Computational flow study of the continuous flow ventricular assist device, prototype number 3 blood pump

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Medical Devices

Background:

• Continuous Flow Ventricular Assist Devices (CFVADs) are crucial for treating heart failure.
• Understanding internal blood flow dynamics is vital for device optimization and patient safety.
• Potential issues include shear stress and flow stagnation, which can lead to hemolysis and thrombosis.

Purpose of the Study:

• To computationally investigate blood flow within the CFVAD3, focusing on recirculation zones.
• To analyze shear stresses and flow patterns in critical areas like impeller blade passages and gap clearances.
• To evaluate the impact of varying gap clearances on pump performance and blood-related risks.

Main Methods:

• Computational Fluid Dynamics (CFD) simulations were employed to model blood flow.
• Multiple geometry models were created to represent impeller-housing interactions and blade configurations.
• Flow fields were calculated across various operating conditions, and pump performance curves were generated.

Main Results:

• Recirculation of blood flow towards the pump inlet was predicted in the gap regions under all operating conditions.
• Pump performance curves derived from simulations showed good agreement with experimental data.
• Two smaller gap clearance designs were numerically tested to mitigate recirculation.

Conclusions:

• The study identified significant recirculation in CFVAD3 gap regions, impacting efficiency.
• Reducing gap clearance is a viable strategy to improve pump efficiency and minimize blood damage.
• The developed models will inform future designs for enhanced efficiency and reduced hemolysis risk.