A5060857025- Cardiac electrophysiology and arrhythmias
- Cardiac pacing and defibrillation studies
- Laser Design and Applications
- Spectroscopy and Laser Applications
- Cardiovascular Function and Risk Factors
- Cardiac Arrhythmias and Treatments
- ECG Monitoring and Analysis
- Elasticity and Material Modeling
- Ion channel regulation and function
- Atmospheric Ozone and Climate
- Cardiomyopathy and Myosin Studies
- Cardiac Structural Anomalies and Repair
- Advanced MRI Techniques and Applications
- Model Reduction and Neural Networks
- Non-Invasive Vital Sign Monitoring
- Gaussian Processes and Bayesian Inference
- Neuroscience and Neuropharmacology Research
- Cardiac Arrest and Resuscitation
- Cardiovascular Effects of Exercise
- Stochastic Gradient Optimization Techniques
- Domain Adaptation and Few-Shot Learning
- Neuroscience and Neural Engineering
- Probabilistic and Robust Engineering Design
- Vestibular and auditory disorders
- Laser-Matter Interactions and Applications
Institute of Problems of Chemical Physics
2016-2021
IBM (United States)
2012-2021
IBM Research - Thomas J. Watson Research Center
2012-2019
Johns Hopkins University
2008-2014
University of Oxford
2009
Johns Hopkins Medicine
2008
Tulane University
2006
Providing therapies tailored to each patient is the vision of precision medicine, enabled by increasing ability capture extensive data about individual patients. In this position paper, we argue that second enabling pillar towards power computers and algorithms learn, reason, build 'digital twin' a patient. Computational models are boosting capacity draw diagnosis prognosis, future treatments will be not only current health status data, but also an accurate projection pathways restore model...
Models of cardiac mechanics are increasingly used to investigate physiology. These models characterized by a high level complexity, including the particular anisotropic material properties biological tissue and actively contracting material. A large number independent simulation codes have been developed, but consistent way verifying accuracy replicability simulations is lacking. To aid in verification current future solvers, this study provides three benchmark problems for mechanics. test...
Although ventricular premature beats (VPBs) during acute regional ischemia have been linked to mechanical stretch of ischemic tissue, whether and how ischemia-induced dysfunction can induce VPBs facilitate their degradation into reentrant arrhythmias has not yet addressed.This study used a novel multiscale electromechanical model the rabbit ventricles investigate origin substrate for spontaneous arising from electrophysiological changes.Two stages were simulated. Dynamic mechanoelectrical...
Computational modeling has traditionally played an important role in dissecting the mechanisms for cardiac dysfunction. Ventricular electromechanical models, likely most sophisticated virtual organs to date, integrate detailed information across spatial scales of electrophysiology and mechanics are capable capturing emergent behavior interaction between electrical activation mechanical contraction heart. The goal this review is provide overview latest advancements multiscale ventricles. We...
Recruitment of stretch-activated channels, one the mechanisms mechano-electric feedback, has been shown to influence stability scroll waves, waves that underlie reentrant arrhythmias. However, a comprehensive study examine effects recruitment channels with different reversal potentials and conductances on wave not undertaken; by which channel opening alters are also well understood. The goals this were test hypothesis affects differently depending potential conductance, uncover relevant...
While pre-clinical Torsades de Pointes (TdP) risk classifiers had initially been based on drug- induced block of hERG potassium channels, it is now well established that improved prediction can be achieved by considering non-hERG ion channels. The current multi-channel TdP categorized into two classes. First, the take as input values drug-induced channels (direct features). Second, are built features extracted from output blockage simulations in in-silico models (derived derived have thus...
Patient specific models of ventricular mechanics require the optimization their many parameters under uncertainties associated with imaging cardiac function. We present a strategy to reduce complexity parametric searches for 3-D FE left contraction. The study employs automatic image segmentation and analysis an database gain geometric features several classes patients. Statistical distributions are then used design studies investigating effects of: 1) passive material properties during...
AbstractWe have developed the capability to rapidly simulate cardiac electrophysiological phenomena in a human heart discretised at resolution comparable with length of myocyte. Previous scientific investigation has generally invoked simplified geometries or coarse-resolution hearts, simulation duration limited 10s heartbeats. Using state-of-the-art high-performance computing techniques coupled one most powerful computers available (the 20 PFlop/s IBM BlueGene/Q Lawrence Livermore National...
Left ventricular-assist devices (LVADs) are used to supply blood the body of patients with heart failure. Pressure unloading is greater for counter-pulsating LVADs than continuous LVADs. However, several clinical trials have demonstrated that myocardial recovery similar both types LVAD. This study examined contractile energy consumption myocardium and LVAD support ascertain effect different on recovery. We a three-dimensional electromechanical model canine ventricles, models circulatory...
Despite significant recent advances in deep neural networks, training them remains a challenge due to the highly non-convex nature of objective function. State-of-the-art methods rely on error backpropagation, which suffers from several well-known issues, such as vanishing and exploding gradients, inability handle non-differentiable nonlinearities parallelize weight-updates across layers, biological implausibility. These limitations continue motivate exploration alternative algorithms,...
We introduce and compare three different modalities to study seismocardiogram (SCG) its correlation with cardiac events. used an accelerometer attached the subject sternum get a reference measure. Cardiac events were then approximately identified using echocardiography. As alternative approximation, we consecutive Cine-MRI images of heart capture movements compared them experimental SCG. also employed anatomically accurate, finite element base electromechanical model geometry built...
Ectopic heartbeats can trigger reentrant arrhythmias, leading to ventricular fibrillation and sudden cardiac death. Such events have been attributed perturbed Ca2+ handling in myocytes spontaneous release delayed afterdepolarizations (DADs). However, the ways which perturbation of specific molecular mechanisms alters probability ectopic beats is not understood. We present a multiscale model tissue incorporating biophysically detailed three-dimensional myocyte. This reproduces realistic waves...
Background: Up to 30-50% of chronic heart failure patients who underwent cardiac resynchronization therapy (CRT) do not respond the treatment. Therefore, patient stratification for CRT and optimization device settings remain a challenge. Objective: The main goal our study is develop predictive model outcome using combination clinical data recorded in before simulations response biventricular (BiV) pacing personalized computational models electrophysiology. Materials Methods: Retrospective...
We describe recent preliminary studies demonstrating that computational analysis of spoken and written language can provide for highly accurate diagnostics over a wide variety psychiatric neurologic conditions, including psychosis, drug abuse, Parkinson's, Alzheimer's. These results are based on the mathematical formalization qualitative knowledge related to characterization conditions (e.g., “derailment” in psychosis) effects increased intimacy/affection with use recreational ecstasy), as...
Multiscale computational models of heart are being extensively investigated for improved assessment drug-induced Torsades de Pointes (TdP) risk, a fatal side effect many drugs. Model-derived metrics such as action potential duration and net charge carried by ionic currents (qN et) have been proposed candidates TdP risk stratification after tested on small datasets. Unlike purely statistical approaches, model-derived thought to provide mechanism-based classification. In particular, qN et has...