keyword
MENU ▼
Read by QxMD icon Read
search

Wavelet transform

keyword
https://www.readbyqxmd.com/read/28626082/significant-role-of-the-cardio-postural-interaction-in-blood-pressure-regulation-during-standing
#1
Da Xu, Ajay Verma, Amanmeet Garg, Michelle Bruner, Reza Fazel-Rezai, Andrew P Blaber, Kouhyar Tavakolian
Cardiovascular and postural control systems have been studied independently despite the increasing evidence showing the importance of cardio-postural interaction in blood pressure regulation. In this study, we aimed to assess the role of cardio-postural interaction in relation to cardiac baroreflex in blood pressure regulation under orthostatic stress before and after mild exercise. Physiological variables representing cardiovascular control (heart rate and systolic blood pressure), lower limb muscle activation (electromyography), and postural sway (center of pressure derived from force and moment data during sway) were measured from 17 healthy participants (25±2 years; 8 females) during a sit-to-stand test before and after sub-maximal exercise...
June 16, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28613239/time-frequency-analysis-of-non-stationary-biological-signals-with-sparse-linear-regression-based-fourier-linear-combiner
#2
Yubo Wang, Kalyana C Veluvolu
It is often difficult to analyze biological signals because of their nonlinear and non-stationary characteristics. This necessitates the usage of time-frequency decomposition methods for analyzing the subtle changes in these signals that are often connected to an underlying phenomena. This paper presents a new approach to analyze the time-varying characteristics of such signals by employing a simple truncated Fourier series model, namely the band-limited multiple Fourier linear combiner (BMFLC). In contrast to the earlier designs, we first identified the sparsity imposed on the signal model in order to reformulate the model to a sparse linear regression model...
June 14, 2017: Sensors
https://www.readbyqxmd.com/read/28599255/research-on-two-port-network-of-wavelet-transform-processor-using-surface-acoustic-wavelet-devices-and-its-application
#3
Shoubing Liu, Wenke Lu, Changchun Zhu
The goal of this research is to study two-port network of wavelet transform processor (WTP) using surface acoustic wave (SAW) devices and its application. The motive was prompted by the inconvenience of the long research and design cycle and the huge research funding involved with traditional method in this field, which were caused by the lack of the simulation and emulation method of WTP using SAW devices. For this reason, we introduce the two-port network analysis tool, which has been widely used in the design and analysis of SAW devices with uniform interdigital transducers (IDTs)...
May 29, 2017: Ultrasonics
https://www.readbyqxmd.com/read/28596962/a-novel-ecg-eigenvalue-detection-algorithm-based-on-wavelet-transform
#4
Ziran Peng, Guojun Wang
This study investigated an electrocardiogram (ECG) eigenvalue automatic analysis and detection method; ECG eigenvalues were used to reverse the myocardial action potential in order to achieve automatic detection and diagnosis of heart disease. Firstly, the frequency component of the feature signal was extracted based on the wavelet transform, which could be used to locate the signal feature after the energy integral processing. Secondly, this study established a simultaneous equations model of action potentials of the myocardial membrane, using ECG eigenvalues for regression fitting, in order to accurately obtain the eigenvalue vector of myocardial membrane potential...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28596697/wavelet-transforms-on-gelfand-shilov-spaces-and-concrete-examples
#5
Naohiro Fukuda, Tamotu Kinoshita, Kazuhisa Yoshino
In this paper, we study the continuity properties of wavelet transforms in the Gelfand-Shilov spaces with the use of a vanishing moment condition. Moreover, we also compute the Fourier transforms and the wavelet transforms of concrete functions in the Gelfand-Shilov spaces.
