Investigation of Materials for Blood‐Immersed Bearings in a Microaxial Blood Pump

Abstract

Rotary blood pumps are gaining popularity among cardiothoracic surgeons. This article presents an in vitro investigation for choosing a suitable mechanical bearing system in a medium-long term microaxial pump. Different metallic, polymeric, and ceramic components are introduced. Polymers displayed mechanical insufficiency for the application, whereas certain ceramics displayed an inconsistent pattern of failure. We are in search of a compromise in properties that would favor a durable material combination.

Use of Zirconia Ceramic in the DexAide Right Ventricular Assist Device Journal Bearing

“…Ceramics have been previously investigated for use in blood pump pivot bearing design. Zirconia pivot bearings for a long-term microaxial blood pump design were tested at the Helmholtz Institute for Biomedical Engineering (Aachen, Germany) (4). From in vitro bearing wear testing, investigators found inconsistent wear behavior, attributed to the presence of defects in the ceramic structure.…”

Design of a Small Centrifugal Blood Pump With Magnetic Bearings

“…Therefore, these pumps can be considered as "low-pulsatility" LVADs. The current designs, however, contain mechanical pivot bearing systems, which are the potential source of thrombogenicity within these pumps due to the flow into and around the highly stressed mechanical contacts (6). Various materials, such as ceramics (silicon nitride, zirconia, and alumina) and polymers (ultrahigh molecular weight polyethylene, polyetheretherketone, and polyoxymethylene), have been evaluated for such systems to prevent wear and thrombosis (6,7).…”

“…The current designs, however, contain mechanical pivot bearing systems, which are the potential source of thrombogenicity within these pumps due to the flow into and around the highly stressed mechanical contacts (6). Various materials, such as ceramics (silicon nitride, zirconia, and alumina) and polymers (ultrahigh molecular weight polyethylene, polyetheretherketone, and polyoxymethylene), have been evaluated for such systems to prevent wear and thrombosis (6,7). Clinical studies and animal trials, however, have shown long-term survival with rotary pumps as bridge to transplant and/or destination therapy (8)(9)(10)(11)(12).…”

Performance Characterization of a Rotary Centrifugal Left Ventricular Assist Device With Magnetic Suspension

“…Recent studies (8) have shown that the strong pulsatility from the native heart imparts pulsatility to the continuous flow pumps. The current designs, however, contain mechanical‐pivot‐bearing systems, which are the potential source of thrombogenicity within these pumps due to the flow into and around the highly stressed mechanical contacts (9). Various materials, such as ceramics (silicon nitride, zirconia, and alumina) and polymers (ultrahigh‐molecular‐weight polyethylene, polyetheretherketone, and polyoxymethylene) have been evaluated for such systems to prevent wear and thrombosis (9,10).…”

“…The current designs, however, contain mechanical‐pivot‐bearing systems, which are the potential source of thrombogenicity within these pumps due to the flow into and around the highly stressed mechanical contacts (9). Various materials, such as ceramics (silicon nitride, zirconia, and alumina) and polymers (ultrahigh‐molecular‐weight polyethylene, polyetheretherketone, and polyoxymethylene) have been evaluated for such systems to prevent wear and thrombosis (9,10). Clinical studies and animal trials, however, have shown long‐term survival with rotary pumps as bridge to transplant and/or destination therapy (11–15).…”