Medtronic won FDA approval, and is consequently making available, the Attain Ability® left-heart lead (Model 4196) for use with cardiac resynchronization devices. The lead is composed of an advanced aerospace resin, named Langley Research Center’s Soluble Imide, or LaRC-SI, and is the first time material developed by NASA has been used in implantable medical devices.
From the Langley Research Center:
LaRC-SI is a wholly aromatic high-performance thermoplastic polyimide that is a selfbonding/non-curing resin made from commercially available monomers. This polyimide has superior mechanical, electrical, and adhesive properties and an extensive range of processing choices that allow it to serve as either a dielectric inner layer, substrate coating, or the substrate. LaRC-SI film is made by casting or spraying a solution consisting of xylene, N-methyl-pyrrolidinone (NMP), and LaRC-SI powder. At different drying temperatures, various amounts of solvent are removed to the point where it becomes insoluble but retains its melt processability. LaRC-SI excels in the following characteristics:
Solubility in conventional high-boiling solvents Melt flow and bonding properties Electrical properties — low dissipation factor and high dielectric strength Resistance to harsh environments such as radiation, cryogenic and elevated temperatures, most fluids, corrosives, and biological inertness
It is highly flexible, resistant to chemicals, and withstands extreme hot and cold temperatures. The “super plastic” was determined to be biologically inert, making it suitable for medical use, including implantable devices.
Medtronic states that the Attain Ability™ lead wire one of the thinnest left-heart AICD leads available and this affords the ability to choose between different sites on the endocardium to deliver the lead for optimal therapy.
Here’s a Medtronic animation showing the placement of the device:
Press release: FDA Approves New Medtronic Left Heart Lead for Cardiac Resynchronization Therapy Devices …
NASA : Polymer Coats Leads on Implantable Medical Device…