2017: Journal of Inequalities and Applications
https://www.readbyqxmd.com/read/28596461/classification-of-pulmonary-pathology-from-breath-sounds-using-the-wavelet-packet-transform-and-an-extreme-learning-machine
#6
Rajkumar Palaniappan, Kenneth Sundaraj, Sebastian Sundaraj, N Huliraj, S S Revadi
BACKGROUND: Auscultation is a medical procedure used for the initial diagnosis and assessment of lung and heart diseases. From this perspective, we propose assessing the performance of the extreme learning machine (ELM) classifiers for the diagnosis of pulmonary pathology using breath sounds. METHODS: Energy and entropy features were extracted from the breath sound using the wavelet packet transform. The statistical significance of the extracted features was evaluated by one-way analysis of variance (ANOVA)...
June 8, 2017: Biomedizinische Technik. Biomedical Engineering
https://www.readbyqxmd.com/read/28594352/automatic-artifact-removal-in-eeg-of-normal-and-demented-individuals-using-ica-wt-during-working-memory-tasks
#7
Noor Kamal Al-Qazzaz, Sawal Hamid Bin Mohd Ali, Siti Anom Ahmad, Mohd Shabiul Islam, Javier Escudero
Characterizing dementia is a global challenge in supporting personalized health care. The electroencephalogram (EEG) is a promising tool to support the diagnosis and evaluation of abnormalities in the human brain. The EEG sensors record the brain activity directly with excellent time resolution. In this study, EEG sensor with 19 electrodes were used to test the background activities of the brains of five vascular dementia (VaD), 15 stroke-related patients with mild cognitive impairment (MCI), and 15 healthy subjects during a working memory (WM) task...
June 8, 2017: Sensors
https://www.readbyqxmd.com/read/28593391/wavelet-decomposition-analysis-in-the-two-flash-multifocal-erg-in-early-glaucoma-a-comparison-to-ganglion-cell-analysis-and-visual-field
#8
Livia M Brandao, Matthias Monhart, Andreas Schötzau, Anna A Ledolter, Anja M Palmowski-Wolfe
PURPOSE: To further improve analysis of the two-flash multifocal electroretinogram (2F-mfERG) in glaucoma in regard to structure-function analysis, using discrete wavelet transform (DWT) analysis. METHODS: Sixty subjects [35 controls and 25 primary open-angle glaucoma (POAG)] underwent 2F-mfERG. Responses were analyzed with the DWT. The DWT level that could best separate POAG from controls was compared to the root-mean-square (RMS) calculations previously used in the analysis of the 2F-mfERG...
June 7, 2017: Documenta Ophthalmologica. Advances in Ophthalmology
https://www.readbyqxmd.com/read/28591674/high-frequency-power-within-the-qrs-complex-in-ischemic-cardiomyopathy-patients-with-ventricular-arrhythmias-insights-from-a-clinical-study-and-computer-simulation-of-cardiac-fibrous-tissue
#9
Takeshi Tsutsumi, Yoshiwo Okamoto, Nami Takano, Daisuke Wakatsuki, Takanobu Tomaru, Toshiaki Nakajima
BACKGROUND: The distribution of frequency power (DFP) within the QRS complex (QRS) is unclear. This study aimed to investigate the DFP within the QRS in ischemic cardiomyopathy (ICM) with lethal ventricular arrhythmias (L-VA). A computer simulation was performed to explore the mechanism of abnormal frequency power. METHODS: The study included 31 ICM patients with and without L-VA (n = 10 and 21, respectively). We applied the continuous wavelet transform to measure the time-frequency power within the QRS...
May 22, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28588203/quantum-coherent-dynamics-in-photosynthetic-charge-separation-revealed-by-wavelet-analysis
#10
Elisabet Romero, Javier Prior, Alex W Chin, Sarah E Morgan, Vladimir I Novoderezhkin, Martin B Plenio, Rienk van Grondelle
Experimental/theoretical evidence for sustained vibration-assisted electronic (vibronic) coherence in the Photosystem II Reaction Center (PSII RC) indicates that photosynthetic solar-energy conversion might be optimized through the interplay of electronic and vibrational quantum dynamics. This evidence has been obtained by investigating the primary charge separation process in the PSII RC by two-dimensional electronic spectroscopy (2DES) and Redfield modeling of the experimental data. However, while conventional Fourier transform analysis of the 2DES data allows oscillatory signatures of vibronic coherence to be identified in the frequency domain in the form of static 2D frequency maps, the real-time evolution of the coherences is lost...
