Read by QxMD icon Read

Wavelet analysis

Anukul Pandey, Barjinder Singh Saini, Butta Singh, Neetu Sood
This paper presents a patient's confidential data hiding scheme in electrocardiogram (ECG) signal and its subsequent wireless transmission. Patient's confidential data is embedded in ECG (called stego-ECG) using chaotic map and the sample value difference approach. The sample value difference approach effectually hides the patient's confidential data in ECG sample pairs at the predefined locations. The chaotic map generates these predefined locations through the use of selective control parameters. Subsequently, the wireless transmission of the stego-ECG is analyzed using the Orthogonal Frequency Division Multiplexing (OFDM) system in a Rayleigh fading scenario for telemedicine applications...
October 18, 2017: Journal of Medical Systems
Ming-Sheng Niu, Pei-Gao Han, Lian-Ke Song, Dian-Zhong Hao, Jing-Hu Zhang, Lili Ma
We propose to use the wavelet transform and Kalman filter methods for processing noise in δ(13)CO2 measurement using laser absorption spectroscopy at 2.008 µm and they have been shown to be useful tool for reducing the intrinsic noise of the optical system. Through the performance comparison and analysis of these two denoising techniques for the intrinsic noise reduction of optical system, it can be found that the Kalman filter is a more suitable approach for the extraction of gas isotope measurement signal from a contaminated signal...
October 2, 2017: Optics Express
Zhiyong Dong, Ranfeng Wang, Minqiang Fan, Xiang Fu
Flotation is an important part of coal preparation, and the flotation column is widely applied as efficient flotation equipment. This process is complex and affected by many factors, with the froth depth and reagent dosage being two of the most important and frequently manipulated variables. This paper proposes a new method of switching and optimizing control for the coal flotation process. A hybrid model is built and evaluated using industrial data. First, wavelet analysis and principal component analysis (PCA) are applied for signal pre-processing...
2017: PloS One
Sardar Ansari, Negar Farzaneh, Marlena Duda, Kelsey Horan, Hedvig B Andersson
There is a growing body of research focusing on automatic detection of ischemia and myocardial infarction (MI) using computer algorithms. In clinical settings, ischemia and MI are diagnosed using ECG recordings as well as medical context including patient symptoms, medical history and risk factors, information that is often stored in the electronic health records. The ECG signal is inspected to identify changes in the morphology such as ST-segment deviation and T wave changes. Some of the proposed methods compute similar features automatically while others use non-conventional features such as wavelet coefficients...
October 16, 2017: IEEE Reviews in Biomedical Engineering
Indie C Rice, Lauren L Zimmerman, Shani E Ross, Mitchell B Berger, Tim M Bruns
OBJECTIVES: Female sexual dysfunction (FSD) affects a significant portion of the population. Although treatment options for FSD are limited, neuromodulation for bladder dysfunction has improved sexual function in some women. A few studies have investigated peripheral neuromodulation for eliciting changes in vaginal blood flow, as a proxy for modulating genital sexual arousal, however results are generally transient. Our central hypothesis is that repeated or extended-duration pudendal nerve stimulation can elicit maintained vaginal blood flow increases...
October 16, 2017: Neuromodulation: Journal of the International Neuromodulation Society
Dong Wang, Alistair G Borthwick, Handan He, Yuankun Wang, Jieyu Zhu, Yuan Lu, Pengcheng Xu, Xiankui Zeng, Jichun Wu, Lachun Wang, Xinqing Zou, Jiufu Liu, Ying Zou, Ruimin He
Accurate, fast forecasting of hydro-meteorological time series is presently a major challenge in drought and flood mitigation. This paper proposes a hybrid approach, wavelet de-noising (WD) and Rank-Set Pair Analysis (RSPA), that takes full advantage of a combination of the two approaches to improve forecasts of hydro-meteorological time series. WD allows decomposition and reconstruction of a time series by the wavelet transform, and hence separation of the noise from the original series. RSPA, a more reliable and efficient version of Set Pair Analysis, is integrated with WD to form the hybrid WD-RSPA approach...
