STP544: High Performance Thermal Insulation for an Implantable Artificial Heart

    Stoner, DR
    Manager of Materials and Components, Westinghouse Electric Corporation, Trafford, Pa.

    Svedberg, RC
    Senior engineers, Westinghouse Astronuclear Laboratory, Westinghouse Electric Company, Pittsburgh, Pa.

    Chi, JWH
    Senior engineers, Westinghouse Astronuclear Laboratory, Westinghouse Electric Company, Pittsburgh, Pa.

    Vojnovich, T
    Senior engineer, Westinghouse Research Laboratories, Westinghouse Electric Company, Pittsburgh, Pa.

    Pages: 15    Published: Jan 1974


    Abstract

    The practicability of an implantable artificial heart is strongly dependent on the availability of a high performance, compact, and lightweight thermal insulation system to contain the radioisotope energy source. The insulation system must limit heat losses to less than 0.024 W/cm2 to maintain an acceptable thermal efficiency with the Stirling engine heat source at 870°C (1600°F). On the basis of the overall system requirements, vacuum metal foil insulation is the only acceptable choice. Concentric nickel foil cups were utilized in place of the standard spiral-wrapped foil design with mitered corners, thereby eliminating a serious heat leak and the structural problems generally associated with the corners. Initial total system thermal performance tests have been very encouraging and predict that a system heat loss of 2 W can be met with about 35 to 40 foil cup layers. Since the implantable system is to be designed for a sealed ten-year lifetime under static vacuum, measurements are also being made to determine the long-time performance and outgassing characteristics of the nickel packages.

    Keywords:

    thermal insulation, heat transmission, mechanical hearts, surgical implantation, metal foils, heating equipment


    Paper ID: STP34784S

    Committee/Subcommittee: C16.30

    DOI: 10.1520/STP34784S


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