A passively suspended Tesla pump left ventricular assist device.

Area of Science:

• Biomedical Engineering
• Cardiovascular Devices
• Fluid Dynamics

Background:

• Left ventricular assist devices (LVADs) are crucial for managing advanced heart failure.
• Current LVADs face challenges including hemolysis and device longevity.
• A passively suspended pump design offers potential advantages in reducing mechanical stress on blood components.

Purpose of the Study:

• To describe the design and initial performance of a new passively suspended Tesla-type LVAD blood pump.
• To evaluate the pump's fluid dynamics, hemocompatibility, and preliminary in vivo performance.
• To assess the feasibility of using computational fluid dynamics (CFD) in the design process.

Main Methods:

• Utilized computational fluid dynamics (CFD) for pump design and analysis.
• Developed a prototype 50 mm diameter, 75 mm length pump.
• Employed buoyant centering force (rotor density < blood) and axial magnetic force for rotor suspension.
• Conducted flow rate, head rise, and hemolysis testing.

Main Results:

• The pump achieved a flow rate of up to 10 L/min at a 70 mm Hg head rise at 8,000 RPM.
• Demonstrated a normalized index of hemolysis below 0.02 mg/dL for flows between 2 and 9.7 L/min.
• Incorporated an inlet pressure sensor for control and showed encouraging initial in vivo results.

Conclusions:

• The passively suspended Tesla-type LVAD pump design shows promising hemocompatibility and performance characteristics.
• CFD analysis is effective in designing advanced LVAD components.
• Further CFD refinement and endurance testing are warranted for clinical translation.