We thank the internal (Columbia SIRS/STAR) and external (AHA, NIH, NSF) funding agencies for generously supporting our work. Some of our ongoing research interests are discussed below

Cardiac Digital Twins

We are interested in developing patient-specific, multiphysics models (i.e., digital twins) of cardiac function. The heart is a complex physical organ, in which different biophysical processes, including cardiac electrophysiology, tissue mechanics, and blood flow, interact across multiple spatial and temporal scales, to perform its function – to pump blood to the body. We aim to computationally model these individual processes using their mathematical description, personalize the model by fitting parameters to match clinical measurements using inverse analysis, and apply this comprehensive model to study cardiac disease and dysfunction. Specific applications include arrhythmia, ventricular dyssynchrony, cardiomyopathies, atrial fibrillation, and other pediatric congenital heart disease applications. (electromechanics, fluid-structure interaction (FSI), finite element analysis (FEA), inverse FEA, optimization, machine learning, parameter estimation)

Collaborators: Hiroo Takayama, Ian Chen
Funding: AHA 24SCEFIA1260268, NSF CAREER

Multiscale fluid-structure interaction (FSI)

We are interested in performing multiscale fluid-structure interaction (FSI) modeling of blood flow in the vasculature, including the aorta, coronaries, and deep veins. `Multiscale’ refers to coupling a high-fidelity, spatially-resolved blood flow model in three spatial dimensions (3D), e.g., Navier-Stokes equations, with a low-fidelity, reduced-order, zero-dimensional (0D) model of the circulatory system based on lumped parameter network (LPN). The 3D model is typically derived from the patient’s medical images (CT, MRI), and the parameters of the coupled 3D/0D model are tuned to fit clinical measurements. (fluid-structure interaction (FSI), finite element analysis (FEA), parameter estimation)

Collaborators: Hiroo Takayama, Ian Chen, Keefe Manning
Funding: 2022 Columbia SIRS/The Blavatnik Fund for Engineering Innovations in Health

Borderline Left Ventricle

The decision to perform a biventricular repair (BiVR) or single ventricle palliation (SVP) in patients born with a borderline left ventricle (BLV) remains challenging and subjective. BLV patients are neonates born with an underdeveloped left ventricle but not severe enough to be classified as hypoplastic left heart syndrome (HLHS). A BiVR is attractive because it restores two functioning ventricles; however, SVP involves multiple staged open-heart procedures, resulting in a single pumping chamber. HLHS patients undergoing SVP have high interstage mortality and poor long-term outcomes. Our overarching goal is to deliver a personalized, predictive, and elegant model that allows clinicians to choose a procedure that will yield the most favorable hemodynamics in this critical population. (lumped parameter network, multiscale modeling, parameter estimation, uncertainty quantification, hemodynamics)

Collaborators: David Kalfa
Funding: NIH R21 LM014881

Pediatric valve device development

More than 16,000 US children need the implantation of a valved conduit to replace the right ventricular outflow tract (RVOT) annually. These children require one to four repeat open-heart surgeries to replace the valved conduit before they reach adulthood because available prostheses do not grow with the child. The long-term goal of our multidisciplinary collaborative team is to develop a biostable polymeric valved conduit that can be implanted surgically to reconstruct the RVOT and then expanded (by successive transcatheter procedures) to avoid multiple surgeries in children. Our role is to optimize the valve’s hemodynamic performance across multiple expansions, combining a robust optimization framework with fluid-structure interaction simulations, under physiological loads. (optimization, fluid-structure interaction, device fabrication, tensile testing, pulse-duplicator testing, fatigue analysis, large animal testing)

Collaborators: David Kalfa (PI), Jeffrey Kysar, Haim Waisman, Giovanni Ferrari
Funding: NHLBI R01 HL155381

Outflow tract (OFT) morphogenesis in developing zebrafish

Our role in this collaborative project is to interrogate the role of blood flow and shear forces in regulating endothelial signaling, promoting extracellular matrix deposition that dictates tissue compliance, and the role of Fibulin (Fbln) genes, in the outflow tract (OFT) of a developing zebrafish. Insights gained here will shed light on the biomechanical mechanisms responsible for compliance and elastic deformation in the OFT with implications for congenital heart disease with conotruncal anomalies, including transposition of great vessels, double outlet right ventricle, and Tetralogy of Fallot. (image-based blood flow modeling, fluid-structure interaction (FSI), vascular mechanics)

Collaborators: Kimara Targoff (PI), Nandan Nerurkar, Elizabeth Hillman
Funding: NHLBI R01 HL170188