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WECC groups and vendors work closely together toward development of new tools and procedures to ensure consistency between the two major models used in WECC, (West-wide System Model (WSM) used by Reliability Coordinators and planning basecases used to perform operational and planning studies), This work includes program features that enable traditional software to read a node-breaker power flow snapshot...
Clinical translation of computational models of the heart has been hampered by the absence of complete and rigorous technical and clinical validation, as well as benchmarking of the developed tools. To address this issue, a dataset containing the cardiac anatomy and fibre orientations from magnetic resonance images (MRI), as well as epicardial transmembrane potentials from optical mapping acquired...
The study of growth model is a basic research in forest growth and yield modeling. Most of growth models were developed using ordinary regression method. It is assumed that the observations were independent and obey Gauss distribution. Those models reflect the average growth across different plots, but neglect the correlation and variance between individuals and plots. However, mixed-effects models...
The ultra rapid potassium current (IKur) is an attractive pharmacological target in atrial fibrillation (AF) management due to its atrial specific nature. An experimentally based 78% IKur reduction was incorporated into a human atrial action potential (AP) model under sinus rhythm (SR) and atrial fibrillation (AF) conditions. Its effects on cell and tissue level electrical activity were simulated...
Functional roles of ionic currents in a membrane delimited sino-atrial node (SAN) cell model were investigated. Ionic currents were blocked and intracellular calcium ([Ca2+]i) buffered to study their effects on action potential (AP) characteristics. The simulations revealed that blocking the hyperpolarization activated current and the T-type calcium current caused an increase of cycle length (CL)...
To investigate complex electrophysiological behaviour (such as reentrant cardiac arrhythmias) in the setting of the complex anatomy of the heart, the use of a simplified model is computationally more effective. In this study, the Rogers-modified FitzHugh-Nagumo model was further modified to allow control of action potential upstroke velocity, conduction velocity, action potential duration and refractory...
The E1784K mutation in SCN5A was reported as a phenotypic overlap between the Type 3 Long QT syndrome (LQT3) and the Brugada syndrome (BrS). However it is still unclear if the E1784K mutation-induced changes at ionic channel level is sufficient to account for the two phenotypic and how they affect ventricular excitation waves at tissue level. In this study, we used a biophysically detailed computer...
This paper proposed an issue that among the objectives it need to weight to reflect the different importance in the fuzzy multi-objective programming. Established a fuzzy multi-objective programming model with preference weight. Taking into account many decision-makers participating in evaluation, gave a method which made the preference information set of different forms assembled into group preference,...
Mechanical contraction alternans of the heart is associated with fatal cardiac death. It is manifested by T-wave alternans in the ECG, and is thought to be possibly related to intracellular Ca2+ transient alternans released from the sarcoplasmic reticulum (SR). However, it is unclear yet how beat-to-beat alternans of intracellular Ca2+ transient is produced. In this study investigated the mechanism(s)...
Purkinje fiber (PF) cells exhibit action potential (AP) morphology and duration markedly different to those of ventricle myocytes. In order to study heterogeneity at the Purkinje-ventricular junction (PVJ), we construct a new AP model for the canine PF cell based on detailed experimental data of ion channel characteristics obtained by voltage clamp techniques. Single-cell PF model is incorporated...
Idiopathic short QT (SQT) syndrome is a recently identified, genetically heterogeneous condition characterized by abbreviated QT intervals and an increased susceptibility to arrhythmia and sudden death. In this computer simulation study, we identify the mechanisms by which cellular electrophysiological changes in the SQT syndrome associated with V307L KvLQT1 (KCNQ1) gene mutation (the gene coding...
We have developed a three-dimensional computational wedge model of canine cardiac ventricular wall electro-physiology that incorporates biophysically detailed, spatially heterogeneous excitation, and high-resolution geometry and fibre orientation. Isolated cell model electrophysiological characteristics reproduce the experimentally observed characteristics under control conditions, and under conditions...
The electrocardiogram (ECG) is an important index of clinical diagnosis of cardiac arrhythmias. Simulations of ECG had revealed the causative relationship between waveforms of ECG and action potentials (APs). However, those studies were mainly based on the Luo-Rudy (LRd) model or the Priebe-Beuckelman (PB) model. In this study, we developed a ID model of transmural ventricular strand based on the...
Sinoatrial (SA) node, the pacemaker of the heart, is a structurally and functionally complex tissue. The role of this complexity in initiation and conduction of the pacemaker activity is not fully understood. Computer modeling provides a powerful alternative way to experiment in studying complex cardiac phenomena. In this work we combine histological, immunochemical, electrophysiological data with...
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