June 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28585579/classification-of-normal-and-arrhythmic-ecg-using-wavelet-transform-based-template-matching-technique
#11
Wajahat Hassan, Saqib Saleem, Aamir Habib
OBJECTIVE: To propose a wavelet-based template matching technique to extract features for automatic classification of electrocardiogram signals of normal and arrhythmic individuals. METHODS: The study was conducted from December 2014 to December 2015 at the Department of Electrical Engineering, Institute of Space Technology, Islamabad, Pakistan. Electrocardiogram signals analysed in this study were taken from the freely available database www.physionet.org. The data for normal subjects was taken from the Massachusetts Institute of Technology-Beth Israel Hospital's normal sinus rhythm database and data for diseased subjects was taken from the arrhythmia database...
June 2017: JPMA. the Journal of the Pakistan Medical Association
https://www.readbyqxmd.com/read/28585253/prediction-of-canned-black-bean-texture-phaseolus-vulgaris-l-from-intact-dry-seeds-using-visible-near-infrared-spectroscopy-and-hyperspectral-imaging-data
#12
Fernando A Mendoza, Karen A Cichy, Christy Sprague, Amanda Goffnett, Renfu Lu, James D Kelly
BACKGROUND: Texture is a major quality parameter for the acceptability of canned whole beans. Prior knowledge of this quality trait before processing would be useful to guide variety development by bean breeders and optimize handling protocols by processors. The objective of this study was to evaluate and compare the predictive power of visible and near-infrared reflectance spectroscopy (Vis/NIRS, 400-2,498 nm) and hyperspectral imaging (HYPERS, 400-1,000 nm) techniques for predicting texture of canned black beans from intact dry seeds...
June 5, 2017: Journal of the Science of Food and Agriculture
https://www.readbyqxmd.com/read/28574347/anisotropic-discrete-dual-tree-wavelet-transform-for-improved-classification-of-trabecular-bone
#13
Hind Oulhaj, Mohammed Rziza, Aouatif Amine, Hechmi Toumi, Eric Lespessailles, Mohammed El Hassouni, Rachid Jennane
This paper deals with a new Anisotropic Discrete Dual-Tree Wavelet Transform (ADDTWT) to characterize the anisotropy of bone texture. More specifically, we propose to extend the conventional Discrete Dual-Tree Wavelet Transform (DDTWT) by using the anisotropic basis functions associated with the Hyperbolic Wavelet Transform (HWT) instead of isotropic spectrum supports. A texture classification framework is adopted to assess the performance of the proposed transform. The Generalized Gaussian Distribution (GGD) is used to model the distribution of the sub-band coefficients...
May 26, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28572762/evaluating-and-improving-automatic-sleep-spindle-detection-by-using-multi-objective-evolutionary-algorithms
#14
Min-Yin Liu, Adam Huang, Norden E Huang
Sleep spindles are brief bursts of brain activity in the sigma frequency range (11-16 Hz) measured by electroencephalography (EEG) mostly during non-rapid eye movement (NREM) stage 2 sleep. These oscillations are of great biological and clinical interests because they potentially play an important role in identifying and characterizing the processes of various neurological disorders. Conventionally, sleep spindles are identified by expert sleep clinicians via visual inspection of EEG signals. The process is laborious and the results are inconsistent among different experts...
2017: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/28571470/choosing-the-filter-for-catenary-image-enhancement-method-based-on-the-non-subsampled-contourlet-transform
#15
Changdong Wu, Zhigang Liu, Hua Jiang
The quality of image enhancement plays an important role in the catenary fault diagnosis system based on the image processing technique. It is necessary to enhance the low contrast image of catenary for better detecting the state of catenary part. The Non-subsampled Contourlet transform (NSCT) is the improved Contourlet transform (CT), which can effectively solve the problem of artifact phenomenon in the enhanced catenary image. Besides, choosing the enhancement function and the filter of the NSCT will directly influence the image enhancement effect...
