Towards Real-Time 3D Coronary Hemodynamics Simulations During Cardiac Catheterisation

Abstract

Virtual Fractional Flow Reserve (vFFR) is an emerging technology that assesses the severity of coronary stenosis by means of patient specific of Computational Fluid Dynamics simulations. To be of practical clinical utility within a catheter laboratory, FFR results must be obtainable within minutes to guide intervention. We present the design of a novel Lattice-Boltzmann method code specifically tailored for fully automatic near real-time 3D coronary blood flow simulations.The key contributions of the work include a hybrid multicore-GPU accelerated sparse lattice generation algorithm and specialized 3D-0D coupled hemodynamics solver. We present results on state of the art GPU hardware, simulating hemodynamics within multi segment coronary tree. The results demonstrate that vFFR simulations can be performed in the order of minutes, making the replacement of pressure wire based FFR in a catheter laboratory setting with vFFR simulations feasible, without the need to reduce the fidelity of the hemodynamics modelling.

Direct 0D‐3D coupling of a lattice Boltzmann methodology for fluid–structure aortic flow simulations

“…In order to extend the clinical applicability of fluid-structure blood flow solvers based on LB equations applied to large vessels, this work introduces a direct 0D-3D coupling for the treatment of physiological boundary conditions that are governed by ordinary differential equations (ODEs) such as lumped parameter Windkessel models 25,26 or more complex hybrid ODE-Dirichlet systems such as time-varying elastance organ models 10 (both known as 0D models due to the absence of spatial dependence). Previous contributions on the 0D-3D coupling for finite element methods 27,28 have been implicit and iterative, and for lattice Boltzmann 29,30 blood flow models usually only a Dirichlet or Neumann pressure or flow is prescribed during the entirety of a cardiac cycle (precluding the use of more sophisticated and nonstationary, i.e., switching, boundary conditions 10 ).…”

Direct 0D-3D coupling of a lattice Boltzmann methodology for fluid-structure hemodynamics simulations

“…In order to extend the clinical applicability of fluid-structure blood flow solvers based on LB equations applied to large vessels, this work introduces a direct 0D-3D coupling for the treatment of physiological boundary conditions that are governed by ordinary differential equations (ODEs) such as lumped parameter Windkessel models [25,26] or more complex hybrid ODE-Dirichlet systems such as time-varying elastance organ models [10] . Previous contributions on the 0D-3D coupling for finite element methods [27,28] have been implicit and iterative, and for lattice Boltzmann [29,30] blood flow models usually only a Dirichlet or Neumann pressure or flow is prescribed during the entirety of a cardiac cycle (precluding the use of more sophisticated and non-stationary, i.e., switching, boundary conditions [10]). Additionally, recent work [30] on LB-based hemodynamics solvers have assumed only rigid walls, and have applied 0D lumped parameter models externally through an iterative procedure where the heart model is evolved and precomputed entirely independently [30] (such that the resultant pressure profile is applied on a 3D LB domain simply as a Dirichlet condition, i.e., not a true mathematical coupling).…”