| 摘要 |
A cardiac pacing lead or other stimulation lead carrying a steroid compounded within a polymer matrix. The steroid is dispersed in thermoplastic or thermoset polyurethane or polyurea forming monomers or prepolymers. The mixture is then chain extended by addition of the appropriate difunctional or multifunctional isocyanate, hydroxyl or amine curing agent to form a solid polymer. The resulting formulation is molded or cast into a desired shape, and incorporated in the distal end of a medical electrical lead, adjacent to or within the electrode. In a preferred embodiment, the medical lead employs an extendable helix which is screwed into body tissue, and the polymer containing the drug takes the form of a generally dimensionally stable annular member mounted to the lead, encircling the helix. |
