The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 25, 2001
Filed:
Nov. 01, 1999
David G. Schaenzer, Minneapolis, MN (US);
Medtronic, Inc., Minneapolis, MN (US);
Abstract
Methods for sensing or electrical stimulation of body organs or tissues are disclosed wherein a lead conductor wire or filament of a stranded lead conductor generates a radioactive emission when it is fractured sufficiently or is completely broken. The conductor wire or filament is formed of an inner core and an outer sheath surrounding the inner core, wherein the inner core is irradiated or is formed of a radioactive isotope in an alloy that provides an enhanced radiopaque aura when the sheath is fractured and the inner core is exposed. When the conductor wire or filament is intact, the radioactive inner core is fully encased within the outer sheath, and the outer sheath blocks or reduces radioactive emission along its length to a constant, relatively low level. In use, the emission is detected externally to the body, and the detection signifies that a fracture or break has occurred. Such leads preferably comprise cardiac leads for delivering electrical stimulation to the heart, e.g., pacing pulses and cardioversion/defibrillation shocks, and/or sensing the cardiac electrogram, having multiple lead conductors encased in a lead body subject to fracture under stress. The lead conductors can comprise mono-filar or multi-filar, parallel wound, coiled wires that arranged in a co-axial manner or in a side-by-side arrangement within the lead body. Or the straight or coiled lead conductors can be formed of a strand comprising a plurality of outer filaments wound helically about a central core filament or of a cable comprising a plurality of such peripheral strands wound helically about a central core strand. At least the outer filaments of a stranded conductor and peripheral strands of a conductor cable are formed with the radioactive core.