title: Optimal design of the hydrodynamic multi-arc bearing in a centrifugal blood pump for the improvement of bearing stiffness and hemolysis level.
abstract: The purpose of the present study is to establish an optimal design of the multi-arc hydrodynamic bearing in a centrifugal blood pump for the improvement of bearing stiffness and hemolysis level. The multi-arc bearing was designed to fulfill the required specifications: (i) ensuring the uniform bearing stiffness for various bearing angles; (ii) ensuring a higher bearing stiffness than the centrifugal force to prevent impeller whirl; and (iii) adjusting the bearing clearance as much as possible to reduce hemolysis. First, a numerical analysis was performed to optimize three design parameters of the multi-arc bearing: number of arcs N, bearing clearance C, and groove depth H. To validate the accuracy of the numerical analysis, the impeller trajectories for six pump models were measured. Finally, an in vitro hemolysis test was conducted to evaluate the hemolytic property of the multi-arc bearing. As a result of the numerical analysis, the optimal parameter combination was determined as follows: N=4, C=100 μm, and H ≥ 100 μm. In the measurements of the impeller trajectory, the optimal parameter combination was found to be as follows: N=4, C=90 μm, and H=100 μm. This result demonstrated the high reliability of the numerical analysis. In the hemolysis test, the parameter combination that achieved the smallest hemolysis was obtained as follows: N=4, C=90 μm, and H=100 μm. In conclusion, the multi-arc bearing could be optimized for the improvement of bearing stiffness and hemolysis level.
authors: Tokyo University of Science, Noda, Chiba, Japan.
authors: Kazuya
authors: K
authors: Yasui
authors: Ryo
authors: R
authors: Kosaka
authors: Masahiro
authors: M
authors: Nishida
authors: Osamu
authors: O
authors: Maruyama
authors: Yasuo
authors: Y
authors: Kawaguchi
authors: Takashi
authors: T
authors: Yamane
mesh_terms: D000818:Animals; D002417:Cattle; D004912:Erythrocytes / Q000473:pathology; D006354:Heart, Artificial / Q000009:adverse effects; D006461:Hemolysis; D057446:Hydrodynamics; D008955:Models, Cardiovascular; D011474:Prosthesis Design
keywords: Artificial heart; Bearing stiffness; Centrifugal blood pump; Hemolysis; Hydrodynamic bearing; Radial bearing