title: Prototype continuous flow ventricular assist device supported on magnetic bearings.
abstract: This article describes a prototype continuous flow pump (CFVAD2) fully supported in magnetic bearings. The pump performance was measured in a simulated adult human circulation system. The pump delivered 6 L/min of flow at 100 mm Hg of differential pressure head operating at 2,400 rpm in water. The pump is totally supported in 4 magnetic bearings: 2 radial and 2 thrust. Magnetic bearings offer the advantages of no required lubrication and large operating clearances. The geometry and other properties of the bearings are described. Bearing parameters such as load capacity and current gains are discussed. Bearing coil currents were measured during operation in air and water. The rotor was operated in various orientations to determine the actuator current gains. These values were then used to estimate the radial and thrust forces acting on the rotor in both air and water. Much lower levels of force were found than were expected, allowing for a very significant reduction in the size of the next prototype. Hemolysis levels were measured in the prototype pump and found not to indicate damage to the blood cells.
authors.affiliation: Department of Mechanical, Aerospace, and Nuclear Engineering, University of Virginia, Charlottesville 22903-2037, USA.
authors.forename: P E
authors.initials: PE
authors.lastname: Allaire
authors.forename: H C
authors.initials: HC
authors.lastname: Kim
authors.forename: E H
authors.initials: EH
authors.lastname: Maslen
authors.forename: D B
authors.initials: DB
authors.lastname: Olsen
authors.forename: G B
authors.initials: GB
authors.lastname: Bearnson
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001783:Blood Flow Velocity / Q000502:physiology; D002417:Cattle; D004574:Electromagnetic Fields; D004912:Erythrocytes / Q000166:cytology / Q000473:pathology; D006353:Heart-Assist Devices / Q000009:adverse effects / Q000592:standards; D006454:Hemoglobins / Q000032:analysis; D008433:Mathematics; D008962:Models, Theoretical; D011312:Pressure
chemical_list: D006454:Hemoglobins