Muscle powered blood pump: design and initial test results.

Area of Science:

• Biomedical Engineering
• Cardiovascular Devices
• Biomechanical Engineering

Background:

• Pneumatic ventricular assist devices (VADs) require external power sources.
• Muscle-powered actuation offers a potential alternative for VADs.
• Existing VAD designs need modification for hydraulic, muscle-driven systems.

Purpose of the Study:

• To redesign a pneumatic VAD for low-volume hydraulic actuation using muscle power.
• To evaluate the efficacy of a piston pump mechanism for VAD actuation.
• To validate the pusher plate design for optimal performance.

Main Methods:

• Modified a Sarns/3M pneumatic VAD by incorporating a bellows/piston mechanism and compliance chamber.
• Fabricated a prototype device by replacing the pneumatic drive housing with a piston/bushing mechanism.
• Utilized a mock circulatory loop to test piston pump actuation, measuring forces, pressures, and stroke volume.

Main Results:

• Stroke volume demonstrated a linear relationship with piston displacement, reaching a maximum of 45 ml.
• Mean compression forces of 46-56 N generated mean afterload pressures of 70-110 mm Hg.
• The device achieved a flow rate of 2.1 L/min at 60 cycles/min with peak forces of 72-86 N.

Conclusions:

• The redesigned VAD is mechanically viable for hydraulic actuation using muscle power.
• The developed piston pump mechanism is compatible with the functional capacity of conditioned latissimus dorsi muscle.
• This approach presents a promising method for muscle-driven blood circulation support.