Magnetic suspension controls for a new continuous flow ventricular assist device

Area of Science:

• Biomedical Engineering
• Medical Devices
• Fluid Dynamics

Background:

• Current pulsatile ventricular assist devices face limitations in reliability and size.
• Continuous flow ventricular assist devices (CFVADs) offer potential improvements.
• Magnetic suspension technology presents an opportunity for advanced CFVAD design.

Purpose of the Study:

• To introduce and detail the design of a new continuous flow ventricular assist device (CFVAD III) employing full magnetic suspension.
• To describe the control system and dynamic model for the magnetic suspension of the CFVAD III impeller.
• To evaluate the feasibility of noncontact impeller operation for improved device performance.

Main Methods:

• Construction of the CFVAD III with a full magnetic suspension system for the centrifugal impeller.
• Development of a five-axis magnetic actuator system for impeller control (3 displacement, 2 angular axes).
• Implementation of decentralized PID controllers for initial suspension tests, considering blood forces, unbalance, and gravitational loads.

Main Results:

• The magnetic suspension successfully centers the impeller, enabling noncontact operation.
• Noncontact operation is expected to yield high mechanical reliability, large clearances, and reduced hemolysis and thrombosis.
• The controller design accounts for various external forces to maintain impeller stability.

Conclusions:

• The CFVAD III design with magnetic suspension offers a promising alternative to current ventricular assist devices.
• Robust control system design is essential to manage dynamic loads and prevent impeller-device or impeller-blood interaction.
• This noncontact approach has the potential to significantly improve patient outcomes through enhanced device safety and efficacy.