title: The balance of the impeller-driver magnet affects the antithrombogenicity in the Gyro permanently implantable pump.
abstract: The Gyro permanently implantable (PI) pump is activated magnetically when a double pivot bearing supported impeller is rotated at predetermined revolutions per minute (rpm). The male bearing shaft of the impeller is supported by the top and bottom female pivot bearing in a loosely mated fashion. The Gyro PI pump's impeller transfers to a floating condition when the rpm is increased. The design objective of the Gyro PI pump is to drive the impeller while maintaining a top contact position to prevent thrombus formation. As a left ventricular assist device (LVAD), the Gyro PI pumps achieved long-term survivals in calves without thrombus formation. However, thrombus formation occurred during a biventricular assist device (BVAD) implantation. Our hypothesis was that the impeller remaining in the bottom contact position during the BVAD experiment caused this thrombus formation. Therefore, a replica of the Gyro PI pump housing was fabricated from a transparent plastic to observe the floating conditions of the impeller. When simulating an LVAD animal experiment, the impeller was at a non-bottom contact position. However, when simulating the BVAD animal experiment, the impeller remained at the bottom contact position. This study shows that the magnet balance affects the antithrombogenicity in a Gyro PI pump.
authors.affiliation: Michael E DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: Seiji
authors.initials: S
authors.lastname: Ichikawa
authors.forename: Ikuya
authors.initials: I
authors.lastname: Nishimura
authors.forename: Minoru
authors.initials: M
authors.lastname: Mikami
authors.forename: Kenji
authors.initials: K
authors.lastname: Nonaka
authors.forename: Joerg
authors.initials: J
authors.lastname: Linneweber
authors.forename: Shinji
authors.initials: S
authors.lastname: Kawahito
authors.forename: Tadashi
authors.initials: T
authors.lastname: Motomura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishitoya
authors.forename: Julia
authors.initials: J
authors.lastname: Glueck
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Shinohara
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Nosé
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology; D002318:Cardiovascular Diseases / Q000503:physiopathology* / Q000628:therapy*; D004195:Disease Models, Animal; D004867:Equipment Design; D005260:Female; D006353:Heart-Assist Devices / Q000009:adverse effects*; D006801:Humans; D008280:Magnetics / Q000627:therapeutic use*; D008297:Male; D008955:Models, Cardiovascular; D013927:Thrombosis / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control*; D013997:Time Factors