title: Flow visualization in the outflow cannula of an axial blood pump.
abstract: The properties of blood flow in the outflow cannula of an axial blood pump play a critical role in potential thrombus formation and vascular injury. In this study, an in vitro flow visualization technique using particle image velocimetry (PIV) was applied to investigate the flow characteristics in the outflow cannula of a FW-2 model axial pump. The two-dimensional (2-D) flow field in the axial central section and the three-dimensional (3-D) flow field in the whole outflow cannula were examined with the PIV system. Tests were carried out with a blood-mimic working fluid in the axial pump at a rotational speed of 8500 ± 20 rpm with a flow rate of 5 L/min. The velocity distribution in the outflow cannula was analyzed to evaluate the flow characteristics. There was no backflow or stagnant flow in the tested area, while the flow velocity rapidly increased outside the boundary layer. A spiral flow was observed near the boundary layer, but this was worn off within the tested area. Based on the results, hemolysis and thrombus formation in the cannula, and injury to aortic endothelium are unlikely to occur due to spiral flow.
authors.affiliation: State Key Laboratory of Cardiovascular Disease, Key Laboratory of Cardiovascular Regenerative Medicine, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: Guangmao
authors.initials: G
authors.lastname: Liu
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Haibo
authors.initials: H
authors.lastname: Chen
authors.forename: Hansong
authors.initials: H
authors.lastname: Sun
authors.forename: Jianye
authors.initials: J
authors.lastname: Zhou
authors.forename: Shengshou
authors.initials: S
authors.lastname: Hu
mesh_terms: D001011:Aorta / Q000473:pathology; D001698:Biomedical Engineering; D001783:Blood Flow Velocity / Q000502:physiology*; D002138:Calibration; D057785:Catheters; D004730:Endothelium, Vascular / Q000473:pathology; D004867:Equipment Design; D006333:Heart Failure / Q000628:therapy; D006353:Heart-Assist Devices; D006461:Hemolysis; D006801:Humans; D008955:Models, Cardiovascular; D012212:Rheology; D012984:Software; D013927:Thrombosis / Q000473:pathology / Q000517:prevention & control; D014783:Viscosity
keywords: axial blood pump; outflow cannula; particle image velocimetry; thrombus formation