Design considerations for the omniscience pivoting disc cardiac valve prosthesis

Area of Science:

• Biomedical Engineering
• Cardiovascular Prosthetics
• Fluid Dynamics

Background:

• Prosthetic heart valves are crucial for patients with valvular heart disease.
• Optimizing the design of pivoting disc valves is essential for improving hemocompatibility and durability.
• Previous designs have faced challenges with suboptimal flow dynamics and potential blood damage.

Purpose of the Study:

• To determine the optimal curvature and eccentricity for concave-convex pivoting disc prosthetic heart valves.
• To evaluate the impact of valve geometry on pressure measurements and velocity fields.
• To assess shear stress distribution and its implications for blood damage and thrombus formation.

Main Methods:

• Parametric studies were performed on prototype valves.
• Steady-state pressure measurements were collected.
• Laser-Doppler anemometry was used to measure the velocity field in a 2D model.
• Shear stress distribution in the valve wake was computed.

Main Results:

• An optimal curvature for the prosthetic heart valve was identified.
• The minimum eccentricity required for full valve opening was determined.
• Shear stress levels were found to be below the threshold for blood cell damage.
• Shear stress levels were above the threshold for stable thrombus formation.

Conclusions:

• The study identified optimal design parameters (curvature and eccentricity) for concave-convex pivoting disc prosthetic heart valves.
• The findings suggest that the optimized valve design promotes safe blood flow dynamics.
• The computed shear stress levels indicate a favorable hemocompatibility profile for the prosthetic valve.