We present a general method of utilizing bioelectric recordings from a spatially sparse electrode grid to compute a dynamic vector field describing the underlying propagation of electrical activity. This vector field, termed the wave-front flow field, permits quantitative analysis of the magnitude of rotational activity (vorticity) and focal activity (divergence) at each spatial point. We apply this method to signals recorded during arrhythmias in human atria and ventricles using a multipolar contact catheter and show that the flow fields correlate with corresponding activation maps. Further, regions of elevated vorticity and divergence correspond to sites identified as clinically significant rotors and focal sources where therapeutic intervention can be effective. These flow fields can provide quantitative insights into the dynamics of normal and abnormal conduction in humans and could potentially be used to enhance therapies for cardiac arrhythmias.
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http://dx.doi.org/10.1103/PhysRevE.94.050401 | DOI Listing |
Med Image Anal
January 2025
Department of Engineering Science, University of Oxford, Oxford, UK.
Cardiac digital twins (CDTs) offer personalized in-silico cardiac representations for the inference of multi-scale properties tied to cardiac mechanisms. The creation of CDTs requires precise information about the electrode position on the torso, especially for the personalized electrocardiogram (ECG) calibration. However, current studies commonly rely on additional acquisition of torso imaging and manual/semi-automatic methods for ECG electrode localization.
View Article and Find Full Text PDFCommun Med (Lond)
November 2024
Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, 55905, USA.
Background: While high-frequency oscillations (HFOs) and their stereotyped clusters (sHFOs) have emerged as potential neuro-biomarkers for the rapid localization of the seizure onset zone (SOZ) in epilepsy, their clinical application is hindered by the challenge of automated elimination of pseudo-HFOs originating from artifacts in heavily corrupted intraoperative neural recordings. This limitation has led to a reliance on semi-automated detectors, coupled with manual visual artifact rejection, impeding the translation of findings into clinical practice.
Methods: In response, we have developed a computational framework that integrates sparse signal processing and ensemble learning to automatically detect genuine HFOs of intracranial EEG data.
J Colloid Interface Sci
February 2025
Advanced Functional Nanohybrid Material Laboratory, Department of Chemistry, Dongguk University Seoul-Campus, Seoul 04620, Republic of Korea; Department of Advanced Battery Convergence Engineering, Dongguk University Seoul-Campus, Seoul 04620, Republic of Korea. Electronic address:
The occurrence of the hydrogen evolution reaction (HER) on the surface of the carbon-based negative electrode of the vanadium redox flow battery (VRFB) causes high charge transfer resistance (R) for the desired V/V redox reaction leading to irreversible capacity loss. To this effect, we have synthesized acetylacetonate-modified TiO (SGTA) and unmodified TiO (SGT) coating colloidal solutions as electrocatalysts for enhanced V/V redox reaction on the carbon-felt negative electrodes of VRFB. The SGTA particles exhibit significantly higher homogeneity with sizes of ≤15 nm, in comparison to the severely aggregated SGT particles with diameters of ∼23-75 nm in colloidal solution.
View Article and Find Full Text PDFACS ES T Eng
October 2024
Department of Civil & Environmental Engineering, Texas A&M University, College Station, Texas 77843, United States.
Electrocoagulation has attracted significant attention as an alternative to conventional chemical coagulation because it is capable of removing a wide range of contaminants and has several potential advantages. In contrast to most electrocoagulation research that has been performed with nonporous electrodes, in this study, we demonstrate energy-efficient iron electrocoagulation using porous electrodes. In batch operation, investigation of the external pore structures through optical microscopy suggested that a low porosity electrode with sparse connection between pores may lead to mechanical failure of the pore network during electrolysis, whereas a high porosity electrode is vulnerable to pore clogging.
View Article and Find Full Text PDFACS Energy Lett
October 2024
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.
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