Time-frequency representations (TFRs) of signals are increasingly being used in biomedical research. Analysis of such representations is sometimes difficult, however, and is often reduced to the extraction of ridges, or local energy maxima. In this paper, we describe a new ridge extraction method based on the image processing technique of active contours or snakes. We have tested our method on several synthetic signals and for the analysis of uterine electromyogram or electrohysterogram (EHG) recorded during gestation in monkeys. We have also evaluated a postprocessing algorithm that is especially suited for EHG analysis. Parameters are evaluated on real EHG signals in different gestational periods. The presented method gives good results when applied to synthetic as well as EHG signals. We have been able to obtain smaller ridge extraction errors when compared to two other methods specially developed for EHG. The gradient vector flow (GVF) snake method, or GVF-snake method, appears to be a good ridge extraction tool, which could be used on TFR of mono or multicomponent signals with good results.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1109/TBME.2008.918556 | DOI Listing |
Biomech Model Mechanobiol
January 2025
Department of Mechanical Engineering, University of Utah, Salt Lake City, UT, 84112, USA.
When infants are admitted to the hospital with skull fractures, providers must distinguish between cases of accidental and abusive head trauma. Limited information about the incident is available in such cases, and witness statements are not always reliable. In this study, we introduce a novel, data-driven approach to predict fall parameters that lead to skull fractures in infants in order to aid in determinations of abusive head trauma.
View Article and Find Full Text PDFVis Comput Ind Biomed Art
January 2025
Research Institute of Trustworthy Autonomous Systems and Department of Computer Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China.
Cataract is the leading ocular disease of blindness and visual impairment globally. Deep neural networks (DNNs) have achieved promising cataracts recognition performance based on anterior segment optical coherence tomography (AS-OCT) images; however, they have poor explanations, limiting their clinical applications. In contrast, visual features extracted from original AS-OCT images and their transform forms (e.
View Article and Find Full Text PDFSci Rep
January 2025
UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria, South Africa.
This research successfully synthesized semiconductive magnesioferrite (MgFeO) nanomaterials using a green chemistry method that utilizes the natural extract of Moringa olefeira serving as both a reducing and oxidizing agent. The optical characteristics and crystalline structure of the MgFeO nanomaterials were analysed using photoluminescence, diffuse reflectance spectroscopy, and X-ray diffraction. Additionally, Fourier transform infrared spectroscopy provided valuable insights into the chemical bonding and composition.
View Article and Find Full Text PDFClin Adv Periodontics
January 2025
Operative Unit of Dentistry, Azienda Unità Sanitaria Locale, Ferrara, Italy.
Background: The purpose of the present case study is to describe the application of a modification of the Biologically-oriented Alveolar Ridge Preservation (BARP) principles in cases of peri-implant bone dehiscence (PIBD) due to a compromised alveolus at immediate implant placement (IIP).
Methods: The technique is based on the stratification of three layers: a deep layer with a collagen sponge (CS) in the apical part of the alveolus (where the buccal bone plate was still present) to support the blood clot; a graft layer to correct the PIBD; and a superficial collagen layer to cover the graft thus providing space and enhancing clot/graft stability. Healing was obtained by primary closure.
J Ethnopharmacol
January 2025
Heilongjiang University of Chinese Medicine, Key Laboratory of Basic and Application Research of Beiyao (Heilongjiang University of Chinese Medicine), Ministry of Education Heilongjiang Touyan Innovation Team Program, Harbin, 150040, People's Republic of China. Electronic address:
Ethnopharmacological Relevance: Schisandra chinensis (Turcz.) Baill (S. chinensis), first recorded in Shennong's Classic of the Materia Medica, is described as a "top grade medicine".
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!