Claims
- 1. A stent constructed and adapted to be implanted in a vessel, duct or channel of the human body to maintain patency of the lumen thereof, said stent comprising a tubular scaffolding structure composed at least primarily of metal having sufficiently low ferromagnetic property, and at least one electrically conductive layer overlying at least a portion of the surface of said scaffolding structure to enhance properties of the stent for magnetic resonance imaging (MRI) of the interior of the stent when implanted.
- 2. The stent of claim 1, comprising electrically insulative layer residing between said at least a portion of the surface of said scaffolding structure and said at least one electrically conductive layer.
- 3. The stent of claim 1, wherein said scaffolding structure and said overlaying electrically conductive layer are geometrically arranged in a composite relationship to form an inductance capacitance (LC) circuit.
- 4. The stent of claim 1, wherein said at least one electrically conductive layer has a geometric formation arranged to function as an electrical inductance element.
- 5. The stent of claim 1, wherein said at least one electrically conductive layer has a geometric formation arranged to function as an electrical capacitance element.
- 6. The stent of claim 1, wherein said at least one electrically conductive layer is structured to function electrically as both an inductance element and a capacitance element.
- 7. The stent of claim 1, wherein said at least one electrically conductive layer has a thickness of less than about 10 μm.
- 8. The stent of claim 1, wherein said tubular scaffolding structure has a thickness considerably greater than the thickness of said at least one electrically conductive layer.
- 9. The stent of claim 2, wherein said at least one electrically conductive layer has a thickness of less than about 10 μm, and said electrically insulative layer has a thickness of less than about 1 μm.
- 10. The stent of claim 2, wherein said at least one electrically conductive layer is spaced apart from the surface of said tubular structure by the thickness of said electrically insulative layer.
- 11. The stent of claim 2, wherein said electrically conductive layer is formed as an oxide of said tubular scaffolding structure.
- 12. The stent of claim 2, wherein said tubular scaffolding structure is compared at least primarily of niobium and said electrically insulative layer is composed of niobium oxide.
- 13. The stent of claim 2, wherein said tubular scaffolding structure is composed at least primarily of niobium zirconium alloy and said electrically insulative layer is composed of niobium zirconium oxide.
- 14. The stent of claim 3, wherein said LC circuit is geometrically formed to have a resonant frequency to enable visualization of body tissue and tissue growth within the lumen of the implanted stent by MRI.
- 15. The stent of claim 3, wherein the resonant frequency of said LC circuit is equivalent to the resonance frequency of the MRI energy.
- 16. The stent of claim 3, wherein said LC circuit is formed to enable measurement of blood flow through the lumen of said stent when implanted in a blood vessel of the body.
- 17. The stent of claim 3, wherein said LC circuit is formed as a bird cage element.
- 18. The stent of claim 3, wherein said LC circuit is formed as a saddle coil element.
- 19. A stent adapted to be implanted in a duct of a human body to maintain an open lumen at the implant site, said stent comprising a tubular scaffold of low ferromagnetic metal, and an inductance-capacitance (LC) circuit integral with said scaffold, said LC circuit being resonant at the resonance frequency of magnetic resonance imaging (MRI) energy to be applied to said body for viewing body tissue and fluid within the lumen of the stent when implanted.
- 20. The stent of claim 19, wherein said metal is at least primarily niobium.
- 21. The stent of claim 20, wherein said LC circuit is composed of successive layers of an oxide of said metal overlying said scaffold and the same composition as said metal overlying said oxide layer.
- 22. A stent adapted to be implanted in a duct of a human body to maintain an open lumen at the implant site, and to allow viewing body properties outside and within the implanted stent by magnetic resonance imaging (MRI) energy applied external to the body, said stent comprising a metal scaffold, and an electrical circuit resonant at the resonance frequency of said MRI energy integral with said scaffold.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is related to U.S. application Ser. No. 09/663,896, assigned to the same assignee as the present application.
Continuations (1)
|
Number |
Date |
Country |
Parent |
09779204 |
Feb 2001 |
US |
Child |
10841113 |
May 2004 |
US |