Numerical model of flow in a sac-type ventricular assist device

Area of Science:

• Biomedical Engineering
• Computational Fluid Dynamics
• Medical Device Design

Background:

• Ventricular assist devices (VADs) are crucial for heart failure treatment.
• Investigating VAD hemodynamics is complex, especially for sac-type VADs.
• Existing simulation methods face challenges with mechanical valves and flexible walls.

Purpose of the Study:

• To develop and validate a simplified 3D numerical model for sac-type VADs.
• To assess the impact of flexible wall motion and valve states on VAD hemodynamics.
• To provide a computationally efficient tool for VAD flow analysis.

Main Methods:

• A simplified 3D numerical model of a sac-VAD chamber was created.
• Flexible wall motion was defined using experimental measurements.
• Valves were modeled in fully open or closed states.
• Model validation was performed against fluid-structure interaction simulations and experimental PIV data.

Main Results:

• Flexible wall motion is sensitive to internal pressure changes.
• Minor variations in wall motion do not significantly alter overall flow patterns.
• The simplified model effectively predicts 3D time-dependent flow fields within the VAD.

Conclusions:

• The simplified numerical model offers a reliable and efficient method for VAD hemodynamics investigation.
• This approach can aid in the design and optimization of sac-type VADs.
• The findings support the use of simplified models for predicting VAD flow characteristics.