Flow visualization for the implantable ventricular assist device EVAHEART®

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Cardiovascular Devices

Background:

• Ventricular assist devices (VADs) are crucial for treating heart failure.
• Ensuring hemocompatibility is paramount to minimize adverse blood-device interactions.
• The EVAHEART device is a recently approved VAD requiring thorough hemocompatibility assessment.

Purpose of the Study:

• To evaluate the hemocompatibility of the EVAHEART ventricular assist device.
• To investigate the fluid dynamics within the device to understand blood flow behavior.
• To verify the device's performance under diverse operational conditions.

Main Methods:

• Utilized flow visualization techniques on a 300% scale-up model of the EVAHEART device.
• Analyzed flow patterns, specifically focusing on flow separation and shear stress.
• Examined the interaction between fluid flow and critical device components like vanes and shafts.

Main Results:

• Absence of flow separations around the centrifugal vanes, indicating optimal vane curvature.
• Sufficient shear stresses generated in the vane-shaft clearance along the stationary shaft.
• Hemocompatibility confirmed across a broad spectrum of flow rates and operating conditions.

Conclusions:

• The design of the EVAHEART device promotes favorable hemocompatibility.
• The observed flow characteristics suggest a low risk of blood damage and thrombosis.
• The device is suitable for clinical use, demonstrating robust hemocompatibility in varied scenarios.