May 2017: Review of Scientific Instruments
https://www.readbyqxmd.com/read/28569617/multimodal-partial-volume-correction-application-to-11-c-pib-pet-mri-myelin-imaging-in-multiple-sclerosis
#16
Elisabetta Grecchi, Mattia Veronese, Benedetta Bodini, Daniel García-Lorenzo, Marco Battaglini, Bruno Stankoff, Federico E Turkheimer
The [(11)C]PIB PET tracer, originally developed for amyloid imaging, has been recently repurposed to quantify demyelination and remyelination in multiple sclerosis (MS). Myelin PET imaging, however, is limited by its low resolution that deteriorates the quantification accuracy of white matter (WM) lesions. Here, we introduce a novel partial volume correction (PVC) method called Multiresolution-Multimodal Resolution-Recovery (MM-RR), which uses the wavelet transform and a synergistic statistical model to exploit MRI structural images to improve the resolution of [(11)C]PIB PET myelin imaging...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28569118/analysis-of-nonstationary-time-series-for-biological-rhythms-research
#17
Tanya L Leise
This article is part of a Journal of Biological Rhythms series exploring analysis and statistics topics relevant to researchers in biological rhythms and sleep research. The goal is to provide an overview of the most common issues that arise in the analysis and interpretation of data in these fields. In this article on time series analysis for biological rhythms, we describe some methods for assessing the rhythmic properties of time series, including tests of whether a time series is indeed rhythmic. Because biological rhythms can exhibit significant fluctuations in their period, phase, and amplitude, their analysis may require methods appropriate for nonstationary time series, such as wavelet transforms, which can measure how these rhythmic parameters change over time...
June 2017: Journal of Biological Rhythms
https://www.readbyqxmd.com/read/28558318/a-new-near-lossless-eeg-compression-method-using-ann-based-reconstruction-technique
#18
Behzad Hejrati, Abdolhossein Fathi, Fardin Abdali-Mohammadi
Compression algorithm is an essential part of Telemedicine systems, to store and transmit large amount of medical signals. Most of existing compression methods utilize fixed transforms such as discrete cosine transform (DCT) and wavelet and usually cannot efficiently extract signal redundancy especially for non-stationary signals such as electroencephalogram (EEG). In this paper, we first propose learning-based adaptive transform using combination of DCT and artificial neural network (ANN) reconstruction technique...
May 24, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28558002/electroencephalogram-based-decoding-cognitive-states-using-convolutional-neural-network-and-likelihood-ratio-based-score-fusion
#19
Raheel Zafar, Sarat C Dass, Aamir Saeed Malik
Electroencephalogram (EEG)-based decoding human brain activity is challenging, owing to the low spatial resolution of EEG. However, EEG is an important technique, especially for brain-computer interface applications. In this study, a novel algorithm is proposed to decode brain activity associated with different types of images. In this hybrid algorithm, convolutional neural network is modified for the extraction of features, a t-test is used for the selection of significant features and likelihood ratio-based score fusion is used for the prediction of brain activity...
2017: PloS One
https://www.readbyqxmd.com/read/28552121/research-and-improvement-of-ecg-compression-algorithm-based-on-ezw
#20
Ziran Peng, Guojun Wang, Huabin Jiang, Shuangwu Meng
Embedded zerotree wavelet (EZW) is an efficient compression method that has advantages in coding, but its multilayer structure information coding reduces signal compression ratio. This paper studies the optimization of the EZW compression algorithm and aims to improve it. First, we used lifting wavelet transformation to process electrocardiograph (ECG) signals, focusing on the lifting algorithm. Second, we utilized the EZW compression coding algorithm, through the ECG information decomposition to determine the feature detection value...
July 2017: Computer Methods and Programs in Biomedicine
keyword
keyword
25001
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"