A continuous and pulsatile flow circulation system for evaluation of cardiovascular devices

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Fluid Dynamics

Background:

• Centrifugal pumps are commonly used in medical devices but typically produce nonpulsatile flow.
• Reproducing pulsatile flow is crucial for accurately evaluating cardiovascular devices in vitro.
• Existing methods for inducing pulsatility with centrifugal pumps may have limitations in range or control.

Purpose of the Study:

• To design and validate a versatile system capable of generating both nonpulsatile and pulsatile flow using a centrifugal pump.
• To enable accurate in vitro evaluation of cardiovascular devices under physiologically relevant flow conditions.
• To achieve precise control over flow rate, pressure, frequency, and amplitude.

Main Methods:

• A centrifugal pump was integrated with an independent, pneumatically driven unit to induce pulsatile flow.
• Pulsatile flow was generated via axial cylinder displacement, periodically compressing a flexible conduit connected to the pump.
• The system's performance was characterized for flow rates, transmural pressures, frequencies, and pressure wave reproducibility.

Main Results:

• The system successfully generated both nonpulsatile and pulsatile flow patterns with adjustable frequencies (up to 4 Hz) and amplitudes.
• It accommodates high flow rates (up to 6,000 ml/min) and transmural pressures (up to 500 mm Hg).
• Reproducible pressure waves mimicking peripheral circulation (80-180 mm Hg) were achieved.

Conclusions:

• The developed apparatus offers a versatile platform for in vitro testing of cardiovascular devices.
• The system's ability to reproduce physiologically relevant pulsatile flow enhances the reliability of device evaluation.
• This design provides a valuable tool for advancing cardiovascular research and medical device development.