Implicit Partitioned Cardiovascular Fluid-Structure Interaction of the Heart Cycle Using Non-newtonian Fluid...

Area of Science:

• Computational mechanics
• Biomedical engineering
• Cardiovascular fluid dynamics

Background:

• Human heart function arises from complex biochemical, mechanical, and fluid dynamics interactions.
• Existing models often simplify or neglect one of these components, limiting accuracy.
• A comprehensive numerical simulation is needed to capture the integrated cardiac system.

Purpose of the Study:

• To develop and validate a coupled numerical model of myocardial mechanics and ventricular blood flow.
• To investigate the interplay between myocardial stress distribution and blood flow during cardiac cycles.
• To derive quantitative metrics for assessing cardiac health based on solid and fluid mechanics.

Main Methods:

• Implemented a finite element package with an orthotropic constitutive law (Holzapfel et al.) for passive myocardium, modified for contraction.
• Coupled structural and fluid models using the Arbitrary Lagrangian-Eulerian (ALE) method.
• Incorporated blood rheology and a circulatory system model into the fluid dynamics component.

Main Results:

• The coupled model demonstrated good quantitative and qualitative agreement with fluid flow data.
• Myocardial motion aligned with physiological observations.
• Calculated wall stresses and distributions were within the physiological range.
• The model successfully calculated wall stresses and characteristic ventricular fluid flow.

Conclusions:

• The developed coupled model accurately represents essential cardiac functions.
• It enables calculation of wall stresses and ventricular fluid flow.
• Derived metrics provide a quantitative assessment of cardiac health, integrating mechanical and fluid aspects.