Proposition of a passive levitation system utilizing thrust and magnetic force for a ventricular assist device

Proposition of a passive levitation system utilizing thrust and magnetic force for a ventricular assist device

Blog Article

For circulation support in patients with heart disease, a miniaturized implantable ventricular assist device (VAD) is required.However, several issues such as hemolysis and miniaturization need to be addressed.The objective of this study is to develop a passive levitation system for an impeller with a large gap without active control.The Fridge Sensor Cover large gap prevents blood damage, and passive levitation contributes to the miniaturization of the VAD.

In this study, a new passive levitation system utilizing thrust and magnetic force is proposed.The thrust generated by the rotation of the impeller changes depending on the interaction between the housing geometry and impeller position, even with a large gap.Considering this characteristic, the impeller was levitated by balancing the magnetic force generated by the permanent magnets and the thrust in the axial direction.The movements in the radial and angular directions are passively supported by the restoring force and torque generated by the permanent magnets.

The thrust was calculated using computational fluid dynamics, and the Boron pump was designed such that the thrust changes according to the axial displacement of the impeller.The magnetic force generated by the permanent magnets was calculated using finite-element method 3D magnetic field analysis.In addition, the required current density flowing into the coil to rotate the impeller is calculated.The levitation of the impeller was confirmed by combining the results of the analyses.

The results show that the motor torque should be improved.In conclusion, this study demonstrates the feasibility of a novel levitation system for implantable miniaturized VADs.