Experimental Performance Evaluation of a novel Ventricle Assist Device as a Function of Impeller`s Design

Background: A novel Ventricle Assist Device (VAD) based on an axial impeller is designed to treat patients with acute heart failure. The device is inserted percutaneously into the left ventricle of the heart. The novel design intended to reduce known complications of VAD including blood damage and thrombus formation due to contact of blood with the impeller`s blades and the non-physiological flow field, including high wall shear stress, stagnation regions, disturbed flow and disturbed flow.

Methods: In this study, we designed and built an experimental system (Figure 1) that evaluates the performance of the pump according to its impeller design. The system is based on the similitude principle which uses an enlarged impeller to operate in scale of a human heart.

The system measures flow rate and pressure head for variable inputs; including differences in loading conditions and rotation speed.

Results: Twelve different impeller designs were examined in different set up configurations. Results showed that the performance of the pump is influenced mainly by the length and width of the impeller blades, and also by the hub shape, blade angles, and inlet to outlet area ratio.

Conclusion: The system can successfully measure objective parameters; it is an integral tool that will be used in the near future for the development and optimization of a blood pump intended for human use.