kinematic changes in events such as heel strike and toe-off...
2018: Frontiers in Aging Neuroscience
Shogo Murayama, Hikaru Kinugawa, Isao T Tokuda, Hiroshi Gotoda
We present an experimental study on the characterization of dynamic behavior of flow velocity field during thermoacoustic combustion oscillations in a turbulent confined combustor from the viewpoints of statistical complexity and complex-network theory, involving detection of a precursor of thermoacoustic combustion oscillations. The multiscale complexity-entropy causality plane clearly shows the possible presence of two dynamics, noisy periodic oscillations and noisy chaos, in the shear layer regions (1) between the outer recirculation region in the dump plate and a recirculation flow in the wake of the centerbody and (2) between the outer recirculation region in the dump plate and a vortex breakdown bubble away from the centerbody...
February 2018: Physical Review. E
M C Bisi, R Stagni
Movement complexity can be defined as the capability of using different strategies to accomplish a specific task and is expected to increase with maturation, reaching its highest level in adulthood.Multiscale Entropy (MSE) has been proposed to estimate complexity on different kinematic signals, at different time scales. When applied on trunk acceleration data during natural walking (NW) at different ages, MSE decreased from childhood to adulthood, apparently contradicting the premises. On the contrary, authors hypothesised that this decrease was dependent on the specific task analysed and resulted from the concurrent increase in gait automaticity...
March 2018: Computer Methods in Biomechanics and Biomedical Engineering
P L Bernard, H Blain, G Tallon, G Ninot, A Jaussent, M C Picot, C Belloc, O Coste, J Bousquet, S Ramdani
This study analyzes the evolution in kinematic and non-linear stabilometric parameters in elderly sedentary women selected to participate in a brisk walking program. Ninety-four women were randomly selected for a program of 78 sessions over 6 months, with three sessions of 60 min per week. On the force platform, participants were assessed with both eyes opened as well as eyes closed during a period of 51.2 s and the sampling frequency was 40 Hz. The main dependent kinematic variables were the length, stabilogram surface, and the mean position in anteroposterior as well as medio-lateral directions...
May 2018: Aging Clinical and Experimental Research
Hong-Yun Liu, Zhao Yang, Fan-Gang Meng, Yu-Guang Guan, Yan-Shan Ma, Shu-Li Liang, Jiu-Luan Lin, Long-Sheng Pan, Ming-Ming Zhao, Wei Qu, Hong-Wei Hao, Guo-Ming Luan, Jian-Guo Zhang, Lu-Ming Li
Vagus nerve stimulation (VNS) is an adjunctive treatment for drug-resistant epilepsy (DRE). However, it is still difficult to predict which patients will respond to VNS treatment and to what extent. We aim to explore the relationship between preoperative heart rate variability (HRV) and VNS outcome. 50 healthy control subjects and 63 DRE patients who had received VNS implants and had at least one year of follow up were included. The preoperative HRV were analyzed by traditional linear methods and heart rhythm complexity analyses with multiscale entropy (MSE)...
March 1, 2018: Scientific Reports
Carlos Granero-Belinchón, Stéphane G Roux, Nicolas B Garnier
For generic systems exhibiting power law behaviors, and hence multiscale dependencies, we propose a simple tool to analyze multifractality and intermittency, after noticing that these concepts are directly related to the deformation of a probability density function from Gaussian at large scales to non-Gaussian at smaller scales. Our framework is based on information theory and uses Shannon entropy and Kullback-Leibler divergence. We provide an extensive application to three-dimensional fully developed turbulence, seen here as a paradigmatic complex system where intermittency was historically defined and the concepts of scale invariance and multifractality were extensively studied and benchmarked...
January 2018: Physical Review. E
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