October 12, 2017: Environmental Research
Teresa Mastantuono, Noemy Starita, Laura Battiloro, Martina Di Maro, Martina Chiurazzi, Gilda Nasti, Espedita Muscariello, Mario Cesarelli, Luigi Iuppariello, Gianni D'Addio, Alexander Gorbach, Antonio Colantuoni, Dominga Lapi
The present study was aimed to in vivo assess the blood flow oscillatory patterns in rat pial microvessels during 30 min bilateral common carotid artery occlusion (BCCAO) and 60 min reperfusion by laser speckle imaging (LSI). Pial microcirculation was visualized by fluorescence microscopy. The blood flow oscillations of single microvessels were recorded by LSI; spectral analysis was performed by Wavelet transform. Under baseline conditions, arterioles and venules were characterized by blood flow oscillations in the frequency ranges 0...
2017: Frontiers in Cellular Neuroscience
Megan Rossi, Raphael Aggio, Heidi M Staudacher, Miranda C Lomer, James O Lindsay, Peter Irving, Chris Probert, Kevin Whelan
BACKGROUND & AIMS: Dietary interventions are effective in management of patients with irritable bowel syndrome (IBS), although responses vary. We investigated whether fecal levels of volatile organic compounds (VOCs) associate with response to dietary interventions in patients with IBS. METHODS: Adults who fulfilled the Rome III criteria for IBS were recruited to a 2x2 factorial randomized controlled trial. Patients were randomly assigned to a group counselled to follow a diet low in fructans, galacto-oligosaccharides, lactose, fructose, and polyols (low-FODMAP diet, n=46) or a group that received placebo dietary advice (sham diet, n=47) for 4 weeks...
October 6, 2017: Clinical Gastroenterology and Hepatology
Martin Holler, Kamil S Kazimierski
The DjVu file format and image compression techniques are widely used in the archival of digital documents. Its key ingredients are the separation of the document into foreand background layers and a binary switching mask, followed by a lossy, transform-based compression of the former and a dictionary-based compression of the latter. The lossy compression of the layers is based on a wavelet decomposition and bit truncation, which leads, in particular at higher compression rates, to severe compression artifacts in the standard decompression of the layers...
October 6, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
Jingyi Huang, Budiman Minasny, Alex B McBratney, José Padarian, John Triantafilis
Much research has been conducted to understand the spatial distribution of soil carbon stock and its temporal dynamics. However, an agreement has not been reached on whether increasing global temperature has a positive or negative feedback on soil carbon stocks. By analysing global maps of soil organic carbon (SOC) using a spherical wavelet analysis, it was found that the correlation between SOC and soil temperature at the regional scale was negative between 52° N and 40° S parallels and positive beyond this region...
October 5, 2017: Science of the Total Environment
Hadi Ghasemifard, Hamid Behnam, Jahan Tavakkoli
Compressive sensing theory has in recent years been increasingly used in various pattern recognition applications. Compressive sensing theory makes it possible, under certain assumptions, to recover a signal or an image sampled below the Nyquist sampling limit. In this work, a new application of compressive sensing based on the threshold algorithm, in the area of controlling and monitoring of high-intensity focused ultrasound therapy, was investigated. In this work, a new method of high-intensity focused ultrasound lesion detection is presented based on a modified compressive sensing method in combination with the threshold algorithm and the wavelet transforms...
October 1, 2017: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine
L M Ferreira, T Sáfadi, R R Lima
The wavelets have become increasingly popular in the field of bioinformatics due to their capacity in multiresolution analysis and space-frequency localization; the latter particularity is acquired due to a moving window that runs through the analyzed space. As a feature, they have a better ability to capture hidden components of biological data and an efficient link between biological systems and the mathematical objects used to describe them. The decomposition of signals/sequences at different levels of resolution allows obtaining distinct characteristics in each level...
September 21, 2017: Genetics and Molecular Research: GMR
Bo Zhang, Jiasheng Zhao, Xiao Chen, Jianhuang Wu
Electrocardiogram (ECG) data analysis is of great significance to the diagnosis of cardiovascular disease. ECG compression should be processed in real time, and the data should be based on lossless compression and have high predictability. In terms of the real time aspect, short-time Fourier transformation is applied to the processing of signal wave for reducing computational time. For the lossless compression requirement, wavelet-transformation that is a coding algorithm can be used to avoid loss of data. In practice, compression is required to avoid storing redundant recording data that are not useful in the diagnosis platform...
2017: PloS One
Jyoti Maggu, Prerna Singh, Angshul Majumdar
In multi-echo imaging, multiple T1/T2 weighted images of the same cross section is acquired. Acquiring multiple scans is time consuming. In order to accelerate, compressed sensing based techniques have been proposed. In recent times, it has been observed in several areas of traditional compressed sensing, that instead of using fixed basis (wavelet, DCT etc.), considerably better results can be achieved by learning the basis adaptively from the data. Motivated by these studies, we propose to employ such adaptive learning techniques to improve reconstruction of multi-echo scans...
