Biomedical Healthcare

A New Eikonal Solver for Cardiac Electrophysiology in LS-DYNA

Heart disease is among the leading causes of death in the western countries; hence, a deeper understanding of cardiac functioning will provide important insights for engineers and clinicians in treating cardiac pathologies. In this paper we will concentrate on electrophysiology (EP), which describes the propagation of the cell transmembrane potential in the heart. In LS-DYNA, EP can be coupled with solid and fluid mechanics for a multiphysics simulation of the heart, but pure EP is also often used to investigate complex phenomena such as cardiac arrhythmia or fibrillations. The gold standard model for EP is the “bi-domain” model, along with the slightly simplified “mono-domain”. These were introduced in LS-DYNA a few years ago [1]. They give very accurate predictions, but the associated computational expenses are significant, which can be an issue for patient-specific predictions, for example, cardiac activation patterns for complex procedures such as cardiac resynchronization therapy (CRT).

Simulation of viscoelastic two-phase flows with LS-DYNA ICFD

Simulations of viscoelastic flows are presented. Viscoelasticity is accounted for by solving a constitutive equation for the conformation tensor - the viscoelastic stress tensor is directly related to the conformation tensor [1] and the divergence of the viscoelastic stress tensor yields an extra momentum source. The Oldroyd-B constitutive model is here considered [1]. Results of several benchmark tests are presented. Implementation is first tested on a two-dimensional lid-driven cavity flow. Results of two-dimensional and three-dimensional Oldroyd-B liquid jets are then presented. Viscoelastic models are used in applications like food-processing, polymer melt processing, blood flow modeling.

Simulating Global Motion of the Brain in Response to Trauma

This research constructs a three-dimensional (3D) topological model that comprehensively predicts the macroscopic movement of the brain within the skull [5]. The consideration of impact angles and cerebrospinal fluid dynamics highlights the unique forces of various injurious scenarios [1][6]. To accomplish these tasks, the project utilizes ANSYS LS-DYNA's finite element capabilities, which captures the nuanced interactions of the aforementioned factors derived through a series of differential equations. This holistic approach provides unprecedented insights into the brain's dynamic response to forces.