TITLE:
In vitro evaluation of a new resilient, hard-carbon, thin-film coating as a bearing material for ventricular assist devices ——In Vitro Bearing Evaluation of BioMedFlex
AUTHORS:
Nicole A. Mielke, Alex L. Massiello, David J. Horvath, Stephen M. Benefit, Darren Burgess, Leonard A. R. Golding, Kiyotaka Fukamachi
KEYWORDS:
Heart Assist Device; Diamond-Like Carbon; Materials Testing; Wear Resistance; Journal Bearing
JOURNAL NAME:
Journal of Biomedical Science and Engineering,
Vol.3 No.5,
May
27,
2010
ABSTRACT: Our aim was to evaluate the potential use of BioMedFlex® (BMF), a new resilient, hard-carbon, thin- film coating, as a blood journal bearing material in Cleveland Heart’s continuous-flow left and right ven- tricular assist devices (VADs). BMF is not classified as a diamond-like carbon (DLC) and differs from other thin-film carbon coatings by its high flexural strength, radiopacity, and wear resistance. A 2- to 4-μm-thick BMF adhesion layer was deposited on the VAD journal bearing surfaces. A commercial DLC coating used in other clinical blood pump applications was used as a control. Durability and reliability of the BMF coating was verified in severe pump start/stop testing using 20 BMF-coated journal bearing pairs. The BMF-coated surfaces showed no coating failures, whereas 57% of the DLC bearing pairs developed scratches through the carbon coating, documenting that BMF can provide a durable coating in our blood journal bearing application. In conclusion, BMF has shown qualities that support its significant advantages as an alternative journal bea- ring material in Cleveland Heart pumps. Our plan includes biocompatibility testing with ongoing animal studies, endurance testing with submerged pumps running in saline, and assessment of batch coating processing capability.