September 28, 2017: Magnetic Resonance Imaging
Amirtaha Taebi, Hansen A Mansy
Accurate estimation of seismocardiographic (SCG) signal features can help successful signal characterization and classification in health and disease. This may lead to new methods for diagnosing and monitoring heart function. Time-frequency distributions (TFD) were often used to estimate the spectrotemporal signal features. In this study, the performance of different TFDs (e.g., short-time Fourier transform (STFT), polynomial chirplet transform (PCT), and continuous wavelet transform (CWT) with different mother functions) was assessed using simulated signals, and then utilized to analyze actual SCGs...
April 7, 2017: Bioengineering
Shasha Yuan, Weidong Zhou, Liyan Chen
Epilepsy is a chronic neurological disorder characterized by sudden and apparently unpredictable seizures. A system capable of forecasting the occurrence of seizures is crucial and could open new therapeutic possibilities for human health. This paper addresses an algorithm for seizure prediction using a novel feature - diffusion distance (DD) in intracranial Electroencephalograph (iEEG) recordings. Wavelet decomposition is conducted on segmented electroencephalograph (EEG) epochs and subband signals at scales 3, 4 and 5 are utilized to extract the diffusion distance...
August 16, 2017: International Journal of Neural Systems
Subhabrata Mitra, Gemma Bale, David Highton, Roxanna Gunny, Cristina Uria-Avellanal, Alan Bainbridge, Magdalena Sokolska, David Price, Angela Huertas-Ceballos, Giles S Kendall, Judith Meek, Ilias Tachtsidis, Nicola J Robertson
Hypoxic ischemic encephalopathy (HIE) leads to significant morbidity and mortality. Impaired autoregulation after hypoxia-ischaemia has been suggested to contribute further to injury. Thalamic lactate/N-Acetylasperate (Lac/NAA) peak area ratio of > 0.3 on proton ((1)H) magnetic resonance spectroscopy (MRS) is associated with poor neurodevelopment outcome following HIE. Cytochrome-c-oxidase (CCO) plays a central role in mitochondrial oxidative metabolism and ATP synthesis. Using a novel broadband NIRS system, we investigated the impact of pressure passivity of cerebral metabolism (CCO), oxygenation (haemoglobin difference (HbD)) and cerebral blood volume (total haemoglobin (HbT)) in 23 term infants following HIE during therapeutic hypothermia (HT)...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
Dimitrios Filos, Ioanna Chouvarda, Dimitris Tachmatzidis, Vassilios Vassilikos, Nicos Maglaveras
BACKGROUND AND OBJECTIVES: Atrial Fibrillation (AF) is the most common cardiac arrhythmia. The initiation and the perpetuation of AF is linked with phenomena of atrial remodeling, referring to the modification of the electrical and structural characteristics of the atrium. P-wave morphology analysis can reveal information regarding the propagation of the electrical activity on the atrial substrate. The purpose of this study is to investigate patterns on the P-wave morphology that may occur in patients with Paroxysmal AF (PAF) and which can be the basis for distinguishing between PAF and healthy subjects...
November 2017: Computer Methods and Programs in Biomedicine
Elisavet Koutsiana, Leontios J Hadjileontiadis, Ioanna Chouvarda, Ahsan H Khandoker
Phonocardiography is a non-invasive technique for the detection of fetal heart sounds (fHSs). In this study, analysis of fetal phonocardiograph (fPCG) signals, in order to achieve fetal heartbeat segmentation, is proposed. The proposed approach (namely WT-FD) is a wavelet transform (WT)-based method that combines fractal dimension (FD) analysis in the WT domain for the extraction of fHSs from the underlying noise. Its adoption in this field stems from its successful use in the fields of lung and bowel sounds de-noising analysis...
2017: Frontiers in Bioengineering and Biotechnology
Jorge Rey-Martinez
To explore the applicability of discrete wavelet transforms in the analysis of vHIT responses. Discrete wavelet transform was applied to vHIT responses and a new method for calculating aVOR gain was developed. A prospective study was performed with two groups of normal (N = 10) and altered (N = 19) gain values; HIMP and SHIMP vHIT protocols were performed on both groups. To evaluate the gain values obtained, Intraclass Correlation Index, Pearson's correlation, linear regression, and t test were performed...
September 22, 2017: European Archives of Oto-rhino-laryngology
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"