Clot embolization studies and computational framework for embolization in a canonical tube model.

Despite recent advances in the development of computational methods of modeling thrombosis, relatively little effort has been made in developing methods of modeling blood clot embolization. Such a model would provide substantially greater understanding of the mechanics of embolization, as in-vitro and in-vivo characterization of embolization is difficult. Here, a method of computationally simulating embolization is developed.

Examining the universality of the hemolysis power law model from simulations of the FDA nozzle using calibrated model coefficients.

Computational fluid dynamics (CFD) is widely used to predict mechanical hemolysis in medical devices. The most popular hemolysis model is the stress-based power law model that is based on an empirical correlation between hemoglobin release from red blood cells (RBCs) and the magnitude of flow-induced stress and exposure time. Empirical coefficients are traditionally calibrated using data from experiments in simplified Couette-type blood-shearing devices with uniform-shear laminar flow and well-defined exposure times.

Toward modeling thrombosis and thromboembolism in laminar and turbulent flow regimes.

Thrombosis and thromboembolism are deadly risk factors in blood-contacting biomedical devices, and in-silico models of thrombosis are attractive tools to understand the mechanics of these processes, though the simulation of thromboembolism remains underdeveloped. The purpose of this study is to modify an existing computational thrombosis model to allow for thromboembolism and to investigate the behavior of the modified model at a range of flow rates. The new and existing models are observed to lead to similar predictions of thrombosis in a canonical backward-facing step geometry across flow rates, and neither model predicts thrombosis in a turbulent flow.

Computational Investigation of Anastomosis Options of a Right-Heart Pump to Patient Specific Pulmonary Arteries.

Patients with Fontan circulation have increased risk of heart failure, but are not always candidates for heart transplant, leading to the development of the subpulmonic Penn State Fontan Circulation Assist Device. The aim of this study was to use patient-specific computational fluid dynamics simulations to evaluate anastomosis options for implanting this device. Simulations were performed of the pre-surgical anatomy as well as four surgical options: a T-junction and three Y-grafts.

Refining a numerical model for device-induced thrombosis and investigating the effects of non-Newtonian blood models.

Thrombosis is one of the main causes of failure in device implantation. Computational thrombosis simulation is a convenient approach to evaluate the risk of thrombosis for a device. However, thrombosis is a complicated process involving multiple species and reactions.

Large-Eddy Simulations of Flow in the FDA Benchmark Nozzle Geometry to Predict Hemolysis.

Purpose: Modeling of hemolysis due to fluid stresses faces significant methodological challenges, particularly in geometries with turbulence or complex flow patterns. It is currently unclear how existing phenomenological blood-damage models based on laminar viscous stresses can be implemented into turbulent computational fluid dynamics simulations. The aim of this work is to generalize the existing laminar models to turbulent flows based on first principles, and validate this generalization with existing experimental data.

Towards uncovering the structure of power fluctuations of wind farms.

The structure of the turbulence-driven power fluctuations in a wind farm is fundamentally described from basic concepts. A derived tuning-free model, supported with experiments, reveals the underlying spectral content of the power fluctuations of a wind farm. It contains two power-law trends and oscillations in the relatively low- and high-frequency ranges.