Abstract
In patients with continuous flow ventricular assist devices, bleeding complications frequently occur due to the enzymatic degradation of von Willebrand Factor (vWF) large multimers. This degradation is caused by high shear stress from the device's high-speed rotating components. Although a double-cylinder-type shear load device has been proposed for the preliminary quantitative evaluation of vWF large multimers, it has not provided sufficient evaluation due to issues with the open-type shear portion and the contact-type mechanical bearings. These issues arise from air bubbles in the blood samples and unstable motor rotation. In this study, we propose a new shear loading device that features a closed-type shear portion and uses magnetic bearings to levitate the inner cylinder and rotate the outer cylinder. We experimentally evaluated that the levitation of the inner cylinder was controlled by two magnetic bearings (upper and lower), and the stability of the levitation.
