This paper presents a new way to solve the inverse problem of electrocardiography in terms of heart model parameters. The developed event estimation and recognition method is based on an optimization system of heart model parameters. An ANN-based preliminary ECG analyzer system has been created to reduce the searching space of the optimization algorithm. The optimal model parameters were determined by minimizing the objective functions, as relations of the observed and model-generated body surface ECGs. The final evaluation results, validated by physicians were about 86% correct. Starting from the fact that input ECGs contained various malfunction cases, such as Wolff-Parkinson-White (WPW) syndrome, atrial and ventricular fibrillation, these results suggest that this approach provides a robust inverse solution, circumventing most of the difficulties of the ECG inverse problem.
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http://dx.doi.org/10.1109/IEMBS.2005.1615348 | DOI Listing |
Environ Toxicol Chem
January 2025
Osnabrück University, Osnabrück, Lower Saxony, Germany.
In regulatory aquatic risk assessment, toxicokinetic-toxicodynamic (TKTD) methods, such as the generalized unified threshold model of survival (GUTS), are already established and considered ready for use, whereas TKTD methods for aboveground terrestrial species, like arthropods, are less developed and currently not intended for risk assessment. This could be due to the fact that exposure in aboveground terrestrial systems is more event-based (feeding, contact, overspray, etc.), whereas exposure in aquatic systems is simply related to substance concentrations in the surrounding water.
View Article and Find Full Text PDFTransl Vis Sci Technol
January 2025
School of Optometry and Vision Science, University of New South Wales, Sydney, Australia.
Purpose: The purpose of this study was to develop and validate a deep-learning model for noninvasive anemia detection, hemoglobin (Hb) level estimation, and identification of anemia-related retinal features using fundus images.
Methods: The dataset included 2265 participants aged 40 years and above from a population-based study in South India. The dataset included ocular and systemic clinical parameters, dilated retinal fundus images, and hematological data such as complete blood counts and Hb concentration levels.
Proc Natl Acad Sci U S A
January 2025
Ernst Strüngmann Institute, Frankfurt am Main 60528, Germany.
The dynamics of neuronal systems are characterized by hallmark features such as oscillations and synchrony. However, it has remained unclear whether these characteristics are epiphenomena or are exploited for computation. Due to the challenge of selectively interfering with oscillatory network dynamics in neuronal systems, we simulated recurrent networks of damped harmonic oscillators in which oscillatory activity is enforced in each node, a choice well supported by experimental findings.
View Article and Find Full Text PDFUnlabelled: One of the principles of prevention and non-drug treatment of liver diseases, including hepatitis of various etiologies, is the normalization of the diet, including the use of daily diet foods with physiologically active ingredients, in particular betulin, which helps to reduce metabolic and oxidative processes within liver cells. The aim of the work was to evaluate the in vivo effect of triterpene alcohol betulin Roth isolated from the bark of birch Betula pendula Roth. added to fat-containing products (for example, mayonnaise) on the biochemical parameters of blood and the morphological structure of the liver of rats with initiated acute toxic hepatitis.
View Article and Find Full Text PDFDokl Biochem Biophys
January 2025
Bakulev National Medical Research Center for Cardiovascular Surgery, Moscow, Russia.
The study presents a numerical parametric investigation of flow structures in channels with a longitudinal-radial profile zR = Const and a spherical dome at the base. The goal of the study was to examine the flow structures in these channels depending on the exponent N of the profile and the height of the dome, to determine the conditions that provide optimal centripetal swirling flow, analogous to blood flow in the heart chambers and major vessels. The investigation was conducted using a comparative analysis of flow structures in channel configurations zR = Const, carried out in two stages.
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